Biofuel Research Research Articles

Exploring the landscape of machine learning-aided research in biofuels and biodiesel: A bibliometric analysis

This bibliometric analysis explores machine learning applications in biofuels and biodiesel research using Elsevier's Scopus database from 2013 to 2023. The research employs co-authorship, co-occurrence, citation, and co-citation analyses with fractional counting. Results indicate a significant rise in publications. Prominent funding agencies along this field include the National Natural Science Foundation of China, Brazil's Conselho Nacional de Desenvolvimento Científico e Tecnológico and the U.S. Department of Energy. Co-authorship analysis reveals contributions from 268 authors across 951 organizations in 71 countries, with strong collaboration in Asia. Citation analysis shows that 95% of articles have received at least one citation, with China and the United States leading in citation counts. This study highlights the interdisciplinary and collaborative nature of machine learning research in biofuels and biodiesel, driven by substantial contributions from key funding bodies and researchers worldwide.

Advancements in biofuel research: Understanding the physical and chemical characteristics of green diesel

Green diesel is a potential biofuel that offers certain advantages over traditional fossil diesel, such as low environmental pollution and no sulfur. However, there is little information available regarding the density and viscosity of green diesel, which is crucial for the quality control of biofuels and their performance in engines. In this study, the properties of green diesel produced from palm and soybean oils hydrotreatment were investigated, and models were developed to predict the physical properties of green diesel and n-alkanes. The experimental measurements had uncertainties of 1×10-4 g/cm3 and 1×10-2 mPa s in density and viscosity, respectively. The models were found to be in good agreement with the experimental values. The study highlights the importance of density and viscosity for quality control and engine performance of biofuels. The developed models for predicting the physical properties of green diesel and n-alkanes can be useful for quality control and optimization of biofuel production processes. The findings can be useful for researchers, engineers, and policymakers working in the field of biofuels and renewable energy. Further research is needed to explore the applicability of the developed models to other types of biofuels and to investigate the environmental and economic sustainability of green diesel production.

Pre‐treatment with Trichoderma viride: Towards a better understanding of its consequences for anaerobic digestion

AbstractUnderstanding and optimising biological pre‐treatment strategies for enhanced bio‐methane production is a central aspect in second‐generation biofuel research. In this regard, the application of fungi for pre‐treatment seems highly promising; however, understanding the mode of action is crucial. Here, we show how aerobic pre‐treatment of crystalline cellulose with the cellulolytic Trichoderma viride affects substrate degradability during mesophilic, anaerobic digestion. It could be demonstrated that fungal pre‐treatment resulted in a slightly reduced substrate mass. Nevertheless, no significant impact on the overall methane yield was found during batch fermentation. Short chain organic acids accumulation, thus, overall degradation dynamics including methane production kinetics were affected by the pre‐treatment as shown by Gompertz modelling. Finally, 16S rRNA amplicon sequencing followed by ANCOM‐BC resulted in up to 53 operative taxonomic units including fermentative, syntrophic and methanogenic taxa, whereby their relative abundances were significantly affected by fungal pre‐treatment depending on the duration of the pre‐treatment. The results demonstrated the impact of soft rot fungal pre‐treatment of cellulose on subsequent anaerobic cellulose hydrolysis as well as on methanogenic activity. To the best of our knowledge, this is the first study to investigate the direct causal effects of pre‐treatment with T. viride on basic but crucial anaerobic digestion parameters in a highly standardised approach.

Exploration of hydrothermal liquefaction of multiple algae to improve bio-crude quality and carbohydrate utilization

With the growing emphasis on biofuels research, enhancing the utilization efficiency of the hydrothermal liquefaction (HTL) process for biomass has emerged as a focal point for researchers. In this study, HTL products from various algae species were analyzed to compare the quality of bio-crude, with a specific focus on the utilization of carbohydrates in biomass. Notably, bio-crude yields from high-lipid algae exhibited less fluctuation with temperature, while the quality showed a significant improvement with increasing temperature, as evidenced by the fatty acids and esters contents in the bio-crude. The results of elemental analysis indicated that bio-crude derived from high-lipid algae had a lower nitrogen content. In the analysis of carbohydrate utilization, it was observed that the aqueous phase products of Chlorella protothecoides demonstrated relatively high yields of furfural and 5-HMF. Similarly, the aqueous phase product of Spirulina exhibited comparatively high yields of levulinic acid. The inclusion of platform compounds in elemental recoveries contributed to an enhancement in the carbon and hydrogen recovery of the product. This study establishes a theoretical foundation for the selection of feedstocks for alternative fuels and highlights the potential of carbohydrates utilization from algal biomass.

Biomass Resources and Biofuel Technologies: A Focus on Indian Development

As a result of the depletion of fossil resources, ongoing population growth, and the industrialized economy, energy demand has been rising quickly throughout the world. India is now the world’s third-largest oil consumer, surpassing Japan and Russia. Today, biofuel research is conducted worldwide because surrounding two essential characteristics: sustainability and renewability. Biofuels have gained considerable significance as a result of dwindling oil sources, worries about energy security, and the escalating environmental issues associated with climate change and greenhouse gas emissions. In most cases, biofuels are produced by subjecting materials that have been densified to the process of heat conversion. In the disciplines of research and development, alternative energy development is a top focus. Due to the depletion of fossil fuel resources, it has become important to find innovative replacements for fossil fuels, such as biofuels, to generate heat and power. Biofuels may be generated using several methodologies, encompassing biological, chemical, and physical approaches. The three steps of densification systems’ pre-, during-, and post-pelletization procedures convert biomass into pellets. Several agricultural wastes, such as grain dust, crop leftovers, and fruit tree residues, are available as sources of agricultural energy. Bioenergy from biomass, such as leftovers and energy crops, can be used to produce contemporary energy carriers. This article focuses on an overview of sustainable and renewable biofuel resources and their commercialization.

Technology Research and Development Prospects of Biofuels

The energy consumption that results from economic growth and the pollution it releases into the environment has been the subject of widespread concern in academics and society in recent years, and they have grown in importance as the times progress. There is a growing need for renewable and alternative energy sources due to the possible depletion of non-renewable fossil energy sources like coal and oil as well as the acceleration of global climate change. One of the hottest areas of study right now is the hunt for clean, renewable, and alternative energy sources. A thorough analysis of the biofuels industry's present level of growth indicates a dynamic environment fueled by the rising demand for sustainable energy throughout the world. This review aims to analyze in detail the research background, significance, and rationale for selecting biofuels. It will start with first-generation biofuels and focus on the current third-generation biofuels. Biofuels derived from renewable bioresources have emerged as a promising alternative because of the need to address environmental issues associated with traditional fossil fuels. The dual impact of biofuels on reducing greenhouse gas emissions and enhancing energy security is explored. The choice to focus on third-generation biofuels emphasizes the commitment to innovation and is in line with the United Nations sustainable development goals, in particular those related to clean energy, climate action, and environmental protection.

Exploring the Synergy of Biofuels and Artificial Intelligence

This abstract provides an overview of Professor Fernando Gomes de Souza Junior's lecture "Exploring the Synergy of Biofuels and Artificial Intelligence," presented at the IBMEC Lecture's Discussion Series on Industry and Energy on September 6, 2023. Prof. Gomes, an accomplished researcher in polymer science and nanotechnology, discusses the intersection of biofuels and artificial intelligence. He highlights the importance of leveraging machine learning and data mining techniques to harness the vast knowledge repository in renewable energy research. Prof. Gomes presents a groundbreaking 2023 study that utilizes advanced computational tools to analyze the dynamics of nanocatalysts in biofuel production, revealing insights into research trajectories, global trends, and shifting focal points. He further discusses the application of machine learning in optimizing biodiesel synthesis, emphasizing its potential for enhancing efficiency and economic benefits in biofuel production. Prof. Gomes underscores artificial intelligence's significance in shaping biofuel research's future and encourages researchers to embrace emerging trends in this transformative field.

Catalytic pyrolysis of vegetable oils over NbOPO4 for SAF and green diesel production

Drop-in biofuels for aviation have been pointed out as a sustainable alternative for reducing the emission of greenhouse gases. These fuels are hydrocarbons and have a performance and composition similar to fossil fuels. Developing conversion routes for their production has stimulated different research projects and is considered one of the most challenging areas in biofuels research. In the present study, the liquid phase was analyzed and the biohydrocarbons were obtained from vegetable oils in the distillation range of gasoline, diesel, and aviation kerosene using NbOPO4 as a catalyst in the pyrolysis process. This catalyst was characterized by XRD and gas adsorption/desorption methods (BET, BJH, and TPD). The fatty materials' simultaneous deoxygenation, cracking, and partial isomerization reactions were performed at 350 °C under N2 atmosphere (10 bar), with up to 95% conversions. Considering the overlap of carbon chains in the fuel ranges, this study demonstrates that it is possible to obtain up to 21%, 83%, and 80% of biogasoline, Sustainable Aviation Fuel (SAF), and green diesel, respectively. The products were characterized by infrared spectroscopy and gas chromatography coupled with mass spectrometry. The freezing temperatures of the products without any purification treatment and their mixtures with fossil kerosene were measured by DSC. The SAF obtained after the distillation step, presented a freezing point of − 47 °C, in agreement with the standard ASTM 7566. This innovative, sustainable, and low-cost process is promising for industrial use, mainly because hydrogen was not used, and reactions were performed in a one-pot procedure.

Algae biogas production focusing on operating conditions and conversion mechanisms – A review

Global warming is the result of traditional fuel use and manufacturing, which release significant volumes of CO2 and other greenhouse gases from factories. Moreover, rising energy consumption, anticipated limitations of fossil fuels in the near future, and increased interest in renewable energies among scientists, currently increase research in biofuels. In contrast to biomass from urban waste materials or the land, algae have the potential to be a commercially successful aquatic energy crop, offering a greater energy potential. Here we discuss the importance of Anaerobic Digestion (AD) for enhanced biogas yield, characterization, and comparisons between algae pretreatment methods namely, mechanical, thermal, microwave irradiation, and enzymatic and catalytic methods. The importance of anaerobic digestion enhances biogas yield, characterization, and comparisons between mechanical, thermal, microwave irradiation, and enzymatic and catalytic treatment. Additionally, operational aspects such as algal species, temperature, C/N ratio, retention period, and particle size impact biofuel yield. The highest algal biogas yield reported was 740 mL/gVS, subtracted from Taihu de-oiled algae applying thermos-chemical pretreatment under conditions of temperature, time, and catalyst concentration of 70 °C, 3 h, and 6%, respectively. Another high yield of algal-based biogas was obtained from Laminaria sp. with mechanical pretreatment under temperature, time, and VS concentration of 38 ± 1 °C, 15 min, and 2.5% respectively, with a maximum yield of 615 ± 7 mL/g VS. Although biofuels derived from algae species are only partially commercialized, the feedstock for biogas might soon be commercially grown. Algae and other plant species that could be cultivated on marginal lands as affordable energy crops with the potential to contribute to the production of biogas are promising and are already being worked on.

Sustainable innovations in biofuels in Brazil and substituion of fossil fuels: a systematic literature review

Given the growing global concern with the increase in terrestrial temperature due to the unrestrained emission of greenhouse gases, solutions have been sought to minimize the environmental and social damage caused by them. One of the best options currently available is biofuels, which are renewable and sustainable and have various applications. In this context, this study aimed to systematically analyze the published studies on new biofuels, time of energy transitions, factors that influence the development and diffusion of technologies capable of replacing fossil fuels, advantages, and disadvantages of each application, in addition to the main trends and gaps in the area in Brazil. The articles were searched in the Science Direct database using the keywords “biofuel AND sustainable innovation AND Brazil AND multi-level” and filtering by category review articles and research articles. One hundred and twenty-six articles were obtained, which were analyzed for objectives, methodology, main results, conclusions, links with sustainable innovation, and the year of publication. The results showed that there is a large focus of research on traditional renewable energy sources, such as ethanol, biomethane, kerosene, and hydrotreated vegetable oil, in addition to the fact that most studies are of the qualitative type. Nonetheless, there has been a significant increase in publications after 2015, mainly justified by creating the Sustainable Development Goals and RenovaBio. Thus, the importance of obtaining new sources and processes for biofuels is highlighted and, in this way, achieving a development that encompasses environmental, social, and financial benefits for all related parties, as well as for the population in general, because there is still a large research gap in the area, and further incentives and investments are necessary for research, development, implementation, and dissemination of biofuels.

Enhancement of biogas yield from dual organic waste using hybrid statistical approach and its effects on ternary fuel blend (biodiesel/n‐butanol/diesel) powered diesel engine

AbstractEconomic and environmental concerns have driven biofuel research in the last few decades. In order to this, biogas production is being encouraged on a worldwide scale to reduce carbon emissions and increase resource recovery from diversified wastes. The present contribution involves finding the best way to turn food waste and animal manure into biogas and its effective utilization in a dual‐fuel mode diesel engine. For the experimentation, a Taguchi approach was used to develop an L25 orthogonal array with three factors and five levels of parameters: cattle dung and food waste ratios, retention times, and digester temperatures. Using the response surface method (RSM), genetic algorithm (GA), and cuckoo search algorithm (CSA), the biogas yield was optimized and compared to get the best optimization technique. Based on the specific goals of the study, GA is the best combination of parameters for producing biogas. The optimal condition for producing biogas was a cattle dung and food waste ratio of 0:100 (wt/wt %) with a retention time of 15 days and a digester temperature of 40°C, and the corresponding value of the biogas yield was 551.633 mL/day. Experiments were done to confirm this prediction. This study also intends to determine the viability of ternary fuel blends (microalgae biodiesel, n‐butanol additive, and diesel) as a pilot fuel and biogas as a primary fuel by changing their mass flow rates (0.5, 1.0, and 1.5 kg/h) in the CI engine. The D70BD20Bu10 ternary fuel blend with 1.5 kg/h of biogas flow rate was found to be an optimum blend due to its improved performance and emission characteristics compared to other tested fuels. This fuel blending improves brake thermal efficiency (BTE) by 6.25% and reduces brake‐specific fuel consumption (BSFC) by 2.14%. NOx and smoke emissions were both reduced by 58.22% and 54.59%, respectively. However, HC and CO emissions were on the higher side compared to diesel.

Effects of Aloe Vera Biodiesel Blends with TiO2 on the Emission and Performance Characteristics of a DI Diesel Engine

Concerns about the effect of activities that need the use of alternative fuels, as well as a growth in demand for clean energy, have made biofuels research more well-known, and so began the search for oilseed plants that can be used to make biodiesel. Present research was carried out the aloe vera oil is used as a biodiesel in diesel engine. Because aloe vera oil having higher calorific value compare to other sources. Potassium hydroxide catalyst was used for transesterification process, which has lesser cost and more availability. And also, in this work conducted diesel engine experiments using four different biodiesel blends (B20, B40, B60, B100) and diesel fuel. Additionally, to reduce the emission nano particles (TiO2) was blended with optimal biodiesel blend (B20). The performance and emission characteristics were conducted with different biodiesel blends. In this blends, B20+ TiO2 blend gives good performance and reduction in emissions compared to other biodiesel blends.

An improved phenol-sulfuric acid method for the quantitative measurement of total carbohydrates in algal biomass

Total carbohydrate analysis with phenol‑sulfuric acid method is the simplest method among many colorimetric and modern instrument analytical methods. It has great potential to be used as a rapid screening method for characterization of algal biomass for algae-based biofuel research. The reproducibility and accuracy of the conventional phenol‑sulfuric method remain to be improved when applied directly to algal biomass. In the present study, several important factors that influenced the colorimetric determination were characterized and methods to eliminate the influences were further developed. Results indicated that system temperature and the addition mode of sulfuric acid and phenol were the key parameters which affected the color development and reproducibility of the conventional methods. A new design using the premixed reagent replacing the individual phenol and sulfuric acid solution solved this problem ideally. The color inferences caused by algal pigments including chlorophylls and carotenoids were quantitatively analyzed. Solutions for reducing overestimation of total carbohydrates were also addressed. In addition, hydrolysis conditions for algae biomass such as type of acids, temperature, and time were also investigated and optimized in this study. The new modified phenol‑sulfuric acid method has been shown to be more reproducible and reliable than the conventional methods for the analysis of total carbohydrates from algal biomass.

Utilization of nanomaterials in accelerating the production process of sustainable biofuels

Around 84 % of the global energy needs are met by fossil fuels, notwithstanding their several drawbacks. Dependence on fossil fuels can be reduced when biofuels become more widely used. Compared to fossil fuel, biofuel is substantially less combustible and derived from renewable resources. Biofuel production from non-edible feedstocks can be enhanced by utilizing nanotechnology. Biofuel research to date has produced promising results, but very few recent studies have underlined the use of nanotechnology to enhance the biofuel production process. This study comprehensively reviews the potential use of nanotechnology in improving biofuel production processes. It also highlights the factors that affect nanomaterial performance in the biofuel production process. The nickel oxide (NiO) nanoparticles (NPs) are shown to be highly efficient, with harvestingChlorella vulgarisbiomass at an efficiency of 98.75 % in 1 min at pH 7. In terms of cost-effectiveness, naked modified magnetic nanoparticles (MNPs) cost significantly less, ranging from £3-500 to £0.5–108 per kg following nanoparticle reactivation. Due to their toxicity, nanomaterials used in biofuel production systems have several detrimental effects on living organisms, the environment, and the economy. Developing non-toxic nanomaterials, utilizing cheaper nanoparticles, and doing additional research might increase knowledge availability and understanding to address the current issues.

Development of a stable semi-continuous lipid production system of an oleaginous Chlamydomonas sp. mutant using multi-omics profiling

BackgroundMicroalgal lipid production has attracted global attention in next-generation biofuel research. Nitrogen starvation, which drastically suppresses cell growth, is a common and strong trigger for lipid accumulation in microalgae. We previously developed a mutant Chlamydomonas sp. KAC1801, which can accumulate lipids irrespective of the presence or absence of nitrates. This study aimed to develop a feasible strategy for stable and continuous lipid production through semi-continuous culture of KAC1801.ResultsKAC1801 continuously accumulated > 20% lipid throughout the subculture (five generations) when inoculated with a dry cell weight of 0.8–0.9 g L−1 and cultured in a medium containing 18.7 mM nitrate, whereas the parent strain KOR1 accumulated only 9% lipid. Under these conditions, KAC1801 continuously produced biomass and consumed nitrates. Lipid productivity of 116.9 mg L−1 day−1 was achieved by semi-continuous cultivation of KAC1801, which was 2.3-fold higher than that of KOR1 (50.5 mg L−1 day−1). Metabolome and transcriptome analyses revealed a depression in photosynthesis and activation of nitrogen assimilation in KAC1801, which are the typical phenotypes of microalgae under nitrogen starvation.ConclusionsBy optimizing nitrate supply and cell density, a one-step cultivation system for Chlamydomonas sp. KAC1801 under nitrate-replete conditions was successfully developed. KAC1801 achieved a lipid productivity comparable to previously reported levels under nitrogen-limiting conditions. In the culture system of this study, metabolome and transcriptome analyses revealed a nitrogen starvation-like response in KAC1801.

Impacts of Palm Oil-based Biofuel Utilization Promotion Policy in the Thai Transport Sector

This paper aims to provide an analysis of the impacts of the promotion policy of palm oil-based biofuel utilization in the Thai transport sector for the period 2020–2037. For this purpose, three scenarios are developed to represent different proportions of palm oil-based biofuel blending implemented in Thailand and their impacts are analyzed through the application of the Low Emissions Analysis Platform (LEAP) model. The analysis reveals that an increase in the proportion of palm oil-based biofuel in a diesel mix would provide several noticeable benefits, for example, help reducing diesel consumption, decreasing crude oil requirement, and mitigating emissions of CO2 and PM2.5 – a major source of current environmental health problems. In addition, increased proportion of palm oil-based biofuel in the diesel mix would contribute to a growing demand for oil palm production and a plantation area to meet an increase in palm oil-based biofuel production. A high demand for oil palm production and plantation land requirement could, however, be emerging challenges. In order to address these challenges, the effective strategies could include a plan for agricultural crop zoning, crop breeding, the efficiency enhancement of biofuel conversion technology, the reduction of chemical fertilizers and pesticides, and the support from the government for research and development of second-generation biofuels. The analysis will be useful for Thai planners and policy makers to design policies to overcome the issues of energy and food security as well as climate change problems.

TRENDS AND PERFORMANCES OF THE ALGAL BIOFUEL: A BIBLIOMETRIC APPROACH

The paper systematically presents a survey of the literature on algal biofuel by a bibliometric assessment. Based on 10,201 articles extracted from the Science Citation Index Expanded database during 1980–2019, a knowledge-generating system about algal biofuel has been established through analysis of publication performance, social networks, citations analysis and keywords analysis. Annual publication output in algal biofuel research has rapidly increased, particularly over the past decade. “Bioresource Technology” is the most outstanding journal when all analysis indices have been taken into account. The USA ranks 1st with 2,151 publications and has a high supremacy in international research collaborations. Through the analysis of keywords, the research trends of algae biofuel in algae selection, cultivation, harvesting, extraction, conversion and bioproducts are reviewed. The future of algal biofuel is quite promising, however, for its commercial production, several technical challenges like large-scale algal biomass production, cheap harvesting technology, etc. have to be met a-priori.

Possibilities of using thermal and mineral springs of the Republic of Kazakhstan as a medium for the cultivation of microalgae – biodiesel producers

Microalgae are characterized by rapid photoautotrophic growth and a high rate of biomass accumulation and are considered as an alternative feedstock for renewable energy sources such as biodiesel. Biofuel research is not just a matter of finding the right type of biomass and converting it into fuel, but also finding environmentally and economically viable options. The paper presents the results of studies on the use of thermal and mineral water sources as a medium for the cultivation of microalgae Parachlorella kessleri DZP-5, Parachlorella kessleri B2 and Ankistrodesmus falcatus B5. It was shown that when using water from the «Arshan» thermal water source and the Balkhash salt lake to dilute the Tamiya medium in a ratio of 50:50, it is possible to obtain an intensive growth of microalgae cultures and at the same time preserve the main characteristics of microalgae producers of biodiesel fuel. The composition of fatty acids of three tested strains of microalgae is also given, which showed their potential as producers of biodiesel. Key words: microalgae, thermal and mineral springs, cultivation, biodiesel producers, fatty acids.

Biofuel formation from microalgae: A renewable energy source for eco-sustainability

In the current scenario, biofuel production from microalgae is beneficial to sustainability. Recently, one of the most pressing concerns has been finding cost-effective and environmentally friendly energy sources to meet rising energy demands without jeopardizing environmental integrity. Microalgae provide a viable biomass feedstock for biofuel production as the global market for biofuels rises. Biodiesel made from biomass is usually regarded as one of the best natural substitutes to fossil fuels and a sustainable means of achieving energy security and economic and environmental sustainability. Cultivating genetically modified algae has been followed in recent decades of biofuel research and has led to the commercialization of algal biofuel. If it is integrated with a favorable government policy on algal biofuels and other byproducts, it will benefit society. Biofuel technology is a troublesome but complementary technology that will provide long-term solutions to environmental problems. Microalgae have high lipid content oil, fast growth rates, the ability to use marginal and infertile land, grow in wastewater and salty water streams and use solar light and CO2 gas as nutrients for high biomass development. Recent findings suggest nano additives or nanocatalysts like nano-particles, nano-sheet, nano-droplets, and nanotubes. Some specific structures used at various stages during microalgae cultivation and harvesting of the final products can enhance the biofuel efficiency and applicability without any negative impact on the environment. It offers a fantastic opportunity to produce large amounts of biofuels in an eco-friendly and long-term manner.

A systematic method for selecting molecular descriptors as features when training models for predicting physiochemical properties

Machine learning has proven to be a powerful tool for accelerating biofuel development. Although numerous models are available to predict a range of properties using chemical descriptors, there is a trade-off between interpretability and performance. Neural networks provide predictive models with high accuracy at the expense of some interpretability, while simpler models such as linear regression often lack in accuracy. In addition to model architecture, feature selection is also critical for developing interpretable and accurate predictive models. We present a method for systematically selecting molecular descriptor features and developing interpretable machine learning models without sacrificing accuracy. Our method simplifies the process of selecting features by reducing feature multicollinearity and enables discoveries of new relationships between global properties and molecular descriptors. To demonstrate our approach, we developed models for predicting melting point, boiling point, flash point, yield sooting index, and net heat of combustion with the help of the Tree-based Pipeline Optimization Tool (TPOT). For training, we used publicly available experimental data for up to 8351 molecules. Our models accurately predict various molecular properties for organic molecules (mean absolute percent error (MAPE) ranges from 3.3% to 10.5%) and provide a set of features that are well-correlated to the property. This method enables researchers to explore sets of features that significantly contribute to the prediction of the property, offering new scientific insights. To help accelerate early stage biofuel research and development, we also integrated the data and models into a open-source, interactive web tool.