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Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

Limestone is calcined into quicklime in lime kilns at temperatures above 1000°C. Heat is supplied through combustion inside the kilns, which are insulated with a lining of refractory bricks to mitigate heat loss and to protect the kiln from the hot, chemically aggressive, and mechanically abrasive environment. While magnesia bricks have proven to be effective lining materials, they are still susceptible to extensive wear in lime kilns, especially in the burn zone. Refractory corrosion, in particular, can occur when melted fuel ash infiltrates the refractory materials through pores and small cracks. This resultant wear can lead to high maintenance and operational costs, often due to unplanned kiln shutdowns. To reduce the release of fossil-based carbon dioxide into the atmosphere from lime production kilns, there is a growing interest in introducing bio-based fuels with only relatively minor modifications to the process. Biomass fuels can be sourced from bio-based waste streams from industries or be specifically cultivated for combustion. However, the ash content and properties of bio-based fuels tend to be problematic from an ash chemistry perspective. Therefore, before introducing a new fuel source, it is essential to investigate its potential effects on the kiln lining material. In this thesis work, the interactions between melted olive pomace ash and coal ash with commercially available magnesia refractory materials, primarily composed of periclase (MgO) with minor amounts of spinel (MgAl2O4), were studied. A procedure for quantifying the intrusion depths was described. Refractory samples were exposed to the fuel ashes under a simulated lime kiln atmosphere with high CO2 levels at 1200 and 1400°C for 15 and 60 minutes. Cold crushing strength tests were conducted on refractory samples exposed to coal and olive pomace ash, along with CaO powder, at 1400°C for 96 hours. Additionally, postmortem analyses of spent MgO-based refractory bricks were carried out to inves

Limestone is calcined into quicklime in lime kilns at temperatures above 1000°C. Heat is supplied through combustion inside the kilns, which are insulated with a lining of refractory bricks to mitigate heat loss and to protect the kiln from the hot, chemically aggressive, and mechanically abrasive environment. While magnesia bricks have proven to be effective lining materials, they are still susceptible to extensive wear in lime kilns, especially in the burn zone. Refractory corrosion, in particular, can occur when melted fuel ash infiltrates the refractory materials through pores and small cracks. This resultant wear can lead to high maintenance and operational costs, often due to unplanned kiln shutdowns. To reduce the release of fossil-based carbon dioxide into the atmosphere from lime production kilns, there is a growing interest in introducing bio-based fuels with only relatively minor modifications to the process. Biomass fuels can be sourced from bio-based waste streams from industries or be specifically cultivated for combustion. However, the ash content and properties of bio-based fuels tend to be problematic from an ash chemistry perspective. Therefore, before introducing a new fuel source, it is essential to investigate its potential effects on the kiln lining material. In this thesis work, the interactions between melted olive pomace ash and coal ash with commercially available magnesia refractory materials, primarily composed of periclase (MgO) with minor amounts of spinel (MgAl2O4), were studied. A procedure for quantifying the intrusion depths was described. Refractory samples were exposed to the fuel ashes under a simulated lime kiln atmosphere with high CO2 levels at 1200 and 1400°C for 15 and 60 minutes. Cold crushing strength tests were conducted on refractory samples exposed to coal and olive pomace ash, along with CaO powder, at 1400°C for 96 hours. Additionally, postmortem analyses of spent MgO-based refractory bricks were carried out to inves

Limestone is calcined into quicklime in lime kilns at temperatures above 1000°C. Heat is supplied through combustion inside the kilns, which are insulated with a lining of refractory bricks to mitigate heat loss and to protect the kiln from the hot, chemically aggressive, and mechanically abrasive environment. While magnesia bricks have proven to be effective lining materials, they are still susceptible to extensive wear in lime kilns, especially in the burn zone. Refractory corrosion, in particular, can occur when melted fuel ash infiltrates the refractory materials through pores and small cracks. This resultant wear can lead to high maintenance and operational costs, often due to unplanned kiln shutdowns. To reduce the release of fossil-based carbon dioxide into the atmosphere from lime production kilns, there is a growing interest in introducing bio-based fuels with only relatively minor modifications to the process. Biomass fuels can be sourced from bio-based waste streams from industries or be specifically cultivated for combustion. However, the ash content and properties of bio-based fuels tend to be problematic from an ash chemistry perspective. Therefore, before introducing a new fuel source, it is essential to investigate its potential effects on the kiln lining material. In this thesis work, the interactions between melted olive pomace ash and coal ash with commercially available magnesia refractory materials, primarily composed of periclase (MgO) with minor amounts of spinel (MgAl2O4), were studied. A procedure for quantifying the intrusion depths was described. Refractory samples were exposed to the fuel ashes under a simulated lime kiln atmosphere with high CO2 levels at 1200 and 1400°C for 15 and 60 minutes. Cold crushing strength tests were conducted on refractory samples exposed to coal and olive pomace ash, along with CaO powder, at 1400°C for 96 hours. Additionally, postmortem analyses of spent MgO-based refractory bricks were carried out to inves

Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

Large shares of variable renewable electricity (VRE) generation increase the demand for flexible power balancing capacities for handling power surpluses and deficits. Within district heating (DH) production systems, electricity can be produced in combined heat and power (CHP) plants but also consumed in heat pumps, and thus contribute with balancing capacity. However, this power balancing potential in DH production units is limited by heat load variations. To improve the potential, large-scale thermal energy storage (TES) can be used to increase heat-load flexibility. This study investigates the power balancing capacity of 85 existing Swedish DH systems, with hypothetical access to rock cavern oil depots assumed to have been converted into TES units. In the study, the Swedish power load is assumed to be covered by 60 % wind and 10 % solar power. The results show that Swedish DH systems, on a national scale, could reduce power deficits and surpluses by approximately 9 % respectively. There will be competition between heat pumps and CHP units for DH load supply while providing power balancing services. The use of heat pumps could also, on national level, yield a reduced fuel use in DH production by about 10 % when compared to conventional DH system operation. The study highlights the impact the temporal distribution and annual shares of VRE surpluses and deficits have on the fuel use.

The global ambitions to hamper the greenhouse effect has led to ambitious targets for increasing renewable energy use. This, in combination with recent years' vast development of wind and solar power, implies that there will be significant amounts of variable renewable electricity (VRE) in future energy systems. With the inherent variability in VRE production comes a need for increased contingency in power systems. This requires both controllable production and consumption of power to cope with VRE deficits and surpluses. The purpose of this doctoral thesis is to investigate the potential for providing such power balancing services from Swedish district heating systems (DHS). Analyses are made for different system levels: community, regional, and national. Computer simulations of DH production systems with combined heat and power (CHP) plants, heat pumps, and thermal energy storage (TES), operated to supply a power balancing demand, are here shown to potentially reduce VRE deficits and surpluses. The results further show that reducing peak deficits and/or surpluses mainly depends on the installed capacities in CHP units and/or heat pumps. However, annual deficits or surpluses are reduced more if the system includes a TES. Also, the shares of wind and solar power in VRE mixes are shown to be relevant for fuel use and system performance. Solar-dominated VRE promotes heat pumps, reduces fuel use in CHP, and motivates a seasonal operation of TESs. Wind-dominated VRE matches with high capacities in CHP units, yields increased fuel use and motivates short-term operation of TESs. A crucial limitation is competition for the heat load between heat pumps and CHP units, which reduces the potential for CHP production. Competition between stored heat and heat pumps also occurs in systems with smaller TESs and large amounts of surplus electricity. In order for power balancing services to be economically viable for DHS operators, changed market structures that appropriately value

The global ambitions to hamper the greenhouse effect has led to ambitious targets for increasing renewable energy use. This, in combination with recent years' vast development of wind and solar power, implies that there will be significant amounts of variable renewable electricity (VRE) in future energy systems. With the inherent variability in VRE production comes a need for increased contingency in power systems. This requires both controllable production and consumption of power to cope with VRE deficits and surpluses. The purpose of this doctoral thesis is to investigate the potential for providing such power balancing services from Swedish district heating systems (DHS). Analyses are made for different system levels: community, regional, and national. Computer simulations of DH production systems with combined heat and power (CHP) plants, heat pumps, and thermal energy storage (TES), operated to supply a power balancing demand, are here shown to potentially reduce VRE deficits and surpluses. The results further show that reducing peak deficits and/or surpluses mainly depends on the installed capacities in CHP units and/or heat pumps. However, annual deficits or surpluses are reduced more if the system includes a TES. Also, the shares of wind and solar power in VRE mixes are shown to be relevant for fuel use and system performance. Solar-dominated VRE promotes heat pumps, reduces fuel use in CHP, and motivates a seasonal operation of TESs. Wind-dominated VRE matches with high capacities in CHP units, yields increased fuel use and motivates short-term operation of TESs. A crucial limitation is competition for the heat load between heat pumps and CHP units, which reduces the potential for CHP production. Competition between stored heat and heat pumps also occurs in systems with smaller TESs and large amounts of surplus electricity. In order for power balancing services to be economically viable for DHS operators, changed market structures that appropriately value

The global ambitions to hamper the greenhouse effect has led to ambitious targets for increasing renewable energy use. This, in combination with recent years' vast development of wind and solar power, implies that there will be significant amounts of variable renewable electricity (VRE) in future energy systems. With the inherent variability in VRE production comes a need for increased contingency in power systems. This requires both controllable production and consumption of power to cope with VRE deficits and surpluses. The purpose of this doctoral thesis is to investigate the potential for providing such power balancing services from Swedish district heating systems (DHS). Analyses are made for different system levels: community, regional, and national. Computer simulations of DH production systems with combined heat and power (CHP) plants, heat pumps, and thermal energy storage (TES), operated to supply a power balancing demand, are here shown to potentially reduce VRE deficits and surpluses. The results further show that reducing peak deficits and/or surpluses mainly depends on the installed capacities in CHP units and/or heat pumps. However, annual deficits or surpluses are reduced more if the system includes a TES. Also, the shares of wind and solar power in VRE mixes are shown to be relevant for fuel use and system performance. Solar-dominated VRE promotes heat pumps, reduces fuel use in CHP, and motivates a seasonal operation of TESs. Wind-dominated VRE matches with high capacities in CHP units, yields increased fuel use and motivates short-term operation of TESs. A crucial limitation is competition for the heat load between heat pumps and CHP units, which reduces the potential for CHP production. Competition between stored heat and heat pumps also occurs in systems with smaller TESs and large amounts of surplus electricity. In order for power balancing services to be economically viable for DHS operators, changed market structures that appropriately value

The global ambitions to hamper the greenhouse effect has led to ambitious targets for increasing renewable energy use. This, in combination with recent years' vast development of wind and solar power, implies that there will be significant amounts of variable renewable electricity (VRE) in future energy systems. With the inherent variability in VRE production comes a need for increased contingency in power systems. This requires both controllable production and consumption of power to cope with VRE deficits and surpluses. The purpose of this doctoral thesis is to investigate the potential for providing such power balancing services from Swedish district heating systems (DHS). Analyses are made for different system levels: community, regional, and national. Computer simulations of DH production systems with combined heat and power (CHP) plants, heat pumps, and thermal energy storage (TES), operated to supply a power balancing demand, are here shown to potentially reduce VRE deficits and surpluses. The results further show that reducing peak deficits and/or surpluses mainly depends on the installed capacities in CHP units and/or heat pumps. However, annual deficits or surpluses are reduced more if the system includes a TES. Also, the shares of wind and solar power in VRE mixes are shown to be relevant for fuel use and system performance. Solar-dominated VRE promotes heat pumps, reduces fuel use in CHP, and motivates a seasonal operation of TESs. Wind-dominated VRE matches with high capacities in CHP units, yields increased fuel use and motivates short-term operation of TESs. A crucial limitation is competition for the heat load between heat pumps and CHP units, which reduces the potential for CHP production. Competition between stored heat and heat pumps also occurs in systems with smaller TESs and large amounts of surplus electricity. In order for power balancing services to be economically viable for DHS operators, changed market structures that appropriately value

The global ambitions to hamper the greenhouse effect has led to ambitious targets for increasing renewable energy use. This, in combination with recent years' vast development of wind and solar power, implies that there will be significant amounts of variable renewable electricity (VRE) in future energy systems. With the inherent variability in VRE production comes a need for increased contingency in power systems. This requires both controllable production and consumption of power to cope with VRE deficits and surpluses. The purpose of this doctoral thesis is to investigate the potential for providing such power balancing services from Swedish district heating systems (DHS). Analyses are made for different system levels: community, regional, and national. Computer simulations of DH production systems with combined heat and power (CHP) plants, heat pumps, and thermal energy storage (TES), operated to supply a power balancing demand, are here shown to potentially reduce VRE deficits and surpluses. The results further show that reducing peak deficits and/or surpluses mainly depends on the installed capacities in CHP units and/or heat pumps. However, annual deficits or surpluses are reduced more if the system includes a TES. Also, the shares of wind and solar power in VRE mixes are shown to be relevant for fuel use and system performance. Solar-dominated VRE promotes heat pumps, reduces fuel use in CHP, and motivates a seasonal operation of TESs. Wind-dominated VRE matches with high capacities in CHP units, yields increased fuel use and motivates short-term operation of TESs. A crucial limitation is competition for the heat load between heat pumps and CHP units, which reduces the potential for CHP production. Competition between stored heat and heat pumps also occurs in systems with smaller TESs and large amounts of surplus electricity. In order for power balancing services to be economically viable for DHS operators, changed market structures that appropriately value

The global ambitions to hamper the greenhouse effect has led to ambitious targets for increasing renewable energy use. This, in combination with recent years' vast development of wind and solar power, implies that there will be significant amounts of variable renewable electricity (VRE) in future energy systems. With the inherent variability in VRE production comes a need for increased contingency in power systems. This requires both controllable production and consumption of power to cope with VRE deficits and surpluses. The purpose of this doctoral thesis is to investigate the potential for providing such power balancing services from Swedish district heating systems (DHS). Analyses are made for different system levels: community, regional, and national. Computer simulations of DH production systems with combined heat and power (CHP) plants, heat pumps, and thermal energy storage (TES), operated to supply a power balancing demand, are here shown to potentially reduce VRE deficits and surpluses. The results further show that reducing peak deficits and/or surpluses mainly depends on the installed capacities in CHP units and/or heat pumps. However, annual deficits or surpluses are reduced more if the system includes a TES. Also, the shares of wind and solar power in VRE mixes are shown to be relevant for fuel use and system performance. Solar-dominated VRE promotes heat pumps, reduces fuel use in CHP, and motivates a seasonal operation of TESs. Wind-dominated VRE matches with high capacities in CHP units, yields increased fuel use and motivates short-term operation of TESs. A crucial limitation is competition for the heat load between heat pumps and CHP units, which reduces the potential for CHP production. Competition between stored heat and heat pumps also occurs in systems with smaller TESs and large amounts of surplus electricity. In order for power balancing services to be economically viable for DHS operators, changed market structures that appropriately value

This work investigates experimentally for the first time the performance of two solid biomass wastes as propellants for a Hybrid Rocket Motor based on the combustion and propulsion parameters such as combustion chamber pressure, thrust force, chamber temperature, combustion characteristics, and flame length generated. The main objective of this study is to examine the performance of the proposed biomass fuels (Date stone powder and Jojoba waste powder) in comparison with typical hydrocarbon fuels. To make an accurate comparison, Paraffin Wax-based propellant was used in this study as a reference fuel to compare with biomass performance using the same testing facility and with the same operating conditions. A lab-scale Hybrid Rocket Motor with gaseous oxygen as an oxidizer operated in three ranges of volume flow rates of 80, 110, and 130 lpm. A compression device is introduced to compress the solid biomass fuel grain with a circular port along with a hot surface ignitor to ignite the system. The results suggested the expected gap in performance between biomass and hydrocarbon propellants, where a noticeable difference in performance was observed in favour of the Paraffin Wax-based propellant. However, Date Stone fuel showed slightly better propulsion and combustion characteristics compared to Jojoba. Both biomass fuel propellants have been tested in Hybrid Rocket Engine for the first time paving the way for further developments in biomass propulsion studies to be a potential replacement for high pollutant and expensive hydrocarbon propellants

The global ambitions to hamper the greenhouse effect has led to ambitious targets for increasing renewable energy use. This, in combination with recent years' vast development of wind and solar power, implies that there will be significant amounts of variable renewable electricity (VRE) in future energy systems. With the inherent variability in VRE production comes a need for increased contingency in power systems. This requires both controllable production and consumption of power to cope with VRE deficits and surpluses. The purpose of this doctoral thesis is to investigate the potential for providing such power balancing services from Swedish district heating systems (DHS). Analyses are made for different system levels: community, regional, and national. Computer simulations of DH production systems with combined heat and power (CHP) plants, heat pumps, and thermal energy storage (TES), operated to supply a power balancing demand, are here shown to potentially reduce VRE deficits and surpluses. The results further show that reducing peak deficits and/or surpluses mainly depends on the installed capacities in CHP units and/or heat pumps. However, annual deficits or surpluses are reduced more if the system includes a TES. Also, the shares of wind and solar power in VRE mixes are shown to be relevant for fuel use and system performance. Solar-dominated VRE promotes heat pumps, reduces fuel use in CHP, and motivates a seasonal operation of TESs. Wind-dominated VRE matches with high capacities in CHP units, yields increased fuel use and motivates short-term operation of TESs. A crucial limitation is competition for the heat load between heat pumps and CHP units, which reduces the potential for CHP production. Competition between stored heat and heat pumps also occurs in systems with smaller TESs and large amounts of surplus electricity. In order for power balancing services to be economically viable for DHS operators, changed market structures that appropriately value

The global ambitions to hamper the greenhouse effect has led to ambitious targets for increasing renewable energy use. This, in combination with recent years' vast development of wind and solar power, implies that there will be significant amounts of variable renewable electricity (VRE) in future energy systems. With the inherent variability in VRE production comes a need for increased contingency in power systems. This requires both controllable production and consumption of power to cope with VRE deficits and surpluses. The purpose of this doctoral thesis is to investigate the potential for providing such power balancing services from Swedish district heating systems (DHS). Analyses are made for different system levels: community, regional, and national. Computer simulations of DH production systems with combined heat and power (CHP) plants, heat pumps, and thermal energy storage (TES), operated to supply a power balancing demand, are here shown to potentially reduce VRE deficits and surpluses. The results further show that reducing peak deficits and/or surpluses mainly depends on the installed capacities in CHP units and/or heat pumps. However, annual deficits or surpluses are reduced more if the system includes a TES. Also, the shares of wind and solar power in VRE mixes are shown to be relevant for fuel use and system performance. Solar-dominated VRE promotes heat pumps, reduces fuel use in CHP, and motivates a seasonal operation of TESs. Wind-dominated VRE matches with high capacities in CHP units, yields increased fuel use and motivates short-term operation of TESs. A crucial limitation is competition for the heat load between heat pumps and CHP units, which reduces the potential for CHP production. Competition between stored heat and heat pumps also occurs in systems with smaller TESs and large amounts of surplus electricity. In order for power balancing services to be economically viable for DHS operators, changed market structures that appropriately value

Agricultural waste products have huge energy content and have the potential to be harnessed to generate energy. This paper presents experimental investigation results on the biomass obtained from Malaysia’s agricultural sector mixed with coal for combustion to generate power. A total of seven different types of biomass samples have been considered, mainly oil palm trunk, oil palm fruit shell, oil palm fruit fiber, oil palm empty fruit bunch, oil palm leaf, oil palm frond, and chicken manure. They were mixed with semi-bituminous coal at several mixing percentages (2% biomass, 5% biomass, 10% biomass, 15% biomass). The mixtures then underwent analyses in the form of energy content or calorific value test, ultimate analysis, and proximate analysis. The results have been presented in terms of the energy content, carbon content, degradation temperature, and combustion-produced matters. Results show that the energy content of the coal-biomass mixture is generally lower than that of pure coal. Biomass can be co-fired with coal but at a low percentage, estimated to be not more than 10% biomass content. A biomass type that has potential and should be studied is the oil palm fruit shell. However, a balance is required for any electricity generation application between the energy content per unit weight and the other parameters such as properties of the released flue gas and ash properties.

This paper investigates the ability of insulation cellulose fiber powder (CFP) to be pelletized for its valorization as biomass fuel. CFP is a waste originating from insulation cellulose manufacturing that lacks any method of valorization because of its boron salts content. A sugar byproduct and lignosulfonate (LS) were considered as binders for the pellet manufacturing process. Physical tests were carried out to characterize the pellets’ performance. Chemical and combustion tests were considered to state the pellets’ potential as a green energy source. Raw CFP showed good ability in its pelletization and durability in the range of 15–30% of moisture content. The pellet’s density decreased as water content increased. Binders increased the pellet’s length before and after the durability test. Binders also increased the CFP pellet’s water absorption, demonstrating a potential decrease in durability against environmental factors. Binders also decreased the lower heating value. Ultimate analysis showed a slight Nitrogen increase in both binder combinations that could potentially raise the pollutant NOx combustion emissions. All the combinations showed adequate combustion characteristics, but binders increased ash production. Additives decreased the CFP volatile matter content and increased the fixed carbon, which could facilitate a more stable combustion. DTA curves showed a mass loss rate decrease in the volatile stage for the binder combinations, which also could be considered as an indicator of a more stable combustion. The ashes’ chemical compositions when analyzed by XPS showed boron contents oscillating between 10.03% and 16.42%, demonstrating the possibility of recovering them from the combustion ashes

This paper investigates the ability of insulation cellulose fiber powder (CFP) to be pelletized for its valorization as biomass fuel. CFP is a waste originating from insulation cellulose manufacturing that lacks any method of valorization because of its boron salts content. A sugar byproduct and lignosulfonate (LS) were considered as binders for the pellet manufacturing process. Physical tests were carried out to characterize the pellets’ performance. Chemical and combustion tests were considered to state the pellets’ potential as a green energy source. Raw CFP showed good ability in its pelletization and durability in the range of 15–30% of moisture content. The pellet’s density decreased as water content increased. Binders increased the pellet’s length before and after the durability test. Binders also increased the CFP pellet’s water absorption, demonstrating a potential decrease in durability against environmental factors. Binders also decreased the lower heating value. Ultimate analysis showed a slight Nitrogen increase in both binder combinations that could potentially raise the pollutant NOx combustion emissions. All the combinations showed adequate combustion characteristics, but binders increased ash production. Additives decreased the CFP volatile matter content and increased the fixed carbon, which could facilitate a more stable combustion. DTA curves showed a mass loss rate decrease in the volatile stage for the binder combinations, which also could be considered as an indicator of a more stable combustion. The ashes’ chemical compositions when analyzed by XPS showed boron contents oscillating between 10.03% and 16.42%, demonstrating the possibility of recovering them from the combustion ashes

Agricultural waste products have huge energy content and have the potential to be harnessed to generate energy. This paper presents experimental investigation results on the biomass obtained from Malaysia's agricultural sector mixed with coal for combustion to generate power. A total of seven different types of biomass samples have been considered, mainly oil palm trunk, oil palm fruit shell, oil palm fruit fiber, oil palm empty fruit bunch, oil palm leaf, oil palm frond, and chicken manure. They were mixed with semi-bituminous coal at several mixing percentages (2% biomass, 5% biomass, 10% biomass, 15% biomass). The mixtures then underwent analyses in the form of energy content or calorific value test, ultimate analysis, and proximate analysis. The results have been presented in terms of the energy content, carbon content, degradation temperature, and combustion-produced matters. Results show that the energy content of the coal-biomass mixture is generally lower than that of pure coal. Biomass can be co-fired with coal but at a low percentage, estimated to be not more than 10% biomass content. A biomass type that has potential and should be studied is the oil palm fruit shell. However, a balance is required for any electricity generation application between the energy content per unit weight and the other parameters such as properties of the released flue gas and ash properties © 2021 WIT Press, www.witpress.com.

This paper investigates the ability of insulation cellulose fiber powder (CFP) to be pelletized for its valorization as biomass fuel. CFP is a waste originating from insulation cellulose manufacturing that lacks any method of valorization because of its boron salts content. A sugar byproduct and lignosulfonate (LS) were considered as binders for the pellet manufacturing process. Physical tests were carried out to characterize the pellets’ performance. Chemical and combustion tests were considered to state the pellets’ potential as a green energy source. Raw CFP showed good ability in its pelletization and durability in the range of 15–30% of moisture content. The pellet’s density decreased as water content increased. Binders increased the pellet’s length before and after the durability test. Binders also increased the CFP pellet’s water absorption, demonstrating a potential decrease in durability against environmental factors. Binders also decreased the lower heating value. Ultimate analysis showed a slight Nitrogen increase in both binder combinations that could potentially raise the pollutant NOx combustion emissions. All the combinations showed adequate combustion characteristics, but binders increased ash production. Additives decreased the CFP volatile matter content and increased the fixed carbon, which could facilitate a more stable combustion. DTA curves showed a mass loss rate decrease in the volatile stage for the binder combinations, which also could be considered as an indicator of a more stable combustion. The ashes’ chemical compositions when analyzed by XPS showed boron contents oscillating between 10.03% and 16.42%, demonstrating the possibility of recovering them from the combustion ashes

Reforms in the energy sector are expected to bring about essential efciency gains, which could result in energy diversifcation and welfare improvements among households. However, there are other unintended social and environmental consequences associated with the process. One signifcant social concern is the likely impact on how low-income families access new energy. The study used a cross-sectional design to undertake a comparative analysis of domestic energy choices. Data was collected from 405 households’ decision makers. An interview schedule and a guide were used for the data collection. The results showed that modern fuels are by far the most predominant source of energy for high and medium class residential households in Kumasi. However, residents in low-class areas preferred to use biomass fuel as their primary energy choice. Contextual variations revealed that general factors such as afordability and accessibility of energy source were exogenous determinants of energy choice. The fndings of the study also lend support to the energy ladder hypothesis that household income is a signifcant determinant of household energy choice. Further, social and demographic factors are critical determinants of cooking fuel type in residential zones. The study recommends the promotion of modern fuels through developing dependable energy distribution systems, and public education campaigns by the Energy Commission of Ghana.

The industrial combustion of biomass, which has always been considered a source of clean and sustainable energy, might be phased out in China because it is believed to cause extremely high emissions of volatile organic compounds (VOCs), which are the key precursors in the formation of ozone and haze, although the emission factors have rarely been measured. In this study, the emissions of VOCs and several other air pollutants from typical industrial bagasse-fired boilers were measured for the first time. It was found that the emission factor (EF) of VOCs was 0.108 ± 0.034 g kg−1 (or 5.31 ± 1.68 g GJ−1 on an energy basis), which was roughly one order of magnitude lower than the officially recommended EF for industrial biomass combustion in China. In addition, the emissions of SO2, NOx and Hg from bagasse-fired boilers were even lower than those stipulated in the regulations for gas-fired boilers, with the exception of the particulate matter (PM), which was much lower than that produced during the open burning of biomass but higher than that from solid-fuel-fired boilers, likely as a result of the application of an ineffective dust removal device. It was demonstrated that the industrial combustion of biomass might produce much lower VOC emissions than expected and could help alleviate air pollution if biomass (at least bagasse) were used on a large scale instead of simply being burned in the field. In the future, dust removal devices with high efficiency should compulsorily be applied to industrial biomass boilers, and additional types of biomass fuel should be thoroughly evaluated to provide air-quality and energy policy makers with important insights.

The association of biomass fuel use with body weight has never been investigated. We therefore examined the effect of biomass fuel use on body weight of adult Ghanaian women. Data from the 2014 Ghana Demographic and Health Survey, a nationally representative population-based survey was analysed for this study. A total of 4751 women who had anthropometric (height and weight) data qualified for inclusion in this study. In linear regression modelling, charcoal use resulted in 3.08 kg (95% CI: 2.04, 4.12) and 0.81 kg/m² (95%CI: 0.29, 1.33) reduction in weight and body mass index (BMI), respectively, compared to clean fuel (electricity, liquefied petroleum gas and natural gas) use. Use of wood resulted in much higher reduction in weight and BMI. In modified Poisson regression, charcoal users had 19% (Adjusted Prevalence Ratio [aPR] = 0.81; 95%CI: 0.71, 0.92) and 29% (aPR = 0.71; 95%CI: 0.61, 0.83) decreased risk of overweight and obesity, respectively, compared to clean fuel users. Wood users had much higher decreased risk of overweight and obesity. In conclusion, biomass fuel use was associated with reduced body weight and BMI of Ghanaian women and is the first report on the relationship. However, it is important that our findings are confirmed and the biological mechanisms elucidated through rigorous study designs.

Reforms in the energy sector are expected to bring about essential efciency gains, which could result in energy diversifcation and welfare improvements among households. However, there are other unintended social and environmental consequences associated with the process. One signifcant social concern is the likely impact on how low-income families access new energy. The study used a cross-sectional design to undertake a comparative analysis of domestic energy choices. Data was collected from 405 households’ decision makers. An interview schedule and a guide were used for the data collection. The results showed that modern fuels are by far the most predominant source of energy for high and medium class residential households in Kumasi. However, residents in low-class areas preferred to use biomass fuel as their primary energy choice. Contextual variations revealed that general factors such as afordability and accessibility of energy source were exogenous determinants of energy choice. The fndings of the study also lend support to the energy ladder hypothesis that household income is a signifcant determinant of household energy choice. Further, social and demographic factors are critical determinants of cooking fuel type in residential zones. The study recommends the promotion of modern fuels through developing dependable energy distribution systems, and public education campaigns by the Energy Commission of Ghana.

Background: Exposure to household air pollution from cooking fires using biomass fuels (e.g., wood, charcoal, dung) is a leading cause of death and disability worldwide. Household air pollution (HAP) is one of the greatest environmental health risks in low-income and middle-income countries where the majority of people use biomass fuels to cook and heat their homes each day. Worldwide, approximately three billion people cook with biomass fuels; most often, these people cook inside homes with poor ventilation and use traditional stoves without chimneys. Even when clean-burning stoves and fuels are introduced in communities using HAP-producing cooking systems, adoption of these systems is often limited, and the use of clean-burning systems is not exclusive or sustained. To date, despite the need to understand behaviors related to smoke from cooking and heating sources, few investigators have used a behavioral theory or framework as a foundation for their investigation. Methods: This qualitative exploratory study using open-ended interviews was conducted in Aleto Wondo, a rural area in southern Ethiopia. This research used grounded theory methodology and the theory of symbolic interaction to investigate the symbolic meaning that motivates actions related to exposures to household air pollution from cooking fire smoke. The target population was women who had children in the home and who primarily used biomass fuels for cooking.Results: Themes that emerged during the analysis process and that are grounded in the data were (a) Awareness, Knowledge, and Interpretation; (b) Traditional Way; (c) Perceived Powerless and Lack of Agency; (d) Opportunities for Clarification and Education; (e) Access and Poverty; and (f) God’s Will. These themes summarized the major factors in the participants’ social world—factors that influence the participant’s symbolic meanings and interpretations that affected actions related to smoke from cooking fires. Conclusions: Using the theoretical an

Improved cookstoves are widely promoted as a health and climate improving technology, yet there remains a wide gap between their reputed benefits and the inconclusive outcomes of most interventions. An increasing number of scientists suggest that the popular lab protocols used to test, rate and model the benefits of improved cookstoves are at least partly to blame. Insights from a recent study of improved cookstove users in Darfur, Sudan, reveal the extent to which the logic and goals of lab-based testing protocols differ from actual cooking practices. We elaborate on the climate and energy policy implications of decontextualized lab tests and conclude with a call to design, test and select for dissemination only those improved cookstoves that are rated on the basis of their intended contexts of use.

Background: Exposure to household air pollution from cooking fires using biomass fuels (e.g., wood, charcoal, dung) is a leading cause of death and disability worldwide. Household air pollution (HAP) is one of the greatest environmental health risks in low-income and middle-income countries where the majority of people use biomass fuels to cook and heat their homes each day. Worldwide, approximately three billion people cook with biomass fuels; most often, these people cook inside homes with poor ventilation and use traditional stoves without chimneys. Even when clean-burning stoves and fuels are introduced in communities using HAP-producing cooking systems, adoption of these systems is often limited, and the use of clean-burning systems is not exclusive or sustained. To date, despite the need to understand behaviors related to smoke from cooking and heating sources, few investigators have used a behavioral theory or framework as a foundation for their investigation. Methods: This qualitative exploratory study using open-ended interviews was conducted in Aleto Wondo, a rural area in southern Ethiopia. This research used grounded theory methodology and the theory of symbolic interaction to investigate the symbolic meaning that motivates actions related to exposures to household air pollution from cooking fire smoke. The target population was women who had children in the home and who primarily used biomass fuels for cooking.Results: Themes that emerged during the analysis process and that are grounded in the data were (a) Awareness, Knowledge, and Interpretation; (b) Traditional Way; (c) Perceived Powerless and Lack of Agency; (d) Opportunities for Clarification and Education; (e) Access and Poverty; and (f) God’s Will. These themes summarized the major factors in the participants’ social world—factors that influence the participant’s symbolic meanings and interpretations that affected actions related to smoke from cooking fires. Conclusions: Using the theoretical an

The objective of this study is to apply neat biomass fuel to a DI diesel engine and investigate the effect of in-cylinder gas flow and combustion on the deposit formation and the fuel dilution in lubricating oil. The study focuses on the low load combustion and emissions considering that low load exhaust contain much unburned fuels and the unburned fuels are the source of the deposit formation and the fuel dilution. Piston configuration and swirl velocity were altered in the engine test. The engine was fueled by neat rapeseed oil. The test was carried out through the four hours continuous engine operation with keeping low load. After the operation, state of deposit formation and fuel dilution in lubricating oil were investigated. Results indicate that Re-entrant piston which creates strong reverse squish and high swirl forms the deposit annular on the piston top. Toroidal piston easily produces deposit on the undersurface of cylinder head. The deposit in the cavity accumulates where initial rapeseed oil spray impinges regardless of piston types. The carbonization of the deposit is promoted on the wall surface where the burned gas with high temperature and high velocity comes into contact. It is important to avoid extremely strong reverse squish to the cylinder liner in order to control the fuel dilution. The deep-bowl chamber changes the direction of reverse squish from the cylinder liner direction to the cylinder head direction. The low velocity outflow from the piston cavity reduces the adhesion of unburned fuel on the cylinder liner, resulting in the smaller amount of unburned fuel scraped off by a piston ring.

Promoters of improved cook stove technologies (ICS) argue that the use of these technologies offers several benefits such as improved health, fuel saving, reduction in green house gases emissions among others. Many of the studies exploring the use of improved cook stoves reveal a strong pro-diffusion bias towards these benefits, and few studies have investigated the adoption and use of ICS from the adopter’s point of view. This qualitative case study therefore attempted to understand the perceived factors that explicitly or implicitly influence the adoption (or not) of Improved cook stoves at household level by listening to potential ICS users. From the study, it was evident that adoption and sustained use of cook stoves is complex and it necessities consideration of a wide range of factors which mutually the influence house hold decision to adopt (or not) an improved cook stove. Consequently, this study emphasized the need for those promoting ICS to have a deeper understanding of the context in which potential adopters are part, and gain insight into the complex factors that govern behavior and provide a basis for doing things in a certain way, in order to ensure adoption and sustained use of ICSs and thereby realize it’s associated long term benefits.

Air pollution from household biomass combustion is an important cause of poor health in developing countries. This study employs national-level longitudinal data for up to 175 countries during 1990–2010 and finds that female labor force participation is associated with reductions in household biomass energy use. Consistent with the “fuel stacking” model, higher incomes are linked to use of other types of energy by households, but not significantly associated with reductions in use of biomass energy. The results highlight the multifaceted nature of household energy transitions and suggest an avenue by which female empowerment can lead to improved health outcomes.

Promoters of improved cook stove technologies (ICS) argue that the use of these technologies offers several benefits such as improved health, fuel saving, reduction in green house gases emissions among others. Many of the studies exploring the use of improved cook stoves reveal a strong pro-diffusion bias towards these benefits, and few studies have investigated the adoption and use of ICS from the adopter’s point of view. This qualitative case study therefore attempted to understand the perceived factors that explicitly or implicitly influence the adoption (or not) of Improved cook stoves at household level by listening to potential ICS users. From the study, it was evident that adoption and sustained use of cook stoves is complex and it necessities consideration of a wide range of factors which mutually the influence house hold decision to adopt (or not) an improved cook stove. Consequently, this study emphasized the need for those promoting ICS to have a deeper understanding of the context in which potential adopters are part, and gain insight into the complex factors that govern behavior and provide a basis for doing things in a certain way, in order to ensure adoption and sustained use of ICSs and thereby realize it’s associated long term benefits.

Detta arbete utfördes i syfte att analysera och utvärdera effekterna av att dosera svavel till förbränningen i en biopanna. En utrustning för detta ändamål installerades till biopannan vid fjärrvärmeverket i Arvika för att få bukt med höga halter av kolmonoxid i rökgaserna. Analysen har genomförts med avseende på hur väl svaveldoseringen uppfyller sitt tilltänkta syfte men även på eventuella bieffekter. Korrosionsrisker, halter av oförbränt svavel i rökgaser, rökgaskondensat, flyg- och bottenaska samt vad som sker kemiskt i förbränningsprocessen vid tillsats av svavel har studerats. Driftrapporter från biopannan analyserades parallellt med en informationshämtning i form av en litteraturstudie och kontakt med sakkunniga personer för att svara på ställda frågor. CO-halten i rökgaser sjunker vid tillsats av svavel. Laboratorieanalyser och driftrapporter visar på en närvaro av svavel i rökgaser, rökgaskondensat samt flyg- och bottenaska. I resultatet framgår att halterna är acceptabla. Risken att svaveltillsats i förbränningen skulle ha en negativ inverkan på korrosion i biopannan anses vara låg. Kunskapsläget om vad som sker kemiskt i förbränningsprocessen vid tillsats av svavel är bristfälligt. Fullskale- samt laboratorieförsök har genomförts utan att kunna påvisa exakt hur svavlet sänker CO-halterna i rökgaser.Nyckelord, This study was performed in order to analyze and evaluate the effects of dosing sulfur to the combustion process in a bio fueled boiler. Equipment for this purpose was installed to the bio boiler at a district heating plant in Arvika in order to overcome high levels of carbon monoxide in the flue gas. The analysis has been carried out with regard to how well the sulfur dosage is fulfilling its intended purpose but also to possible side effects. Corrosion risks, levels of unburned sulfur in flue gas, flue gas condensate, air and bottom ash along with what happens chemically in the combustion process have been studied. Operational reports from the bio fueled boiler was studied and analyzed. To find out other effects of adding sulfur to the combustion a literature study was performed as well as direct contact with experts on the subject. CO content in the flue gas drops when adding sulfur to the combustion process. Laboratory analysis and operational reports indicate a presence of sulfur in the flue gas, flue gas condensate and fly ash and bottom ash. The results show that the levels are acceptable. The risk of causing corrosion in the plant by adding sulfur to the combustion is considered low. The current knowledge of what is happening chemically in the combustion process by the addition of sulfur is insufficient. Full-scale and laboratory experiments have been carried out without being able to show exactly how the sulfur lowers CO concentrations in flue gases.

Detta arbete utfördes i syfte att analysera och utvärdera effekterna av att dosera svavel till förbränningen i en biopanna. En utrustning för detta ändamål installerades till biopannan vid fjärrvärmeverket i Arvika för att få bukt med höga halter av kolmonoxid i rökgaserna. Analysen har genomförts med avseende på hur väl svaveldoseringen uppfyller sitt tilltänkta syfte men även på eventuella bieffekter. Korrosionsrisker, halter av oförbränt svavel i rökgaser, rökgaskondensat, flyg- och bottenaska samt vad som sker kemiskt i förbränningsprocessen vid tillsats av svavel har studerats. Driftrapporter från biopannan analyserades parallellt med en informationshämtning i form av en litteraturstudie och kontakt med sakkunniga personer för att svara på ställda frågor. CO-halten i rökgaser sjunker vid tillsats av svavel. Laboratorieanalyser och driftrapporter visar på en närvaro av svavel i rökgaser, rökgaskondensat samt flyg- och bottenaska. I resultatet framgår att halterna är acceptabla. Risken att svaveltillsats i förbränningen skulle ha en negativ inverkan på korrosion i biopannan anses vara låg. Kunskapsläget om vad som sker kemiskt i förbränningsprocessen vid tillsats av svavel är bristfälligt. Fullskale- samt laboratorieförsök har genomförts utan att kunna påvisa exakt hur svavlet sänker CO-halterna i rökgaser.Nyckelord, This study was performed in order to analyze and evaluate the effects of dosing sulfur to the combustion process in a bio fueled boiler. Equipment for this purpose was installed to the bio boiler at a district heating plant in Arvika in order to overcome high levels of carbon monoxide in the flue gas. The analysis has been carried out with regard to how well the sulfur dosage is fulfilling its intended purpose but also to possible side effects. Corrosion risks, levels of unburned sulfur in flue gas, flue gas condensate, air and bottom ash along with what happens chemically in the combustion process have been studied. Operational reports from the bio fueled boiler was studied and analyzed. To find out other effects of adding sulfur to the combustion a literature study was performed as well as direct contact with experts on the subject. CO content in the flue gas drops when adding sulfur to the combustion process. Laboratory analysis and operational reports indicate a presence of sulfur in the flue gas, flue gas condensate and fly ash and bottom ash. The results show that the levels are acceptable. The risk of causing corrosion in the plant by adding sulfur to the combustion is considered low. The current knowledge of what is happening chemically in the combustion process by the addition of sulfur is insufficient. Full-scale and laboratory experiments have been carried out without being able to show exactly how the sulfur lowers CO concentrations in flue gases.

Energy use is central to human society and provides many health benefits. But each source of energy entails some health risks. This article reviews the health impacts of each major source of energy, focusing on those with major implications for the burden of disease globally. The biggest health impacts accrue to the harvesting and burning of solid fuels, coal and biomass, mainly in the form of occupational health risks and household and general ambient air pollution. Lack of access to clean fuels and electricity in the world's poor households is a particularly serious risk for health. Although energy efficiency brings many benefits, it also entails some health risks, as do renewable energy systems, if not managed carefully. We do not review health impacts of climate change itself, which are due mostly to climate-altering pollutants from energy systems, but do discuss the potential for achieving near-term health cobenefits by reducing certain climate-related emissions.

Biomass is a renewable and carbon neutral solid fuel. Utilization of biomass in iron ore roasting process as heating agent and reducing agent contributes to energy conservation and emission reduction, and can partially replace for coal and coke. The biomass instead of coke was mixed together with iron ore powder from the north of Hainan province into ball roasting process to investigate the effects of mixture composition, reduction temperature, reaction time, the thermal reduction and magnetic properties of the mixture. The results show that the reduction temperature, reaction time and dosage of the biomass are correlated to the quality of the reduction and the magnetism of the iron ore, within the experimental conditions. The mechanism of the biomass reducing the weakly magnetic goethite into stronger magnetic iron oxide has been discussed. The results show that the goethite ores is dramatically reduced and magnetized by about 20 wt.% biomass at low roasting temperature. Application of biomass energy in iron ores roasting process is prospective to the effective use of biomass and for decreasing the consumption of fossil fuels in the steelmaking process., Qc 20120725

Use of biomass fuel in traditional cooking stoves (TCS) is a long-established practice that has incomplete combustion and generates substances with global warming potential (GWP). Improved cooking stoves (ICS) have been developed worldwide as an alternative household fuel burning device, as well as a climate change mitigation. A study was conducted among female Forest User Groups (FUGs) of Rema-Kalenga Wildlife Sanctuary, Bangladesh, to assess the status of ICS disseminated by the Forest Department (FD) under the Nishorgo (2009) Support Project, along with the community's biomass fuel consumption pattern. Wood consumption was highest (345kg month-1 household-1) followed by agricultural residues (60kg month-1 household-1), tree leaves (51kg month-1 household-1) and cow dung (25kg month-1 household-1). Neighbouring forests of the sanctuary was the core source for wood fuel, with little or no reduction in the extraction even after joining the FUG. Twenty-two species, both indigenous and introduced, were preferred as wood fuel. None of the respondents were found willing to use ICS although 43% owned one; either as a status symbol or to meet the conditions of the FD for membership in FUG. Seven negative features of the disseminated ICS were identified by households, which made them unwilling to use them further. Manufacturing faults may be responsible for some ICS demerits, while the FD failed to convince the community of the benefits. A proper examination of the disseminated ICS efficacy is crucial, with active involvement of community members. The Sustainable Energy Triangle Strategy (SETS) could be implemented for this purpose. Findings of the study are of immense importance in designing a strategy for the introduction of ICS into Bangladesh., This is an electronic version of an article published in International Journal of Sustainable Development & World Ecology, 1745-2627, 18(1) 2011, 88-97. International Journal of Sustainable Development & World Ecology is available online at: http://www.informaworld.com/smpp/content~db=all~content=a933218896~frm=titlelink

This dissertation examines the level of two major pollutants in the kitchens from biomass, kerosene and liquefied petroleum gas (LPG) stoves, and two health problems associated with use of biomass and kerosene compared with LPG stove in Nepal. Its chapter a) characterizes the exposure levels of two pollutants-fine particles (PM2.5) and naphthalene from three cookstoves, b) validate exposure questionnaire used in two epidemiological studies with the gold standard, c) showcase method to estimate sample size (duration of measurements) to reliably characterize levels of PM2.5 across rural households from continuously measured PM2.5 data, and d) examines the association of use of biomass and kerosene fuel with pre-clinical damage of lens (lens opacity) and tuberculosis in women. Divided on 5 chapters, the chapter 1 gives an overview of the dissertation. Chapter 2 provides a detailed background, materials and methods and results of validity study, and measurement results of naphthalene and PM2.5 from passive samplers. Similarly chapter 2 validates method for determining sample size from continuously measured PM2.5 data. Although there exist studies of associations of TB and cataracts from use of biomass fuel but the possible associations of TB and cataracts with the use of kerosene fuel are virtually uninvestigated. Chapter 3 investigates association between biomass and kerosene fuel use and pre-clinical damage of lens (lens opacity) in women and chapter 4 investigates the association between biomass and kerosene fuel use and TB in women. The chapter 5 summarizes the main findings of chapters 2, 3 and 4. The results of the three main chapters suggest that in Nepal cooks who use unvented biomass cookstoves experience very high mean and peak exposure of PM2.5 compared with kerosene and LPG stoves. By contrast, the cooks experience higher exposure of naphthalene from both kerosene and biomass cookstoves compared with LPG cookstoves. Current and past use of biomass cookstoves

BackgroundIn Nepal, tuberculosis (TB) is a major problem. Worldwide, six previous epidemiologic studies have investigated whether indoor cooking with biomass fuel such as wood or agricultural wastes is associated with TB with inconsistent results.ObjectivesUsing detailed information on potential confounders, we investigated the associations between TB and the use of biomass and kerosene fuels.MethodsA hospital-based case-control study was conducted in Pokhara, Nepal. Cases (n = 125) were women, 20-65 years old, with a confirmed diagnosis of TB. Age-matched controls (n = 250) were female patients without TB. Detailed exposure histories were collected with a standardized questionnaire.ResultsCompared with using a clean-burning fuel stove (liquefied petroleum gas, biogas), the adjusted odds ratio (OR) for using a biomass-fuel stove was 1.21 [95% confidence interval (CI), 0.48-3.05], whereas use of a kerosene-fuel stove had an OR of 3.36 (95% CI, 1.01-11.22). The OR for use of biomass fuel for heating was 3.45 (95% CI, 1.44-8.27) and for use of kerosene lamps for lighting was 9.43 (95% CI, 1.45-61.32).ConclusionsThis study provides evidence that the use of indoor biomass fuel, particularly as a source of heating, is associated with TB in women. It also provides the first evidence that using kerosene stoves and wick lamps is associated with TB. These associations require confirmation in other studies. If using kerosene lamps is a risk factor for TB, it would provide strong justification for promoting clean lighting sources, such as solar lamps.

This dissertation examines the level of two major pollutants in the kitchens from biomass, kerosene and liquefied petroleum gas (LPG) stoves, and two health problems associated with use of biomass and kerosene compared with LPG stove in Nepal. Its chapter a) characterizes the exposure levels of two pollutants-fine particles (PM2.5) and naphthalene from three cookstoves, b) validate exposure questionnaire used in two epidemiological studies with the gold standard, c) showcase method to estimate sample size (duration of measurements) to reliably characterize levels of PM2.5 across rural households from continuously measured PM2.5 data, and d) examines the association of use of biomass and kerosene fuel with pre-clinical damage of lens (lens opacity) and tuberculosis in women. Divided on 5 chapters, the chapter 1 gives an overview of the dissertation. Chapter 2 provides a detailed background, materials and methods and results of validity study, and measurement results of naphthalene and PM2.5 from passive samplers. Similarly chapter 2 validates method for determining sample size from continuously measured PM2.5 data. Although there exist studies of associations of TB and cataracts from use of biomass fuel but the possible associations of TB and cataracts with the use of kerosene fuel are virtually uninvestigated. Chapter 3 investigates association between biomass and kerosene fuel use and pre-clinical damage of lens (lens opacity) in women and chapter 4 investigates the association between biomass and kerosene fuel use and TB in women. The chapter 5 summarizes the main findings of chapters 2, 3 and 4. The results of the three main chapters suggest that in Nepal cooks who use unvented biomass cookstoves experience very high mean and peak exposure of PM2.5 compared with kerosene and LPG stoves. By contrast, the cooks experience higher exposure of naphthalene from both kerosene and biomass cookstoves compared with LPG cookstoves. Current and past use of biomass cookstoves

BackgroundIn Nepal, tuberculosis (TB) is a major problem. Worldwide, six previous epidemiologic studies have investigated whether indoor cooking with biomass fuel such as wood or agricultural wastes is associated with TB with inconsistent results.ObjectivesUsing detailed information on potential confounders, we investigated the associations between TB and the use of biomass and kerosene fuels.MethodsA hospital-based case-control study was conducted in Pokhara, Nepal. Cases (n = 125) were women, 20-65 years old, with a confirmed diagnosis of TB. Age-matched controls (n = 250) were female patients without TB. Detailed exposure histories were collected with a standardized questionnaire.ResultsCompared with using a clean-burning fuel stove (liquefied petroleum gas, biogas), the adjusted odds ratio (OR) for using a biomass-fuel stove was 1.21 [95% confidence interval (CI), 0.48-3.05], whereas use of a kerosene-fuel stove had an OR of 3.36 (95% CI, 1.01-11.22). The OR for use of biomass fuel for heating was 3.45 (95% CI, 1.44-8.27) and for use of kerosene lamps for lighting was 9.43 (95% CI, 1.45-61.32).ConclusionsThis study provides evidence that the use of indoor biomass fuel, particularly as a source of heating, is associated with TB in women. It also provides the first evidence that using kerosene stoves and wick lamps is associated with TB. These associations require confirmation in other studies. If using kerosene lamps is a risk factor for TB, it would provide strong justification for promoting clean lighting sources, such as solar lamps.

A mathematical model has been formulated for predicting the main chemical and physical processes taking place during the fixed-bed gasification of biomass fuels using high temperature air (up to 1000 degrees C). Predicted gas species concentrations profiles and their maximum values are in good agreement with measurements. The results also show that when the temperature of feed gas (air) is increased a higher gasification rate, higher molar fractions of fuel gases (CO, H-2 and CmHn) are obtained, thus resulting in a higher LHV. At a high flow rate of the feed gases, the peaks of the fuel gas concentrations are slightly increased, and the gasification rate is strongly increased. A smaller particle size of the biomass fuels leads to higher peak values of the fuel gas species molar fractions, and a more stable gasification zone for a relatively long period of time., QC 20100525