In Poland, rapeseed production has been the fastest growing branch of plant production since 2000. Rapeseed yields have increased 2.5 times in the last 20 years. The main reason for this trend was the implementation of obligations resulting from legal acts by Member States relating to increasing the share of RES in the structure of primary energy production, and in particular relating to the share of biofuels in fuels used in transport. In Poland in the years 2010−2020, about 1.0−1.6 million tonnes of rape seeds were used for this purpose annually. Due to the fact that biofuel production competes for raw materials with the food economy, at the end of the first decade of the 21st century, many representatives of various circles intensified their voices, calling for withdrawal from the policy supporting the biofuel sector, which may have resulted in a decrease in oilseed plant cultivation areas. As a result of the research conducted here, it was determined that the place of oilseed rape... [more]

The potential of using the biomass of four wetland plant species (Iris pseudacorus, Juncus effusus, Phragmites australis and Typha latifolia) grown in treatment wetland systems and under natural conditions were tested to produce high-value materials using hydro-thermal liquefaction (HTL). The results show that the wetland plants biomass is suitable for biocrude and biochar production regardless of the origin. The hydrothermal liquefaction products’ (biocrude, biochar, aqueous and gaseous phase) yields vary according with the specific biomass composition of the species. Furthermore, the results show that the biomass composition can be affected by the growing condition (treatment wetland or natural unpolluted conditions) of the plants. None of the single components seems to have a determinant effect on the biocrude yields, which reached around 30% for all the analyzed plants. On the contrary, the biochar yields seem to be affected by the composition of the biomass, obtaining different yi... [more]

The lignocellulosic perennial crop miscanthus, especially Miscanthus × giganteus, is particularly interesting for bioenergy production as it combines high biomass production with low environmental impact. However, there are several varieties that pose a hazard due to susceptibility to disease. This review contains links showing genotype and ecological variability of important characteristics related to yield and biomass composition of miscanthus that may be useful in plant breeding programs to increase bioenergy production. Some clones of Miscanthus × giganteus and Miscanthus sinensis are particularly interesting due to their high biomass production per hectare. Although the compositional requirements for industrial biomass have not been fully defined for the various bioenergy conversion processes, the lignin-rich species Miscanthus × giganteus and Miscanthus sacchariflorus seem to be more suitable for thermochemical conversion processes. At the same time, the species Miscanthus sinens... [more]

Xylose is the second most abundant monomeric sugar on earth. Nevertheless, metabolizing xylose into ethanol is a complex process due to several biochemical reactions. Some microorganisms of the genus Mucor are suitable for this bioprocess. Using metal ions, such as zinc and calcium, allows some fungal species to increase their ethanol yield. In this work, the wild strain Mucor spp. (C1502) was molecularly identified via internal transcribed spacer (ITS) sequencing. Secondly, an optimization using response surface methodology (RSM) with a central composite experimental design (CCD) was carried out. The independent variables (X) were ZnSO4·7H2O (X1, 0.0−1.5 g/L) and CaCl2 (X2, 0.0−2.5 g/L) concentration in the fermentation broth in order to demonstrate the effect of these ions, xylose was used as the only carbon source. The dependent variables (Y) measured were ethanol yield (Y1, g ethanol/g xylose) and xylitol yield (Y2, g xylitol/g xylose). The identified strain, Mucor circinelloides,... [more]

A lot of residual biomass has energy value and can be used for further applications through suitable treatments, such as pelletization. This treatment can improve properties, mainly energy density, but can also lead to problems due to their low ash melting temperatures, high ash content, and the formation of harmful compounds during combustion. This article deals with the energy potential of pellets produced from spruce sawdust, spruce bark, and pine cones in different proportions. The impact of cone and bark contents on pellet properties was also observed. The energy properties of the produced pellets were measured, such as the contents of carbon, hydrogen, nitrogen, moisture, volatile, fixed carbon, and ash, as well as calorific values and ash melting temperatures. Based on the results, it can be concluded that the addition of pine cones and spruce bark to spruce sawdust mainly affected the contents of nitrogen and ash and melting temperatures. Despite this, all produced pellets met... [more]

This study analyzes the household energy needs of the indigenous community of San Francisco Pichátaro, Michoacán, Mexico, and the use of Pinus spp. wood residues for the production of briquettes. The energy and emission performances of wood briquettes were evaluated on the field and in the laboratory. On-field surveys and measurements show that most users combine the use of fuelwood and LPG for cooking and heating water, and 65% of people use fuelwood daily (40% of houses consumed more than 39 kg per week). The use of biomass waste is an energy option in rural communities and contributes to reducing firewood consumption and mitigating GHGs. Briquettes gasification to heat water reduces 74% of GHG emissions, increases the thermal efficiency by 30%, and reduces pollutant emissions of CO, CH4, and PM2.5, NMHC, EC, and OC by 50% to 75% compared to a three-stone fire. The use of briquettes on the Patsari stove showed energy savings of 12% and a 36% reduction in CO2e compared to the “U” type... [more]

The production of biofuels (biogas, ethanol, methanol, biodiesel, and solid fuels, etc.), beginning with cocoa pod husk (CPH), is a way for obtaining a final product from the use of the principal waste product of the cocoa industry. However, there are limitations to the bioconversion of the material due to its structural components (cellulose, hemicellulose, and lignin). Currently, CPH pretreatment methods are considered a good approach towards the improvement of both the degradation process and the production of biogas or ethanol. The present document aims to set out the different methods for pretreating lignocellulosic material, which are: physical (grinding and extrusion, among others); chemical (acids and alkaline); thermochemical (pyrolysis); ionic liquid (salts); and biological (microorganism) to improve biofuel production. The use of CPH as a substrate in bioconversion processes is a viable and promising option, despite the limitations of each pretreatment method.

Continuous urbanization and modernization have increased the burning of fossil fuels to meet energy needs across the globe, emanating environmental pollution and depleting fossil fuels. Therefore, a shift towards sustainable and renewable energy is necessary. Several techniques to exploit biomass to yield energy are trending, with pyrolysis one of them. Usually, a single feedstock is employed in pyrolysis for anoxygenic generation of biochar together with bio-oil at elevated temperatures (350−600 °C). Bio-oil produced through pyrolysis can be upgraded to crude oil after some modification. However, these modifications of bio-oil are one of the major drawbacks for its large-scale adoption, as upgradation increases the overall cost. Therefore, in recent years the scientific community has been researching co-pyrolysis technology that involves the pyrolysis of lignocellulosic biomass waste with non-biodegradable waste. Co-pyrolysis reduces the need for post-modification of bio-oil, unlike p... [more]

Biofuels are becoming more important in the renewable energy sources mix. Liquid biofuels are products of agriculture. Bioethanol can be prepared from corn, beetroot and other plants. Biodiesel is mainly made from rapeseed. This paper presents information about biodiesel development in Poland, as well as some background information about its development in the European Union (EU). We analyzed the data about biofuels in the literature, and provide statistical data about liquid biofuel in Poland and other countries of the EU. The aim of the study is to assess the viability of liquid biofuel development in Poland. The base for biodiesel production in Poland and the EU is rapeseed. The production yields and sown area of rapeseed increased in Poland from 2005−2020. This was due to integration and European Union policies which aim to supply clean energy. The energy mix in Poland differs from that of the EU. Solid biofuels have made up the biggest share of renewable energy sources in Poland (... [more]

The objective of this research project is to study the economic development model of the Angolan economy in order to analyze the adoption of an alternative strategy capable of leveraging the economy, based essentially on alternative energies, and therefore, to demonstrate and prove the need to diversify Angola’s economic model, highlighting the benefits of a diversified versus a non-diversified economy with respect to sustainability. The first stage of the design of this empirical study involved establishing a focus group in order to construct and adjust a data collection instrument in the form of a questionnaire to be applied to a broader set of managers and informed professionals with a critical view of the country’s future and the models and alternatives to economic development and diversification of the economy on a sustainable basis. Energy plays a fundamental role in Angola’s economic and social development. Excessive dependency on the oil sector and inefficient production due to... [more]

The European Union requirements related to the quality parameters for fatty acid methyl esters (FAMEs) are gathered in the standard EN 14214:2012 + A2:2019 that also includes reference to low-temperature properties. This paper presents studies on the obtaining of modified FAMEs, featuring improved low-temperature properties. Investigated fatty acid methyl esters (FAMEs) were subjected to a solvent dewaxing process with a methyl ethyl ketone and the mixture of methyl ethyl ketone—Toluene. It was found that the application of a process carried out under conditions similar to solvent dewaxing, used as a standard procedure for oils dewaxing and slack waxes of petroleum origin deoiling usually used in refinery industrial installations, allows us to achieve the intended goal. The modification of three different types of FAME by the dewaxing process with MEK-TOL and MEK solvents allows for the improvement of low-temperature properties of the obtained modified FAME, consistent in obtaining red... [more]

Miscanthus is a perennial wild plant that is vital for the production of paper and roofing, as well as horticulture and the development of new high-yielding crops in temperate climates. Chromosome-level assembly of the ancient tetraploid genome of miscanthus chromosomes is reported to provide resources that can link its chromosomes to related diploid sorghum and complex polyploid sugarcane. Analysis of Miscanthus sinensis and Miscanthus sacchariflorus showed intense mixing and interspecific hybridization and documented the origin of a high-yielding triploid bioenergetic plant, Miscanthus × giganteus. The Miscanthus genome expands comparative genomics functions to better understand the main abilities of Andropogoneae herbs. Miscanthus × giganteus is widely regarded as a promising lignocellulosic biomass crop due to its high-biomass yield, which does not emit toxic compounds into the environment, and ability to grow in depleted lands. The high production cost of lignocellulosic bioethano... [more]

Pyrolysis has been applied in the human economy for many years, and it has become a significant alternative to the production of chemical compounds, including biofuels. The article focuses mostly on recent achievements in the technical and processing aspects of pyrolysis. The aim of the review is to present the latest research on the process of waste biomass pyrolysis to fuel production. The paper describes the mechanisms of the pyrolysis process, composition, and properties of the obtained fractions, namely pyrolysis gas, bio-oil, and biochar. Additionally, the technical aspects of the pyrolysis process are mentioned, with particular attention to the construction of the reactors. The process of waste biomass pyrolysis allows for obtaining many chemical compounds (second-generation biofuels). Optimization of the pyrolysis process allows obtaining the desired products that are applied in the chemical industry, energy, and transport. The application of pyrolysis gas, oil, and biochar as... [more]

Biofuels are sustainable alternatives to fossil fuels because of their renewable and low-cost raw materials, environmentally friendly conversion technologies and low emissions upon combustion. In addition, biofuels can also be upgraded to enhance their fuel properties for wide applicability in power infrastructures. Biofuels can be produced from a wide variety of biomasses through thermochemical and biological conversion processes. This article provides insights into the fundamental and applied concepts of thermochemical conversion methods such as torrefaction, pyrolysis, liquefaction, gasification and transesterification. It is important to understand the physicochemical attributes of biomass resources to ascertain their potential for biofuel production. Hence, the composition and properties of different biomass resources such as lignocellulosic feedstocks, oilseed crops, municipal solid waste, food waste and animal manure have been discussed. The properties of different biofuels such... [more]

This article reviews a study of the impact of synthetic biocomponents on the operational properties of aviation turbine engine fuels. The objective of the research was to simulate the functioning of aircraft fuel supply systems during the popularization of synthetic components and to provide a preliminary study of the impact of particles of various synthetic components on processes within aviation turbine engine fuel systems—particularly the aviation turbine engine combustion system. The authors produced Jet A-1 fuel blends with two selected synthetic components A and B, accepted as per the ASTM D4054 procedure. The concentrations of each of the components were selected to simulate fuel compositions in an aircraft tank that could result from supplying fuel with different synthetic components. Such blends were studied using selected laboratory tests, lubricity using the BOCLE rig and an engine test using the MiniJetRig stand. The parameters of the following power functions were adopted... [more]

In this present investigation, emittance and performance attributes of a diesel engine using micro-algae spirulina blended biodiesel mixtures of various concentrations (20%, 35%, 50%, 65%, 80%, and 100%) were evaluated. An optimization model was also developed using an Artificial Neural Network (ANN) to characterize the experimental parameters. Experimental findings demonstrated significant improvement in brake specific fuel consumption (BSFC) using varied blends. Furthermore, brake thermal efficiency (BTE) is decreased gradually for biodiesel blends as compared to diesel. Micro-algae spirulina blends have shown lower concentrations of NOX and HC while increasing CO2 relative to pure diesel. To develop the model, three sets of optimizers, namely, adam, nadam, and adagrad, along with activation functions, such as sigmoid, softmax, and relu, were selected. The results revealed that sigmoid activation function with adam learning optimizer by using 32 hidden layer neurons has given the lea... [more]

Biofuels are increasingly important renewable resources in the world’s energy matrix that have challenged the scientific community as well as small and large farmers to develop alternatives to fossil fuels in order to achieve the aims of energy transition. In particular, Brazil’s proven competitiveness in agribusiness together with its rich biodiversity put the country in a key position in the biofuels market. The semiarid Caatinga of northeastern Brazil, an exclusive biome rich in many oilseed species suitable for potential energy purposes, is of particular interest in this field. Nowadays, soybeans are the main feedstock used for the production of biodiesel, but, due to the increasing demand for biofuels, the search for alternative sources of oil from tropical flora with high productivity is crucial. Under this premise, this systematic review focuses on mapping Caatinga’s vegetable oil crops that could be used as alternative raw materials for biofuels’ production in Brazil, in additi... [more]

Among the different alternatives for the production of biofuels, food waste could be a favorable bioenergy source. Using food waste as a feedstock has the potential to meet the expectations of the second generation of biofuels, in terms of environmental savings and revenue-generation, and which, along with other valuable co-products, can contribute to biorefinery profits. This study aimed to investigate the early stages of life-cycle assessment (LCA) for restaurant food waste processed into bioethanol, biomethane, and oil, split over different scenarios. Based on a life cycle inventory analysis, the environmental impacts were assessed using an IMPACT 2002+ methodology. The characterized impacts were then normalized against the average impacts, and the normalized results were weighted and aggregated to provide single score LCA results. The overall findings showed that electricity consumption and condensates included VFAs, as well as enzymes, yeast, and n-hexane, were the main contributo... [more]

While world energy demand has certainly decreased with the beginning of the COVID-19 pandemic in 2020, the need has been significantly on the rise since 2021, all as the world’s fossil fuel resources are depleting; it is widely accepted that these resources emit greenhouse gases (GHG), which are the leading cause for the climate crisis. The main contributors to global warming are manufacturing, energy, and agriculture. The agricultural sector is composed of diversified and potential mobilizable sources of waste which can become an attractive alternative to fossil fuels for energy production, and thus sequester and use carbon. Therefore, a paradigm shift towards more sustainable energy alternatives, efficient waste management, and new technologies is necessary. One good solution is the energetic valorization of lignocellulosic biomass (LCB) which can also originate from agricultural wastes. The biomass consists of cellulose, hemicellulose, and lignin, which are sources of fermentable su... [more]

In this study, two types of fermentation methods: SSF and consolidation SHF/SSF were used for production of acetone-butanol-ethanol (ABE) from corn straw as a feedstock. Clostridium acetobutylicum DSM1731 was used as the fermenting organism. Corn straw was thermochemically pretreated and then hydrolyzed using three types of enzymes. The impact has been investigated on the effect of mineral compounds supplementation ((NH4)2SO4, MgSO4, (NH4)3PO4) on ABE productivity and butanol content. From the SSF, where mineral salts were supplemented into the fermentation medium, it was found that the maximum ABE and butanol concentrations were 28.35 g/L and 24.03 g/L, respectively, corresponding to a productivities of 0.295 g/L/h (ABE) and 0.250 g/L/h (butanol). In the consolidation SHF/SSF method with mineral compounds supplementation, the maximum ABE and butanol concentrations were 31.35 g/L and 28.64 g/L, respectively, corresponding to productivities of 0.327 g/L/h (ABE) and 0.298 g/L/h (butanol)... [more]

In this work, a techno-economic assessment of the production of bio-oil, coke and gas, via thermo-catalytic pyrolysis followed by distillation, is accomplished. The raw materials were two solid wastes: lipid-based material (residual fat/scum from a fat retention box from the University Restaurant at the Federal University of Pará—UFPA) and a lignin-cellulosic material of açaí seed (Euterpe oleracea Mart.). From the literature, a review is made of the physicochemical analysis of the raw materials, of the bio-oil, and of the chemical composition of the biofuels produced (kerosene, light diesel, and heavy diesel). The bio-oil yields for each experiment of pyrolysis and distillation are also presented and compared with the literature. The economic indicators for the evaluation of the most viable cracking (pyrolysis) and distillation process of bio-oils were: (a) the simple payback criterion, (b) discounted payback, (c) net present value (NPV), (d) internal rate of return (IRR), and (e) ind... [more]

is a commercially exploitable source of bioactive compounds and biofuels with potential applications in microalgae-based industries. Despite this, little taxonomical information is available. Therefore, proper identification and characterization are needed for the sustainable utilization of isolated microalgae. In this study, an axenically isolated unicellular green alga from the Geumgang Estuary, Korea was investigated for its morphological, molecular, and biochemical characteristics. The morphological characteristics were typical of G. emersonii. Molecular phylogenetic analysis of the 18S rDNA sequence verified that the isolate belonged to G. emersonii and was subsequently named G. emersonii GEGS21. It was isolated from brackish water, and its optimal growth temperature, salinity, and light intensity were at 28−32 °C, 0 M NaCl, and 130−160 µmol m−2 s−1, respectively. The strain thrived over a range of temperatures (5−40 °C) and withstood up to 0.5 M NaCl. The isolate was rich in omeg... [more]

Microbial electrosynthesis is the process of supplying electrons to microorganisms to reduce CO2 and yield industrially relevant products. Such systems are limited by their requirement for high currents, resulting in challenges to cell survival. Electrofermentation is an electron-efficient form of microbial electrosynthesis in which a small cathodic or anodic current is provided to a culture to alter the oxidation−reduction potential of the medium and, in turn, alter microbial metabolism. This approach has been successfully utilised to increase yields of diverse products including biogas, butanediol and lactate. Biomass conversion to lactate is frequently facilitated by ensiling plant biomass with homofermentative lactic acid bacteria. Although most commonly used as a preservative in ensiled animal feed, lactate has diverse industrial applications as a precursor for the production of probiotics, biofuels, bioplastics and platform chemicals. Lactate yields by lactic acid bacteria (LAB)... [more]

Nitrogen explosive decompression pretreatment was tested on barley straw, aspen wood, and pine wood in a two-step pretreatment approach. The two-step approach aims to avoid the uncontrolled degradation of hemicellulose during pretreatment and to recover high sugar yields from hemicellulose and cellulose. Additionally, the pretreated biomass was filtered after each pretreatment step with a fine metal sieve so that fermentation and hydrolysis inhibitors were removed. A total sugar yield of 43 g per 100 g of dry biomass was achieved from barley straw and aspen wood. For pine wood, the total sugar yield was significantly lower, with 12 g per 100 g of dry biomass. Possible reasons for this low sugar yield are the adsorption and deactivation of cellulases on softwood hemicellulose and on repolymerized lignin after pretreatment.

The growing level of modern environmental problems and the need to ensure energy security creates new challenges for the development of the energy sector. Nowadays, countries must balance their international competitiveness and progress in achievement the Sustainable Development Goals. This provides a necessity for the development of alternative energy technologies. Modern trends in the development of alternative energy indicate a gradual increase in the relevance of biofuel production. At the same time, the development of clean energy technologies needs significant investments, and their commercial implementation is a long process. Moreover, energy industry transformations require significant changes in the functioning of complementary spheres. That makes necessary the use of additional incentives for the development of the bioenergy sector. Thus, an assessment of the impact of environmental taxes on biofuel production and consumption becomes crucial. This research is aimed at the ide... [more]