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The pulp and paper industry (PPI) has several opportunities to contribute to meeting prevailing climate targets. It can cut its own CO2 emissions, which currently account for 2% of global industrial fossil CO2 emissions, and it has an opportunity to produce renewable energy, fuels, and materials for other sectors. The purpose of this study is to improve understanding of the decarbonization prospects of the PPI. The study provides insights on the magnitude of needed annual renewal rates for several possible net-zero target years of industrial fossil CO2 emissions in the PPI and discusses decarbonization opportunities, namely, energy and material efficiency improvement, fuel switching, electrification, renewable energy production, carbon capture, and new products. The effects of climate policies on the decarbonization opportunities are critically evaluated to provide an overview of the current and future business environment of the European PPI. The focus is on Europe, but other regions are analyzed briefly to widen the view. The analysis shows that there are no major technical barriers to the fossil-free operation of the PPI, but the sector renovates slowly, and many new opportunities are not implemented on a large scale due to immature technology, poor economic feasibility, or unclear political environment. [ABSTRACT FROM AUTHOR]

The EU has set the ambitious target of raising the share of EU energy consumption produced from renewable resources to 32% by 2030, with a target of climate neutrality by 2050. The aim of this paper is to assess the role of biomass usage in the context of these targets. The paper identifies the progress made between 2013 and 2022 by focusing on a selection of EU countries. The largest bioenergy increments of 130, 77, and 60 PJ were reported for Poland, Sweden, and the Netherlands. This study evaluates the crucial role of co-generation and heat in EU regions, with biomass usage between 55 and 80% of the combined heat and power (CHP) energy in Nordic countries. The future perspectives for bioenergy based on EU policies, biomass resources, and technical issues were addressed. The EU possesses around 9% of the global biomass supply, ensuring a certain level of biomass resource dependence. Thus, the biomass usage demand in energy production, non-energy sectors, and transport is expected to rise, leading to increments of 13–76% on biomass imports. It appears that bioenergy development is mostly limited by economic issues and uneven support for bioenergy in different EU countries as well as environmental issues. The study shows a promising and sustainable potential of bioenergy in the EU as a renewable energy source while minimizing negative impacts on the environment and the economy. By 2050, liquid biofuels are likely to be increasingly used in the transport sector. Non-energy sector usage of biomass is still in an early stage of development, except for the pulp and paper industry, and significant use of biomass in non-energy sectors seems unlikely in the near future. [ABSTRACT FROM AUTHOR]

The energy use of residues from agriculture, forestry, and solid waste can foster the transition towards a more renewable energy supply. This paper analyzes the energy potential of the above-mentioned sources for energy applications in Kosovo. The analysis is based on statistical data from different studies and reports, analyzing and calculating them to determine the theoretical and energy biomass potential. Kosovo can increase its self-sufficiency by taking advantage of its rich but under-utilized potential of biomass energy sources. This is a novelty study in this area, considering Kosovo lignite-dominated heat energy and electricity consumption and the available special literature. According to our estimates, the theoretical potential is 6.13 million tons/year, while the biomass energy potential should be around 4.57 million tons/year, including approximately 74.6% of biomass, which can be used for energy needs (heating and electricity). Based on the data and calculations, the available and usable potential shows biomass as an energy source with high potential in Kosovo; its share is very low, but it is reasonable to grow for both environmental and economic reasons. [ABSTRACT FROM AUTHOR]

For all of human history except the past two centuries or so, bioenergy provided nearly all the world's primary energy. Then, fossil fuels largely replaced bioenergy, but concern about climate change and fossil fuel depletion will force a move back to renewable energy, including bioenergy. The main method used here to study the future of global bioenergy was a literature surview of relevant published papers, with emphasis both on those published after 2020, and those having a global focus. The key finding is that bioenergy is unlikely to greatly increase its share of global energy consumption, for several reasons. Liquid biofuel production for transport is likely to almost disappear as countries progressively phase out internal combustion engine vehicles. Traditional firewood use is also projected to fall. There are also doubts about the technical potential of bioenergy, not only because it must compete with the other uses for biomass—food, fodder, fibre and timber—but also because in many cases its climate change mitigation impact is less than for other approaches, including alternative renewable energy sources. The overall conclusion is that bioenergy will have a minor but still useful role in the future global energy system, but global energy reductions are likely to be more important for climate stability than bioenergy. [ABSTRACT FROM AUTHOR]

The paper presents an analysis of the development of the alternative energy market between 2010 and 2022 in seven Central European countries, namely Poland, the Czech Republic, Slovakia, Romania, Lithuania, Hungary, and Bulgaria. Analyzing changes in electricity generation from hydro, solar, wind and bioresources makes it possible to comprehensively assess trends in the development of alternative energy. The countries of Central and Eastern Europe are economically and climatically similar to Ukraine, so studying the development of their renewable energy is of scientific value for the drafting of both Ukrainian and European energy strategies in the context of the transforming global energy system. Additionally, the article discusses the impact of renewable energy development on the labor market, outlining potential challenges and threats to regional labor markets. Research conclusions confirm the practical development and effective implementation of RES in the European energy system, even in countries that do not take the lead in generating energy from renewable sources, i.e., in Central Europe. [ABSTRACT FROM AUTHOR]

This paper provides an overview of the Special Issue on Wastewater Treatment and Reuse: Past, Present, and Future. The papers selected for publication include advanced wastewater treatment and monitoring technologies, such as membrane bioreactors, electrochemical systems; denitrifying biofilters, and disinfection technologies. The Issue also contains articles related to best management practices of biosolids, the influence of organic matter on pathogen inactivation and nutrient removal. Collectively, the Special Issue presents an evolution of technologies, from conventional through advanced, for reliable and sustainable wastewater treatment and reuse. [ABSTRACT FROM AUTHOR]

Renewable energy sources such as biomass, solar, hydro and geothermal energy can provide important energy services based on the use of available local resources, studies to date show that the potential of these energy sources is enormous, they can cover in principle several times energy demand. This paper presents some considerations on the methods of converting biomass into convenient energy, respectively the most used method for obtaining biodiesel. [ABSTRACT FROM AUTHOR]

Renewable energy resource utilisation is becoming more prevalent in society and can be a sustainable method to meet rising energy demand and consumption. The International Renewable Energy Agency reports that presently, approximately 33% of total electricity output around the world is from renewable energy sources. However, in Nigeria, the World Bank reported this figure as 18.2% in 2015. It is important to understand how Nigeria can raise this average as the world moves towards less use of fossil fuels. Therefore, the aim of this work was to provide a review of the established literature, which can then be used to support the development of renewable energy systems in Nigeria. The methodology employed for the study of the literature involved a systematic review method, including identification, screening, eligibility and inclusion criterium steps. Understanding the national energy landscape is essential to support potential projects, and consequently, energy supply, demand and consumption in Nigeria are observed. The review examined renewable energy sources in Nigeria with a focus on solar and biomass/bioenergy. The levelised cost of electricity from renewable technologies was analysed, and the paper identified and evaluated past projects centered on solar and biomass, presenting three main case studies. The results indicate that solar and biomass have the most potential for energy generation in Nigeria, with 4–6.5 kWh/m2 of solar irradiation available per day and approximately 2.3 × 109 GJ bioenergy potential per year. However, solar PV is currently of most interest in Nigeria due to the lower cost of on-grid solar PV electricity, which can comfortably compete with fossil fuels. Nevertheless, costs still need to be lowered to compete fully. Finally, the findings also indicate that there is an omission in the literature surrounding the existing renewable projects and technologies in Nigeria. [ABSTRACT FROM AUTHOR]

The depletion of fossil fuels and climate change concerns are drivers for the development and expansion of bioenergy. Promoting biomass is vital to move civilization toward a low-carbon economy. To meet European Union targets, it is required to increase the use of agricultural residues (including straw) for power generation. Using agricultural residues without accounting for their energy consumed and carbon dioxide emissions distorts the energy and environmental balance, and their analysis is the purpose of this study. In this paper, a life cycle analysis method is applied. The allocation of carbon dioxide emissions and energy inputs in the crop production by allocating between a product (grain) and a byproduct (straw) is modeled. Selected crop yield and the residue-to-crop ratio impact on the above indicators are investigated. We reveal that straw formation can consume between 30% and 70% of the total energy inputs and, therefore, emits relative carbon dioxide emissions. For cereal crops, this energy can be up to 40% of the lower heating value of straw. Energy and environmental indicators of a straw return-to-field technology and straw power generation systems are examined. [ABSTRACT FROM AUTHOR]

The growing demand for social and regulatory forest ecosystem services can significantly modify the availability and cost of biomass for energy purposes. This article presents a model for optimizing biomass supply chains using a linear programming framework integrated with a geographic information system (GIS). Based on a given type of biomass resource, its calorific value, price, distance from the power plant, and transportation costs, the model identifies the optimal source of biomass, allowing it to cover the demand for the required total energy value with the lowest possible costs. The case study includes the Połaniec power plant in southeastern Poland and potential sources of forest biomass and agricultural straw within 100 km of the plant. The impact of constraints on the availability and cost of biomass was analyzed in the following scenarios: (1) all forest and agriculture biomass is available, (2) forest area in Natura 2000 network is excluded, and (3) firewood and forests with dominated ecological and social function are excluded. Unit costs of biomass varied depending on biomass availability and energy demands. The lowest unit costs of biomass (3.19 EUR/MJ) were for energy demand at the level of 1 TJ yearly for all kinds of biomass and the highest (4.91 EUR/MJ) for ecological and social constraints and energy demand 4 TJ. As energy demand increased, unit costs increased, and the ability to meet this demand with just one type of biomass decreased. The energy biomass sector can utilize the model to benefit both biomass producers and their final buyers. [ABSTRACT FROM AUTHOR]

Background: Policymakers are tasked with both driving the rapid expansion of renewable energy technologies and, additionally channelling the limited national potential of biomass into areas where it can provide the greatest benefit to the energy system. But do current policy instruments promote the use of biomass in these areas? As biomass is limited, its use must be sustainable without leading to further biodiversity loss or depleting forest or soil resources. In this study, short-term energy scenarios are generated using the BenOpt model, which take into account both current and alternative policy instruments under limited biomass utilisation. The results are compared with long-term, cost-optimal energy scenarios for the use of biomass. Results: The analysis reveals that the instrument of a GHG quota does not promote the use of biofuels in hard-to-electrify areas of the transport sector, where they should be cost-optimally allocated according to long-term energy scenarios. Biofuels are promoted for use in passenger road transport and not in the shipping or aviation sector. In contrast, alternative policy scenarios indicate that the sole instrument of a high CO2 price is more conducive to direct electrification and could displace more fossil fuels by 2030 than the GHG quota alone. This instrument also promotes the optimal use of biogas plants in the power sector in accordance with long-term cost-optimal developments. Conclusions: The instrument of a GHG quota might lead to counterproductive developments in passenger road transport, but it also helps to ramp up the biofuel capacities required in shipping and aviation in the long term. However, it does not provide the necessary incentives for the ramp-up of battery electric vehicles, which would be the cost optimal solution in passenger road transport according to the long-term scenarios. Even though alternative policy scenarios show that the sole instrument of a high CO2-price is more conducive to direct electrification, a high CO2 price alone is not enough (e.g. in the heat sector) to promote the efficient use of biomass instead of simply covering the base load demand. [ABSTRACT FROM AUTHOR]

In recent years, population growth and lifestyle changes have led to an increase in energy consumption worldwide. Providing energy from fossil fuels has negative consequences, such as energy supply constraints and overall greenhouse gas emissions. As the world continues to evolve, reducing dependence on fossil fuels and finding alternative energy sources becomes increasingly urgent. Renewable energy sources are the best way for all countries to reduce reliance on fossil fuels while reducing pollution. Biomass as a renewable energy source is an alternative energy source that can meet energy needs and contribute to global warming and climate change reduction. Among the many renewable energy options, biomass energy has found a wide range of application areas due to its resource diversity and easy availability from various sources all year round. The supply assurance of such energy sources is based on a sustainable and effective supply chain. Simultaneous improvement of the biomass-based supply chain's economic, environmental and social performance is a key factor for optimum network design. This study has suggested a multi-objective goal programming (MOGP) model to optimize a multi-stage biomass-based sustainable renewable energy supply chain network design. The proposed MOGP model represents decisions regarding the optimal number, locations, size of processing facilities and warehouses, and amounts of biomass and final products transported between the locations. The proposed model has been applied to a real-world case study in Istanbul. In addition, sensitivity analysis has been conducted to analyze the effects of biomass availability, processing capacity, storage capacity, electricity generation capacity, and the weight of the goals on the solutions. To realize sensitivity analysis related to the importance of goals, for the first time in the literature, this study employed a spherical fuzzy set-based analytic hierarchy method to determine the weights of goals. [ABSTRACT FROM AUTHOR]

The present study aims to resolve the existing research gaps on olive pomace (OP) hydrochars application as a fuel by evaluating its molecular structures (FTIR and solid NMR analysis), identifying influential characteristics (Pearson correlation analysis), process optimization (response surface methodology), slagging–fouling risks (empirical indices), and combustion performance (TG-DSC analysis). The response surfaces plot for hydrothermal carbonization (HTC) of OP slurry performed in a pressure reactor under varied temperatures (180–250 °C) and residence times (2–30 min) revealed 250 °C for 30 min to be optimal conditions for producing hydrochar fuel with a higher heating value (32.20 MJ·Kg−1) and energy densification ratio (1.40). However, in terms of process efficiency and cost-effectiveness, the optimal HTC conditions for producing the hydrochar with the highest energy yield of 87.9% were 202.7 °C and 2.0 min. The molecular structure of hydrochar was mainly comprised of aromatic rings with methyl groups, alpha-C atoms of esters, and ether bond linkages of lignin fractions. The slagging and fouling risks of hydrochars were comparatively lower than those of raw OP, as indicated by low slagging and fouling indices. The Pearson correlation analysis emphasized that the enrichment of acid-insoluble lignin and extractive contents, carbon densification, and reduced ash content were the main pivotal factors for hydrochar to exhibit better biofuel characteristics for energy applications. [ABSTRACT FROM AUTHOR]

Energy production from coal combustion is responsible for nearly 40% of global CO2 emissions including SOx and NOx. This study aims to produce solid biomass fuels from oil-palm residues by torrefaction, having a high heating value (HHV) equivalent to fossil coals. The experiments were designed using Design Expert version 13 software to optimize the conditions affecting the fuel characteristics of the torrefied products. The statistical analysis suggested that the optimal conditions to achieve a high HHV and fixed carbon content while retaining the mass yield of biomass mainly depended on the temperature and torrefying time, while the size played a less important role in affecting the properties. The optimal conditions were observed to be at 283 °C (120 min) for EFBs, 301 °C (111 min) for PF, and 285 °C (120 min) for PKSs. The maximum HHV of 5229, 5969, and 5265 kcal/kg were achieved for the torrefied EFBs, PF, and PKSs, respectively. The energy efficiency of torrefied biomass was increased to 1.25–1.35. Ecoefficiency analysis suggested that torrefaction should be carried out at high temperatures with a short torrefying time. This low-cost bio-circular torrefied biomass showed promising fuel characteristics that could be potentially used as an alternative to coals. [ABSTRACT FROM AUTHOR]

As a renewable energy, biofuel has greatly attracted worldwide attention due to the growing demands for cleaner sources of energy as an intervention to mitigate the serious environmental problems associated with fossil fuel consumption. As an important non‐food biodiesel plant, Pistacia chinensis has a promising prospect for bioenergy development. Based on the principles of multifactor integrated assessment, this paper provides an operational method for comprehensively evaluating the marginal land resources suitable for developing the plantation of Pistacia chinensis in Shaanxi province, China. The results show that the areas of marginal land resources suitable and fairly suitable for growing Pistacia chinensis in Shaanxi province are 1.21 million hectares and 4.45 million hectares, respectively. The suitable land resources are mainly located in Hanzhong (0.44 million hectares), Ankang (0.30 million hectares), and Shangluo (0.31 million hectares), most of which are moderate dense grassland (accounting for 50.65%), dense grassland (accounting for 21.83%), shrub land (accounting for 8.62%), and sparse forest land (accounting for 15.32%). The comparison between the results and field work data suggests that the pixel size of spatial data and soil organic matter content have important impacts on the final results. The outcome of this research can be used to implement specific policies for developing Pistacia chinensis in China and other countries especially the countries along the Silk Road. [ABSTRACT FROM AUTHOR]

This paper explores the viability of utilizing agricultural biomass-based energy potential, employing mathematical, engineering, and economic modeling techniques. Moreover, the potential of a biogas-based co-digestion (CD) system, integrating its techno-economic performance and environmental sustainability in terms of electricity generation, has also been studied. In this investigation, the categorization of 25 different plant species into two groups: arable field crops (AFCs) and horticultural plants (HPs), was performed. Data was collected during the 2021‐–2022 cropping season in Bangladesh from various sources, including literature reviews, governmental, and non-governmental organizations. The findings revealed that the available agricultural biomass residues, totaling 1,02,585.75 KT, have the capacity to generate 1,33,815 million m3/year of biogas. This energy potential corresponds to 291,125.85 TJ/year or 9231.60 MW of electricity, which can fulfill 88% of the national total energy demand. In terms of levelized cost, the proposed approach is more competitive and shows a greater promise compared to other technologies. Furthermore, it demonstrates environmental friendliness by reducing CO 2 emissions by 156 tons at a cost of $7/ton while earning $1092 annually from the potential carbon-credit market. This approach presents a potential solution to address Bangladesh's energy crisis. The payback period of the system ranged from 2.93 to 3.75 years, with and without the inclusion of a slurry, respectively. The recommended methods hold significant promise for meeting national energy demands. A case study was provided as a proof-of-concept (PoC) to validate the approach. This study is the first of its kind, providing valuable insights into the renewable energy potential in Bangladesh. The results will assist policymakers in formulating sustainable energy policies. • Mathematics, engineering, economics and environmental modeling explored renewable energy. • Techno-economics and environmental sustainability validated the proposed methodology. • Bioenergy-based electricity could supply 88% of the national energy demand of Bangladesh. • A case study was provided as a proof-of-concept (PoC) to validate the approach. [ABSTRACT FROM AUTHOR]

Agroindustry waste has exponentially increased in recent years, generating economic losses and environmental problems. In addition, new ways to generate sustainable alternative electrical energy are currently being sought to satisfy energy demand. This investigation proposes using avocado waste as fuel for electricity generation in single-chamber MFCs. The avocado waste initially operated with an ambient temperature (22.4 ± 0.01 °C), DO of 2.54 ± 0.01 mg/L, TDS of 1358 ± 1 mg/L and COD of 1487.25 ± 0.01 mg/L. This research managed to generate its maximum voltage (0.861 ± 0.241 V) and current (3.781 ± 0.667 mA) on the fourteenth day, operating at an optimal pH of 7.386 ± 0.147, all with 126.032 ± 8.888 mS/cm of electrical conductivity in the substrate. An internal resistance of 67.683 ± 2.456 Ω was found on day 14 with a PD of 365.16 ± 9.88 mW/cm2 for a CD of 5.744 A/cm2. Micrographs show the formation of porous biofilms on both the anodic and cathodic electrodes. This study gives preliminary results of using avocado waste as fuel, which can provide outstanding solutions to agro-industrial companies dedicated to selling this fruit. [ABSTRACT FROM AUTHOR]

The role of final consumers in energy transition and renewable energy development is undeniable. Furthermore, the acceptability and intention to use renewable energy very much depends on different factors behind. This study, based on representative survey in Lithuania, aims to analyse in the line with sociodemographic variables the influence of positive and negative perceptions of renewable energy on intention to use it. The study analyses not only intention to use renewable energy sources (RES) in general but addresses bioenergy and other RES separately. The results indicate higher knowledge of other RES to compare to the bioenergy. Usage of some RES also have influence on RES knowledge and negative environmental perceptions. Applied regression analysis reveals that positive environmental impacts and economy outcomes contribute to the intention to use RES the most. Age, gender, living place and usage of RES are also predictors of intention to use RES, though difference in between predictors behind intention to use bioenergy and other RES is observed. This study could help policy makers and informational campaigns managers to reach the targeted final consumers and improve RES development. [ABSTRACT FROM AUTHOR]

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

The study focused on a forensic assessment of bioenergy utilization in developing countries, emphasizing how to improve bioenergy resources for a sustainable economy and development. First, a holistic review of energy sources and their impacts on sustainable development was highlighted. The study also looked at the relationships between various energy sources, both the supply and demand of energy, as the population statistics in developing countries. However, renewable energy is yet to be harnessed fully as it lagged by 0.7%. Shockingly, the African continent is backward in both the global energy supply and in tapping renewable energy sources, as only 6% is contributed. More so, applying a clean development mechanism (CDM) for energy utilization and control shows that net emission reduction and global temperature reduction of 1.5°C by 2030 is attainable. Thus, helping to realize low-cost and sustainable energy (SDG 7) and sustainable cities and communities (SDG11). Further, the assessment of the level of bioenergy availability and its utilization shows that 10% of the world's energy is provided by bioenergy. Interestingly, it is available in every region in the form of biomass. The study is helpful for stakeholders, policymakers, and governments managing the affairs of the energy sector on the need to formulate policy that will guide effective bioenergy utilization and reduction in greenhouse gas emissions, especially in developing countries thereby, promoting sustainable economic growth. [ABSTRACT FROM AUTHOR]

Rice straw (RS) is the residue obtained during the rice processing process, and is recognized as one of the most abundant biomass resources in the world. Approximately 800 million to 1 billion tons of rice straw are produced globally every year, and most of them are considered general waste and typically end up in landfills or incineration. This approach wastes resources and can also lead to environmental pollution. In the current study, the RS was used as the source of biodiesel production and a comprehensive process model of the RS valorization process was developed to evaluate the energy flow, production efficiency, production costs, and greenhouse gas emissions in Hunan Province, China. The evaluation results showed that the energy efficiency of biodiesel production from rice strawand the overall energy efficiency of the rice straw valorization process are reported as 52.1% and 56.1%, respectively. The minimum selling price of biodiesel, which is CNY 3.03/kg, is considerably lower than the current market prices for similar products in China. The largest proportion of the production cost of biodiesel is the cost of natural gas, followed by utilities, capital, transportation, plant maintenance and overheads, consumables, labor, and waste disposal. For the current RS valorization plant with a 5000 kg/h RS feed rate, the investment payback times are 8.9 yr and 7.1 yr when the biodiesel is sold at the lowest (CNY 4/kg) and highest (CNY 4.6/kg) market price, respectively. Environmental analysis shows that the greenhouse gas emissions intensity of biodiesel production is 75.8 g CO2eq/MJ, which is only about 52% of traditional fossil diesel and indicating that biodiesel is an environmentally friendly energy source. [ABSTRACT FROM AUTHOR]

Algal biomass is a prospective feedstock for the eco-sustainable production of many different products with added value, such as meals, feeds, and fuels. The remaining biomass from the algae can be used as raw material and can be transformed into useful secondary products after the important macromolecules have been removed. By optimizing algal biomass hydrolysate utilizing microbial fermentation, several studies demonstrated the generation of bioenergy (bioalcohol, biogas, and biohydrogen) and biochemicals (organic acids and biopolymers). Since the harvest and maintenance of sustainable algal cultivation incur considerable energy and economical prowess, developing products from algae remains a challenge to be countered in commercial applications. This is a typical bottleneck issue when processing algae for fuels or chemicals at the pilot scale. Implementation of integrated algae biorefinery methods can substantially reduce the cost of production and energy consumption. An algae-based green economy can be financially more viable and utilizable, especially for countries with weaker economies. This review's goal is to examine the implementation of integrated biorefineries for the recovery of bioproducts generated from algae and potential applications. In this context, the life cycle analysis and business elements of a unified algal biorefinery are also addressed. [ABSTRACT FROM AUTHOR]

Biogas production by fermentation is a relatively low-cost and simple method for the transformation of a substrate into an energy carrier with a wide range of possible applications. The aim of this study was to determine the potential of Arthrospira platensis biomass as a source of bioenergy produced during anaerobic digestion (AD). The studies were carried out on a fractional-technical scale. Biogas yield and composition were analyzed as a function of the amount of biomass subjected to anaerobic digestion, the substrate dosing frequency in the digester and the use of biomass pre-hydrolysis in the mixing compartment. The energy efficiency of the process was also compared for each sample. In addition, a biomass conversion power index was developed and determined. It was found that A. platensis biomass had significant energy potential, and the amount of biogas obtained and its calorific value changed depending on the applied treatments. The maximum cumulative biogas production was 505 L kg−1 volatile solids (VS), while the maximum average methane (CH4) content was 67.32%. A two-fold increase in the organic loading rate from 1 g VS·L−1 volatile solids (VS) to 2 g VS·L−1 had a positive effect on methane concentration. The highest energy efficiency of the AD process was obtained for 2 g VS·L−1, with a single feedstock input into the digester, in a single-stage process (2/s/-), while the highest conversion power ratio was for a feedstock of 1 g VS·L−1, under the same process conditions (1/s/-). Moreover, the energy efficiency of the microalgae fermentation process obtained in the study is higher compared to conventional substrates used in biogas plants. This energy analysis can support the selection of cogeneration power engines in a biogas plant and help to determine the potential output of the biogas plant, especially with varying energy and heat demand. [ABSTRACT FROM AUTHOR]

In Northeast Brazil, the use of biomass for energy generation is settled on traditional productive arrangements, such as a sugarcane production system in the humid Atlantic coastal area and firewood extraction from native tropical dry forests in the west. In parallel, substantial amounts of other biomass sources, such as residues from agricultural or urban processes, are still little used or wholly wasted, fudging the opportunity to generate new value chains based on these biomass sources. We hypothesize that using these non-traditional biomass sources to produce biofuels would significantly increase the regional bioenergy supply. In this context, this article discusses the potential for the production and use of biofuels and bioenergy in Northeast Brazil and its effects on regional development, which may be useful for both private actors and policymakers in the energy sector. The use of biomass sources for energy in the region is significant, reaching approximately 8.8 million tons of oil equivalent (toe) per year, emphasizing the already consolidated production of sugarcane and its derivatives. The use of all biomass resources in the Northeast region could supply around 4% of the Brazilian national electrical energy demand, with an environmental footprint of 0.055 tCO2eq per toe, which would contribute to reducing emissions from the Brazilian energy matrix generation. Regarding the spatial distribution of biomass sources, sugarcane prevails on the coast, firewood and livestock manure in the dryland area towards the west, and municipal solid waste is distributed throughout the region within urban areas. Different from what we expected, the potential energy recovery from municipal waste and animal manure would increase by only 17% the current bioenergy supply. In the future, since the majority of the region presents a semi-arid climate with limited rainfall, to increase the use of biomass as an energy source, there is a need to increase the supply of biomass sources with high efficiency in water use and good yields in drylands. For this, the cultivation and use of cacti and agave, for example, could contribute to making biorefineries viable in the region. Above all, public policies for harnessing bioenergy in NE Brazil must seek opportunities associated with the carbon/decarbonization economy, with studies being needed to assess the technical, economic, social, and environmental viability of future productive arrangements. [ABSTRACT FROM AUTHOR]

Microalgae biomass (MB) is a promising source of renewable energy, especially when the cultivation is associated with wastewater treatment. However, microalgae wastewater technologies still have much to improve. Additionally, microalgae biomass valorization routes need to be optimized to be a sustainable and feasible source of green bioenergy. Thus, this paper aimed to evaluate the environmental impacts of the production of briquettes from MB, cultivated during domestic wastewater treatment. Also, it was evaluated how much the drying of the MB affected the life cycle and the environment. Improvements in the life cycle to mitigate the environmental impacts of this energy route were proposed. Cradle-to-gate modeling was applied to obtain a life cycle assessment (LCA) from cultivation to the valorization of MB, through its transformation into a solid biofuel. With LCA, it was possible to identify which technical aspect of the process needs to be optimized so that environmental sustainability can be achieved. Two scenarios were compared, one with the microalgae growth in a high-rate algal pond (HRAP) (scenario 1) and the other in a hybrid reactor, formed by a HRAP and a biofilm reactor (BR) (scenario 2). LCA highlighted the electric power mix, representing, on average, 60% of the total environmental impacts in both scenarios. The valorization of MB in briquettes needs to consume less energy to offset its yield. The environment suffered pressure in freshwater eutrophication, due to the release of 3.1E-05 and 3.9E-05 kg of phosphorus equivalent; in fossil resources scarcity, with the extraction of 1.4E-02 and 4.5E-02 kg of oil equivalent; and in climate change, by the emission of 1.0E-01 and 1.9E-01 kg of carbon dioxide (CO 2) equivalent, in scenarios 1 and 2, respectively. Scenario 1 was highly damaging to terrestrial ecotoxicity, with the release of 3.5E-01 kg of 1,4 Dichlorobenzene, coming from the CO 2 used in MB growth. This category was the one that most negatively pressured the environment, differing from scenario 2, in which this input was not required. This was the only impact category in which scenario 2 had a better environmental performance when compared to scenario 1. Cotton, required in scenario 2, represented up to 87% of emissions in some of the evaluated categories. Despite the impacts that occurred in the two modeled scenarios, the environmental gains due to the use of wastewater for microalgae growth, replacing the synthetic cultivation medium, stood out. In the sensitivity analysis, two alternative scenarios were proposed: (i) electricity consumption for drying has been reduced, due to the natural decrease of MB humidity, and (ii) MB briquettes were considered a substitute for coal briquettes. Results indicated that pressures on climate change and fossil resource scarcity were eliminated in both scenarios and this also occurred for freshwater eutrophication in scenario 2. This paper contributes to the improvement and development of converting MB routes into more sustainable products, causing less pressure on the environment. Also, the study contributes to filling a gap in the literature, discussing methods and technologies to be improved, and consequently making microalgae biotechnology environmentally feasible and a potential renewable energy alternative. [Display omitted] • Environmental impacts of microalgae biomass briquette were obtained. • The environment was stressed on terrestrial ecotoxicity, by CO 2 supplementation. • The net energy of the process was negative due to drying. • Optimizing biomass drying improved energy and environmental performance. • Microalgae biomass briquettes to replace coal benefit the environment. [ABSTRACT FROM AUTHOR]

This paper makes projections of the theoretical and technical potentials of bioenergy supply for 2050. The projections consider changes in available land for bioenergy and food for the global demand and advancements in yield, productivity, expansion of bio-waste recovery, and energy conversion. We present a literature review on projections. We introduced a novel logical and transparent forecasting model. Three future scenarios were established: business as usual (BUS), optimistic trends (OPT), and full adaptation response (FAR). The projection is carried out based on four adjusting factors. An uncertainty analysis was carry-out based on a Monte-Carlo method. Projections of bioenergy production in 2050 were compared with other projections in the literature. The FAR scenario showed that it would be possible to produce twenty-one times the current primary bioenergy supply and to even supply all global primary energy demand in 2050, mostly by energy crops. The assumptions adopted for the BUS and OPT scenarios make their projections more likely. Therefore, the contribution of bioenergy in the global energy matrix is expected to be between 64 and 313 EJ (7.5%–37%) in 2050. There would be a significant change in the composition of the bioenergy supply from today's mostly firewood to energy crops and biowastes. The technical potential for fuel and electric power mostly follow the supply trends for primary bioenergy (theoretical). The potential avoided greenhouse emissions are estimated. The heuristics and the level of transparency of the novel model will allow adjustments and exploration of other scenarios as time passes. • Novel model for projections of the potential of global primary bioenergy supply. • Bioenergy supply potential is shown for 11 different groups of biomass. • Global primary bioenergy supply could increase up to 6 times by 2050 (37% of demand). • Full adaptation response scenario could meet 100% of the global energy demand. • Bioenergy can play a major role in the global energy supply. [Display omitted] [ABSTRACT FROM AUTHOR]

The current legislative framework and the recent energy crisis ask for massive applications of renewable energy sources (RES) in the built environment to reduce energy demand, environmental emissions, and energy costs. The uncritical application of these policies, especially on architectural heritage, could generate serious conservation issues, compromising their heritage values, biodiversity, traditional appearance, and materiality. Thus, there is an urgent call to balance architectural heritage preservation with energy production using clear rules, policies, criteria, and heritage-compatible technologies. The present study aims at defining an updated overview of the application of solar, wind, geothermal energy, and bioenergy on architectural heritage. A deep literature review of the studies published in the years 2020–2023 has been performed, identifying main topics, challenges, advanced solutions, and future perspectives. Acceptability, design criteria, and cutting-edge technologies are also illustrated through case studies to better understand practical approaches. [ABSTRACT FROM AUTHOR]

The growing demand for energy and the concern about environmental impacts reinforce the necessity for renewable energy sources such as biofuels. In this study, cake generated in the babassu oil extraction was evaluated as a potential feedstock for solid biofuel production, and it contains a blend of cashew nutshell, sugarcane bagasse, carnauba straw, and carnauba stalk. All samples were characterized by proximate analysis and Higher Heating Value. Carbonization was used to improve energy performance and compaction to understand the mechanism and the characteristics of the biomasses compacted. In the extraction of babassu oil, fresh and aged (90 days) kernel samples were used. The fresh samples reached a yield of 59.8%, and the aged samples reached a yield of 70.66%. The carbonization of babassu cake was carried out in a Muffle furnace at temperatures of 250, 300, 350, and 400 °C. The fresh babassu cake showed an HHV of 23.06 MJ kg−1 and after carbonization of 28.07 (250 °C), 30.69 (300 °C), 28.24 (350 °C), and 18.27 MJ kg−1 (400 °C). At 400 °C, a decrease in HHV of 20.8% occurred, and an increase in Ash (%) of 195% occurred. Proximate analysis showed that biomasses are compatible, with some having a higher compatibility than other biological materials already used as fuels in the industry. [ABSTRACT FROM AUTHOR]

Wood and bark chip mulch has been shown to reduce net orchard greenhouse gas (GHG) emissions on an Okanagan Valley (British Columbia, Canada) apple orchard. However, this benefit was shown to be outweighed by the (attributional) life cycle impacts associated with mulch production. The current study expanded the scope of prior investigations to perform a consequential life cycle assessment of the impacts of increasing wood chip/bark mulch use in the production of apples on Okanagan orchards. This assessment included the impacts of the orchard system as well as other current alternative uses of wood chip/bark mulch which included bioenergy production and paper manufacturing. Many environmental impact categories were examined including human toxicity, freshwater aquatic ecotoxicity, depletion of abiotic resources (elements, ultimate reserves), photochemical oxidation, ozone layer depletion, terrestrial ecotoxicity, acidification potential, climate change, eutrophication, land use – land competition, and energy use (including non-renewable: fossil, nuclear, primary forest; and renewable: biomass, geothermal, solar, water and wind). One scenario was modelled to represent the case in which no mulch was used on orchards (only used for alternative products). A second model was created to represent the marginal impacts of adding the amount of mulch to an apple orchard necessary to produce 1 kg of apples (0.575 kg bark and 0.144 kg wood chips). These amounts of bark and wood chips were assumed to be taken away from their current alternative uses (co-generation for bark and paper production for wood chips), thereby decreasing the amount of electricity and heat produced by bark by 0.653 kWh electricity and 0.653 MJ heat, and the amount of paper produced by wood chips by 0.144 kg paper. In turn, these amounts of electricity, heat and paper were assumed to be produced by their marginal production technologies – hydro-electric generation for electricity, natural gas for heat, and recycled paper for paper production. Finally, the scenarios were modelled assuming the marginal market for co-generation from bark was in Washington, USA rather than the Okanagan, as a sensitivity analysis. The results did not show a clear environmental benefit to either using or not using mulch on orchards. In the scenario in which bark mulch was assumed to be used either on apple orchards or for co-generation in British Columbia, impacts in 14 categories (including climate change, eutrophication, acidification, all toxicities, land use and some renewable energy use) were lower when mulch was used on the orchard, and results for 5 categories (including some non-renewable and renewable resources/energy use) were higher. When bark mulch was assumed to be used either on orchards or for co-generation in Washington, terrestrial ecotoxicity, land use, biomass and solar energy use were lower when mulch was used on the orchard, and all others (15 categories) were higher. There was a large amount of uncertainty in the model, coming from data variability, data quality and impact assessment uncertainty. Overall, the orchard system played a significant role in the impact assessment results, and was the main contributor to the overall uncertainty. Based on these results, mulch use on orchards cannot be recommended to reduce environmental impacts, but the marginal impacts of using mulch warrant further investigation. • Wood/bark mulch can reduce direct greenhouse gas emissions on orchards. • Increased use of mulch on orchards would decrease its use in energy and paper production. • Impacts of energy and paper production without mulch are variable. • Overall net impacts of mulch use on orchards depend on displaced alternative uses. [ABSTRACT FROM AUTHOR]

The paper discusses alternatives for biofuel-based district heating using simulation analysis in a real-life case example. First, the paper illustrates the current supply chain structure of forest chips from harvest to the heat energy plant. Usually the chips are naturally dried, chipped on the roadside and transported to the heating plant based on the orders. Second, the study demonstrates how a regional bioenergy system could be developed with the help of a simulation model for evaluating the feasibility of different wood fuel supply chain options. The model mimics a real-life example of an industrial area in a small Finnish municipality planning to invest in a CHP plant. The results show that the investment in a CHP plant and use of artificially dried wood fuel can be profitable in the circumstances where local demand exists for heat energy. The simulation-based vision can be compared with the presently dominant concept of highly decentralized supply chains for wood chips that is widely used among energy suppliers. However, to optimize the transportation costs and the moisture content of the chips changes are needed in the supply chain processes and structure. The results of this study are useable for practical decision-making and offer useful ideas for continuing research on alternative ways to produce energy wood biomass in the future. • Supply chain of forest chips in Finland is presented. • A real-life case of an industrial area demostrating how a regional bioenergy system could be developed is presenting. • The simulation model created minics the real-life case. • Feasibility of different wood fuel supplu chain options are discussed. [ABSTRACT FROM AUTHOR]

Earlier studies have highlighted the importance of quality and quantity in forest fuel supply chains, since these parameters affect product value and handling properties, but both are constantly changing over time. Great monetary losses can be incurred if forest fuel material has to be delivered to end-users in non-optimal condition, e.g. to meet seasonal fuel demand with its large short-term variations. Thus earlier studies have also highlighted the importance of more information on the forest fuel supply chain. This paper describes development of a model for Weather-driven Analysis of Forest Fuel Systems (WAFFS) that can be used when analysing forest fuel supply chains and that accounts for both active machine activities and passive activities such as quality changes during storage. The aim was to develop a methodology that can be used to evaluate forest fuel supply chain scenarios and analyse various delivery strategies under different conditions. Application of WAFFS to evaluate delivery strategies for forest fuels showed that system improvements were possible when the right biomass was delivered at the right time. The WAFFS model gives an overview of biomass actually stored at different geographical locations and places (heaps or windrows) in terms of both quality and quantity. Delivery strategies actively prioritising biomass storage proved capable of delivering more energy when most needed, thereby improving yearly machine utilisation for contractors in the supply chain. [ABSTRACT FROM AUTHOR]

Circular economy principles can lead to a series of opportunities to tackle climate change, particularly in cities of developing countries where the generation of waste, consumption and demand for energy is growing rapidly. This paper aims to advance the understanding of the expansion of circularity for tackling climate change using biomass for energy at the urban scale. In addition, little is known about how Circular Economy (CE) flows can be quantitatively integrated, what potential trade-offs exist in promoting Circular Economy using biomass, and how governance models can integrate these flows and contribute to a Circular Economy transition in cities. Based on an empirical study of a city in India, where the private sector participation through an innovative Public-Private Partnership (PPP) model enabled the use of urban wastewater in thermal power plants, the study presents the viability of Circular Economy models at the city scale. The feasibility of a further expansion of this circularity by co-firing biomass in local thermal power plants was analyzed, as a potential solution for reducing pollution and carbon emissions in a hard-to-abate sector. The result indicated an average 20.5 MJ kg−1 calorific value for torrefied mixed biomass pellets from crop residues, which, if applied to about 447 kt y−1 surplus biomass available in Nagpur would amount to 9.18 PJ of energy (per year). Overall, local power plants demanded about 19.85 Mt of coal in 2017–18, equivalent to 297.8 PJ in that fiscal year. Thus, the supply of torrefied pellets from peri-urban crop residues can meet between 2 and 3% of the demand from coal-fired power plants, resulting in a 0.3% decrease in the emissions from the power sector in India in 2017–18 (i.e., 922 MtCO 2), benefiting different sectors and levels of government. The analysis provides a framework for understanding the technical and institutional possibilities for strengthening the relationship between circular economy and climate change in the cities of developing countries by connecting flows and systems within and beyond urban centers. Therefore, the expansion of Circular Economy in cities can occur by integrating urban sectors and policy coordination at different levels of governance. Partnerships between local governments, utilities, and civil society for co-managing energy, water, and waste in cities can reduce the financial burden on national governments, including meeting national emission targets. [Display omitted] • Urban circular economy can be advanced using biomass in thermal power plants. • Our model estimates biomass contribution to national decarbonization targets. • Biomass pellets can meet between 2 and 3% of the demand from local coal-fired power plants. • Such replacement accounts for a 0.3% decrease (or 922 MtCO 2) in the emissions from India's power sector. • Results contribute to the design of CE models for cities and regions by including different levels of government and sectors. [ABSTRACT FROM AUTHOR]

British Columbia (BC) recently released the CleanBC policy framework to promote clean energy and mitigate greenhouse gas (GHG) emissions. However, CleanBC lacks concrete measures to reverse the growth of energy demand. Although BC has rich biomass and hydroelectric resources, it remains unclear whether these renewable resources will be enough to meet future energy demand. In this work, the potential in BC for increasing production and use of bioenergy, renewable electricity, and low‐carbon hydrogen was assessed, and the most efficient measures were identified. Energy scenarios were constructed to explore BC's future renewable energy demands for meeting GHG mitigation targets. The results show that CleanBC will drastically raise renewable energy demands but fail to achieve the 2030 target without radical demand reduction. Seen as the core strategy in CleanBC, electrification will require at least 60 PJ of additional electricity supply for 2030 and 160 PJ for carbon neutrality in 2050. This implies implementing wind and solar generation in capacities comparable to massive hydroelectric projects. Alternative to electrification is the bioenergy‐centred strategy. Existing waste biomass must be fully exploited; even then, roughly 250 and 460 PJ of additional primary bioenergy will be needed for 2030 and 2050, respectively, well beyond any foreseeable waste supply within BC. Hence, it is essential to utilize all the available biomass and renewable electricity resources and promote a diversified renewable energy portfolio. Hydrogen used as an energy carrier must be produced from natural gas with carbon capture to avoid competition for the limited renewable energy resources. [ABSTRACT FROM AUTHOR]

An increase in energy demand, fossil fuel reserves depletion, and environmental issues are primary reasons for renewable energy use, including power generation. Bioenergy is the primary alternative to conventional hydrocarbon fuels. Biomass-based power generation is increasing due to some reasons, including a gradual decrease in the levelized cost of electricity and a reduction of carbon dioxide emissions. Sorghum is a promising energy crop for semi-arid climate zones, including southern Ukraine. It can be used for both biofuel production and power generation. However, there is a lack of methodology for energy and environmental assessments of sorghum-based power generation. Some possible technologies were analyzed. The novelty of this study is the accounting of energy consumed and carbon dioxide emissions during crop cultivation. We have determined that sorghum-based power plants can generate from 2 to 12 MWh per hectare. Their operation significantly reduces carbon dioxide emissions (from 613 to 3652 kg of carbon dioxide per hectare of sorghum silage cultivation). Sorghum-based biogas plants have energy and environmental advantages if they use co-generation technologies and utilize digestate as a biofertilizer. The utilization of digestate (obtained from silage production per hectare) substitutes up to 12.8 MWh of indirect energy. The results obtained can be used by farmers and authorities for bioenergy development. [ABSTRACT FROM AUTHOR]

Over the years, cities have undergone transformations that, invariably, overload and even compromise the functioning of an energy matrix dependent on increasingly scarce resources. The high demand for energy has challenged stakeholders to invest in more sustainable alternatives, such as bioenergy, which, in addition, helps to reduce the pressure for finite resources, enable the energy recovery of waste and contribute to the mitigation of carbon emissions. For these improvements to be successful, stakeholders need specific technological strategies, requiring tools, methods and solutions that support the decision-making process. In this perspective, the current work aimed to develop a framework optimizing the evaluation of waste bioenergy projects through the application of algorithms. Therefore, a literature review was carried out to select the algorithms and identify the sectors/areas and stages in which they are applied. These algorithms were then grouped into two sequential phases. The first targeted the evaluation of region, based on the type and supply of biomass, while the second sought to optimize aspects related to infrastructure and logistics. Both phases were concluded with the application of multi-criteria methods, thus, identifying the areas/regions with the greatest potential for implementing bioenergy projects. In general, it was observed that there are different algorithms and multi-criteria analysis methods that can be suitable in bioenergy projects. They were used to identify and select the regions with the greatest potential for bioenergy plant implementation, focusing on the type, quantity and perpetuity of biomass supply, to assess the operational efficiency of machines, equipment, processes and to optimize the logistics chain, especially the collection and transport of biomass. Thus, the joint work between the use of algorithms and multi-criteria decision methods provides greater assertiveness in choices, helping to identify the most viable projects and mitigating risks and uncertainties for decision-makers. [ABSTRACT FROM AUTHOR]