Biodiesel Production Research Articles

Carbon Footprint Mitigation in the Manufacture of Biodiesel from Recycled Frying Oil Using Ethanol as an Alternative

Increasing climate change is driving the search for more sustainable strategies to mitigate the environmental impacts associated with the production of biodiesel derived from frying oil. Although the transesterification of frying oil (FA) allows obtaining biodiesel, the inputs used in this process can have a high environmental cost, particularly in terms of Carbon Footprint (CF). The use of ethanol as a reagent in the transesterification of FA appears as a promising alternative, with the potential to significantly influence the Life Cycle Assessment (LCA) of biodiesel and reduce its carbon footprint. In this study, the HC was evaluated for the LCA of the production of 1 kg of biodiesel under two experimental conditions: a 1:6 molar ratio of methanol-AF and a 1:9 ratio of ethanol-AF, using potassium hydroxide (KOH) at 0.35 % as catalyst and the subcritical temperatures of both alcohols to obtain biodiesel in a short time. The methodology included the definition of the LCA according to ISO 14067:2018, the elaboration of a greenhouse gas (GHG) emissions inventory for each stage of the production process and the calculation of the HC using CCalC2 software. Five key stages in the production of biodiesel from FA were identified. The results showed that the CH of biodiesel produced with methanol is 5.79 kg CO2eq per functional unit (FU), while biodiesel obtained with ethanol plus 5 has a CH of 5.35 kg CO2eq/UF. This represents an environmental improvement of 7.60 % in favour of ethanol. Thus, it is concluded that the use of ethanol offers superior environmental performance in the LCA of biodiesel made from frying oil.

Enhancing Lipid Extraction and Transesterification Efficiency to Optimise Microalgal Biodiesel

The global quest for sustainable energy solutions has intensified as the adverse effects of fossil fuel consumption become increasingly evident. Rising energy demand underscores the need for biofuels derived from biological sources to reduce reliance on fossil fuels. Among various biomass sources, microalgae have emerged as promising biodiesel feedstock due to minimal resource requirements, rapid growth, and superior carbon fixation efficiency compared to terrestrial crops. In this contribution a review on the microalgae-derived biodiesel is presented, with particular attention to the role of lipid extraction and transesterification processes. Advancements in upstream processes – cultivation methods such as phototrophic, heterotrophic, and mixotrophic systems, harvesting, and dewatering – and downstream processes, including lipid extraction, conversion, and purification are critically discussed. A scheme of the key steps is represented in the figure. The review focuses on the role of chemical and enzymatic catalysts in enhancing transesterification efficiency, achieving yields of up to 94 %. Homogeneous catalysts, including base and acid types, are highlighted for the high activity, with base catalysts excelling under mild conditions and acid catalysts proving more effectiveness for high free fatty acid content. Heterogeneous catalysts are emphasized for the reusability, non-corrosiveness, and reduced environmental impact, although challenges like limited mass transfer and catalyst deactivation persist. Enzymatic systems, especially those enhanced with magnetic nanoparticles, are shown to achieve up to 93 % fatty acid ethyl ester yields while mitigating issues such as saponification and high energy demands of traditional methods. Additionally, emerging non-catalytic approaches, such as supercritical fluid technology, are highlighted for the ability to achieve single-step conversion of algal lipids to biodiesel, with yields exceeding 85 %. Finally, this contribution explores the potential of genetic and biochemical engineering to boost lipid productivity and metabolic efficiency, advancing toward fourth-generation biofuels. Indeed, recent results underscore the viability of microalgae as keystone in the global transition to sustainable energy. However, economic and technical barriers, such as high production costs and energy requirements, currently hinder large-scale implementation of microalgae-based biodiesel. Current interdisciplinary research prioritize cost-effective cultivation systems, innovative reactor designs, and strategies for co-product utilization within algal biorefineries to achieve scalable and sustainable biodiesel production.

Influence of methyl and ethyl esters-based biodiesel synthesized from safflower oil on the performance, combustion, and exhaust emissions

Abstract Methanol production relies mainly on fossil resources, while ethanol is largely produced from renewable feedstocks. This distinction supports transitioning biodiesel production from fossil-based methanol to bio-based ethanol. While safflower methyl ester has undergone extensive investigation as an alternative fuel source, research exploring safflower ethyl ester remains limited. This experimental study aims to reveal the effects of safflower oil-derived ethyl ester blends on diesel engine performance, combustion, and emission characteristics. The research compared pure ethyl and methyl esters, ester blended fuels, and ultra-low sulfur diesel under various engine loads at a constant speed of 1500 rpm. All fuels exhibited similar cylinder pressure curves, with pressure increasing proportionally to engine load. Ethyl ester fuels showed the earliest combustion start, while pure methyl ester and diesel had retarded ignition timing. Ester blends generally showed lower brake thermal efficiency up to an average of 8.49%. However, this was followed by ethyl ester–diesel blends with a slight decrease up to 1.8%. Ethyl ester fuels had lower mass fuel consumption at low loads. The blends of ethyl esters with 20% diesel showed the second lowest brake-specific fuel consumption but it showed an average reduction of 8.2%, while diesel had the lowest value throughout experiments. Ester fuels generally produced lower carbon monoxide emissions up to an average value of 13.4% compared to diesel. Methyl ester with 20% diesel blend showed lower carbon dioxide emissions by 2% compared to other fuels. Pure biodiesels showed significantly increased hydrocarbons emissions up to 50.8% on average. Ester fuels produced lower nitrogen oxides emissions up to an average of 17.8% relative to diesel fuel. The study concludes that safflower-based biodiesel, particularly with ethyl and methyl esters, is a viable alternative fuel. Graphical abstract

From Waste to Polyurethanes: Environmental Assessment of Bio-Polyols Based on Used Cooking Oil

Used cooking oil (UCO) is a valuable resource that can be utilized in different ways, from animal feed and biodiesel production to bio-based feedstock for polymeric materials. UCO is a cheap, renewable resource that can be utilized as an input to produce polymer precursors like polyols, the starting material for polyurethane. Due to the fact that the European Union has recognized the bio-based industrial sector as a priority area for sustainability, it is crucial to evaluate the environmental performance of bio-based products. UCO was successfully employed to synthesize bio-polyols that will be used to produce a two-component polyurethane system. Experimental results at the laboratory showed that UCO, a biogenic waste stream, can be successfully used as a renewable feedstock for polyurethane production. The aim of the study was to evaluate the environmental impact of UCO-based bio-polyols developed at the Latvian State Institute of Wood Chemistry suitable for development of flexible polyurethane foams. The chosen system boundary was cradle-to-(laboratory) gate and the functional unit was 1 kg UCObased bio-polyol. The production system for bio-polyols included feedstock production, required energy, and other chemicals needed for the synthesis process. The LCA model was built according to the ISO 14040/44:2006 series. LCA analysis was performed using SimaPro 9.6 software by Pré Consultants. Potential environmental impacts were assessed according to ReCiPe’s (2016) v1.1 midpoint method and global warming potential (GWP) was assessed using the Intergovernmental Panel on Climate Change (IPCC), 2021 GWP 100a’ method. Results show that GWP for UCO-based bio-polyols was more than 40 % lower than petrochemical polyols. ReCiPe results indicate that chemicals besides the UCO used in bio-polyol synthesis contribute around 70 % to the environmental impact, electricity consumption 20 % and 10 % contributes waste generated. LCA results can provide guidance on the improvement options of the UCO-based bio-polyol synthesis process. The results show the importance of life cycle assessment integration in the earlystage development of new bio-based precursors and polymers.

Experimental Investigation of Performance and Emission tests using biodiesel from custard apple seeds oil in CI engine

The depletion of world petroleum reserves and increase environmental concern have stimulated the search of alternative fuel which is to be environment friendly. Bio-fuels have the potential to become alternative fuel for fossil fuels. Biodiesel is renewable, reliable, biodegradable and regarded as clean alternative fuel to reduce exhaust emission. In recent years, much research has been carried to find suitable alternative fuel to petroleum products. In the present investigation experimental work has been carried out to analyze the performance and emission characteristics of a single cylinder compression ignition CI engine fueled with the blends of mineral diesel and biodiesel. The custard apple seeds oil biodiesel is considered as alternative fuels to diesel. A large amount of tree borne oil and fats are available for biodiesel production in developing and under develop countries. Custard apple seeds oil is one of these oils. The utilization of liquid fuels such as biodiesel production from custard apple seeds oil by transesterification process represents one of the most promising options for the use of conventional fossil fuels. However, as the biodiesel is produced from vegetable oils and animal fats, there are concern that biodiesel feed stock may compete with food supply in the long-term. Hence, the recent focus on using custard apple seeds as the substantial feed stocks for biodiesel production.

The Use of Canola for Biofuel Production in the Context of Energy Security—A Systematic Literature Review

This study examines the evolving role of canola biofuel in achieving energy security, analyzing its historical significance, current challenges, and prospects. Once a dominant feedstock for biodiesel production in Europe, canola biofuel is facing a decline in relevance due to the emergence of second- and third-generation biofuels, which offer greater economic and environmental advantages. The research highlights key factors influencing this shift, including high production costs, resource-intensive cultivation, and suboptimal life cycle environmental performance. Through correlation and causality analyses, the study finds no definitive relationship between oil prices and the frequency of scientific publications on canola biofuels, suggesting other drivers, such as policy and technological advancements, play a more significant role. Despite its diminishing prominence, canola biofuel retains value in energy diversification and rural agricultural support, due to geographic, policy, and investment constraints. The findings emphasize the need for prioritizing the development of more sustainable and efficient biofuel technologies to address global energy and environmental challenges.

Enhancing sustainability in meat production through insect biorefinery

Valuable feed crops and fossil fuel energy are used to produce animal meat. To become sustainable, meat production methods must adapt to include non-food substrates and renewable fossil-fuel alternatives. We evaluated the potential of protein livestock feed and biodiesel production through insect biorefining. The bioconversion efficiency of organic waste into black soldier fly larvae (BSFL) biomass was 32.0–35.8% after 24 d. The protein and lipid composition of BSFL changed with the cultivation time. The substrate influenced lipid content, and low lipid content led to lower lipid accumulation in the BSFL. Nevertheless, the potential productivity of proteins (42,471–48,345 kg ha−1 y−1) and lipids (41,642–64,708 kg ha−1 y−1) from BSFL cultivation with organic waste was higher than that of conventional livestock feed/biodiesel feedstocks, such as maize or soybean. In conclusion, insect biorefineries using BSFL can contribute significantly to the establishment of sustainable meat production.

Optimization of Fuel Injection Timing and Pressure in CI Engines Using Waste Cooking Oil Biodiesel with Response Surface Methodology

<p>The global automotive industry is under mounting pressure to adopt highly efficient, low-emission engine technologies due to stringent regulations and increasing environmental awareness. In response, researchers are exploring alternative fuels, such as biodiesel, to enhance energy independence and reduce emissions. Waste cooking oil (WCO) is a particularly promising biodiesel feedstock as it addresses the food-versus-fuel debate, provides a waste management solution, and is widely available. Many countries, both developed and developing, are actively encouraging biodiesel production from WCO. This research looks at a water-cooled farm engine with one cylinder and four strokes that uses WCO instead of diesel. Using diesel and WCO at conventional injection times and pressures, preliminary testing established baseline performance. The engine was then sent through its paces with different fuel pressures (200, 350, and 500 bar) and injection timings (23°, 25°, and 27° crank angle). Experimental results revealed that variations in FIT and FIP with WCO biodiesel significantly improved engine performance. Injection pressure of 350 bar with advanced injection time of 27° CA resulted in the greatest Brake thermal efficiency (BTE) of 31.18%. Compared to a FIP of 350 bar and FIT of 23° CA, BTE increased by 2.93% and 12.21% at FIPs of 200 bar and 500 bar, respectively, with the same FIT at maximum load. Hydrocarbon (HC) emissions were reduced by 1.29% and 6.5% at a FIP of 350 bar and 200 bar, respectively, compared to 500 bar, all with a FIT of 27° CA at maximum load. Carbon monoxide (CO) emissions also showed significant reductions of 12.2% and 5.6% at FIPs of 350 bar and 500 bar, respectively, compared to 200 bar with the same FIT at maximum load. However, nitrogen oxide (NOx) emissions increased with both advanced FIT and higher FIP under maximum load conditions. Smoke emissions decreased by 2.14% and 20.27% at FIPs of 350 bar and 500 bar, respectively, compared to 200 bar, all at a FIT of 27° CA. These findings highlight the potential of optimizing FIT and FIP to enhance performance and reduce emissions when using WCO biodiesel.</p>

High-yield extraction of long-chain fatty acids from Chlorella vulgaris: Comparative analysis of ozone extraction methods.

High-yield extraction of long-chain fatty acids from Chlorella vulgaris: Comparative analysis of ozone extraction methods.

Transesterification of biodiesel from non-edible oils using heterogeneous base catalysts: A comprehensive review of potential renewable biomass feedstocks

Transesterification of biodiesel from non-edible oils using heterogeneous base catalysts: A comprehensive review of potential renewable biomass feedstocks

Green synthesis of titanium oxide nanoparticles using aqueous extracts of Limnospira fusiformis and their multifunctional applications in biomedical and biodiesel production

Green synthesis of titanium oxide nanoparticles using aqueous extracts of Limnospira fusiformis and their multifunctional applications in biomedical and biodiesel production

Value-added utilisation of industrial by-products from bioenergy processes for growth of the PHB synthesising bacterium Cupriavidus necator.

Value-added utilisation of industrial by-products from bioenergy processes for growth of the PHB synthesising bacterium Cupriavidus necator.

Evaluation of the greenhouse gas emissions of the Brazilian biodiesel and the impact of the mandatory blending of the biofuel into commercial diesel fuel.

Evaluation of the greenhouse gas emissions of the Brazilian biodiesel and the impact of the mandatory blending of the biofuel into commercial diesel fuel.

Biodiesel production from Chlorella sp. microalgae using new derived calcium methoxide-microalgae based catalyst

Biodiesel production from Chlorella sp. microalgae using new derived calcium methoxide-microalgae based catalyst

Designing an effective incentive scheme for climate change mitigation in energy forests.

Designing an effective incentive scheme for climate change mitigation in energy forests.

Unleashing carbon quantum dots as novel nanocatalyst from waste plastic wrappers towards biodiesel production

Unleashing carbon quantum dots as novel nanocatalyst from waste plastic wrappers towards biodiesel production

Economic analysis and optimization of an integrated biodiesel and hydrogen production plant

Economic analysis and optimization of an integrated biodiesel and hydrogen production plant

Efficient application of rice husk ash-derived silica combined with calcined orange peel as catalysts for biodiesel production from Nigella sativa seed oil within a circular economy framework.

Efficient application of rice husk ash-derived silica combined with calcined orange peel as catalysts for biodiesel production from Nigella sativa seed oil within a circular economy framework.

Novel polymeric supports for lipase immobilization and their application in the transesterification of soybean oil for biodiesel production

Novel polymeric supports for lipase immobilization and their application in the transesterification of soybean oil for biodiesel production

A comprehensive insight into the role of synthesis methods on the properties and performance of bio-derived heterogeneous catalysts for biodiesel production

A comprehensive insight into the role of synthesis methods on the properties and performance of bio-derived heterogeneous catalysts for biodiesel production