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The biorefinery design has attracted interest from the industry and scientific community due to its main role in a future transition to a sustainable bioeconomy. This paper provides a critical review of the integration of biorefinery concepts in the pulp and paper industry, focusing on gasification-based biorefineries, including technological and commercial drivers and barriers, and biorefinery general opportunities and challenges. The pulp and paper industry is commonly recognized as highly suitable to integrate biorefinery concepts. For this purpose, various integrable biorefinery designs composed of distinct conversion processes are proposed in the literature. However, key technologies and biorefinery concepts must firstly be improved and proven at a market level to increase stakeholders confidence. Gasification can be a driving force for this integration and efficient replacement of natural gas by producer gas in burners is the first and most immediate step. Nonetheless, drawbacks associated with the contaminants present in the producer gas (e.g., tars) must be addressed. Research rarely focus on this first step and is more centered on sophisticated gasification applications (e.g., methanol synthesis), without considering associated technological and commercial barriers. Furthermore, supporting policies are generally required to make the integration of biomass gasification technologies in the pulp and paper industry profitable and to avoid the interruption of operation of fully functioning large-scale gasification plants. • Integration of biorefinery concepts in the pulp and paper industry is reviewed. • Gasification-based biorefineries opportunities and drawbacks are discussed. • Producer gas has large potential by representing a middle platform compound. • Efficient replacement of natural gas by producer gas is a driving force. • Government policies and improvement of key technologies are main factors. [ABSTRACT FROM AUTHOR]

In recent years, the utilization of biomass through advanced power technologies has intensified to achieve carbon neutrality. An oxy-fuel circulating fluidized bed combustor of biomass with higher efficiency supercritical carbon dioxide cycle has been developed with the aim of compensating the penalties for carbon capture and storage. The combustor fuelled with waste paper, waste wood, and cow manure, at an input of 200 ton/day is economically evaluated. Waste paper is on the verge of becoming an economically feasible fuel, more so than the other biomass examined. The use of waste paper led to a positive net present value, an internal rate of return of 3.8%, a benefit-cost ratio of 1.025, and a payback period of 17.7 years. Subsequent sensitivity analyses conducted for the waste paper fuelled power plant indicated that the capital cost is the most influential factor; the boiler, supercritical carbon dioxide cycle, and oxygen fuel combustion system were indicated in descending order of related subdivided sensitiveness. Both renewable energy certificate and carbon credit has contributed to the feasible economic of the system, with former one took precedence over later one. Sensitivity from the technical perspective, improvement in air separation unit is likely to greatly improve the economic feasibility of the proposed system. The power consumption of the air separation unit, as well as that of the carbon dioxide compression and purification unit, were highly sensitive to the implementation cost. [Display omitted] • Integration of oxygen combustion and supercritical carbon dioxide power cycle. • Economic feasibility study of integrated biomass circulating fluidized bed. • Capital cost demonstrated the foremost sensitivity factor. • Waste paper as potential economically feasible fuel. • Innovation in air separation unit improves economic feasibility. [ABSTRACT FROM AUTHOR]

The Tailor-made Fuels from Biomass (TMFB) project aims to develop renewable and environmentally friendly fuels suitable for internal combustion engines (ICEs). The TMFB fuels can be produced from lignocellulose, helping to avoid land competition with edible food for production. After years of research, 2-butanone, 2-methylfuran (2-MF), 2-methyltetrahydrofuran (2-MTHF), n-octanol, and di-n-butyl ether (DnBE), have been identified as the promising TMFB fuels that are suitable for ICEs. This paper first discusses the physicochemical properties of the above five fuels. It then reviews the experimentally measured fundamental combustion characteristics, including ignition delay and flame speed. In addition, progress in detailed chemical kinetic modeling of the TMFB fuels is also presented individually. These models are validated against measured experimental ignition delay or flame speed data. The reaction pathway analysis for the five fuels can be performed based on these validated kinetic models. Next, the effects of the above five TMFB fuels on the combustion and emission characteristics of ICEs are summarized. 2-Butanone and 2-MF can be used as gasoline replacement fuels for spark ignition engines. 2-MF and 2-MTHF can be used in compression ignition engines by blending with highly reactive fuels. N-octanol and DnBE are isomers and can be used either alone or as blended fuels for compression ignition engines. Both the advantages and disadvantages of the above-mentioned fuels used in ICEs have been discussed in this paper. Finally, the remaining research gaps in fundamental combustion characteristics and engine applications are discussed to guide future research directions. • A comprehensive summary of five TMFB fuels is given. • The physical and chemical properties of TMFB fuels are compared. • Experimental and kinetic modeling of the oxidation process are discussed in detail. • Their impacts on engine combustion and emissions formation are presented in detail. [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]

Low-carbon and environmentally friendly development are becoming increasingly important in the metallurgical industry. In this study, the use of biomass as a source of both material and energy in metallurgical technologies is reviewed. The paper discusses the preparation of bio-based raw materials, their utilization in metallurgical processes, phytoremediation and metal extraction technology, and forestry as a carbon dioxide sequestration method. Bio-based raw materials, such as bio-based fuels, reductants, adhesives, and activated carbons, are found to provide energy, act as reductants and binders, dispose metallurgical flue gas, and adjust metal melt composition, thereby reducing energy consumption in metallurgical processes. Additionally, heavy metals can be enriched in plants through biomass-mediated soil remediation, and these metals can then be processed to obtain raw materials for metallurgical processes. Moreover, metallurgical waste heat can be used to prepare biomass as soil amendments, remediate deserts, and indirectly reduce metallurgical industry carbon dioxide emissions through forest carbon sinks. Based on these findings, the concept of biomass metallurgy is proposed, which promotes the use of biomass as energy or raw materials, ecological restoration and reforestation, and reduction of carbon dioxide and pollutant emissions in metallurgical processes. This study emphasizes the advantages of biomass metallurgy and encourages the development of low-carbon and green metallurgical processes. [Display omitted] • Development of metallurgical technologies using bio-based material and energy. • Bio-based materials including fuels, reductants, adhesives, and activated carbon. • Biomass used in metallurgy for combustion, reductants, pellets making, etc. • Heavy metals in hyperaccumulators extracted and recovered by biochemical methods. • Indirectly reducing CO 2 by transforming metallurgical waste heat into carbon sinks. [ABSTRACT FROM AUTHOR]

Graphical abstract fx1 Abstract Biomass raw materials are widely regarded as a significant source of renewable energy, which significantly reduces the dependence on traditional fossil fuels, especially in the case of countries that are able to obtain biomass from various sources. Recently, pelletization has been widely used for mass and energy densification of biomass to overcome the problems associated with raw material use. As the global pellet market has developed quickly, the use of wood residues became no longer sufficient to fulfill the market needs. The standards of pellets provide limits for both physical and mechanical characteristics of produced pellets. Characteristics of produced pellets depend mainly on the feedstock characteristics as particle size and moisture content and operating conditions as applied pressure and die temperature. Thus, this paper provides rich information on the factors affecting the physical and mechanical properties of granules included in pellets. The main goal of the paper is to review the latest and comprehensive research on the physical and mechanical properties of most types of single and mixed pellets from biomass. The analysis of the effect of properties, adhesives, humidity, pressure and temperature as well as the physical and mechanical properties of the pellets studied was carried out. In addition, the critical and optimal values of various factors for different materials in which the following is of importance: high quality of pellets and biomass from which they are produced were analyzed. The principle and effect of applying post-production conditions as steam explosion and torrefaction on the characteristics of the pellets were reviewed in details. Moreover, this study proposes some recommendations for further development of the pelletization analysis and characteristics. Highlights • Comprehensive research on the characteristics of biomass pellets was studied. • The effect of operating parameters on the characteristics of pellets was analyzed. • New types of binder materials and their impact on the pellets have been introduced. • Future prospects for of the pelletization analysis have been suggested. [ABSTRACT FROM AUTHOR]

Abstract Growing concerns over the environmental impact of greenhouse gas (GHG) emissions, uncertainty of future fossil fuel prices, geopolitical instability, and consumer preferences are a few factors driving the development and use of biomass as a source of renewable energy. Government mandates and policy frameworks have further built consensus for effective utilization of sustainable resources for energy. As a result, biomass derived densified solid biofuels have experienced a phenomenal growth in the last decade and are expected to grow by 56% during the three decades from 2010 to 2040. Solid biomass represents the largest share of biomass used for heat and electricity generation. Biomass sources range from agricultural, municipal, and commercial wastes, to forest-litter, and energy crops. Because of the varied nature of these sources, harvesting practices and the cost of transportation, several methods have been developed to densify the biomass. The long-term viability and growth of biobased energy products hinges on the technical innovation and wider societal acceptance of these products. This paper reviews multiple biomass feedstock, processing characteristics, product properties, transportation, and storage options. The paper also discusses the economics of densifying biomass, the impacts to regions where biomass utilization is implemented, outstanding challenges, and national and global trends in biomass utilization. Highlights • Biomass feedstocks are major source for densified solid biofuels. • Environmental concerns, GHG gases emission and government mandates driving biomass utilization. • Woody and non-woody biomass represent largest share of biomass for heat and electricity generation. • Biomass feedstock type, preprocessing, densification, and transportation are critical factors for adoption of biomass for energy applications. • Technical innovation and wider societal acceptance important for growth of solid biofuels. [ABSTRACT FROM AUTHOR]

The Chinese government has made significant effort to promote biomass based electricity generation in recent years. Yet, little is known about consumers’ preferences for biomass electricity and associated environmental impacts. This paper uses discrete choice experiments (DCE) to investigate Chinese consumers’ preference for electricity generated from various biomass sources. Based on 548 responses, the paper finds that Chinese households are willing to pay a premium of around 27 Yuan per month or 0.20 Yuan per kilowatt hour (kWh) to replace coal-fired electricity. Among the various biomass sources, electricity generated from agricultural and forestry biomass is most preferred, followed by biogas electricity and waste-to-energy. It is also found that respondents have a significant willingness to pay for reducing haze. Consumers’ household structure and environmental awareness also affect their preference for biomass electricity. These results have significant implications for the prioritization, design and communication of biomass promoting schemes. [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]

Hydrogen is an important raw material for chemical industry and feasible renewable energy carrier that could replace fossil fuels. However, the specie seldom exists in a form of pure H 2 . Therefore, to obtain hydrogen in volumes suitable to be used as a raw material it is necesary to decompose hydrogen-rich compounds. The carbohydrate-rich biomass can be an important source of hydrogen by applying the process of dark fermentation. In this paper potential ways of hydrogen production from organic wastes (biomass) by means of dark fermentation are reviewed and discussed. The bacteria used for dark fermentation are enlisted, characterized and compared. The pretreatment processes and various reactor designs are analyzed and discussed. The hydrogen separation by membrane method (which can provide the most pure hydrogen) are presented. The paper describes recent achievements in optimizing parameters, conditions and reactors used to industrialize dark fermentation. [ABSTRACT FROM AUTHOR]

Activated carbon is a porous material that has been in many important ages of the human history. Lignocellulosic precursors and biomass sources have become important materials to produce it because their use produces many benefits, mainly environmental. Nowadays, it is possible to find numerous research papers devoted to the synthesis characterization and applications of novel precursors to produce activated carbon. Hence, special attention must be given to the relationship among the selected precursor characteristics, the final microstructure and properties of carbon. The present work provides a summary of research works outlining the use of lignocellulosic–based precursors to obtain activated carbons. A brief description of the characterization techniques for both, the precursors and activated carbons, comprising: physicochemical, micro/nanostructural, surface chemistry, textural and adsorption capacity features is presented. Finally, the application of these materials in adsorption of heavy metals, dyes, volatile organic compounds, gas storage and electrochemical capacitors is also included. [ABSTRACT FROM AUTHOR]

As a result of the growing global demand for energy, together with the depletion of resources and the growing emphasis on mitigating climate change and greenhouse gas emissions, an urgent need for an evolution of the renewable energy resources has emerged. On the architectural scene, we have become accustomed to seeing buildings incorporated with photovoltaics and wind turbines. Despite the great contribution of biomass as a clean energy producer, the integration of biomass into architecture is quite modest and still in its initial phases. Microalgae, as a plant-based biomass, can outperform other renewable resources with their potential to absorb CO 2 , recycle wastewater, and release O 2 . The limited experience regarding building-integrated microalgae photobioreactors (PBRs) requires shedding light on some issues. So, this paper aims to explore the following: 1) the proper types of PBRs for integration with buildings, 2) the overall bioprocess and the design considerations regarding PBRs and their technical requirements, 3) the environmental and energetic performance of PBRs, 4) their challenges, and 5) their prospects. Thus, the paper's methodology consists of 1) reviewing the promulgated literature concerning microalgae and PBRs, 2) reviewing and analyzing three building-integrated PBRs and three urban-integrated PBRs, and 3) reviewing the environmental and energetic performance of building-integrated PBRs. The paper has concluded that the symbiosis between PBRs and façades encounters some challenges, including 1) the biorefinery infrastructure, 2) the provision of a source of CO 2 , and 3) the high initial cost. On the other hand, the multifaceted environmental prospects of building-integrated PBRs are represented in 1) energy savings; 2) GHG emissions reduction; 3) oxygen and hydrogen release; 4) biofuel production; and 5) wastewater treatment. The unique benefits of the bio-façades through the combination of the technical and biological cycles within buildings inaugurate an innovative approach to sustainability by integrating environmental, energetic, and iconic values. [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]

India as a developing economic power, has to rely much on its energy sector for growth and development. The growth is largely interlinked with the availability of energy and its judicious utilization. Also involved is the question whether the available energy is environmentally acceptable and technically viable. With the growth of country's economy, per capita power consumption has also increased resulting greater demands for power. India's power sector is mainly dependent on conventional or fossil fuels i.e., coal (60.1%) and gas (8.7%) (2015). India has around 10% of the world's coal reserves that will last for about another 30–40 years at the present consumption rate. The use of conventional fossil fuels has a negative impact on the environment due to the emission of harmful greenhouse gases. On the other hand, according to the Ministry of New and Renewable Energy (MNRE), Government of India, the country has untapped source of renewable energies such as, wind, solar power, nuclear energy and biomass. Globally, depletion of conventional fuel resources, is increasingly turning the focus on non-conventional sources of energy. The present paper is a review of biomass energy, its sources and its energy efficiency. Even though sources of biomass fuels are widely available all across India, these are still largely underutilized. According to the available statistics, in India the share of renewable energy has increased from 7.8% to 12.3% during 2012-13 and to 12.95% as on 31st March 2014, this paper also highlights the challenges and advantages of biomass energy over conventional fuels as well as utilization and applicability of biomass in sintering process as a replacement for coke. [ABSTRACT FROM AUTHOR]

With the rising population in India the demand for energy is also shooting up. This paper examines the potential, scope and the opportunities of biomass in the Indian economy. India, being an agricultural country, has a lot of possible resources from the agronomic sector like crop residue, animal manure, etc., which has not been utilised in an efficient way. This paper also gives an insight into anaerobic digestion and the many other digesters implemented in India. The accelerating economic growth leads to the rapid rise in urbanisation which in turn generates an increased production of Municipal Solid Waste (MSW). This MSW can be used in biomass production in quite a lot of innovative ways. The study also focused on the potential sources and their proper conversion technique. The feasibility of biomass conversion and achievements made by India was also looked into. Use of bioenergy in cheaper and economically feasible ways is also a practical solution to the energy crisis. [ABSTRACT FROM AUTHOR]

Due to their potential role in addressing the challenges of energy and environment, biofuels have been receiving significant attention from scientists in various disciplines and countries. Over the past few decades, the biofuel science has undergone major changes with regard to its rate of development, focus, and the contributing countries. We put the evolution the biofuel science into context by analyzing 49,000 relevant papers (comprising 0.26% of all publications across physical and life sciences) published between 1990 and 2014. We first determine the scientific contributions of different countries to the science on biofuels, and then analyze how the R&D expenditure and biomass availability is associated with their outputs. Subsequently, the structure of biofuel science in terms of the links between biomass feedstocks and final products are quantitatively discussed. We find that 28%, 16%, and 15% of all papers considered are published by researchers from the EU, China, and USA, respectively. Denmark, Sweden, and Finland have the highest number of biofuel-related publications per capita (i.e. 133, 113, and 103 papers per million capita and annum, respectively). The percentage share of studies on edible, lignocellulosic, and algal biomass are 46%, 40%, and 14%, respectively. Fermentation, hydrolysis, and esterification are the most widely studied conversion pathways, while liquefaction and life cycle assessment are the most cited subfields. Finally, using United States’ statistics, it is shown that upon accounting for the time delay between the nominal budget release year and the calendar year in which corresponding papers would ultimately appear in print, the publication trend was closely correlated to the R&D expenditure (r=0.98). [ABSTRACT FROM AUTHOR]

Lignin is a complex phenylpropanoid biopolymer conferring mechanical strength to plant cell walls. Biorefineries, along with pulp and paper industry, generate large quantities of lignin. Lignin valorization is an essential process for an advanced, sustainable, and economical biomass-based industry. However, converting lignin into value-added products remains a challenge due to its heterogeneity and irregular structure. Many wild microorganisms have evolved complex metabolic and enzyme systems for lignin degradation and conversion. Great efforts have been made to explore their potentials for lignin valorization. This paper reviews the recent development in biological conversion of lignin into value-added products. It also covers potential catabolic pathways, exploration of new lignin degradation systems, and lignin consolidated bioprocessing (Lignin CBP). [ABSTRACT FROM AUTHOR]

Canada is endowed with abundant lignocellulosic biomass from agriculture and forestry. These sources provide a foundation for the development of Canada's cellulosic ethanol biorefinery concept which is supported by government renewable energy policy initiatives. However, the chemical structure of lignocellulosic biomass comprising carbohydrate polymers and lignin makes the structure recalcitrant to deconstruction, thereby constraining the ability of enzymes to convert these polymers into fermentable sugars without expensive and highly capital intensive pretreatment processes. The challenges are further compounded by the diversity of lignocellulosic biomass available in Canada, which typically necessitates commercial pretreatment pathways optimized for each feedstock type. In turn, these conditions constrain the development of viable business models for the commercialization of Canada's cellulosic ethanol biorefinery concept. In order to address these challenges, Canadian researchers have continued to undertake research to develop pretreatment technologies applicable to several Canadian lignocellulosic biomass sources. The objective of this paper is to review contributions by Canadian researchers vis-à-vis the development of bioconversion pretreatment technologies needed to advance the commercialization of Canada's cellulosic biorefinery concept. These pretreatment technologies include physical, physico-chemical, biological, and processes that combine these methods. This paper also highlights the role of multi- institutional science and innovation collaborative approaches for advancing Canada's cellulosic ethanol biorefinery concept further downstream. [ABSTRACT FROM AUTHOR]

The quality and composition of biomass as used in Portugal's thermal power plants is highly variable. The biomass consists mainly of residual forest biomass derived from forestry operations and wood waste from industrial processes, in particular paper and pulp industry. Its quality and composition is influenced by the presence of moisture and inert fragments, the latter being incorporated during collection or as a consequence of adherence to the biomass prior to collection. This variability presents difficulties for the thermal power plants; besides being an additional operational cost, the presence of large amounts of water and inerts in biomass used as a fuel, can result in problems related to the instability of the combustion and the accumulation of ash or rock that have to be removed and discarded. The objective of this paper is to review the main parameters that influence the quality of biomass, while analysing the current state-of-the-art power generation from the biomass sector in Portugal, as a new contribution to earlier studies. [ABSTRACT FROM AUTHOR]

This paper provides a critical review on the current status and potential of biomass utilization in ferrous metallurgical processes, i.e., the blast furnace (BF) – basic oxygen furnace (BOF) route, the direct reduction (DR) – electric arc furnace (EAF) route, the scrap – EAF route and the other routes. In the BF-BOF route, biomass can be used as a fuel for iron ore sintering, or as a raw material for the production of bio-coke, and utilized for blast furnace injection. In the DR-EAF route, direct reduction iron can be produced form iron ore and biomass pellet. In the scrap – EAF route, biomass can be utilized in EAF through a cogeneration system. In addition, biomass can be utilized in magnetic separation of refractory low-grade iron ore, in reuse of iron and steel slag, or as an adsorbent for pollutant control, etc. The challenges and outlook of biomass utilization in metallurgical industry are also discussed in this paper. [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]

Synthesis gas, also known as syngas, produced from biomass materials has been identified as a potential source of renewable energy. Syngas is mainly consists of CO and H 2 , which can be used directly as fuel source for power generation and transport fuel, as well as feedstock for chemical production. Syngas is produced through biomass gasification process that converts solids to gas phase via thermochemical conversion reactions. This paper critically reviews the type of gasifiers that have been used for biomass gasification, including fixed bed, fluidized bed, entrained flow and transport reactor types. The advantages and limitations of these gasifiers are compared, followed by discussion on the key parameters that are critical for the optimum production of syngas. Depending on the biomass feedstock, the properties and characteristics of syngas produced can be varied. It is thus essential to thoroughly characterise the properties of biomass to understand the limitations in order to identify the suitable methods for gasification. This paper later focuses on a specific biomass – oil palm-based for syngas production in the context of Malaysia, where palm biomass is readily available in abundance. The properties and suitability for gasification of the major palm biomass, including empty fruit bunch, oil palm fronds and palm kernel shells are reviewed. Optimization of the gasification process can significantly improve the prospect of commercial syngas production. [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]

Due to the scarcity of fossil fuels and to population increases, there is an urgent need for renewable energy sources that can replace petroleum-derived fuels. Lignocellulosic biomass, a renewable resource, can be converted to bio-oil by fast pyrolysis and further upgraded to renewable diesel through hydroprocessing. The upgrading of oil by fast pyrolysis is the main focus of this paper. Bio-oil has a higher energy density and heating value than biomass, but it cannot be used in place of petro-diesel as it is highly unstable, polar, and immiscible with hydrocarbons. Thus upgrading is necessary as it removes oxygen-containing compounds from bio-oil. Hydroprocessing was chosen for this review paper as the method of upgrading bio-oil because there are hydrotreating units in place in refineries. To upgrade bio-oil, hydrodeoxygenation (HDO) in the presence of both a catalyst and hydrogen can replace hydrodesulfurization (the removal of sulfur compounds from crude oil). A sulfided NiMo/CoMo catalyst supported on gamma alumina is used as a benchmark catalyst for a hydrodesulfurization reaction in refineries and is considered the reference catalyst for HDO in the production of renewable diesel. The properties of renewable diesel made through hydroprocessing are similar to those of petro-diesel. Catalyst deactivation and techno-economic assessments of the whole pathway are areas that need more attention before renewable diesel can be commercialized. This review paper concentrates on the reaction mechanism in bio-oil upgrading, process parameters, and the limitations of hydroprocessing technology. This paper will be helpful for further modeling of techno-economic analysis in renewable diesel production from lignocellulosic biomass. [ABSTRACT FROM AUTHOR]

With respect to the application of upgraded oils derived from biomass materials, the goal is to produce either high yields of transportation fuel compounds ( e.g. aromatics, olefins) and specialty chemicals ( e.g. phenolics), or just a drop-in refinery feedstock to be blended with the feed streams of existing petroleum refineries. It has already been recognized in the early days of fast pyrolysis R&D that the application of catalysis could be of major importance in controlling the quality and chemical composition of bio-oil. For this purpose catalytic fast pyrolysis (CFP) of biomass, which is a single step process based on the use of heterogeneous catalysts in the fast pyrolysis process, can be put in service. While the literature on CFP of biomass – mainly focused on catalyst screening – is rapidly expanding, there is an urgent need for the translation of laboratory results to viable process concepts and pilot plant trials by addressing key issues like the most suitable processing mode, reactor technology, and the way of heat integration of the process. The present paper discusses the CFP of lignocellulosic biomass in a process oriented way that may initiate a useful process technology development in near future. The final goal is to come up with recommendations and suggestions on how to realize this technique at a commercial/industrial scale. That requires a better understanding of the precise effects of the essential process parameters ( e.g. processing mode; in - or ex situ ) and design elements ( e.g. reactor type, catalyst type) on one hand, and definitions and outcomes of possible obstacles ( e.g. successive regeneration of the catalyst, effect of biomass ash) on the other. In this paper, the efficient and economical use of the primary and secondary products, and the heat integration of the process is discussed. Moreover, some process alternatives for an efficient CFP operation are suggested. [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]

The term “polygeneration” is referred to as “an energy supply system, which delivers more than one form of energy to the final user”, for example: electricity, heating/cooling, desalination can be delivered from polygeneration process. The polygeneration demonstrates unique integration of energy efficiency and renewable energy. It is the next generation energy production technique with a potential to overcome intermittence of renewable energy, reduce cost of power generation and greenhouse gas emissions. The feasibility study of this paper is divided in three sections: In first section of this study, solar and biomass have been arranged to produce steam for power generation. In the second section, cooling is produced by vapor absorption refrigeration (VAR; LiBr-H 2 O) system as per demand load requirement using steam, extracted from pass-out turbine. In the last section of this paper, multi effect dehumidification (MED) water desalination is produced by using limited amount of heat from water vapor (refrigerant; H 2 O) through HE1 of VAR cooling system. [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]

Biomass fuels have long been accepted as useful renewable energy sources, especially in mitigating greenhouse gases (GHG), nitrogen oxides, and sulfur oxide emissions. Biomass fuel is carbon neutral and is usually low in both nitrogen and sulfur. For the past decade, various forms of biomass fuels have been co-combusted in existing coal-fired boilers and gas-fired power plants. Biomass is used as a supplemental fuel to substitute for up to 10% of the base fuel in most full commercial operations. There are several successful co-firing projects in many parts of the world, particularly in Europe and North America. However, despite remarkable commercial success in Europe, most of the biomass co-firing in North America is limited to demonstration levels. This review takes a detailed look at several aspects of biomass co-firing with a direct focus on North America. It also explores the benefits, such as the reduction of GHG emissions and its implications. This paper shows the results of our studies of the biomass resources available in North America that can be used in coal-fired boilers, their availability and transportation to the power plant, available co-firing levels and technologies, and various technological and environmental issues associated with biomass co-firing. Finally, the paper proffers solutions to help utility companies explore biomass co-firing as a transitional option towards a completely carbon-free power sector in North America. [ABSTRACT FROM AUTHOR]

Briquettes made from biomass residues could contribute to ensuring the sustainable supply of biomass energy. The paper reviews the present briquette making process in Kenya especially in Nairobi and peri-urban areas. The paper introduces the energy situation in Kenya, then the briquette making process and finally presents the challenges and opportunities in briquette making. In the opportunities section, eighteen briquette producers participated in the question and answer exercise to quantitatively provide information on briquette making. Most producers use bare hands (handmade briquettes), others make use of novel-based machines such as ram-piston type, motorized screw press, shredder, wooden press and the mold-box piston type all made from locally available materials. The mixing ratios and the various ingredients used in briquette making are haphazard with no standard ratio and specific mixture for optimum briquette production. Despite these, most briquette producers are well along in the briquette business. At the same time, the end-use consumers are very positive in using the briquette fuel as an alternative fuel. Some of the end-use consumers are the schools, churches, hotels and some households. This study indicates that the opportunities for briquette making are immense and could help curb deforestation thereby reduce environmental degradation. [ABSTRACT FROM AUTHOR]

The main objective of this review paper is analyzes perspectives of manufacturing bioethanol via biotechnology, using sustainable management. Two categories are emphasized: (i) agro-industrial valuation, which represents alternative methods for bioethanol production, and (ii) Agro-industrial Techniques and Infrastructure Analysis. Future of biofuels is addressed in terms of applicability and production methods. Authors perform a systematic literature review to characterize the present state of knowledge on ethanol production. The study is conducted from a decision-making standpoint, so that they identify several problems (subcategories) in bioethanol production. The section on technology and industrial infrastructure focuses on advances in biorefineries, revealing technical and economic limitations, and also the gap between sustainable production policies and environmental impact. The second part of the paper presents the evolution of the industrial sector toward technological innovation and adoption of complex bio-production methods for clean energy production. This review mostly covers results reported over the past decade, with a special emphasis on papers published recently, from 2010 to 2021, therefore, it can serve for extended future research that would address additional specific categories. One concludes that the industrial sector must promote bioethanol production efficiently and sustainably, harmonized with the society and the environment. Sustainable production points to alternative energy sources based on cellulosic materials and third generation materials derived from algal biomass. • Chemical processes in the agro-industrial production sector include clean technologies. • Critical gaps for biofuel production contain factors that must be related to industrial processes and uncertain economic cost. • Technological integration of 1G and 2G bioethanol production can reduce operating costs and investment risks. • Biorefinery models use various biomass feedstocks, and they integrate 1st/2nd generation technological processes. [ABSTRACT FROM AUTHOR]

Abstract: Biomass supply chain optimisation is essential to overcome barriers and uncertainties that may inhibit the development of a sustainable and competitive bioenergy market. The number of research papers presenting optimisation models in the field of bioenergy systems rises exponentially. This paper gives an overview of the optimisation methods and models focussing on decisions regarding the design and management of the upstream segment of the biomass-for-bioenergy supply chain. After a general description of the supply chain and the decisions coming along with the design and management, all selected publications are classified and discussed according to (1) the mathematical optimisation methodology used, (2) the decision level and decision variables addressed and (3) the objective to be optimised. This classification allows users to identify existing optimisation methods or models that satisfy specific requirements. Moreover, the factual description of the presented optimisation methods and models points to opportunities for development of an integrated, holistic approach to optimise decisions in the field of biomass supply chain design and management. Such approach must be based on the consideration of the interrelationships and interdependence between all operations in the entire biomass-for-bioenergy supply chain. [Copyright &y& Elsevier]

Abstract: Steel is one of the most important materials used in modern society. The majority of the steel produced today is based on the use of virgin raw materials such as iron ore and fossil-based energy sources such as coal and oil. Recently, emphasis has been laid on the possibility to replace part of the fossil-based energy sources in ironmaking with renewable, biomass-derived reducing agents (bio-reducers). Modern thermochemical conversion processes could be utilized to produce solid, liquid and gaseous bio-reducers from biomass feedstock. This paper provides an in-depth review, first of its kind, of the possibility to replace part of the fossil-based reducing agents with bio-reducers in the blast furnace ironmaking route. In the first part of the paper, blast furnace process and the role of the reducing agents are discussed. In the second part of the paper, thermochemical biomass conversion technologies and resulting product properties are reviewed. Chemical and physical properties of the bio-reducers are compared to fossil-based reducing agents. In the third part of the paper, the implications related to bio-reducer use are evaluated in separate system levels including unit process assessment (blast furnace), process integration opportunities, biomass availability, life cycle impact and economic evaluations. The fourth part of the paper is dedicated to the discussion of the future of bio-reducers in ironmaking applications. It is concluded that bio-reducers can contribute to more environmentally sound steelmaking. The most promising bio-reducer seems to be charcoal with its high coke replacement ratio in blast furnace and straightforward integration of slow pyrolysis by-products to heat and power applications. [Copyright &y& Elsevier]

Abstract: Biofuels are identified as the potential solution for depleting fossil fuel reserves, increasing oil prices, and providing a clean, renewable energy source. The major barrier preventing the commercialization of lignocellulosic biorefineries is the complex conversion process and their respective supply chain. Efficient supply chain management of a lignocellulosic biomass is crucial for success of second generation biofuels. This paper systematically describes energy needs, energy targets, biofuel feedstocks, conversion processes, and finally provides a comprehensive review of Biomass Supply Chain (BSC) design and modeling. Specifically, the paper presents a detailed review of mathematical programming models developed for BSC and identifies key challenges and potential future work. This review will provide readers with a starting point for understanding biomass feedstocks and biofuel production as well as detailed analysis of the BSC modeling and design. [Copyright &y& Elsevier]

Abstract: The quality of life and safeness of the present and future generations are strongly intertwined with the availability of energy sources and the sustainability of the energy infrastructure. Energy consumption in developed countries grows at a rate of approximately 1% per year, and that of developing countries, 5% per year (Muneer et al., 2005 ). Present reserves of oil and natural gas can only cover consumption at this rate for the next 50 years in the case of oil, and for the next 70 years in the case of natural gas. Therefore, one of the fundamental priorities for a country such as Algeria is to use several renewable energies (RE) sources and environmentally friendly energy conversion technologies. Algeria is endowed with large reserves of energy sources, mainly hydrocarbons and a considerable potential for the utilisation of RE sources especially with respect to solar energy. Algeria has the potential to be one of the major contributors in solar energy and become a role model to other countries in the world. RE are now one of the major elements of Algeria''s energy policy and in view of boosting the national effort in terms of RE beyond 2011, Algeria has developed a national programme for the period 2011–2030 to promote concrete actions in the fields of energy efficiency and RE in line with the approach adopted by the government on February 3, 2011. Besides, it confirms Algerian''s ambition to become an international hub for industrial and energy production and exportation in the solar sector. With this in mind, along with the environmental responsibility issues, public awareness gradually increased over the last seven years and alternative energy resources have become a new area of interest. As a tangible target, the Ministry of Energy and Mines (MEM) strategic plan aims to reach a 40% share of RE (mainly solar) in electric energy production by 2030. The various future projects are all factors that will undoubtedly give Algeria an important role in the implementation of RE technology in North Africa, the capacity for providing sustainable supply of cost-effective electricity from RE sources for the needs of the population, and the possibility of even exporting 10,000MW to neighbouring and European market. This paper provides a detailed analysis of the existing renewable energy sector and a forecast for demand growth, additional capacity, investment requirements and Algeria''s ambitious objectives of use of RE and environment protection. The paper also discusses the current energy scenario and explores the alternative energy like solar and wind to ensure energy security supply, reliability, greater efficiency in energy conversion, transmission and utilisation. Particular attention is paid to Algeria''s global and sustainable solutions of the environmental challenges and the problems of conservation of fossil energy resources under the clean development mechanism (CDM) structure. The report also provides a detailed analysis of the existing renewable energy sector and a forecast for demand growth, additional capacity, and investment requirements [Copyright &y& Elsevier]

Abstract: Volatile oil price and growing emphasis on environmental conservation have stimulated the development and utilisation of biomass as a vital source of renewable energy. In reducing the global dependency on fossil fuels, rice husk and rice straw which are the widely abundant agricultural wastes from the rice industry have a vital role to play. This paper reviews the key aspects of the utilisation of rice husk and rice straw as important sources of renewable energy. The paper provides some essential background information that includes the physical and chemical characteristics that dictates the quality of these rice biomasses. This paper also describes the various chemical and physical pretreatment techniques that can facilitate handling and transportation of rice straw and husk. Finally, the paper presents the state-of-the-art on thermo-chemical and bio-chemical technologies to convert rice husk and rice straw into energy. [Copyright &y& Elsevier]

Abstract: It has become imperative for the power and energy engineers to look out for the renewable energy sources such as sun, wind, geothermal, ocean and biomass as sustainable, cost-effective and environment friendly alternatives for conventional energy sources. However, the non-availability of these renewable energy resources all the time throughout the year has led to research in the area of hybrid renewable energy systems. In the past few years, a lot of research has taken place in the design, optimization, operation and control of the renewable hybrid energy systems. It is indeed evident that this area is still emerging and vast in scope. The main aim of this paper is to review the research on the unit sizing, optimization, energy management and modeling of the hybrid renewable energy system components. Developments in research on modeling of hybrid energy resources (PV systems), backup energy systems (Fuel Cell, Battery, Ultra-capacitor, Diesel Generator), power conditioning units (MPPT converters, Buck/Boost converters, Battery chargers) and techniques for energy flow management have been discussed in detail. In this paper, an attempt has been made to present a comprehensive review of the research in this area in the past one decade. [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]

Biomass energy has extensive application foreground in power generation because of its economic and social benefits. Aiming at selecting the best biomass fuel procurement and storage modes in Jilin province, this paper proposes an evaluation model with linguistic hesitant fuzzy sets (LHFSs), which is good at expressing the hesitancy, inconsistency and uncertainty of subjective evaluation information. Based on cloud model and three entropy principle, the transformation between linguistic hesitant fuzzy sets and comprehensive cloud model is realized. In order to eliminate interdependency among criterion, a new Choquet integral aggregation operator based on the Sigmoid function is proposed. According to the expectation values, the ranking result of aggregated LHFSs is obtained. At last, an illustrative example of modes evaluation in Jilin province is taken in the present study to make the proposed method comprehensible. The result shows that mode 3: farmer + middleman + third-party logistics + power plant, is the most reasonable mode for Jilin biomass energy development. From the perspective of supply chain, middlemen and third party logistics can reduce the procurement and transportation cost in the supply chain, which are two bigger influential factors of fuel cost. Middlemen are not only a bridge between plants and farmers, but also the operator in the supply chain. Through the analysis of the result, suggestions from the perspective of power plants and the government are given. • Linguistic hesitant fuzzy sets are used for evaluating biomass power generation fuel procurement and storage modes. • A multi-criteria decision-making method based on cloud model and Choquet integral is proposed. • A new linguistic hesitant fuzzy aggregation operator based on Choquet integral and the Sigmoid function is presented. • "farmer, middleman, third-party logistics and power plant" is the best mode for Jilin biomass power development. [ABSTRACT FROM AUTHOR]

Nowadays, gasification is seen as a worldwide settled technique for sustainably generating energy from residues. Its final product is a synthetic gas which may be used for several purposes such as fueling engines, industry and the transport sector. This technique involves several complex reactions, different thermodynamic regimes and environments, and may be held under a myriad of operational conditions. Thus, simulation tools have become very useful to predict the optimal parameters to be applied and the heating content of the final product, therefore producing the most suitable syngas for the desired utilizations. Computational fluid dynamics (CFD) reduces the time needed to design and implement each gasification experiment, using mathematical approaches and developing specific codes regarding the type of feedstock, reactor utilized and expected atmosphere. This paper reviewed the major works on numerical methods for gasification and co-gasification of feedstocks, such as biomass, waste and fossil fuels, published in the last two decades. A thorough explanation of the solid and gaseous phases, their interconnections and behavior was presented, while relating the characteristics of the main methods to the final product obtained. Major trends were identified as well as some suggestions regarding future perspectives were done. Kinetic, thermodynamic and computational fluid dynamic models were seen to be preferred concerning the study of syngas production from distinct types of feedstocks. Also, biomass and coal were the most frequently used feedstocks, with 37% and 24% of the total share, respectively. Relative to the gasifier type, fluidized beds were used in almost 50% of the assessments, followed by entrained beds, mostly used for coal gasification. Only major trends could be identified for some of the experimental conditions applied, due to the high variances seen for different feedstocks or reactor features. This review supports the need to continue developing new models and adapting the existing ones in order to reach broader conclusions, since distinct parameters afford completely different outcomes. • Main works on numerical gasification of different feedstocks were reviewed. • Distinct type of numerical models was explained, examples for each being reported. • The relevant software and environments for developing numerical models were stated. • Key trends on gasification were highlighted, based on the reviewed parameters. • A roadmap was settled, stating the challenges and opportunities of the technique. [ABSTRACT FROM AUTHOR]

Abstract Dual fluidized bed steam gasification is a well-known technology for the thermochemical conversion of biogenic fuels into a valuable product gas comprising hydrogen, carbon monoxide, carbon dioxide, and methane. Based on the dual fluidized bed gasification principle, further benefits can be obtained by considering the bed material: Limestone allows the removal of carbon dioxide from the gasification reactor and its release in the combustion reactor. Therefore, the gasification and combustion reactors must be operated at 650 °C and 830 °C, respectively. Moreover, this sorption enhanced reforming process affords hydrogen contents of ~70 vol.-% db and allows an adjustment of the hydrogen-to-carbon monoxide ratio in the range of 2–10. The circulating bed material undergoes carbonation and calcination cycles, that lead to a decrease in the carbon dioxide sorption capacity with time. This paper discusses the main reasons for this decrease as well as the positive or negative effects of steam and carbon dioxide. The major disadvantage of using limestone in the fluidized beds is its low attrition resistance. Thus, gentle separation units for the limestone as bed material are recommended to overcome this problem. Several process configurations have been published by different institutions, mainly by IFK Stuttgart and TU Wien. The most important experimental and theoretical results, including the dependence of the product gas composition on the gasification temperature and the bed material cycle rate, tar content in the product gas, and test runs in the industrial scale are summarized and discussed. Sorption enhanced reforming of different fuel types, sorption enhanced reforming with oxyfuel combustion, and performance indicating key figures of the process are also investigated. Highlights • Detailed description of SER process and influencing parameters on CO 2 sorption. • Existing plants and concepts are summarized and simplified schemes are displayed. • Results from different plants are summarized and presented in an unique way. • Equilibrium modelling of product gas based on results from different plants. [ABSTRACT FROM AUTHOR]

Abstract Deoxygenating biomass pyrolysis vapors prior to condensation would ideally yield chemically stable and petroleum-miscible streams comprised primarily of hydrocarbons that could be integrated into the existing refinery infrastructure. Both in-situ and ex-situ catalytic fast pyrolysis have shown promising results in terms of product quality, i.e., lower acidity, higher heating values, and product stability. However, these improvements come at the expense of carbon loss as CO, CO 2 , and coke, as well as cracking of larger molecules (potentially more valuable) into smaller molecules. It is thus of utmost importance to track the carbon, both product distribution and carbon yields, in order to obtain the full picture of deoxygenation efficacy. Despite potentially interesting results reported in the literature, it is unfortunately difficult to compare the true ability of various catalyst systems for deoxygenating biomass pyrolysis vapors primarily due to insufficient product characterization and data reporting. In this review paper, it is argued that results ultimately need to be reported in terms of carbon yields of individual products. This would enable an accurate accounting of where the carbon ultimately resides after processing, which is required for a more conclusive comparison between various systems. This information would enable the identification of effective catalytic systems for pyrolysis vapor deoxygenation and accelerate the advancement of catalyst design. Additionally, hydrodeoxygenation is discussed as a promising process in terms of carbon recovery. This article aims to propose a set of standard criteria for future reports on deoxygenation of biomass pyrolysis vapors by scrutinizing the existing literature. Highlights • Pyrolysis vapor deoxygenation holds promise for bio-oil integration in refineries. • Deoxygenation efficacy depends on product quality, quantity, and speciation. • Measuring the quantity of product species requires individual carbon yields. • Carbon should be tracked from feed into all products (i.e. gas, liquid, solid). • The field's progress relies on a standard reporting method accounting for carbon. [ABSTRACT FROM AUTHOR]

Abstract Biomass is vital for future energy use, but several disadvantages obstruct its commercial applications. Co-thermochemical conversions of biomass and fossil fuels are alternative methods for offsetting the disadvantages of biomass and improving the quality of bio-oil. This paper overviewed the state-of-the-art research and development of co-thermochemical conversions of biomass and fossil fuels (i.e., coal, oil sand and oil shale). Emphasis was placed on different types of feedstocks, three thermochemical conversion methods (i.e., co-pyrolysis, co-gasification and co-liquefaction) and the synergistic effects. Furthermore, the influencing factors, advantages and disadvantages, and the possible mechanisms related to these co-thermochemical conversion technologies are discussed. The current developments and prospects for co-thermochemical conversions of biomass and fossil fuels are also proposed. Graphical abstract fx1 Highlights • The co-thermochemical conversions of biomass and fossil fuels were discussed. • Synergistic effects regarding products compositions and yields were overviewed. • The possible mechanisms of synergistic effects studied before were summarized. • The prospects of co-thermochemical methods of biomass and fossil fuels are discussed. [ABSTRACT FROM AUTHOR]

Abstract Pyrolysis is one of the most efficient and environmentally attractive thermochemical processes for conversion of both biomass and wastes to energy products. This review focuses on the use of auger reactors, also known as screw reactors, for the pyrolysis of carbonaceous solids into liquid, gaseous and solid products that can be used in the production of fuels and other valued-added products. The auger reactor is attractive for its versatility in transforming a wide range of feedstocks, and has been recognized as one of the technologies with better strengths not only for fast pyrolysis, but also for slow or intermediate pyrolysis. Auger pyrolyzers are of relatively simple design and overcome some of the problems of conveying heat for pyrolyzing biomass or wastes. The mechanical forces associated with auger reactors enhance particle mixing and heat transfer, which are key to successful pyrolysis. This paper presents a comprehensive review of the advantages and challenges of this technology and identify the main characteristics of both single- and twin-screw auger technology. The effect of operating conditions on yield and some properties of pyrolysis products are also provided. The review includes examples of commercial/demonstration-scale auger pyrolysis plants operated around the world. Highlights • The literature on auger pyrolyzers is widely surveyed. • Auger technology is attractive for pyrolyzing a wide range of feedstocks. • Auger pyrolyzers are able to work for fast, intermediate and slow conditions. • Yields and products characteristics are described for different plants. [ABSTRACT FROM AUTHOR]

Abstract: A major focus of the current energy debate is how to meet the future demand for electricity. Conservation in buildings and industry, and conversion of utility central station capacity to alternate fuels will play a major role in meeting this demand. But cost-effective conservation measures can only go so far, and the industrial and commercial sectors ultimately will have to seek alternative sources of energy. Moreover, electric utilities may face financial, environmental, or other constraints on the conversion of their existing capacity to fuels other than oil, or on the construction of new alternate-fuelled capacity. A wide range of alternate fuels and conversion technologies has been proposed for the industrial, commercial, and electric utility sectors. One of the most promising commercially available technologies is cogeneration. Cogeneration systems produce both electrical (or mechanical) energy and thermal energy from the same primary energy source. This paper reviews the present day cogeneration technologies based on renewable sources of energy. Study of novel methods, existing designs, theoretical and experimental analyses, modeling and simulation, environmental issues and economics and related energy policies have been discussed in this paper. [Copyright &y& Elsevier]

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: Diversification of fuel sources is imperative to address the energy security, climate change, and sustainable development issues; therefore, it is essential to address the energy crisis through the extensive utilization of abundant renewable energy resources, such as biomass energy, solar energy, wind energy and geothermal energy. Improving energy services for poor households in developing countries remains one of the most pressing challenges facing the development community. Earlier studies suggest in South Asia the households are likely to follow the energy ladder comprising fuels like dung, crop residue, firewood, kerosene, gobar gas, LPG, and electricity for cooking purposes. Evidence suggests that while it is possible to observe such transition in urban and semi-urban areas, the change is very slow in rural areas. In rural Pakistan, the access to commercial energy resources is limited, the majority of the households still heavily rely on traditional methods of using wood, animal waste and crop waste for domestic fuel needs. Efficiencies of use are very low and most of the potential is wasted because of non-scientific conventional technologies. Consequently there is an obligatory need to develop modern bio-energy technologies since renewable resources may serve to supplement the long-term energy needs of Pakistan to a significant level. Though the bio-resource base of Pakistan is substantial, its contribution to useful energy is low. In this paper we called attention to issues and challenges in biomass utilization for energy in Pakistan in context of sustainable development. This paper has identified areas in Pakistan where there is considerable scope to modernize biomass energy production delivery systems to provide varied energy carriers such as electricity, industrial and domestic fuel and gases. Barriers are examined over the whole biomass energy spectrum and policy issue and institutional roles and responsibilities are discussed. [Copyright &y& Elsevier]

Abstract: The whole world is now concentrating on advancing their pool of renewable energy resources. Immense growth has happened in the field of renewable energy and the energy harvesting methods in the past decade. It is estimated that there is still a huge potential of growth remaining in the field of renewable energy resources in the coming years. Generation of renewable energy at the source end to the transmission of the energy to the utility end is done at various interstates coupled with power electronic equipments and systems. Applications of power electronics are expanding at a high pace in industrial power generation, utility, grid integration, and transmission environments due to the advancements in technology and reduction in cost and size of the components and systems. There are numerous multistage converters and inverters topologies being developed for processing and delivering the gigawatt level of renewable power being produced. This paper highlights the growth of power electronics starting from semiconductor type switching devices to various multistage topologies which will extensively contribute to the development and growth of renewable energy resources around the globe. It is a fact that power electronics is an integral part of renewable energy generation and utilization and its optimization of size, cost, and performance is necessary for the most efficient harvesting. Latest advancements in the various ratings of switching devices and components are discussed in the paper. Proper topology based implementation of power electronics and motor drives in the generation of various renewable energy sources such as solar power, wind power, fuel cells, biomass, and other energy storage elements are discussed in details. Individual sources of renewable energy resources interfaced with multistages of power electronic systems are elaborated in the paper. [Copyright &y& Elsevier]