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Abstract In this paper technical-economic feasibility is analyzed about a gas-steam combined-cycle, fueled by syngas produced in a local downdraft gasifier. At first, the downdraft gasifier model is briefly described, where a biomass mix of Refused-Derived Fuel, RDF, and sewage sludge is transformed into syngas; then, the economic model is introduced with the graph about the economic trends of the most important plant components. Starting from the Design of Experiment (DOE) analysis, this paper proposes a multi-objective optimization methodology to obtain the Pareto Frontier of micro gas turbine technologies. In particular, this study allowed us to determine which micro gas turbine technology is more suitable to attract investment capital. The considered performance parameters are: the nominal power of the cycle; the total plant efficiency; the net revenues; the pay back period. On the other hand, the input design variables are represented by the turbine intake temperature, the compression ratio and the biomass chemical composition. [ABSTRACT FROM AUTHOR]

Abstract Seaweed biomass is a valuable marine resource that can be used for energetic purposes or high value-added product production. Cultured locally, seaweed is considered to reduce pressure on agricultural lands and reduce eutrophication. Seaweed cultivation success is dependent from several factors which includes seaweed reproduction, where spore release takes important place. Stress induced spore release is a part of fertilization material preparation. Stress can be obtained by drying seaweed. Drying in aluminium foil and in wet paper were tested on brown seaweed Fucus vesiculosus to determine if they have an impact on the amount on released spores and on spore fertilization. Wet paper and aluminium foil were used for material drying. Drying in foil increase the number of released gametes, but do not have an impact on fertilization rate. Drying length 6 days and 2 days were tested and 6 days gave better results. [ABSTRACT FROM AUTHOR]

In this paper, Aspen Plus® models of biomass gasification process combined with plasma reactor for tar removal and plasma gasification process were developed respectively, validated and analyzed thermodynamically. The analysis shows that plasma technology is capable of producing syngas with acceptable tar content for gas turbine application. However, this comes with a huge energy penalty. For example, within the context of the analysis carried out in this paper, the thermodynamic efficiency of the biomass gasification process combined with plasma tar cleaning was found to be 43.6% while that of the plasma gasification process was 37.3% despite its higher bio-syngas calorific value. The lower efficiency recorded for the plasma gasification process occurs as a result of the higher electrical energy required to attain the high temperature needed for the gasification of the biomass material. As a result of the low efficiency, plasma tar cleaning of raw bio-syngas or plasma gasification, although technologically feasible, may not be a viable route for producing bio-syngas for gas turbine application. However, it may be a viable option for energy storage if the plasma reactor will be powered with electricity from wind and other renewable energy resources during off peak period. [ABSTRACT FROM AUTHOR]

In this paper, a two-staged entrained-flow bed gasifier is proposed for the co-gasification of coal and biomass. The effect of biomass blending ratio on the two-staged co-gasification characteristics and the influence of fuel price, loan ratio, biomass blending and electricity price on the technical and economic efficiency of the IGCC system are considered. The results indicated that the content of H 2 in syngas increased firstly and then decreased with the addition of biomass, which reached the maximum value of 30.87 % at 10 % biomass ratio. The content of CO increased with the raising of biomass ratio, and the growth rate reached the maximum at 10 % biomass ratio. The carbon conversion (CC) firstly raised and then decreased with the increase of the biomass ratio at the second stage. The cold gas efficiency (CGE) increased nearly 10 % when the biomass ratio increased from 0 to 10%. The CGE of two-stage co-gasification was above 85%, indicating two-staged co-gasification of coal and biomass can significantly improve the efficiency of cold gas. The technical-economical analysis on the IGCC system indicated that the loan rate had a significant influence on the system dynamic investment, internal rate of return and net present value. With the increasing of loan rate, the total dynamic investment based the benchmark interest rate of 6.15 increased from 413.67 million to 431.58 million under the maximum lending rate of 8.61%. When the lending rate was larger than 8.15%, the internal rate of return (IRR) was slightly higher than the benchmark rate of return in the power sector. The further increase of the loan interest rate would result in a reduction of the internal rate of return and a negative net present value.The internal rate of return, the cost ratio, and the net present value decreased with the increase in the fuel price. When the price ceiling of coal and biomass was 600 RMB·t -1 and 450 RMB·t -1 , the IGCC system was economically viable. The influence of biomass blending ratio on technical, economic indicators was nonlinear. When the biomass ratio increased from 0 to 50%, the IRR, income ratio and net present value of the project increased firstly and then decreased. The effect of the grid price on the technical economic indicators was opposite to that of the fuel price. This paper provides a useful guide for optimization of the co-gasification process. [ABSTRACT FROM AUTHOR]

This paper investigates how glass contamination in refuse-derived fuel can be quantitatively detected using near-infrared spectroscopy. Near-infrared spectral data of glass in four different background materials were collected, each material chosen to represent a main component in municipal solid waste; actual refuse-derived fuel was not tested. The resulting spectra were pre-processed and used to develop multi-variate predictive models using partial least squares regression. It was shown that predictive models for coloured glass content are reasonably accurate, while models for mixed glass or clear glass content are not; the validated model for coloured glass content had a coefficient of determination of 0.83 between the predicted and reference data, and a root-mean-square error of validation of 0.64. The methods investigated in this paper show potential in predicting coloured glass content in different types of background material, but a different approach would be needed for predicting mixed type glass contamination in refuse-derived fuel. [ABSTRACT FROM AUTHOR]

The aim of this paper is to investigate the thermodynamic performance of a novel small-scale power plant that employs a combined cycle for the energy generation from carbon-neutral biomass, such as pruning residues. The combined cycle is composed of an externally fired Joule Brayton cycle followed by a bottoming steam cycle. The topping cycle has the unique particularity of being composed of a cost-effective turbocharger taken from the automotive industry, in place of a more expensive commercial micro-turbine. The turbocharger can be either directly connected to the electric generator (after a few modifications) or coupled (without modifications) with a power turbine moving the generator. The use of solid biomass in the proposed plant is allowed by the presence of an external combustor and a gas-to-gas heat exchanger. The warm flue gases exhausted by the topping cycle are used in a bottoming cycle to produce steam, which can power a steam expander. This paper thermodynamically assesses the novel combined cycle in the configuration for the topping cycle that employs a turbocharger coupled with a power turbine capable of generating 30 kW of electrical power. Furthermore, the comparison between the performance obtained using the bottoming water Rankine cycle and a bottoming Organic Rankine Cycle is provided. [ABSTRACT FROM AUTHOR]

The ultimate aim of the project, where the work presented in this paper is inserted, is the design of an ORC based cogeneration biomass-fired mini scale CHP system (10-100kWe). For this purpose, a medium power range (500 kWt) biomass boiler will be modified in order to use part of the energy contained in biomass combustion gases to, indirectly, evaporate the working fluid of an ORC which condenser will be responsible for pre-heating the water demanded by the users. The work presented in this paper refers to the development of a model capable of predict with accuracy the quasi-steady behavior of the ORC by affording an adequate engineering understanding of the physical phenomena affecting their performance. A good and satisfactory agreement was obtained between experimental results and computational outputs of sub-models which allow simulating with some confidence other different conditions. [ABSTRACT FROM AUTHOR]

Thanks to various feed-in-tariff programs, aimed to the development of electric energy production from renewable sources, several biomass firing power plants have been realized in Italy in the last few years, contributing to the reduction of greenhouse gas emissions and fossil fuel energy dependence. In particular, during 2012 there was a rush for the completion of several renewable energy conversion power plants, leading up to 986 new plants to get the first connection to the grid (+81,3% with respect to 2011); among those, 80 new plants were solid biomass firing plants (+47,1% with respect to 2011) [1]. Linea Energia S.p.A., the Energy Business Unit of the multiutility company LGH, Linea Group Holding, which operates over the areas of Brescia, Cremona, Crema, Lodi and Pavia, gave its contribution in 2012 with the realization and start-up of two waste wood fueled energy conversion plants located in the Northern Italy, more exactly in Cremona and Rodengo Saiano (Brescia). This paper focuses on the operation and maintenance experience of the waste wood conversion power plant of Cremona, which is capable for a gross electric power production of up to 1.0 MW and a thermal power recovery of up to 5.5 MW. In the first part of this paper a description of the plant is presented, giving an insight of the engineered process. In the second part, the performance analysis of the energy conversion process is discussed by comparing actual performance of the system with the originally defined reference performance. In 2016, as a consequence of the operation of the unit in anomalous conditions (air entering in the system) the turbine blades got scaled. The output of the turbine progressively decreased but was then successfully re-established after an extraordinary maintenance carried out by the turbine supplier. [ABSTRACT FROM AUTHOR]

The ultimate aim of the project, where the work presented in this paper is inserted, is the design of an ORC based cogeneration biomass-fired mini scale CHP system (10-100kWe). For this purpose, a medium power range (500 kWt) biomass boiler will be modified in order to use part of the energy contained in biomass combustion gases to, indirectly, evaporate the working fluid of an ORC which condenser will be responsible for pre-heating the water demanded by the users. The work presented in this paper refers to the development of a model capable of predict with accuracy the quasi-steady behavior of the ORC by affording an adequate engineering understanding of the physical phenomena affecting their performance. A good and satisfactory agreement was obtained between experimental results and computational outputs of sub-models which allow simulating with some confidence other different conditions. [ABSTRACT FROM AUTHOR]

Thanks to various feed-in-tariff programs, aimed to the development of electric energy production from renewable sources, several biomass firing power plants have been realized in Italy in the last few years, contributing to the reduction of greenhouse gas emissions and fossil fuel energy dependence. In particular, during 2012 there was a rush for the completion of several renewable energy conversion power plants, leading up to 986 new plants to get the first connection to the grid (+81,3% with respect to 2011); among those, 80 new plants were solid biomass firing plants (+47,1% with respect to 2011) [1]. Linea Energia S.p.A., the Energy Business Unit of the multiutility company LGH, Linea Group Holding, which operates over the areas of Brescia, Cremona, Crema, Lodi and Pavia, gave its contribution in 2012 with the realization and start-up of two waste wood fueled energy conversion plants located in the Northern Italy, more exactly in Cremona and Rodengo Saiano (Brescia). This paper focuses on the operation and maintenance experience of the waste wood conversion power plant of Cremona, which is capable for a gross electric power production of up to 1.0 MW and a thermal power recovery of up to 5.5 MW. In the first part of this paper a description of the plant is presented, giving an insight of the engineered process. In the second part, the performance analysis of the energy conversion process is discussed by comparing actual performance of the system with the originally defined reference performance. In 2016, as a consequence of the operation of the unit in anomalous conditions (air entering in the system) the turbine blades got scaled. The output of the turbine progressively decreased but was then successfully re-established after an extraordinary maintenance carried out by the turbine supplier. [ABSTRACT FROM AUTHOR]

This paper presents a research activity aimed at exploiting combined cycles (gas turbine plants coupled with steam cycles) for small-scale energy generation from carbon-neutral biomass. Such a goal has never been achieved before, since combined cycles are generally suited only for large-scale applications and for clean fuels. In order to adapt combined cycles to small-scale energy generation using dirty fuels, the implementation of cost-effective and commercially available components is studied, such as the use of a turbocharger and a power turbine taken from the automotive industry. The ongoing realization of the first prototype of small-scale combined cycle is presented in this paper, providing a detailed description of both the plant architecture and the main components chosen. In addition, a commercially available tool (Cycle Tempo) is used to demonstrate the high feasibility and potential of the plant in terms of efficiency. To that end, different plant configurations are studied and the effects of losses on the plant performance are investigated in detail. [ABSTRACT FROM AUTHOR]

The fundamentals of pyrolysis, its latest developments, the different conditions of the process and their relative residues are of great importance to evaluate the applicability of the pyrolysis process within the waste management sector and waste treatments. In particular the type of residues and their further use or treatment is of extreme interest as they could become the source of secondary raw material or generate beneficial influence in waste treatments. The main area of focus of this paper is the investigation of the link between the pyrolysis conditions, the chemical and mineralogical composition of their products and the benefits of pyrolysis in the waste management sector. More specific the paper covers the fast, intermediate and slow pyrolysis of organic and a mixture of inorganic/organic charge from households. The catalysts influence during fast pyrolysis on products yields and composition is not being considered in the review. [ABSTRACT FROM AUTHOR]

The fundamentals of pyrolysis, its latest developments, the different conditions of the process and their relative residues are of great importance to evaluate the applicability of the pyrolysis process within the waste management sector and waste treatments. In particular the type of residues and their further use or treatment is of extreme interest as they could become the source of secondary raw material or generate beneficial influence in waste treatments. The main area of focus of this paper is the investigation of the link between the pyrolysis conditions, the chemical and mineralogical composition of their products and the benefits of pyrolysis in the waste management sector. More specific the paper covers the fast, intermediate and slow pyrolysis of organic and a mixture of inorganic/organic charge from households. The catalysts influence during fast pyrolysis on products yields and composition is not being considered in the review. [ABSTRACT FROM AUTHOR]

Biomass power is an important routine to source more energy needs from renewables and to mitigate global warming. This paper presents an overview of all the key technologies currently used for direct biomass co-firing for combined heat and power production, among which grate-firing is regarded to well suit decentralized biomass and municipal/industrial wastes combustion. This paper discusses with concrete examples how to advance grate-firing for greater efficiency and environmental impacts, e.g., use of advanced secondary air system, flue gas recycling and optimized grate assembly, which are of great interest and relevance for further development of this technology. [ABSTRACT FROM AUTHOR]

Biomass is plant origin organic waste that is used for energy production, generally as a fuel. Co-firing is a combustion technology where two or more fuels are burned at the same time. It is a source of interest for many, due to provided greenhouse gas reduction and controlled use of fossil fuels. This paper takes a closer look at biomass co-firing equipment in the Riga Technical University (RTU). It offers a literature review on co-firing technologies, characteristics and implementation experiences. The paper includes a description of the laboratory equipment, possible experiment plan and the design of three factor experiment for an example of CO 2 emissions. Calculations for determining necessary fuel proportions are made. It was determined that the most appropriate amount of biomass used for co-firing in the existing equipment is between 60 and 70% of mass proportions. [ABSTRACT FROM AUTHOR]

The thermochemical pyrolysis process is one of the key intermediate processes to flexibly produce electric/thermal power output. In this paper, experimental results of a small externally heated biomass screw reactor are presented. This paper aims at validating a 1D-DAEM model with experimental data collected by varying maximum temperature in fast pyrolysis conditions. The experimental system, here used for the spent coffee conversion, has been specifically designed for allothermic processes, allowing for controlling heating and mass flow rates. A comparison with pellet has been performed to refer the observed yields to literature available data. The implemented four parallel reaction framework coupled with a DAEM model, is able to give results in very good agreement with the bio-oil experimental data yields, showing in any case prediction errors lower than 4.5%. The maximum bio-oil production has been observed at 500°C, both for the pellet and the spent coffee with yields respectively of 66% and 56%. [ABSTRACT FROM AUTHOR]

With rapid population growth there is an increased trend of global energy consumption. On a global scale most of the energy supply is currently generated by fossil fuels with all the subsequent consequences including depletion of non-renewable energy resources (e.g. oil, coal and natural gas), greenhouse gas emissions and climate change. With respect to the increasing global demand for cheap, reliable and environmentally safe energy, there is a need for innovative technologies and an increase in renewable energy share. Biomass is a unique renewable resource with a wide range of uses and a huge potential. However its relevance for food industry poses an ethical dilemma. Therefore, finding the possible solutions for more efficient biomass use are increasingly important. In this paper, results of a study identifying parameters and conditions necessary for increasing the quality of outgoing gases from biomass gasification and digestion processes are presented. A methanation process is simulated for upgrading the quality of the gases. It is a reaction where carbon oxides present in the gases react with hydrogen to produce methane. The reaction is condition-dependent, therefore a mathematical model is developed for simulating parametric values that influence the process. In the paper, the simulation results are presented. [ABSTRACT FROM AUTHOR]

This paper presents and evaluates initiatives taken in Morocco to reduce wood consumption, improve energy efficiency and reduce deforestation due to the operation of hammams (Turkish baths). First, the paper examines the vernacular energy systems used in heritage hammams and their lessons of sustainability. Second, it presents the problems associated with the new hammam furnaces and how they replicate vernacular systems. Third, the various initiatives for more energy efficient systems are presented. These include hybrid solar/biomass hammam systems. The paper evaluates the opportunities for addressing local and global concerns over deforestation and CO 2 emissions and discusses various difficulties and challenges. [ABSTRACT FROM AUTHOR]

Nowadays, the development of new power plants capable of effectively using non-conventional energy sources is strongly desirable in order to obtain a significant reduction in costs of energy. In this regard, this paper proposes a new small scale (about 100 kW) combined cycle plant which can be fired externally by any kind of biomass. Particularly, the research activity presented here is concerned with the preliminary design of this innovative plant, which will be built, by means of a project funded by “Apulia Region”, at the LabZero Research Centre of Polytechnic University of Bari in the south of Italy. The goal of the paper is to demonstrate the effectiveness of the plant in terms of energy efficiency and availability and reliability of its components. The plant is mainly composed of a centrifugal compressor and a centripetal turbine of an automotive turbocharger, with the working fluid (clean air) being heated in a high temperature heat exchanger (HTHE) by using hot flue gases produced in an external combustion chamber burning biomass. The clean hot air expands in the turbine and then feeds the combustion chamber, where biomass is burned. In order to increase the efficiency, the flue gases exiting the HTHE are delivered into a heat recovery steam generator to generate water steam which can finally expand through a rotary actuator. Two configurations, employing an open Rankine cycle and a close one respectively, are analysed, and the use of biomass is compared with methane. [ABSTRACT FROM AUTHOR]

One of the key strategies towards the European goals is the exploitation of local and renewable energy sources: the paper analyses the benefits and the feasibility of a woody biomass cogeneration plant in Luserna San Giovanni (Torino, Italy). The first part of the paper presents a graphical method to evaluate the thermal energy use of public and residential buildings. Then, after the selection of the buildings with both higher energy consumption and higher specific energy consumption, a thermal analysis allows the assessment of energy savings potential of these buildings. The results of this first analysis permit to estimate the effective and peak power of the plant considering different scenarios of buildings’ renovation and then of heat distribution. The second part of the paper describes the pre-feasibility analysis of the district heating network supported by a GIS-based tool (Geographical Information System). Main results are the evaluation of the environmental and economic impacts of the biomass plant and of the connection to the district heating network on a short and long term horizon. [ABSTRACT FROM AUTHOR]

This paper provides an in-depth review and analysis on the science technology and innovation (STI) barriers in order to achieve bioenergy implementations in Thailand. Though, Thailand appears to have clear targets on alternative energy in the next 10 years according to the master plan formulated by Ministry of Energy but these ambitious-bioenergy targets are based solely on the potential of resources existing and planned planting in the country. In order to transform biomass to end-used consumption, it is a need to define the STI platform for actions. However, there is no study on the STI policy for bioenergy implementations. Yet, there are several concepts of best-practices in difference prospects but there is no integration of science technology and innovation policy as a whole. This paper utilized the qualitative method, the research data sources, and the industrial interviews in person. This paper contends the STI roles currently accorded to biomass to energy supply chain in Thailand and an early attempt at developing policy recommendations. [ABSTRACT FROM AUTHOR]

Forest biomass is a renewable and sustainable source of energy that can be used for producing electricity, heat, and biofuels. The production of biomass for energy is considered to be an important step in developing sustainable communities and managing greenhouse gas emissions effectively. Biomass properties vary and are commonly associated with plant species. Hence, efficient methods to predict biofuel characteristics will greatly affect the utilization and management of feedstock production. In this paper attempt was made to correlate various chemical characteristics with NIR spectra. Wood chips from various plant species was analyzed for lignin content, heating value, ash content and NIR and the results were evaluated with correlation, PCA and PCR. Initial evaluation showed promising results where chemical components in the wood correlate to NIR spectra. A selection of results will be presented in this paper. Further analysis as well as results from PCA and PCR models will be presented in the full paper version. [ABSTRACT FROM AUTHOR]

Biorefinery as a concept for polygeneration of various bio-based materials, fuels and chemicals has been more and more attractive. This concept is applied to the thermomechanical pulp (TMP) and paper industry in the present study to evaluate the possibility of co-production of substitute natural gas (SNG), electricity and district heating (DH) in addition to mechanical pulp and paper. In TMP mills, wood and biomass residues are commonly utilized for electricity and steam production through an associated combined heat and power (CHP) plant. This CHP plant is designed to be replaced by a biomass-to-SNG (BtSNG) plant including an associated heat and power centre. Implementing BtSNG in a mechanical pulp production line might improve the profitability of a TMP mill and also help to commercialize the BtSNG technology by taking into account of some key issues such as, biomass availability, heat utilization etc.. A TMP+BtSNG mathematical model is developed with ASPEN Plus. [ABSTRACT FROM AUTHOR]

Abstract Presently, the crisis of energy has become a growing concern all over the world and a serious barrier for the developing nations. Conversely, the resources of fossil fuels are limited and depleting due to the exploration and higher production activities around the glove. The impact of fossil fuels exploration has become a serious threat for naturalism and creates environmental hazardous accidents. However, the demand for energy in Bangladesh is increasing day by day and fossil fuel reserves continue the countries demand almost only 50 years. So, it is the high time to utilize its natural biomass resources to fulfill energy demand. The climate condition and waste generation rate of Bangladesh is key factors for biomass energy production. Nowadays the Bangladeshi government has made an agenda "waste to electricity" thus the utilization of biomass resources has become a blessing for the static economic growth in the nation. Recently Bangladeshi government has made an extra effort for the commercialization and marketable of biomass energy engendering and production in the country. This paper explored the potential of biomass energy as a sustainable energy source and their future implementation challenges in Bangladesh. [ABSTRACT FROM AUTHOR]

Abstract Biomass drying has always been a big issue in biomass thermal treatment. Especially in pyrolysis, combustion and gasification, water evaporation is a necessary step before other reactions can take place. This paper presents a detailed drying for single poplar particle pyrolysis under nitrogen. In this model, the transport equations are numerically solved using finite volume method to obtain the pressure, temperature and species fractions. Two different water contents found from literature are applied to test the model. The result shows that this numerical model can predict water behavior during biomass drying process of pyrolysis. [ABSTRACT FROM AUTHOR]

Abstract Metallurgical industry accounts for 20.40% of the total energy consumption in the industry of China. Energy saving from furnace slag of the steel industry is essential for the clean and green development of China. Thus, in this paper, the thermal effect and kinetic analysis of the biomass mixed with furnace slag at different mass ratios (10 wt%, 30 wt.% and 50 wt.%) was investigated via TGA under different heating rate from ambient temperature to 900 oC. Cellulose was selected as the primary organic compound in biomass, and iso-conversional method was applied for calculating activation energy. The maximum decomposition rate and temperature of maximum decomposition rate get higher as the heating rate increases. Furnace slag shows positive synergistic effects under 30% mass ratio with 6% higher volatile yield than that from theory calculation. The average activation energy values of CE, Slag-CE-10, Slag-CE-30, Slag-CE-50 were 187.54 kJ·mol-1, 260.81 kJ·mol-1, 132.79 kJ·mol-1 and 159.45 kJ·mol-1. [ABSTRACT FROM AUTHOR]

Abstract Higher alcohol (C5/C6 alcohol) blended with diesel or bio-diesel is a promising alternative clean fuel for the compression ignition engine. The most important puzzle is the technology development of biomass to higher alcohol fuels. In this paper, a novel approach of hydrothermal conversion of biomass into C5/C6 higher alcohol fuels was proposed. High yield of higher alcohol fuels was obtained from the real biomass with the C5/C6 alcohol selectivity of 77% under the mild hydrothermal conditions. The properties of the produced higher alcohol fuels are similar to that of 0# diesel. The exhaust emission of compression ignition engine decreased vigorously by blending the higher alcohol fuels with diesel at weight ratio of 20/80. [ABSTRACT FROM AUTHOR]

Abstract A first of its kind concentrated solar power (CSP) installation has been integrated together with a biomass heat and power (CHP) plant using an organic rankine cycle (ORC) unit. The plant has been deployed in the northern part of Jutland in Denmark, right next to the city of Brønderslev. The plant has been supplying heat to the local district heating network since the end of 2016. Aalborg CSP has developed and built the CSP plant consisting of parabolic trough collectors with an aperture reflecting area of 26,920 m2. The CSP plant is able to deliver 16.6 MWth at its peak while it can supply the district heating or the ORC with approximately 16,000 MWh of heat annually. This paper serves as a description of the technical aspects of the system with specific focus on the CSP field as well as present the first measured performance from the Summer of 2017. [ABSTRACT FROM AUTHOR]

Abstract Biomass will play a pivotal role in the future economy. Within the context of the development of bioeconomy in the European Union, large-scale replacement of fossil fuels with bio-based feedstock is a topical issue not only for energy applications but also for chemicals, materials and bioproducts. The transition to bio-based economy poses a challenge of sustainable and efficient use of the limited biomass feedstock. This paper presents a conceptual methodology for an optimum supply and use of biomass resources. Authors propose a three-dimensional model called the 3D Model merging three inter-related aspects of the bioeconomy – bioresources, bioproducts and bioenergy, biomass consumers and logistic chains. The research focuses on low-quality and waste biomass resources and their use for bioenergy production such as wood residues, energy wood plantations, agriculture waste and by-products, green waste and organic waste. The importance of low-quality biomass lies in the untapped potential for low-quality biomass applications in Latvia that can help meeting environmental, climate, energy and waste policy targets. This is the first step to evaluate the potential of low-quality biomass application potential in Latvia. The proposed 3D methodology serves as a platform for further policy planning studies in the field of bioeconomy and sustainable use of bioresources. [ABSTRACT FROM AUTHOR]

The ash deposition process in biomass boilers can induce many ash-related problems. It will reduce the heat transfer in the furnace walls and convective pass tubes and decrease the boiler efficiency and capacity. Previous review work and experience about the ash deposition process was almost focusing on coal-fired utility boiler, providing an extensive summary of knowledge and current developments about ash deposition processes, but few was concentrating on the biomass fuel-derived boiler. Numeral empirical and traditional methods, such as ash fusibility, ash viscosity, and slagging and fouling indices, which are based on the temperature and the chemical compositions, cannot fully predict the complicated ash deposition processes. To understand the nature of ash deposition in biomass boilers, full attention should be paid to the ash deposition processes, including the transformation process of mineral matter in biomass fuels and deposition characteristics. To predict the ash deposition process, some ash deposition models, such as the ash transportation model, the ash formation model, the ash impacting model, the ash sticking model and the ash growth model, should be developed. This paper will give a brief introduction to the traditional methods about the ash deposition. In additional, an extensive state-of-the-art review of the ash deposition in biomass fuel-derived boiler will be presented. Lastly, the comprehensive ash deposition models including the mechanistic models and CFD modelling will be built to address the ash-related issues, which can guide further investigation. [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 most prohibitive aspect with the commercialisation of biomass gasification technology is tar fouling of the product gas. The presence of tar impacts the efficiency of gasification systems and compromises gas quality, rendering it less useful for some downstream applications sensitive to gas quality. Various tar detection methods are reported in the literature which can be differentiated into offline and online techniques. However, offline techniques are found to be time consuming, expansive and require sufficient instrumentation and knowledge to achieve reliable results. Recent advances in online tar detection based on spectral information of individual tar component have attracted much research attention. Among these, fluorescence spectroscopy is a highly promising technique for the provision of distinctive, non-invasive and real time data collection for tar levels which can be easily installed on gasification product gas streams. This paper presents the initial work on developing a low cost tar detection system based on LED induced fluorescence. The detection system mainly consists of a photomultiplier tube (PMT), LED (emission wavelength of 280 nm) and 300 nm longpass colour glass filter. Initial experiments have been carried out with different concentrations (0 to 100 wt%) of phenol (used as a model tar compound) and bio-oil samples from an in-house, downdraft (throated) fixed bed gasification system. The results show a linear increase of fluorescence with phenol and the gasifier bio-oil at different concentrations. [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]

This research paper describes results of experimental tests of Biomass gasification system. The biomass gasification system was developed as a part of the triple hybrid generation system, which consists of wind power 40 kW, solar panels 20 kW and biomass 20 kW in Ashikaga Institute of Technology (AIT). This research will enable rural areas to elaborate autonomous systems of electrification due to the availability of abundant biomass resources. The downdraft type gasifier, which is being used, was designed and assembled by AIT. One feature of this biomass gasification system is that the produced gas operates a rotary engine for power generation. In the experiment, temperatures are monitored both at the oxidation and reduction layers in the furnace. In addition, contents of produced gas such as Carbon monoxide (CO) and Hydrogen (H 2 ) gas are monitored. Experimental test was carried out in two different operational conditions. These conditions include closed top operation and open top operation. In closed-top operation, the top lid of the gasifier is closed during operation and opened except when feeding biomass resources. In open top operation, the top lid is opened throughout operation. Finally, it was observed that in closed top operation, the temperature gradient was more constant with greater output of CO and H 2 . In the open top operation, there was a drop in temperature with smaller output of CO and H 2 being produced compared to closed operation. [ABSTRACT FROM AUTHOR]

This paper focuses on the thermodynamic modelling and thermo-economic assessment of a novel arrangement of a combined cycle composed of an externally fired gas turbine (EFGT) and a bottoming organic Rankine cycle (ORC). The main novelty is that the heat of the exhaust gas exiting from the gas turbine is recovered in a thermal energy storage from which heat is extracted to feed a bottoming ORC. The thermal storage can receive heat also from parabolic-trough concentrators (PTCs) with molten salts as heat-transfer fluid (HTF). The presence of the thermal storage between topping and bottoming cycle facilitates a flexible operation of the system, and in particular allows to compensate solar energy input fluctuations, increase capacity factor, increase the dispatchability of the renewable energy generated and potentially operate in load following mode. A thermal energy storage (TES) with two molten salt tanks (one cold and one hot) is chosen since it is able to operate in the temperature range useful to recover heat from the exhaust gas of the EFGT and supply heat to the ORC. The heat of the gas turbine exhaust gas that cannot be recovered in the TES can be delivered to thermal users for cogeneration. The selected bottoming ORC is a superheated recuperative cycle suitable to recover heat in the temperature range of the TES with good cycle efficiency. On the basis of the results of the thermodynamic simulations, upfront and operational costs assessments and subsidized energy framework (feed-in tariffs for renewable electricity), the global energy conversion efficiency and investment profitability are estimated. [ABSTRACT FROM AUTHOR]

This paper focuses on the thermodynamic modelling and thermo-economic assessment of a novel arrangement of a combined cycle composed of an externally fired gas turbine (EFGT) and a bottoming organic Rankine cycle (ORC). The main novelty is that the heat of the exhaust gas exiting from the gas turbine is recovered in a thermal energy storage from which heat is extracted to feed a bottoming ORC. The thermal storage can receive heat also from parabolic-trough concentrators (PTCs) with molten salts as heat-transfer fluid (HTF). The presence of the thermal storage between topping and bottoming cycle facilitates a flexible operation of the system, and in particular allows to compensate solar energy input fluctuations, increase capacity factor, increase the dispatchability of the renewable energy generated and potentially operate in load following mode. A thermal energy storage (TES) with two molten salt tanks (one cold and one hot) is chosen since it is able to operate in the temperature range useful to recover heat from the exhaust gas of the EFGT and supply heat to the ORC. The heat of the gas turbine exhaust gas that cannot be recovered in the TES can be delivered to thermal users for cogeneration.The selected bottoming ORC is a superheated recuperative cycle suitable to recover heat in the temperature range of the TES with good cycle efficiency. On the basis of the results of the thermodynamic simulations, upfront and operational costs assessments and subsidized energy framework (feed-in tariffs for renewable electricity), the global energy conversion efficiency and investment profitability are estimated. [ABSTRACT FROM AUTHOR]

Due to the need for the optimization of industrial furnaces Computational Fluid Dynamics (CFD) is an important and indispensable tool for understanding for instance the mixing between flue gases, combustion air and the pollutant formation. This paper reports a computational fluid dynamics analysis of an industrial biomass boiler. The analysis was carried out using a CFD model for the combustion of the volatile gases released from the biomass combustion in the grate. The results obtained for the temperature, velocity and concentration of species fields within the boiler are now being used to enable the analysis and optimization of the combustion process. Moreover, the results show that inside the furnace the mixing of the gases with the combustion air could be improved, for instance through the optimization of the secondary air flow in relation to the operating conditions of the boiler, which would lead to the lower pollutant emissions. [ABSTRACT FROM AUTHOR]

In this paper we present our investigations on biomass used as renewable energy. The numerical study of biomass gasification and methanation in fluidized bed was carried out in the framework of the GAYA project supported by ADEME (French Agency For Environmental Protection and Energy). We have developed a sharp expertise in the modeling of the hydrodynamic of single or multiple phase fluidized beds. Indeed, specific sub-models have been developed to represent particles/particles and fluid/particles interactions. Our tools are now able to help improving an industrial scale gasifier and methanation reactor unit design by defining optimal operating conditions and instrumentations location. [ABSTRACT FROM AUTHOR]

To satisfy the market demand for fuel-flexible low-emission biomass combustion systems a new approach based on an updraft gasifier directly coupled with a multi-stage gas burner and a boiler has been developed. In the gasifier semi-volatile ash forming elements (i.e. mainly K) are released in the hot charcoal combustion zone and are precipitated again in the upper regions of the fuel bed. Therefore, an almost particle free product gas can be achieved which can then be efficiently combusted at low excess air ratios in the subsequent multi-stage burner. In this paper the principle of ash embedding in the gasifier is described with a special focus on the K chemistry. Combining this approach with appropriate fuel bed cooling measures, the new technology can be applied for a wide spectrum of biomass fuels reaching from conventional wood fuels over short rotation coppice to agricultural fuels/residues such as miscanthus and olive stones. Test runs performed at a lab-scale testing plant confirmed this high fuel flexibility and the possibility to operate this system at almost zero CO and OGC emissions as well as dust emissions of less than 5 mg/MJ NCV . [ABSTRACT FROM AUTHOR]

The scope of this paper is to make a feasibility analysis for energy production from sugarcane byproducts in Perú. Therefore, it is shown the history, methods, current scenario and future prospects of sugarcane plantations related to the ethanol industry and the sugar industry. There will be shown analysis of harvest residues (top and leaves). Bagasse is a mill residue, produced after sugarcane juice is extracted from the sugarcane. Nowadays this residue is burnt in boilers and this energy is used to generate steam. In the other hand, harvest residues represent a significant part of the energy contained in the sugarcane, but it is left in the field, or worse; burnt before the harvest. There will also be shown an estimated value of the electricity generation potential from sugarcane residues. [ABSTRACT FROM AUTHOR]

Microalgae cultivated in waste water could contribute to increased biomass production at municipal waste water treatment plants. The biomass could be utilized for biogas production when co-digested with sewage sludge. In this paper previous published results on co-digestion of sewage sludge and microalgae are summarized and remaining knowledge gaps are identified. The available batch tests in literature mostly concern digestion at mesophilic conditions. Some of those tests indicate a synergetic effect for the co-digestion. Investigations at thermophilic conditions and of semi-continuous processes are scarce. The available results show good possibilities for co-digestion of sewage sludge and microalgae. Further investigations are needed to find optimal conditions for biogas production. [ABSTRACT FROM AUTHOR]

This paper focuses on the thermo-economic analysis of a hybrid solar-biomass CHP combined cycle composed by a 1.3-MW externally fired gas-turbine (EFGT) and a bottoming organic Rankine cycle (ORC) plant. The primary thermal energy input is provided by a hybrid concentrating solar power (CSP) collector-array coupled to a biomass boiler. The CSP collector-array is based on parabolic-trough concentrators (PTCs) with molten salts as the heat transfer fluid (HTF) upstream of a fluidized-bed furnace for direct biomass combustion. Thermal-energy storage (TES) with two molten-salt tanks (one cold and one hot) is considered, as a means to reducing the variations in the plant's operating conditions and increasing the plant's capacity factor. On the basis of the results of the thermodynamic simulations, upfront and operational costs assessments, and considering an Italian energy policy scenario, the global energy conversion efficiency and investment profitability are estimated for 2 different sizes of CSP arrays and biomass furnaces. The results indicate the low economic profitability of CSP in comparison to only biomass CHP, because of the high investment costs, which are not compensated by higher electricity sales revenues. [ABSTRACT FROM AUTHOR]

The filtration of condensable tars is a necessary step before biomass syngas can be used in spark ignition engines. In small scale gasifiers, this step represents one third of the investment cost and create several issues of maintenance. Since tar related problems occur primarily due to tar condensation, an alternative system is being developed where a Homogeneous Charge Compression Ignition (HCCI) engine is operated at intake temperatures above the tar dew point, thereby eliminating the need for tar filtration. Based on a conservative estimate of tar dew points, HCCI combustion has been studied at an intake temperature of 250 °C. This paper presents a comprehensive study of the first HCCI engine operated with syngas. In particular, it addresses a control technique based on Exhaust Gas Recirculation (EGR). Simulated biomass syngas and simulated EGR were used on a 500cc mono-cylinder HCCI engine operated at 1000 RPM. The effects of charge dilution, thermal and kinetic damping as a consequence of EGR and the consequential combustion control have been discussed. In addition to being an effective control, the use of EGR decreases the Maximum Pressure Rise Rate and allows increasing the upper limit of the Indicated Mean Effective Pressure from 2.8 bar at EGR=0% to up to 3.5 bar at EGR=25%, a rise of about 25%. [ABSTRACT FROM AUTHOR]

The focus of this paper is on the energy performance and thermo-economic assessment of a small scale (100 kWe) combined cooling, heat and power (CCHP) plant serving a tertiary/residential energy demand fired by natural gas and solid biomass. The plant is based on a modified regenerative micro gas-turbine (MGT), where compressed air exiting the recuperator is externally heated by the hot gases produced in a biomass furnace. The flue gases after the recuperator flow through a heat recovery system (HRS), producing domestic hot water (DHW) at 90 °C, space heating (SH), and also chilled water (CW) by means of an absorption chiller (AC). Different biomass/natural gas ratios and an aggregate of residential end-users in cold, average and mild climate conditions are compared in the thermo-economic assessment, in order to assess the trade-offs between: (i) the lower energy conversion efficiency and higher investment cost when increasing the biomass input rate; (ii) the higher primary energy savings and revenues from feed-in tariffs available for biomass electricity exported into the grid; and (iii) the improved energy performance, sales revenue and higher investment and operational costs of trigeneration. The results allow for a comparison of the energy performance and investment profitability of the selected system configuration, as a function of the heating/cooling demand intensity, and report a global energy efficiency in the range of 25-45%, and IRR in the range of 15-20% assuming the Italian subsidy framework. [ABSTRACT FROM AUTHOR]

The work presented in this paper aimed to examine the effect of heating rate on the bio-crude yield of wood hydrothermal liquefaction. Three different heating methods were developed, resulting in heating rates ranging from 66 °C/min to 179 °C/min. The experiments were conducted using Norway spruce wood as feedstock at an operation temperature of 350 °C and with a total reaction time of 15 minutes. The bio-crude product was collected and separated using dichloromethane (DCM) as solvent and a centrifugal separator. The results confirm that heating rate has a clear positive effect on the bio-crude oil yield, increasing from 18.9 wt% for the lower heating rate of 66 °C/min to 35.8 wt% for the higher heating rate of 179 °C/min. It is also shown that the effect of feedstock pre-treatment via torrefaction on the bio-crude yield is negative. [ABSTRACT FROM AUTHOR]

This paper presents a non-stoichiometric equilibrium model for the simulation of biomass downdraft gasifiers. The chemical equilibrium is determined by minimizing the Gibbs free energy. Five elements characterize the biomass and 15 chemical species are considered in the syngas. The model calculates the lower heating value of the syngas and the relative abundances of gasification products. An advantage of this model is that it can easily calculate not only the concentrations of the main gasification products, but also the concentrations of minor product, especially the pollutant chemical species containing Nitrogen and Sulfur. To analyse the model behaviour, a sensitivity analysis on process parameters is presented. The model is validated by comparing its results with the results of simulation carried out with a stoichiometric model and with experimental data found in literature. Finally, the model is applied to the study of the gasification of forest waste. [ABSTRACT FROM AUTHOR]

Research on utilization of abundant rice residue for valuable bioenergy products is still not explored completely. A simple, robust, cheap and one step fast pyrolysis reactor is still a key demand for production of bioenergy products, i.e. high quality bio-oil and bio char. Bio-oil produced from fast pyrolysis has poor quality (e.g. acidic and highly oxygenated). Catalytic fast pyrolysis using zeolites in the fast pyrolysis process effectively reduce the oxygen content (no H 2 required). In this paper, zeolites having a variety of pore size and shape (small pore: SAPO-34 (0.56), Ferriertite (20), medium pore: ZSM-5 (23), MCM-22 (20), ITQ-2 (20) and large pore zeolite Mordenite (20) were tested in a drop type fixed-bed pyrolyzer. The catalytic deoxygenation is conducted at 450 °C at the catalyst/biomass ratio of 0.1. Zeolite catalysts, its pore size and shape could influence largely on deoxygenation. Small pore zeolites did not produce aromatics while medium pore zeolites formed higher amount of aromatics. ZSM-5 and ITQ-2 zeolites were especially efficient for the higher deoxygenation of biomass pyrolysis vapors due to better pore dimension and higher acidity. [ABSTRACT FROM AUTHOR]

Micropower optimization model is used in this study to design renewable energy-based micro grid system: solar-biomass hybrid system for the electrification of the city of Sharjah. The principal objective is to explore the available renewable resources in Sharjah and to determine the optimal configuration to meet the desired electric loads of the city. The hybrid system consists of electrical loads, solar resources, biomass resources, and system components such as solar photovoltaic, biogas generators, biomass power, battery and converters. Input information on the primary loads, solar and biomass resource availability, technology options, components cost, constraints, and controls are determined. Hourly simulations with sensitive analysis were performed to calculate the energy to and from each component to design the most favorable renewable energy-based system. The optimized results of the alternative renewable energy-based hybrid systems with different levels of contributions by renewable resources are presented in this paper taking into account the technology costs, energy resource availability and the efficiency of the renewable energy system. [ABSTRACT FROM AUTHOR]

The aim of the paper is to compare from an energetic, exergetic and economic viewpoint different plant configurations of Organic Rankine Cycles matched with biomass-fired boilers for electricity production or combined heat and power generation. To this purpose, a computer tool able to perform the fluid selection and plant layout optimization has been developed. The devices efficiency charts are used to predict the components performance while the fluid thermodynamic properties have been retrieved from two databases. Results show that Toluene guarantees the highest performance in both cases while the most suitable configuration is the recuperative one. [ABSTRACT FROM AUTHOR]

Small scale Combined Heat and Power (CHP) plants present lower electric efficiency in comparison to large scale ones, and this is particularly valid when biomass fuels are used. In most cases, the use of both heat and electricity to serve on site energy demand is a key to achieve acceptable global energy efficiency and investment profitability. However, the heat demand follows a typical daily and seasonal pattern and it is influenced by climatic conditions. During low heat demand periods, a lot of heat produced by the CHP plant is discharged. In order to increase the electric conversion efficiency of small scale biomass CHP plants, a bottoming ORC system can be coupled to the cycle, however this decreases the temperature and quantity of cogenerated heat available to the load. In this perspective, the paper proposes a thermo-economic analysis of small scale CHP plants based on steam turbine (ST) or externally fired micro gas turbine (EFGT) coupled to different typologies of bottoming Organic Rankine Cycles (ORC). The research assesses the influence of the thermal energy demand and CHP plant operational strategies on the global energy efficiency and profitability of the proposed cogeneration options, taking into account the part load efficiency and the heat to electricity ratio flexibility that could be achieved through a switch on-off of the bottoming ORC. The thermodynamic cycles and their part load efficiency are modeled by Gate-Cycle (Brayton cycles) and Cycle-Tempo (Rankine cycles). The research explores the profitability of bottoming ORC in view of the higher efficiency and electricity generation revenues but higher costs and reduced heat available for cogeneration in the case of bottoming ORC. The results indicate the optimal CHP technology and configuration for each energy demand segment and the relative key technical and economic factors in the Italian legislative framework. [ABSTRACT FROM AUTHOR]