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The present study investigates the effect on methane production from waste paper when co-digested with macroalgal biomass. Both feedstocks were previously mechanically pretreated to reduce their particle size. The study was planned according two factors: the feedstock to inoculum (F/I) ratio and the waste paper to macroalgae (WP/MA) ratio. The F/I ratios checked were 0.2, 0.3 and 0.4 and the WP/MA ratios were 0:100, 25:75, 50:50, 75:25 and 100:0. The highest methane yield (386 L kg −1 VS added ) was achieved at an F/I ratio of 0.2 and a WP/MA ratio of 50:50. A biodegradability index of 0.87 obtained in this study indicates complete conversion of feedstock at an optimum C/N ratio of 26. Synergistic effect was found for WP/MA 25:75, 50:50 and 75:25 mixing ratios compared with the substrates mono-digestion. [ABSTRACT FROM AUTHOR]

In the anaerobic digestion of lignocellulosic materials such as waste paper, the accessibility of microorganisms to the fermentable sugars is restricted by their complex structure. A mechanical pretreatment with a Hollander beater was assessed in order to reduce the biomass particle size and to increase the feedstock’ specific surface area available to the microorganisms, and therefore improve the biogas yield. Pretreatment of paper waste for 60 min improves the methane yield by 21%, from a value of 210 ml/gVS corresponding to untreated paper waste to 254 ml/gVS. 30 min pretreatment have no significant effect on the methane yield. A response surface methodology was used to evaluate the effect of the beating time and feedstock/inoculum ratio on the methane yield. An optimum methane yield of 253 ml/gVS was achieved at 55 min of beating pretreatment and a F/I ratio of 0.3. [ABSTRACT FROM AUTHOR]

This work reports an innovative simulation method for effectively utilizing paper-mill sludge based on the co-gasification approach for energy-enriched renewable fuel production. An Aspen plus-based co-gasification model was developed to simulate and examine the synergetic effects of biomass and paper-mill sludge co-gasification. Initially, the model was validated using experimental data from the reported literature and found good agreement regarding gasification and co-gasification approaches. Sensitivity analysis of biomass gasification revealed that the maximum H 2 content of 29.6% and CO (36.0%), LHV (7.8 MJ/Nm3), 72.2% (CCE) was obtained at optimal (850 °C: temperature; 1 bar: pressure; 0.2: ER) conditions. Further, the H 2 proportion enhanced, and CO declined to 38.8 and 30.7% at the same operating conditions, respectively, with a co-gasification ratio of 50% compared to 0% (H 2 : 29.6% and CO: 36.0%). However, with increasing the co-gasification ratio beyond 20%, the CO content started to follow upward trends; at the same CGR, the H 2 , LHV, and CCE observed were 36.0%, 7.76 MJ/Nm3, and 65.2%, respectively. Hence, the developed co-gasification model can provide vital information for large-scale gasifier design, operating decisions, and optimization using different biomass blends. • Biomass and PMS utilization to produce renewable fuel. • Co-gasification parametric effects evaluation on product yield. • Increasing the proportion of PMS in feedstock mixture increases H 2 content. • 20% PMS co-gasification provided consistency with reported literature. [ABSTRACT FROM AUTHOR]

This study aims to investigate the gasification potential of olive pomace with using different fixed-bed gasifier systems. Olive pomace as a dried form was supplied from a chemical industry plant working on olive oil soap, located in Izmir, Türkiye. After a complete characterization of olive pomace, gasification experiments by using fixed bed reactor systems were done at three different gasifier temperatures as 700, 800 and 900 °C. As a gasification agent, dry air was used with four different flowrates (0.4, 0.2, 0.1, 0.05 L/min) while pure oxygen experiments were carried out with a flow rate of 0.01 L/min. Syngas with H 2 content of 48% and 45% (volumetric) were obtained in updraft and downdraft gasifiers, respectively, by using dried air as a gasifying agent. Heating value of syngas was around 12.4 MJ/Nm3. In the pure oxygen atmosphere, H 2 contents of the syngas were measured as 53% and 39%vol. In the updraft and downdraft gasifiers. This paper presents the research results on the olive pomace gasification study as a part of a large-scale research project and discuss them in the context of hydrogen production from the fixed bed reactors. [Display omitted] • Pomace gasification process was carried out in two different fixed bed reactors. • The volumetric percentage of H 2 gas was found to be in the range of 40–50%. • The maximum volume of methane was measured approximately as 20%. • The maximum volume of CO was measured in the range of 20–30% in both reactors. • The maximum volume of hydrogen in the updraft gasifier was measured as 48%. [ABSTRACT FROM AUTHOR]

• The paper investigates the degree of social acceptance of biogas. • The determinants of citizens' perception of new biomass plants. • Two waves of surveys has handed out in order to assess an empirical strategy. • The paper provides some insights on the social acceptability of biogas. • Results assessed the biogas acceptability. The degree of social acceptance of biogas as a renewable green energy source is still somewhat disregarded. Although many initiatives have focused on the construction of new biogas plants around the world, local protests on the construction of new plants often arise. This study aims to analyse the determinants of citizens' perceptions regarding the construction of new biomass plants in their neighbouring areas. In particular, the focus is on prior knowledge of the production process of biogas as well as on other individual characteristics. The investigation is based on two repeated surveys conducted among the population living in two Italian areas where the construction of new large biogas plants were planned (the provinces of Oristano and Andria). The first survey analyses the main variables correlated with the degree of biogas acceptability particularly the biogas knowledge. The second survey (differentiated in two waves) focuses on the role of participatory processes and information campaigns undertaken by policy makers and environmental associations to increase the social acceptance of communities regarding the construction of new biogas plants. [ABSTRACT FROM AUTHOR]

This review paper explores the potential for seawater desalination plants to operate as integrated hubs for addressing the increasing demand for water, energy, mineral resources, and foods, particularly in resource-scarce regions. The integrated seawater hub (ISH) utilizes seawater as a common input, provides multipurpose facilities that can cater to freshwater and agricultural requirements, brine processing for salt and minerals extraction, promotes energy recovery, and mitigates greenhouse gas emissions by employing renewable and alternative energy technologies, thereby bolstering sustainable development. Capitalizing on seawater, the most abundant resource on our planet, these plants can contribute significantly to the sustainability sector. This study delves into the essential aspects of integrating mainly the seawater reverse osmosis (SWRO) desalination process to create a portfolio of clean, sustainable water supplies, energy sources, and other valuable products. Furthermore, this paper seeks to offer a comprehensive analysis within a unified framework, incorporating various established technologies that demonstrate the multifaceted capabilities of desalination plants. This includes the delivery of a freshwater supply and effectively repurposing the brine, the primary liquid waste product from these facilities. Emphasizing the potential to achieve a circular economy centered on brine management, our review presents an environmentally friendly approach to urban development. The study also explores emerging research domains where seawater desalination plants utilize renewable energy sources like solar, wind, and biomass to produce clean water and green hydrogen. It suggests that further research and investment in the realm of integrated seawater resource hubs could yield significant benefits for both local communities and the wider global community. • Multipurpose SWRO facilities promoting resource and energy recovery, mitigating emissions • Osmotic energy recovery from RO brine • H 2 generation by direct seawater electrolysis • Agricultural utilization of SWRO desalination product water and reject brine [ABSTRACT FROM AUTHOR]

Malaysia is one of the leading producers and exporters of oil palm, and the industry contributes significantly to the growth of the national economy. Nonetheless, the consequential oil palm biomass (OPB) with a potential yield of ∼97 million tonnes annually presents both challenges and opportunities, demanding innovative waste management solutions. This paper explores the feasibility of converting OPB into valuable commodities by employing concentrated solar-driven pyrolysis. A detailed overview of the biomass produced from oil palm plantations and mills is provided, along with a discussion of the industry stakeholders and associated biomass management challenges. The pyrolysis of OPB is explored, emphasizing benefits, potential barriers, and techniques. The focus then shifts to Malaysia's solar potential, which ranges from 1470 to 1900 kWh/m2 annually. The potentials of solar pyrolysis are explored, encompassing discussions on solar concentrator types, reactors, and the distribution of solar and OPB resources throughout Malaysia. The paper then recommends Tawau in Sabah, as an ideal location for OPB solar pyrolysis, due to its solar availability (up to 1873 kWh/m2), potential OPB resources from 19 mills and 241 plantations, and supportive infrastructure. The paper proposes solar-driven pyrolysis as a sustainable solution for Malaysia's OPB management, offers insights for policy initiatives and technological innovations in optimizing OPB and solar energy utilization. • Analyzes oil palm biomass potential for solar pyrolysis in Malaysia. • Explores solar resources in Malaysia for solar-driven pyrolysis. • Examines solar concentrators and reactors for pyrolysis. • Identifies potential city, as the optimal location for solar pyrolysis. • Discusses commercialization challenges of solar-driven pyrolysis. [ABSTRACT FROM AUTHOR]

Cheap Production of bioethanol from renewable lignocellulosic waste has the imperative potential to economically cut burgeoning world dependency on fossils while reducing net emission of carbon dioxide (CO 2), a principal greenhouse gas (GHGs). This paper highlights key benefits and status of bioethanol production technologies, aiming mainly on recent developments and its key potentials in Pakistan. Most sector of Pakistan economy heavily rely on the energy and power that is being produced using traditional approaches like from oil and hydel. However, the sedimentation in dams cut-down the energy generation and overwhelmed severe energy crisis that are witnessed since last decade. Thus, Pakistan must go to avail alternative sources of energy like hydro, biomass and solar so that energy security can be ensured to recover the tremendous loss of economy. Renewable biomass is abundantly available in Pakistan which can be used to produce bioethanol and electricity. Currently, 22 distilleries are producing the ethanol from sugar cane bagasse and out of these only 8 distillation units are producing motor fuel grade ethanol. The current bioethanol production of country is about 403,500 tons/year along with 2423 tons of biodegradable waste available in major cities. In addition, Pakistan produces 6.57, 0.5, 0.66, and 2.66 million tons of sugarcane, corn, rice, and wheat straw per annum, respectively. This biomass can produce 1.6 million liters of bioethanol which can produce approximately 38% of Pakistan's electricity annually. Despite having large potential, Pakistan is still producing a few volumes of ethanol from sugarcane bagasse. The production of bioethanol can be boosted using (I) pretreatment of agricultural biomass by alkali (II) enzymatic and bacteria-based hydrolysis of the biomass (III) post-hydrolysis using pressurized steam above 100 °C (IV) Fermentation of the biomass@ 7–10 h and (V) and (VI) distillation of bioethanol. This study recommends (1) increase R&D capacities mainly in the west and central regions of Pakistan, (2) initiate mega-projects to promote integrated bio-ethanol production at agriculture farms by providing 1/3 subsides, (3) purchase of bioethanol directly from the major agricultural farms, (4) produce bioethanol related manpower from the key research institutes as specified in this study. • Upgradation of inefficient biogas to bioethanol can solve energy crisis. • Study witnessed huge potential of bioethanol (403,500 tons/year) from cheap biomass. • Key technical barriers in the green development of ethanol is emphasized fact-sheet. • Study implementation will replace inefficient biomass burn into ethanol combustion. • Study will definitively help policy makers to sustain lives of Pakistan people. [ABSTRACT FROM AUTHOR]

The small island developing states of the Pacific suffer from both the high cost of fossil fuel imports and from numerous climate-related disasters. These vulnerabilities will worsen unless there is a substantial global shift away from fossil fuels towards renewable energy (RE) sources, coupled with significant improvements in energy efficiency. Apart from traditional biomass-fuelled cooking, the most substantial uses of RE in the Pacific in 2016 were hydropower in some of the hillier island countries and the thousands of household photovoltaic (PV) systems in the remoter parts of island countries. This paper considers also the prospects for grid PV, geothermal, and biofuels – all of which have good technical potential in at least some islands. Barriers to wider use of RE in the region are mostly institutional and financial, but also include opportunity costs, environmental factors, and the limited skills base in small island states. The paper examines the mixed progress since the 1990s towards overcoming these barriers. The Fiji Electricity Authority has a reasonably realistic plan to have 81% of its supply from RE by 2020, drawing on hydropower (~ 50% in 2015), biomass (including bagasse), and some solar and wind. Tonga has its Renewable Energy Roadmap with clear milestones. Several other Pacific Island countries have ambitious RE targets but some are rather vague about how they are to be achieved. [ABSTRACT FROM AUTHOR]

Energy scarcity and environmental pollution from biogenic residues and wastes are major challenges in the 21st century, which can be converted to useful renewable energy and reduce environmental threats. In Bangladesh, a tremendous amount of biogenic residues is generated which remains largely underutilized. Mono-digestion, which is a common practice in Bangladesh for biogenic residue processing, resulted in low biogas yield. However, Bangladesh has a vast source of biogenic residues which can be utilized through anaerobic co-digestion to increase biogas production. In this paper, a desk study and comprehensive review has been conducted in finding potentiality of biogenic residues in biogas production from available biogenic residues in Bangladesh. Research studies on co-digestion of biogenic residues were reviewed critically, and their practices and benefits on energy production and impact on the environment were stipulated in this study. The study shows that co-digestion of biogenic residues in appropriate ratio increases the biogas production, improves digested quality and reduces GHG emissions. [Display omitted] • Biogas production potential from agricultural and livestock sectors were analyzed. • State of art co-digestion options of animal dung as main feedstock was reviewed. • Co-digestion of crop residues and animal dung lessened environmental burden. • Digestate can be used as bio fertilizer or converted into other forms of fuels. [ABSTRACT FROM AUTHOR]

The demand for biofuels is rising with the growing population and decreasing reserves of petroleum. Indeed the rising population and increasing level of greenhouse gases not only contribute for global warming, but also imparts serious effects on humans and the environment. There is a constant urge to find other alternatives to the petroleum-based products. Of the three generations of biofuel feed stocks i.e. food crops, non-food crops and microalgae-derived biofuels; it is discussed that microalgae can be the best source of feed stock in terms of food security and for reducing the harmful impact on the environment. This paper serves as base to discuss the benefits of using microalgae as a source of biomass for biofuels and the methods that can be used to enhance the microalgal biology in order to improve their production. It reviews how the use of optimized nutrient concentration and culture conditions increase the yield, cell density and lipid productivity. It further reviews the role of bacteria in enhancing/inhibiting the microbial biomass and lipid productivity in microalgal-bacterial biological associations. The final part of the paper lays emphasis on the importance of improving microalgal biology by the use of genetic engineering and metabolic engineering in order to obtain desired results. Overall stress is placed upon unfolding and unraveling the gaps present in producing microalgal biomass, such as inefficient and reduced production, poor penetration of light in dense cultures, low oil content and higher harvesting costs. Overcoming of these major bottlenecks by ecologically engineering species specific valuable microalgal-bacterial mini consortium might lead to specific and noteworthy breakthrough in the production of clean, green, renewable, sustainable and high yielding microalgal biofuel. [ABSTRACT FROM AUTHOR]

The benefits of biomass as an alternative fossil fuel can be realized mainly through biomass consumption. This paper examines the growth rate and spatial patterns of biomass consumption in the United States (hereafter US) during the period 2000–2012, using the SLOPE index, Moran's I and local Moran's I. Results indicate that US States show either slow growth or slow decline in biomass consumption during the period 2000–2012. The number of States that have slow growth in biomass consumption is slightly larger than the number of States showing slow decline. The pattern of growth rate of biomass consumption revealed by the SLOPE index and the observed pattern of the temporal variation of biomass consumption ensures that the SLOPE index can catch the growth rate of biomass consumption. This pattern does not align with the increased annual investment in biomass, indicating that the investment in biomass does not flow down to the biomass industry effectively. The pattern of growth rate of biomass consumption will provide additional evidence for the debates about the effectiveness of State renewable energy policy, and demonstrates an urgent need for appropriate State renewable energy policies. There is a High-High spatial cluster around the Southeast of the US and a Low-Low spatial cluster in the Middle of the US in 2000, 2004, 2008 and 2012. The regional spatial cluster in biomass consumption has somewhat relationship with the growth rate of biomass consumption, which can help the understanding of the growth rate of biomass consumption. • The SLOPE index is used to investigate the growth rate of biomass consumption. • The pattern of growth rate does not align with the increased annual investment. • There is an urgent need for appropriate State renewable energy policies. • There are regional clusters in biomass consumption in 2000, 2004, 2008 and 2012. • The regional spatial cluster has somewhat relationship with the growth rate. [ABSTRACT FROM AUTHOR]

The European Union has set ambitious targets of raising the share of EU energy consumption produced from renewable resources from 20% by 2020 to 27% by 2030. The aim of this paper is to assess the role of woody biomass in renewable energy as gross final energy consumption in the European Union (the EU-28). The paper identifies leading and lagging countries in biomass development by focusing on their current biomass use and forecasts future perspectives. The research compares and evaluates the role of biomass in renewable energy in the EU-28 focusing on countries' potential resources and policy support. The study shows that all countries are making efforts to reach the 20% target in 2020 and exhibit a trend of increasing renewable energy as gross final energy consumption towards the new target of 2030. Solid biomass plays an important role in reaching the EU's renewable energy targets. The majority of the EU-28 countries are close to reaching their national renewable energy targets and show a very attractive biomass development. Unless energy consumption decreases however, some member states will face serious problems in reaching their renewable energy target in 2020. Following our analysis, the largest problems occur in those MS having a relative high-energy consumption pattern: France, Germany and the United Kingdom. It is unlikely that they can comply with expected renewable energy demand, unless they mobilize more woody biomass from their available domestic potential (France, Germany) or considerably increase their woody biomass imports (mostly wood pellets) from elsewhere (United Kingdom). [ABSTRACT FROM AUTHOR]

Off grid electrification is key to achieving universal electricity access. Despite the potential of biomass gasifiers as a clean technology to ensure reliable systems, they are not as well looked upon as their advantages suggest. In particular, the software HOMER, which researchers and technicians use the most to simulate and design Microgrids, does not include biomass gasification among its simulation technologies. Although some authors did simulate biomass gasifiers in HOMER, the necessary parameters and procedures to calculate and include them in the tool remain unclear, non-replicable, and leave open research questions as regards modelling. Using the inbuilt Biogas power plant modules in HOMER, this paper presents a set of steps to include the technical and economic parameters to simulate fuelling an electric generator through the syngas produced in a downdraft biomass gasification plant. Two case studies of isolated rural communities in Honduras and Zambia show the viability of the procedure. These case studies also confirm the technical and economic viability of islanded biomass-photovoltaic hybrid renewable energy microgrids. In both cases, the energy demand supplied and distributed by the microgrid had a Levelized Cost of Energy lower than the alternative of extending the electric grid to the communities. • HOMER can model modify gasifiers with the presented methodology. • Technical and economic parameters need to be edited. • Two case studies of rural communities in Honduras and Zambia. • Dry biomass and agricultural waste are the main energy sources of most rural areas. • Gasifiers help to optimise HRES. [ABSTRACT FROM AUTHOR]

This paper explores several renewable energy sources to help Malaysia reduce its carbon footprint. Accordingly, this study employs a partial equilibrium model to examine the potential of the Malaysian agricultural sector to supply biodiesel, bioethanol, and bioelectricity on a commercial scale to mitigate greenhouse gas (GHG). The model includes the fourteen agricultural commodities of Malaysia. The results show that bioethanol is economically feasible with its fossil fuel counterpart, while bioelectricity is almost economically feasible. Both bioethanol and bioelectricity have the potential to offset significant GHG emissions of fossil fuels. Furthermore, this study finds that biodiesel has little mitigation on GHG emissions and cannot compete with diesel. Biodiesel also would expand the agricultural industry, which could raise agricultural prices and hasten deforestation. Therefore, the Malaysian government should further study bioethanol and bioelectricity as two candidates to supply renewable energy and help the nation meets its GHG commitment under the Paris Agreement. This study highlights further research for cellulosic ethanol because it is still in the experimental stage. • The results show that Malaysia could develop a large-scale renewable energy sector by producing bioelectricity or bioethanol from waste biomass. • Bioelectricity and bioethanol could help Malaysia reduce its carbon footprint and meets its commitment of the Paris Agreement. • The results indicate that palm biodiesel is not cost-competitive with diesel and shows modest reductions in carbon emissions. • Large-scale biodiesel production may raise agricultural prices and hasten deforestation. [ABSTRACT FROM AUTHOR]

Biobased products are complete or partial derivatives from naturally occurring/growing materials such as agricultural, plants, and forest materials and serve as an alternative to traditional product derivatives of petroleum. Technically, biobased product counterparts can replace almost every fossil resource-based industrial material. Adopting life cycle analysis and circular economy concepts has also accelerated the move towards biobased products. It meets the criteria for easy recycling and can facilitate the shift from linear fossil-based productions to a greener circular economy. In line with the Renewable and Sustainable Energy Reviews (RSER) policy, this Virtual Special Issue (VSI) published two types of articles, high-quality review papers and original research papers with a strong review component. After a rigorous peer-review process, 32 articles were accepted and published in this VSI. This editorial overview these articles and examines their contribution to the field. This RSER VSI has contributed with new insights on value-added biobased products from various bioresources to their applications, technical challenges and advancement in a sustainable manner. • VSI is focused on the recent development of biobased biorefineries. • Greener technologies offering biobased products. • Sustainable bioprocesses and bioproducts development from bioresources. [ABSTRACT FROM AUTHOR]

The population of Pakistan is increasing rapidly and hence the energy demand. Since ninety׳s, people of Pakistan has been experiencing load shedding because of the intense shortfall throughout the country. Pakistan, being an agricultural country, has a lot of potential of renewable energy sources especially biomass. The thing is to utilize the potential in a right direction. This paper presents the policy direction to get rid of the current energy crisis in the country through utilization of different types of biomass. The animal manure, municipal solid wastes and the crop residues are the main biomass sources in the country. This study also focuses the potential of main biomass sources present in the country and its technical routes for the production of bioenergy. The design parameters for standard bioreactor of gasifier and anaerobic digestion and their economic comparison are highlighted with respect to Pakistan environmental conditions. The development of anaerobic digestion technology is reviewed critically. This paper also discusses the different scenarios for the use of biomass sources in urban and rural environment. This verifies the use of biogas energy as the cheapest and the safest way to remove the crisis from the country. The stand-alone biogas plants should be constructed throughout the country where there is not electrification infrastructure exists. [ABSTRACT FROM AUTHOR]

The use of renewable energy is projected to increase substantially in the European Union to reach a share of 20% in final energy consumption and 10% renewable energy in transport by 2020. The renewable energy contribution is further expected to increase to 55%–75% of gross final energy consumption in 2050. According to the latest reports, the European Union has made significant progress since 2005 and is on track to reach its 2020 renewable energy targets. This paper provides a review of the policy framework for renewable energy in the European Union and an analysis of the progress made by the use of renewable energy as well as the expected developments until 2020 and beyond. It focusses on the contribution of bioenergy, the major source among renewables in the European Union. As biomass availability is a critical issue for the bioenergy production, this paper provides an analysis of the biomass demand for reaching the 2020 targets, in relation with the expected domestic supply and biomass potential. [ABSTRACT FROM AUTHOR]

Energy is one of the indispensable inputs for the survival of human being in the earth. Bangladesh has the very inadequate amount of indigenous non-renewable energy resources even which is being diminished rapidly to increase the electricity generation. Although the installed electricity generation capacity has been increased to 10,709 MW, still the amount is insufficient to meet the demand of the country. In addition to this, the insufficient power generation hinders the socio-economic and industrial development. This current problem in power generation of Bangladesh can be removed by incorporating renewable energy into electricity generation. Recently, utilization of renewable energy and Renewable Energy Technologies (RETs) is getting momentum in the country to achieve not only energy security but also to reduce environmental pollution and to limit the imminent depletion of the non-renewable energy resources. Overall, Bangladesh has the vast potential of biomass, solar, hydro, wind, and tidal powers. This paper outlines the present energy scenario of the country. Following this, the potential of available renewable energy resources is also reviewed and presented in this paper. [ABSTRACT FROM AUTHOR]

The objective of this paper is to establish a theoretical framework for the exergy analysis and advanced exergy analysis of a real biomass boiler. These analyses can be used for both the diagnosis and optimization of a biomass boiler as well as for the design of a new biomass boiler. Conventional exergy analysis is performed to recognize the source(s) of inefficiency and irreversibility and identify exergy destruction in different components of the biomass boiler. An advanced exergy analysis is performed to provide comprehensive information about the avoidable exergy destruction and real fuel-saving potential for each component, as well as the overall system. Sensitivity studies of several design parameters including the excess air, biomass moisture and steam parameters were evaluated. The results show that the maximum exergy destruction occurs in the combustion process, followed by the Water Walls (WW) & Radiant Superheater (RSH) and the Low Temperature Superheater (LTSH). The fuel-saving and exergy efficiency improvement strategies for different components are discussed in this paper. [ABSTRACT FROM AUTHOR]

Biogas is the gas produced by the anaerobic degradation of organic matter. In addition to the usual uses in burning, it has widespread applications as a raw material in some industries. The biomass of organic matter decomposition is a good fertilizer for agriculture. Unfortunately, despite such a large potential for reasons such as the cheapness of energy in Iran, the use of this benefical capacity has not been addressed so far. This paper investigates the potential of biogas production from poultry manure sources in Iran and demonstrates the examples of biogas plants in Iran. Also, the information about the capacity of biogas production has been investigated and reported in different provinces in Iran. The results consist of economic analysis as the cost of biogas production, and the environmental analysis as the environmental impact of the biogas production and carbon footprint. Kermanshah, Chaharmahalbakhtiari, Golestan, Bushehr and North Khorasan provinces have the highest capacity for biogas production from poultry manure. The highest cost savings by using the biogas are in Khorasan Razavi and Isfahan provinces and the lowest levels have been found in Ardebil and North Khorasan provinces. • Biogas production potential from poultry's manure resource in Iran is investigated. • Energy, Economics, Exergy, and environmental impacts analyses are performed. • Footprint analysis is performed for monitoring impacts on sustainability. • Share of poultry's manure in natural gas demand of each province is predicted. • Good results related to energy saving, costs, environmental issues are achieved. [ABSTRACT FROM AUTHOR]

Although it is widely accepted that renewable energy consumption is vital for environmental sustainability, the environmental effectiveness of individual renewable energy types is often overlooked. Therefore, this paper examined the multivariate relationship between disaggregated renewable energy (hydroelectricity, wind, solar and biomass) consumption, economic growth and environmental pollution for the period from 1991 to 2014 in G-7 (The Group of Seven) countries. The study used both augmented mean group estimator and panel bootstrap causality method to consider the cross-sectional dependence and country specific heterogeneity across G-7 countries. Empirical findings indicate that increasing biomass energy consumption was efficient to reduce carbon emission in France, Germany, Japan and the United States; increasing hydroelectricity usage was efficient to reduce carbon emission in Italy and the United Kingdom; wind energy consumption reduced emission in Canada and solar energy usage was efficient on reducing emission in France and Italy for observed period. Moreover, in case of panel, it is found that increasing hydroelectricity, biomass and wind energy consumption reduced carbon emissions while the impact of solar energy consumption is statistically insignificant in G-7 countries. In addition, the hydroelectricity consumption was found the most efficient renewable energy source to reduce environmental pollution for the panel of G-7 countries. • Disaggregated renewable usage consumption and carbon emission nexus is investigated. • Increasing hydroelectricity usage reduces emission in Italy, the UK and the US. • Increasing wind energy usage reduces emission in all G-7 countries excluding Japan. • The effect of solar energy consumption on emissions is statistically insignificant. [ABSTRACT FROM AUTHOR]

The paper reports on an experimental study aimed at investigating the potential of performing biomass torrefaction using air instead of nitrogen as a carrier gas, which allows reducing the operating costs of upgrading biomass. Specifically, the performances of oxidative and non-oxidative torrefaction treatments were comparatively investigated by using commercial wood pellets and olive pomace pellets as a feedstock. Batch torrefaction tests at three different temperature levels (200, 230 and 250 °C) were performed in a laboratory-scale fluidized bed reactor by fixing the reaction time equal to 15 min; this allowed to investigate the impact of the torrefaction temperature and atmosphere on: a) the distribution of the main output products of the torrefaction process (torrefied solids, condensable volatiles and permanent gases); b) the properties of torrefied pellets as a fuel (i.e., proximate composition, ultimate composition and calorific values); c) the process performances in terms of mass and energy yields of the solid product; and d) the quality of torrefied pellets in terms of mass and energy densities, hardness (shore D) and non-standard durability index. Fluidized-bed torrefaction tests were also complemented by non-isothermal thermogravimetric measurements (TG/DTG/DSC) performed in both air and nitrogen atmospheres. Results show that, under the same operating conditions, the process performance of oxidative torrefaction (i.e., mass and energy yields of the solid product) are worse than that of the non-oxidative treatment, particularly in the case of olive pomace pellets. This is mostly a consequence of the higher degradation rate triggered by oxidative reactions. On the other hand, the physical properties (i.e., mass density, energy density, hardness and durability) of torrefied olive pomace pellets obtained under oxidative atmosphere are better than those obtained via non-oxidative torrefaction. A similar behavior, however, was not observed in the case of woody fir pellets. This confirms that the fluidized bed torrefaction is feedstock-sensitive process; in particular, non-woody olive pomace pellets can be torrefied in oxidative environments, whereas fir pellets are more suitable for non-oxidative torrefaction. Since the torrefaction treatment of biomass pellets in a fluidized bed reactor has not been investigated so far, findings of this work can be useful to highlight potential advantages related to use of such a technology in this specific application. Unlabelled Image • Torrefaction of biomass pellets in inert and oxidative environment is investigated. • Woody and non-woody biomass pellets are tested as a feedstock. • The mechanical properties of pellets torrefied in air and nitrogen are compared. • Non-woody olive pomace pellets can be torrefied in oxidative environments. • Woody fir pellets are more suitable for non-oxidative torrefaction. [ABSTRACT FROM AUTHOR]

Abstract: The security of supply and climate change issues and the linked recent growth of the local power generation by means of renewable energies technologies are providing real opportunities for the development of small scale biomass gasification systems. The present paper reports the state of art of the small scale gasification power plants. Initial attention has been given to the different biomass feedstock suitable for gasification, focusing on residues with low cost and low environmental impact. Then the two major typologies of gasifiers (fixed and fluidized bed) have been analyzed in terms of raw gas yield, composition and tar and particulate content. The different cold and hot raw gas conditioning systems, highlighting their compatibility with the different gasification system, are described. High efficiency examples of power production by means of internal combustion engine, micro gas turbine, Solid Oxide Fuel Cell or a mix of them, both as realized plants and process simulated ones, have been then reported. The paper provides an overview of the different power plants in terms of efficiency, reliability and cost. [Copyright &y& Elsevier]

Abstract: In this paper, the implementation of biogas technologies in animal farms in Thailand and the government policies used to promote these technologies are presented. The Thai government has created a goal of achieving 14% of all energy needs from renewable resources by 2022. As a renewable technology, biogas has the potential to reduce Thailand's dependence on fossil fuels which make up over 90% of Thailand's electricity generation. An unfortunate by-product from animal farm waste is the greenhouse gas, methane. The benefits from capturing and utilizing this gas include increased electric generation, less odor in the local community, less greenhouse gas emissions, more revenue for farmers and production of raw fertilizer material. Thailand has the potential to produce over onebillionm3 of biogas per annum from its agricultural industry alone. Current utilization is only 36% of this potential. This paper will briefly discuss the technology used to capture and use biogas from animal farms in Thailand. The effect of government policies on this technology deployment shall be discussed. This paper demonstrates how technology and policy need to work together in order to best provide a practical solution for energy problems. In 2012, greenhouse gases worth 1400Gg CO2 equivalent were saved from entering the atmosphere from animal farms in Thailand. [Copyright &y& Elsevier]

Abstract: Biomass will make a vital contribution to the EU renewable energy targets, however large amounts need to be mobilised to achieve policy goals. To promote action, the European Commission sent a firm call to member states for coordinated biomass strategies and plans, and engagement of sub-national actors. This paper examines how regional level biomass planning can benefit national planning and EU target achievement, and addressing of broader concerns of increased bioenergy production. It assesses a set of regional biomass action plans and their linkages to national level plans. The study indicates that regional and national planning address measures to reach targets in several ways, but that impacts related to the increased bioenergy production are often weakly assessed. Regional level strengths appear to include mobilisation of new biomass resources and involvement of stakeholders, while matters related to the sources of biomass and implementation details are better delineated by national plans. Areas with scope for improvement exist at both levels and include consideration of other uses of biomass and clarification of linkages between various targets. The paper concludes that regional planning clearly has the capacity to contribute to the concretisation of national level actions as well as enhancement of local economy and expertise; however at present, national level planning does not adequately link to such planning efforts. Further, the study indicates that the value of national planning work can be enhanced if efforts are made to recognise regional planning strengths and competence to bring about the planned changes. [Copyright &y& Elsevier]

Abstract: Wood biomass in Serbia is traditionally used for energy. However, the manner of its use is outdated, and efficiency is very low. Annually over 3.5millionm3 of wood is cut down for energy needs in Serbia. In order to better exploit all forms of woody biomass, especially the one that is now treated as waste, and in order to fulfil the obligations from the outlined Convention on Climate Change it is necessary to switch to a modern way of production and utilization of woody biomass. Serbia is now at the very beginning of this process. This paper gives an overview and an analysis of the possibilities of utilization of wood waste as a renewable source of energy and the problems that producers in Serbia are facing due to undeveloped markets and excessive funds that are needed to start the production of briquettes and pellets. The ecological and economical advantages of using woody biomass, as well the possible support measures for the use of woody biomass in Serbia are also the topic of this paper. The present situation in this area, the manner of waste management in sawmills and the reasons for the necessity of future development of this industrial production are also briefly described. [Copyright &y& Elsevier]

Abstract: Power production from renewable energy resources is increasing day by day. In the case of Spain, in 2009 it represented 26.9% of installed power and 20.1% of energy production. Wind energy makes the most important contribution to this production. Wind generators are greatly affected by the restrictive operating rules of electricity markets because, as wind is naturally variable, wind generators may have serious difficulties in submitting accurate generation schedules on a day-ahead basis, and in complying with scheduled obligations. Weather forecast systems have errors in their predictions depending on wind speed. Therefore, if wind energy becomes an important actor in the energy production system, these fluctuations could compromise grid stability. In the previous paper in this brief series , the authors showed technical results of the proposed solution, which consists of combining wind energy production with a biomass gasification system and a hydrogen generation system based on these two sources. In the present paper it is shown the economic results of the study, considering the most profitable technical configurations and three possible economic scenarios. [Copyright &y& Elsevier]

This study presents the research results acquired from conducting municipal sludge gasification in a downdraft type gasifier at pilot scale. The assessment of the results was not only focused on syngas characteristics, but also on the gasification residues: char ash and glassy material. The gasification temperature was varied from 1000 to 1150 °C during the gasification trials. The produced high quality syngas was transferred to the engine to generate the electricity. About 1 kWh electrical power was achieved for approximately 1.2 kg municipal sludge gasified. Most of the heavy metals available in the sludge was found as fixed form in the glassy material. The gasification residues evaluated as valuable materials regarding their characteristics have reuse potential for different beneficial usage alternatives. Based on the costs for the investment and operation and incomes, the return on the investment for this pilot scale system was roughly found as 3.3 years. This study showed that the municipal sludge had an important fuel merit and the energy recovery from the sludge was possible via the gasification application. In this paper, the research results were discussed in detail to make better insight to full-scale applications as a promising alternative for sludge disposal. Image 1 • The municipal sludge gasification experiments were conducted in a pilot-scale downdraft fixed bed gasifier. • The sludge showed high gasification potential. • Approximately 1 kWh electrical energy was produced per 1.2 kg sludge gasified. [ABSTRACT FROM AUTHOR]

Abstract The dominant transitional path towards a low carbon electricity industry for systems which have been heavily dependent upon coal is through its replacement by large scale wind farms and the widespread emergence of distributed solar. In this pathway, maintaining resource adequacy in the context of increased intermittency in generation has become a major concern. This paper examines this requirement to maintain resource adequacy and compare the costs and carbon impacts for new gas turbines or biomass conversions to achieve this in an expedient transitional way. This is formulated as a policy optimization in which the imperative is to replace existing coal with a renewable alternative (in this case study, wind) and to maintain the system security at the existing level, and thereby find the optimal subsidies, either as energy credits ("green certificates" or "contracts-for-differences") or capital benefits ("capacity payments" or tax allowances). In a model of the GB system, the results show that biomass-conversion outperforms investment in peaking gas turbines to deal with the transitional economic externality of extra reserve costs. In particular, the results suggest benefits of 10% lower costs of subsidies, 70% lower implied costs of carbon, and a reduction of 18% in wholesale power prices. Highlights • Biomass has a transitional role alongside wind and solar. • We compare gas turbines and biomass coal conversions as reserves. • We show that biomass coal conversions have lower costs for reserve. • Biomass coal conversions have a lower cost of carbon reduction. • And lead to lower wholesale prices. [ABSTRACT FROM AUTHOR]

Abstract: This paper attempts to review and discuss the status and future prospects of renewable energy in Oman. Renewable energy sources like solar, wind, hydro, geothermal, and biomass have been revised. The electricity shortages and the challenges to overcome the increase in electrical demands for the near future have been discussed. The investigations found that solar, shore-wind and geothermal could play an important role in the future of renewable energy in country. Also, it is found that there is need to investigate the potential of offshore-wind, biomass, and hydro (tide, wave and ocean thermal energy). The appearance and weight of renewable energy in the higher education programs and the Oman commitment toward renewable energy have been discussed. The paper finishes with some conclusions and recommendations. [Copyright &y& Elsevier]

Abstract: This paper analyses the reality of total renewable electricity scenario (TRES) from renewable energy sources (RES) as a totally green strategy of electric energy production. The paper is based on the EREC''s Agency forecast until the year 2040, which foresees the share of 82% of RES, extended to 100% of RES. The key element that creates conditions for achieving this ambitious scenario is an innovative combination of RES and pump storage hydroelectric (PSH) power plants, the so-called Concept-H, which can simultaneously use the energy of local RES (sun and wind) and local precipitation (natural waterflows) and in this way can provide continuous supply of electric power and energy to consumers. The methodology is based on the model of equivalent RES and equivalent reservoir that allows a comprehensive view of available RES and hydro system. The total required land use of RES system would be 29,517km2 of RES (which would amount to about 0.5% of the total technical potential of using RES), total reservoir volumes would be 880km3 (which is only 8% of all artificial reservoirs built in the world to the date) and the orientation estimate of investment in TRES would then be approximately 1% of world GDP in 2009, which clearly shows that the TRES is realistically feasible. It has been shown that implementation of the green strategy of energy balance fulfilling can be realized with present day technology. Precisely this fact shows that further increase of efficiency of RES and their combining into RES–PSH power plants, along with increase in the cost of classic power fuels and the growing needs for environment protection, the proposed solution of TRES realization could be widely important and thus become a serious alternative to the existing energy strategies and a guideline to decision makers throughout the world. [Copyright &y& Elsevier]

Recently, biomass represents about 14% of primary energy consumption and expected to provide 50% of world total primary energy consumption by 2050. This paper clarifies an appraisal of the possibilities available in Egypt to become one of the countries of the production of bioenergy, especially from the crop remnants of agriculture production. Egypt annually produces a large amount of biomass of up to 40 million tons. Unfortunately, instead of the possibility of exploiting these wastes to contribute to the energy sector and economic growth, about 52% of these wastes are disposed of by direct burning, which may cause many environmental problems. The only widespread form of biomass use in Egypt is biogas used in rural areas. In addition, the potential theoretical energy from the most important crop residues available in Egypt is evaluated according to previous studies. It is found that energy of 189.76 PJ/year can be produced from dry crop residues of 12.5 million tons/year. For livestock residues, specifically cattle manure, it is estimated in this study that the potential biogas in Egypt of 7.2 million head of cattle is 53.2 million m 3 / day with a total potential energy of 699 TJ per year. However, the potential of bioenergy depends largely on the availability, geographical distribution and accessibility of the actual waste. The most likely areas for these potentials are Middle Delta and Upper Egypt. This could potentially develop a long-term strategy for the smart use of vital waste available for bioenergy production to be economically profitable and sustainable. [ABSTRACT FROM AUTHOR]

Microalgae biofuel is one of the most promising renewable energy sources that can contribute to the replacement of fossil fuels globally because of its sustainability and its ability to reduce the carbon dioxide emission in the atmosphere. However, the rigidity of microalgae of microalgae cell wall inhibits the extraction of lipids for biofuel production. To improve microalgae biofuel production, different pre-treatment techniques have been studied to evaluate their effectiveness on microalgae cell wall disruption. The main objective of this paper is to review the different pre-treatment technologies used in biofuel production from microalgae biomass and to critically discuss the current limitations and promising perspectives towards achieving economic and industrial scale production. Pre-treatment methods reviewed are categorized into mechanical techniques (e.g. high-pressure homogenizer and bead mills), physical techniques (e.g. ultrasonic and microwave methods), thermal pre-treatment techniques (e.g. autoclave and steam explosion), chemical techniques (e.g. catalytic and enzymatic), and combined techniques. Furthermore, comparisons of these techniques are discussed. The overall effect of the applications and methods on biofuel production together with energy consumption are critically examined. [ABSTRACT FROM AUTHOR]

Abstract: Renewable energy sources and technologies have potential to provide solutions to the long-standing energy problems being faced by the developing countries. The renewable energy sources like wind energy, solar energy, geothermal energy, ocean energy, biomass energy and fuel cell technology can be used to overcome energy shortage in India. To meet the energy requirement for such a fast growing economy, India will require an assured supply of 3–4 times more energy than the total energy consumed today. The renewable energy is one of the options to meet this requirement. Today, renewable account for about 33% of India''s primary energy consumptions. India is increasingly adopting responsible renewable energy techniques and taking positive steps towards carbon emissions, cleaning the air and ensuring a more sustainable future. In India, from the last two and half decades there has been a vigorous pursuit of activities relating to research, development, demonstration, production and application of a variety of renewable energy technologies for use in different sectors. In this paper, efforts have been made to summarize the availability, current status, major achievements and future potentials of renewable energy options in India. This paper also assesses specific policy interventions for overcoming the barriers and enhancing deployment of renewables for the future. [Copyright &y& Elsevier]

Abstract: District energy systems, in which renewable energy sources may be utilized, are centralized systems to provide energy to residential and commercial buildings. The aim of this paper is to evaluate and rank energy sources available for a case of district heating system in Vancouver, Canada, based on multiple criteria and the view points of different stakeholders, and to show how communication would affect the ranking of alternatives. The available energy sources are natural gas, biomass (wood pellets), sewer heat, and geothermal heat. The evaluation criteria include GHG emissions, particulate matter emissions, maturity of technology, traffic load, and local source. In order to rank the energy options the PROMETHEE method is used. In this paper, two different scenarios were developed to indicate how the communication between the stakeholders would affect their preferences about criteria weights and would change the ranking of alternatives. The result of this study shows that without communication the best energy source for the considered district energy system is different for different stakeholders. While, addressing concerns through efficient communication would result in a general consensus. In this case, wood pellet is the best energy alternative for all the stakeholders. [Copyright &y& Elsevier]

Abstract: There are considerable biomass resources in the European Union (EU) and mature conversion technologies to exploit the potentials of bioenergy. The challenge confronting the EU and member states is how to accelerate the implementation of bioenergy systems. This paper contributes to the identification, analysis, and discussion of barriers for bioenergy in the EU. Adopting an innovative methodology involving industry interactions, research workshops, and case studies, this paper identified economic conditions, know-how and institutional capacity, and supply chain co-ordination as the key barriers obstructing the expansion of bioenergy. The case studies expose four points about barriers to bioenergy. First, there are no absolute barriers to realising the potentials of bioenergy in the EU. Second, it is non-technical challenges that are hindering bioenergy rather than technical issues. Third, barriers for bioenergy are dynamic and depend on the context. Fourth, there are consistent strategies and interventions in the case studies to overcome barriers. [Copyright &y& Elsevier]

Limiting the negative effects of human-induced global warming is the focus of climate policy worldwide. In the European Union (EU), the target for reaching carbon neutrality is set to 2050, including a proposed renewable energy target of 45% for 2030. In Finland, the government has pledged to reach net-zero emissions already by 2035, which is expected to require large increases in wind and nuclear capacity, as well as sector coupling with, e.g., transport and heating. In view of these plans, this study evaluates the feasibility of attaining carbon neutrality in Finland by 2035, while considering delays from potential bottlenecks, such as limited raw material availability, fuel availability, manufacturing capacity, and import reliance. The literature review highlights the considerable dependence of renewable technologies on critical raw materials and other minerals, largely imported from non-EU countries. Modelling revealed how increased biomass usage considerably reduces the size of national carbon sinks, vital for reaching net-zero emissions in Finland in the coming decade. In light of this, current climate strategy was shown to be partially outdated and short of reaching carbon neutrality by 2035, already without including potential delays from the analyzed bottlenecks. Subsequently, alternative measures to improve sustainability and reduce emissions are presented. The findings of this paper are also relevant for other countries aiming to reach net-zero emissions, especially for those which have climate strategies emphasizing bioenergy and wind power. [Display omitted] • Raw material and manufacturing bottlenecks can delay renewable implementation. • Maintaining carbon sinks critical for climate neutral Finland in 2035. • Limits to biomass usage are needed, but result in adverse industrial impacts. • Further nuclear capacity needed for 2035 climate target and electricity sufficiency. • Finland will rely on electricity imports in 2035, despite plans to become exporter. [ABSTRACT FROM AUTHOR]

Given both the ongoing expansion of world population and development of climate change conditions, it is increasingly imperative to develop and deploy sustainable biomass production methods to allow establishment of a flourishing and sustainable bioeconomy. Green technologies, including biofuels and bioproducts, are among the most effective strategies for decreasing greenhouse gas emissions and global warming, while meeting humanity's energy requirements. Biomass now provides a measure of energy to many countries, however supporting technologies are not widely accepted, largely because of low returns for biomass producers. This paper provides an overview of world biomass production and utilization. It also indicates potential approaches for enhancing biomass production: agronomic practices, associated microorganisms, genome editing, selection of optimal technologies, best combination approaches for feeding global human and animal populations, while, decreasing greenhouse gas emissions and replacing demand for fossil energy with bioenergy. A more novel concept is proposed, microbe-to-plant signal compounds, as the potential approach to address the challenges we are facing. These compounds (e.g., lipo-chitooligosaccharide and thuricin 17) have been shown to increase growth for diverse plant species, particularly when they are growing under stressful conditions, however, their commercial development/utilization is far from complete. This review paper will expand the understanding of using the signal interaction between crop and beneficial microorganisms not only to enhance plant growth but also promote agricultural sustainability and a stronger bioeconomy. • We must address the challenges of sustainable energy supply in the face of climate change and increased population. • By better understanding their biology and economics, biofuels and associated high-value bioproducts will be key to this. • A comprehensive overview of world biomass production and utilization is provided. • Enhanced biomass production through management of associated microorganisms, genetics and management are considered. • Microbe-to-plant signal compounds can contribute to climate change resilient agriculture. Then, this paper ends with a discussion of challenges and obstacles to promoting the application of advanced technologies and what is needed to overcome these. Establish the long-term benefits and value of biomass and the bioeconomy will also be discussed. [ABSTRACT FROM AUTHOR]

Biodiesel is gaining attention as a remedy for the increasing demand of fossil fuels which is depleting rapidly. Commercial homogeneous catalysts in the biodiesel production industry are facing challenges such as separation difficulties and severe corrosion which will lead to the increment of production and maintenance cost. Herein, this paper focuses on the comprehensive review of literature reported on the usage of biomass as the precursor for the catalyst used in biodiesel production. Compared to other commercial catalysts, the usage of biomass as catalyst precursor possesses several advantages such as abundantly available, cheaper raw materials, reusable, non-toxic and biodegradable. Carbon material synthesized from biomass which acts as the efficient support for active sites due to its high porosity and surface area characteristic has been studied widely. The latest development of biomass derived basic, acidic and magnetic heterogeneous catalyst through several state of the art synthesis pathways starting from the synthesis of the supporting material (carbon) until the functionalization process to form the complete catalyst was reviewed. Apart from direct sulfonation using sulfuric acid, sulfonation by reduction and arylation were less hazardous and provided comparable active sites activity. Most biomass based catalysts exhibited good catalytic performance by providing high biodiesel yield of above 80% at optimum conditions. Besides that, various kinetic models developed from the reaction kinetic study catalyzed by biomass based catalyst were also reviewed as a preparatory stage for the scaled-up commercialization process of the studied catalyst in the biodiesel production sector. This catalyst could assist to lower the activation energy required for the reactions and thus enables higher reaction rate to reach equilibrium. Continuous research on producing high performing biomass based catalyst with minimum resources is needed in order to achieve the ultimate goal of green and sustainable biodiesel industry. [ABSTRACT FROM AUTHOR]

In order to increase the methane yield from biomass, this paper investigates the mechanical pretreatment effect of a Hollander beater on the anaerobic digestion process of Pelvetia canaliculata macroalgae using a response surface methodology (RSM). Higher values on methane yield were obtained at lower F/I ratios, with an increase up to 2.5-fold at an F/I value of 0.3. A multi-objective optimization study was carried out with the aim of maximizing the methane yield while minimizing the pretreatment time. An optimum methane yield of 283 ml/gVS was obtained for 50 min pretreatment time and a ratio F/I of 0.3, which represents an increase of 45% compared to non-pretreated algae. [ABSTRACT FROM AUTHOR]

This paper presents the emission spectroscopy method for registering chemiluminescent radical species of OH ∗ , CH ∗ , C 2 ∗ by means of optical flame imaging using optical bandpass filters, corresponding to emission wavelengths of the radicals of interest, and by scanning the flame using optical fibers coupled to a spectrometer for recording the emission spectra. The aim of this research is to analyse the distribution of chemiluminescence intensity along the flame axis from various angles simultaneously in order to determine the effect of the air equivalence ratio (ER) and mixing of producer gas (PG) from biomass gasification into the natural gas flow to spectral characteristics of flame at specific wavelengths representing formation reactions of OH ∗ radical species. The experiments were carried out with pure natural gas (NG) and air mixture and a premixed air/gas mixtures (80%NG and 20% PG, 65%NG and 35%PG). Flows of air, NG and PG were premixed before entering the combustion chamber. For flame emission spectroscopy, two different methods were used: 1) imaging by an ICCD camera through optical bandpass filters suitable for OH ∗ , CH ∗ , C 2 ∗ chemiluminescence intensity registration; 2) by a combination of a spectrometer and five optical fibers to collect the flame spectra from 5 different angles and in various heights from the burner outlet. The distribution of chemiluminescent species intensity along the burner vertical axis was analyzed and zones with most intense OH ∗ , CH ∗ , C 2 ∗ generation in flame were identified, and the effect of addition of PG to NG and ER to the OH ∗ chemiluminescence was analysed. [ABSTRACT FROM AUTHOR]

In the wake of recurrent electricity blackouts during the summer months of the three consecutive years since 2012, each lasting for several hours daily, it became clear that Egypt is facing a severe energy shortage where peak electricity demand was fast outpacing supply. An investigation of the reasons of the widespread blackouts revealed that the power shortages were primarily attributed to the unavailability of natural gas to meet peak demand loads. Although agricultural residues account for the lion’s share of the solid waste generated in Egypt, sustainable usage of this substantial quantity of bio-residues continues to present a formidable challenge for Egypt. The primary objective of the authors of this paper was to shed light on how to capitalize on Egypt’s extensive resources from agricultural residues and to propose enablers for promoting sustainable energy generation using biomass to ultimately help in bridging Egypt’s current energy gap using indigenous resources. In view of the current state of technological maturity, a temporal recommendation for energy generation was provided. Three energy conversion technologies covering combustion (direct firing), co-firing and gasification were chosen for the analysis presented in this work. Within the context of Egypt’s top energy consuming sectors of power, transport and industry, energy end-uses comprising electricity generation, cement production and chemicals production were considered for the analysis. Accordingly, four alternative waste-to-energy pathways, each representing an energy end-use, were investigated. In order to holistically evaluate the four-alternative biomass waste-to-energy pathways against criteria representing environmental, societal and economic pillars of sustainable development, a Multi-Criteria Decision Analysis was performed. This analysis tool was specifically chosen because of its capability of handling the different criteria associated with the aforementioned pillars, each with its relevant varying dimension. Considering the analysis outcomes, gasification of bio-mass for chemicals production was identified as the optimal waste-to-energy pathway. On a short-term scale implementation horizon, the first priority for utilizing the energy content of the discarded agricultural residues was for cement production using co-firing, and the second priority is for electricity generation using direct firing. To accelerate fossil fuel substitution by agricultural residues, in lieu of coal, for cement production in Egypt, an initial substitution target of at least 20% should be established. This would result in annual greenhouse gas emissions savings of about 8.5 million tons of Carbon Dioxide equivalent. For medium and long-term implementation horizons, the recommended energy generation pathway is gasification for production of ammonia and diesel fuel, respectively. Based on a total annual quantity of approximately, fifteen million tons of discarded agricultural residues, there is a yearly potential for producing up to one million tons of diesel fuel and about seven million tons of ammonia (urea) for fertilizers. Regarding Egypt’s renewable energy generation targets for 2022, for which there are no targets announced for biomass energy, a proposed share of 3% should be allotted for biomass. To entice private investment into biomass-to-energy applications, a Feed-In-Tariff of thirteen US cents per KWH was proposed. The government should offer a suite of policy, institutional, market, financial, technical and informational incentives to encourage and promote energy generation from agricultural residues. [ABSTRACT FROM AUTHOR]

Increasing demand for fossil fuels worldwide coupled with environmental concerns has intensified the focus on Renewable Energy Sources. So-called ‘2nd generation’ biofuels, produced from residues, waste or cellulosic material, present distinct advantages over fossil fuels and can contribute to energy security and sustainable development of society. This paper aims to demonstrate that Greece holds sufficient resources to support indigenous and possibly economic production of 2nd generation biofuels in order to meet the European Union ‘Renewable Energy Directive’ targets. These mandate 10% share of biofuels in the transport sector for member states by 2020 with continuous penetration of advanced biofuels towards the 2030 horizon (RED II). A market analysis has been performed to review the biofuels market in Greece and investigate the availability of 2nd generation resources, followed by economic feasibility assessment of their production routes. Individual results identify substantial market gap, with potential to be filled through indigenous production of 2nd generation biofuels. This presents significant short to medium term growth opportunity as well as an attractive investment, provided appropriate technological pathways and feedstocks are selected that minimize overall supply-chain and productions costs, further supported by robust policies. In order to pursue this growth potential, careful central planning, de-risking and policy support from the government is required, followed by a radical reformation of the biofuels industry. [ABSTRACT FROM AUTHOR]

The recently legislated European Union (EU) Directive 2009/28/EC entitles Member States (MSs) to implement Cooperation Mechanisms, in order to promote the use of energy from renewable sources (RES) and enables them to achieve their binding national targets for 2020. The RES Directive introduces, inter alia, the implementation of joint RES projects between at least one MS and one or more neighbouring countries, in this direction. This paper aims to develop a methodological approach for the multi-criteria assessment of potential opportunities and risks that lie in the implementation of RES electricity (RES-E) projects incentivised by a Cooperation Mechanism between the EU and the Western Balkan (WB) region. Nine evaluation criteria are selected to cover all three aspects of the assessment, namely (a) the Investment Framework, (b) the Social Framework, and (c) Energy Security. Eventually, the seven Western Balkan countries are evaluated and ranked using UTASTAR, a multi-criteria additive value model based on ordinal regression and preference disaggregation, and the presented results are discussed. [ABSTRACT FROM AUTHOR]

There is growing interest for utilization of biomass and waste for the significant environmental benefits, energy security and long-term fuel sustainability. Malaysia has enormous biomass resources that is currently under-utilized for electricity generation. The variation in the chemical composition, moisture and alkali contents across different biomass feedstocks requires pre-treatment to avoid problem during thermochemical conversion processes. On the other hand, the problem associated with municipal solid waste limit the application for useful fuel due to heterogeneous in nature and high moisture content. This paper reviews the prospective waste to energy technologies in Malaysia using hydrothermal treatment for production of solid fuel from biomass and municipal solid waste. The selection of thermochemical conversion technologies will be based on the fieldwork, characterization and laboratory experiments, environmental and economic evaluations. The overall objectives are to enhance the physical and chemical properties of the biomass and waste and to increase the thermal efficiency of power plant as part of nation renewable energy mix to reduce dependency to fossil fuels particularly coal. The effective use of biomass and waste can supply the required fuel for future electricity generation. [ABSTRACT FROM AUTHOR]

The importance of renewable energy usage is increasing gradually due to the reasons of energy supplying security, environmental pollution and reducing dependency on external sources in all over the world as also same in Turkey. Biomass is a clean and sustainable energy source that can be produced from various kind of organic waste. Turkey has considerable biomass energy potential, and about 6% of the total potential is located in the eastern region. Ardahan is one of the eastern cities of the country whose economy mainly relies on livestock farming. This paper presents biogas energy potential from animal manure and agricultural residue and corresponding CO 2 emission reduction in Ardahan. Calculations were made according to the analysis of the animal manure and the agricultural crop quantities of 2015 data considering of the biochemical methane potential (BMP), availability factors, volatile solid ratio of the manure, harvested area and unit methane potential of cereals. The total electricity production potential of the evaluated biomass sources is 323 GWh/year. The total CO 2 emission reduction is about 2 million tons/year in the case of biogas combustion power plant exists instead of coal fired power plants. [ABSTRACT FROM AUTHOR]

Pyrolysis of eucalyptus wood and refuse derived fuel was carried out in a continuously weighing fixed bed reactor performing as a macro thermogravimetric analyzer (macro-TGA). All samples were heated from ambient temperature to 800 ºC at different heating rates; 5, 10, and 15 ºC/min. Because of buoyancy effect and measurement uncertainties, noises were generally detected in mass change or thermogravimetric (TG) data obtained from the macro-TGA. The noises led to high degree of fluctuation in the derivative TG (DTG) data. These fluctuating data could not be used directly to analyze kinetic parameters. Smoothing was required in eliminating the noise to obtain reliable DTG data used for subsequent kinetic analysis. In this paper, Gaussian smoothing technique was applied to characterize the smoothing quality, based on mathematics and kinetics points of view. In mathematical analysis, values of smoothing parameters σ within 4-15 showed that raw-data can be improved to be sufficiently smooth to achieve DTG curves without high fluctuation by fourth-order central difference method. Smoothed TG curves did not significantly differ from the original signals. However, kinetic analysis results indicated that only Gaussian smoothing with 7 ≤ σ ≤ 10 can provide meaningful kinetic parameters ( E a ~ 140-150 kJ/mol), which can be used to describe pyrolysis behavior in macro-TGA satisfactorily (R 2 ≥ 0.99). [ABSTRACT FROM AUTHOR]

The targets for renewable energy set by the European Union have resulted in a surge in consumption of wood pellets, and the demand is expected to further increase the next decade. We use economic modelling to assess the impact on global wood-based product markets of gradually increasing wood pellets consumption within the EU. Comparing a scenario wherein consumption is determined exclusively by market forces with one where EU consumption is set to double between 2015 and 2030, we characterize the deviation from the unregulated market equilibrium that would attain. Our results highlight the necessity of assessing market impacts over time, with a sufficient geographical disaggregation. An increased EU demand for wood pellets would, apart from increased EU production, results in increased imports. The main sources are projected to be Russia, Canada, and, particularly, the USA. The results indicate synergies and competition between wood-based products and wood pellets. In general sawmilling stand to gain from increased wood pellets' consumption, while the opposite holds for wood-based panels and most paper grades. Due to the feedstock mix used in production of wood pellets and wood-based products, effects vary over time and among different EU members, as well as between EU and other regions. [ABSTRACT FROM AUTHOR]