Sustainable Biodiesel Production Research Articles

Sustainable biodiesel production from microalgae Graesiella emersonii through valorization of garden wastes-based vermicompost

Biodiesel production from microalgae has gained significant interest recently due to the growing energy demand and non-renewable nature of petroleum. However, high cost of production and environmental health related issues like excess use of inorganic fertilizers, eutrophication are the major constraints in commercial-scale biodiesel production. Besides this, solid wastes (garden-based) management is also a global concern. In the present study, to overcome these limitations vermicompost extract was tested as nutrient source to enhance growth performance and lipid production from a freshwater microalga (Graesiella emersonii MN877773). Garden wastes were first converted into vermicompost manure and its extract (aerobic and anaerobically digested) was prepared. The efficacy of the extract was then tested in combination with BG11 medium. The mixotrophic cultivation of microalgae in anaerobically digested vermicompost extract at 50:50 combination with BG11 medium enhanced the cell biomass (0.64 g d. wt. L−1) and lipid productivity (3.18 mg L−1 day−1) of microalgae by two times. Moreover, the combination also improved the saturated (methyl palmitate) and monounsaturated fatty acids (oleic acid) content in the test algae. The quality of biodiesel also complies with all the properties of biodiesel standard provided by India, the USA, and Europe except the cold filter plugging property. The combination was also found to improve the cell biomass (0.041 g L−1) as compared to BG11 medium in mass-scale cultivation. Hence, the study proved that G. emersonii grown in media supplemented with garden waste-based vermicompost extract had significant potential for mass-scale biodiesel and bioproduct production.

Integrated polylactic acid and biodiesel production from food waste: Process synthesis and economics

In this study, techno-economic analysis of the sustainable production of polylactic acid (PLA) and biodiesel from Food Waste (FW), with a plant capacity of 50 tons/day, was investigated. In addition, FW of four countries (China, India, Brazil, and the USA) with different compositions of water, protein, lipid and carbohydrate were proposed. Each country has different PLA production rates based on carbohydrate and biodiesel production based on fat. In this study, the FW composition of the USA shows better economic feasibility than other countries. The actual minimum selling price is 6.53 (China), 5.35 (India), 4.75 (Brazil), and 4.29 (US) $/kg. The uncertainty of the MSP was analyzed based on various input limits. The sensitivity analysis was conducted based on biodiesel-selling price, PLA-selling price, income tax, and project lifetime on techno-economic analysis parameters, such as ROI, payback period, IRR and NPV were investigated.

Assuaging Microalgal Harvesting Woes via Attached Growth: A Critical Review to Produce Sustainable Microalgal Feedstock

Third-generation biofuels that are derived from microalgal biomass have gained momentum as a way forward in the sustainable production of biodiesel. Such efforts are propelled by the intention to reduce our dependence on fossil fuels as the primary source of energy. Accordingly, growing microalgal biomass in the form of suspended cultivation has been a conventional technique for the past few decades. To overcome the inevitable harvesting shortcomings arising from the excessive energy and time needed to separate the planktonic microalgal cells from water medium, researchers have started to explore attached microalgal cultivation systems. This cultivation mode permits the ease of harvesting mature microalgal biomass, circumventing the need to employ complex harvesting techniques to single out the cells, and is economically attractive. However, the main bottleneck associated with attached microalgal growth is low biomass production due to the difficulties the microalgal cells have in forming attachment and populating thereafter. In this regard, the current review encompasses the novel techniques adopted to promote attached microalgal growth. The physicochemical effects such as the pH of the culture medium, hydrophobicity, as well as the substratum surface properties and abiotic factors that can determine the fate of exponential growth of attached microalgal cells, are critically reviewed. This review aims to unveil the benefits of an attached microalgal cultivation system as a promising harvesting technique to produce sustainable biodiesel for lasting applications.

Synthesis and Characterization of Heterogeneous Solid Acid Catalyst from Alstonia scolaris Stalks for Biodiesel Production using Waste Cooking Oil

Background: Waste biomass derived reusable heterogeneous acid based catalysts are more suitable to overcome the problems associated with homogeneous catalysts. The use of agricultural biomass as catalyst for transesterification process is more economical and it reduces the overall production cost of biodiesel. The identification of an appropriate suitable catalyst for effective transesterification will be a landmark in biofuel sector Objective: In the present investigation, waste wood biomass was used to prepare a low cost sulfonated solid acid catalyst for the production of biodiesel using waste cooking oil. Methods: The pretreated wood biomass was first calcined then sulfonated with H2SO4. The catalyst was characterized by various analyses such as, Fourier-transform infrared spectroscopy (FTIR), Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-ray diffraction (XRD). The central composite design (CCD) based response surface methodology (RSM) was applied to study the influence of individual process variables such as temperature, catalyst load, methanol to oil molar ration and reaction time on biodiesel yield. Results: The obtained optimized conditions are as follows: temperature (165 ˚C), catalyst loading (1.625 wt%), methanol to oil molar ratio (15:1) and reaction time (143 min) with a maximum biodiesel yield of 95 %. The Gas chromatographymass spectrometry (GC-MS) analysis of biodiesel produced from waste cooking oil was showed that it has a mixture of both monounsaturated and saturated methyl esters. Conclusion: Thus the waste wood biomass derived heterogeneous catalyst for the transesterification process of waste cooking oil can be applied for sustainable biodiesel production by adding an additional value for the waste materials and also eliminating the disposable problem of waste oils.

Genetic engineering of microalgae lipid biosynthesis for sustainable biodiesel production

Biofuel is one of the most promising alternative energy sources for reducing human reliance on fossil fuels. Microalgae has recently emerged as the most promising biofuel source. However, biofuels from microalgae are still not feasible to replace fossil fuels because of their high production costs, therefore, it is necessary to pick microalgae species with high growth rates and lipid content. Overexpression of lipid biosynthesis enzymes and inhibition of competitive metabolic pathways are two genetic engineering strategies that can be developed to assess microalgae lipid production. Malate and multienzyme enzymes (GPAT, LPAAT and DGAT) can be overexpressed in microalgae to boost lipid production. The strategy of blocking competitive metabolic pathways can be carried out through suppression of starch metabolism and lipid catabolism. The strategy of blocking competitive metabolic pathways has been carried out in several microalgae and is effective for enhancing lipid biosynthesis. Several mutations that block both the starch metabolic and lipid catabolic pathways can result in increased levels of microalgal lipid accumulation.

Genetic engineering of microalgae lipid biosynthesis for sustainable biodiesel production

Genetic engineering of microalgae lipid biosynthesis for sustainable biodiesel production

Towards sustainable biodiesel production by solar intensification of waste cooking oil and engine parameter assessment studies

Renewable energy sources for harnessing biofuels are the viable solution to substitute fossil fuels and reduce production cost. In this study, waste cooking oil was converted into biodiesel via a customized solar reactor. The solar reactor was customized using copper tubes and black surface to trap solar energy for conversion of waste cooking oil into biodiesel. The main experimental parameters studied are temperature (30 to 50 °C), stirring speed (100 to 500 rpm), catalyst loading (0.25 to 1.25 wt%), flow rate (3 to 15 LPH), and methanol to oil ratio (3:1 to 15:1), respectively. The uppermost conversion of 82% was achieved at catalyst load of 0.75 wt%, stirring speed of 300 rpm, flow rate of 3 LPH and methanol/oil ratio of 12:1. Performance of biodiesel blend (D80 + BD20) in CI engine showed a decrease in ignition delay (10.5 deg. CA) and brake thermal efficiency (32.7%) at maximum load (100%). Smoke emission was also decreased with an increase in biodiesel blend at lower brake power, but an increase in brake power increased the smoke emission.

Bioconversion of sago processing wastewater into biodiesel: Optimization of lipid production by an oleaginous yeast,\xa0Candida tropicalis\xa0ASY2 and its transesterification\xa0process using response surface methodology

BackgroundBiodiesel is an eco-friendly and renewable energy source and a valuable substitute for petro-diesel. Sago processing wastewater (SWW), a by-product of the cassava processing industry, has starch content ranging from 4 to 7 g L–1 and serves as an outstanding source for producing microbial lipids by the oleaginous microorganisms. In the present study, Candida tropicalis ASY2 was employed to optimize single-cell oil (SCO) production using SWW and subsequent transesterification by response surface methodology. Variables such as starch content, yeast extract, airflow rate, pH, and temperature significantly influenced lipid production in a preliminary study. The lipid production was scaled up to 5 L capacity airlift bioreactor and its optimization was done by response surface methodology. The dried yeast biomass obtained under optimized conditions from 5 L bioreactor was subjected to a direct transesterification process. Biomass: methanol ratio, catalyst concentration, and time were the variables used to attain higher FAME yield in the transesterification optimization process.ResultsUnder optimized conditions, the highest lipid yield of 2.68 g L–1 was obtained with 15.33 g L–1 of starch content, 0.5 g L–1 of yeast extract, and 5.992 L min–1 of airflow rate in a bioreactor. The optimized direct transesterification process yielded a higher FAME yield of 86.56% at 1:20 biomass: methanol ratio, 0.4 M catalyst concentration, and a time of 6.85 h.ConclusionsThus, this optimized process rendered the microbial lipids derived from C. tropicalis ASY2 as potentially alternative oil substitutes for sustainable biodiesel production to meet the rising energy demands.

Critical review on use of different types of bio-diesel as sustainable fuel for Internal Combustion Engines

World’s major transportation energy requirement cannot be met alone by use of fossil fuel based petroleum products. So, as a supplement and sustainable energy usage scope and production of bio diesel is highlighted in this article. Bio-diesel can also be the part of renewable biomass sources available freely on this planet. Use of bio diesel can be made successfully by minor modification in existing transportation vehicles easily. Still further research is going on for to overcome the limitations regarding use of bio diesel in I.C. engines like as piston ring sticking, injector chocking etc. due to its high viscosity. The present work focuses on use of bio diesel in terms of its performance characteristics in IC Engines. Keywords: Bio-Fuel; Diesel Engine; Vegetable Oil; Pollutants

Waste sugarcane bagasse‐derived nanocatalyst for microwave‐assisted transesterification: Thermal, kinetic and optimization study

AbstractThe production of biodiesel has increased globally during the last decade to overcome the problems of increasing prices of petro‐diesel and the depletion of fossil fuels. The present study aimed to utilize agro‐waste sugarcane bagasse (SCB) to synthesize a heterogeneous acid catalyst for biodiesel production using waste cooking oil. Waste sugarcane bagasse was converted into biochar through partial carbonization and activated via sulfonation by using acid solutions of different concentration i.e., 1M, 3M, 5M and concentrated sulfuric acid at a sulfonation temperature of 180 °C for 5 h. The prepared catalysts were characterized by using Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), the Brunauer–Emmett–Teller (BET) technique, X‐ray diffraction (XRD), and the Carbon, Hydrogen, Nitrogen and Sulfur (CHNS) analyzer. The prepared catalyst exhibited an excellent surface area of 20.78 m2 g–1 and a total acid density of 3.94 mmol g–1. The biodiesel production process was optimized by varying reaction temperature from (40–70 °C), methanol to oil molar ratio (5:1–20:1), catalyst loading (1–7 wt.%) and reaction time (5–25 min) by using a microwave reactor. The maximum conversion of 95.45% and yield of 92.12% was obtained under optimum conditions: catalyst loading 5 wt%, methanol‐to‐oil molar ratio (15:1), temperature (60 °C) after 15 min. The results of the experiments were validated by using response surface methodology, which validated the predicted model. The kinetic study of experiments showed that the use of sulfonated catalysts lowered the activation energy (10.5 kJ mol–1) and reactants attained an equilibrium point after a short interval under microwave heating. Reusability of catalyst up to seven cycles with 77.34% yield of biodiesel using low‐grade feedstock showed that the catalyst is stable and can be used for sustainable biodiesel production. The utilization of wastes for catalyst synthesis and for biodiesel production can help to minimize the overall production cost of biodiesel. © 2021 Society of Chemical Industry and John Wiley & Sons, Ltd

Overview of Feedstocks for Sustainable Biodiesel Production and Implementation of the Biodiesel Program in Pakistan.

The energy demand of the world is skyrocketing due to the exponential economic growth and population expansion. To meet the energy requirement, the use of fossil fuels is not a good decision, causing environmental pollution such as CO2 emissions. Therefore, the use of renewable energy sources like biofuels can meet the energy crisis especially for countries facing oil shortages such as Pakistan. This review describes the comparative study of biodiesel synthesis for various edible oils, non-edible oils, and wastes such as waste plastic oil, biomass pyrolysis oil, and tyre pyrolysis oil in terms of their oil content and extraction, cetane number, and energy content. The present study also described the importance of biodiesel synthesis via catalytic transesterification and its implementation in Pakistan. Pakistan is importing an extensive quantity of cooking oil that is used in the food processing industries, and as a result, a huge quantity of waste cooking oil (WCO) is generated. The potential waste oils for biodiesel synthesis are chicken fat, dairy scum, WCO, and tallow oil that can be used as potential substrates of biodiesel. The implementation of a biodiesel program as a replacement of conventional diesel will help to minimize the oil imports and uplift the country’s economy. Biodiesel production via homogeneous and heterogeneous catalyzed transesterification is more feasible among all transesterification processes due to a lesser energy requirement and low cost. Therefore, biodiesel synthesis and implementation could minimize the imports of diesel by significantly contributing to the overall Gross Domestic Product (GDP). Although, waste oil can meet the energy needs, more available cultivation land should be used for substrate cultivation. In addition, research is still needed to explore innovative solvents and catalysts so that overall biodiesel production cost can be minimized. This would result in successful biodiesel implementation in Pakistan.

Evaluation of microalgal strains and microalgal consortium for higher lipid productivity and rich fatty acid profile towards sustainable biodiesel production

This present study has attempted to screen four microalgal strainsChlorella vulgaris, Coelastrellasp.Scenedesmus dimorphusandChlorococcumsp. and consortium for biodiesel application.Coelastrella sp. was found to show marginally higher optical density of 1.13 on 19th day whereas C. vulgaris and S. dimorphus consortium showed 1.59 OD. Regarding the dry cell weight, S. dimorphus and Chlorella vulgaris was found to yield higher DCW at about 0.544 and 0.508 g/L, respectively. In outdoor pond raceway pond, C. vulgaris and S. dimorphus yielded 0.76–0.80 g/L while consortium showed 0.87 g/L biomass. In the case of lipid content, S. dimorphus, C. vulgaris and consortium accumulated 36.4, 35.5 and 39.2% lipids, respectively in lab, whereas in outdoor raceway pond it was 26.4, 32.3 and 34.5%, respectively. The fatty profile of Chlorella and Scenedesmus sp. showed linolelaidic acid, and cis-8,11,14-eicosatrienoic acid as prevalent fatty acids whereas the consortium has 53.5% oleic acid than other fatty acids.

Bio-Derived Catalysts: A Current Trend of Catalysts Used in Biodiesel Production

Biodiesel is a promising alternative to fossil fuels and mainly produced from oils/fat through the (trans)esterification process. To enhance the reaction efficiency and simplify the production process, various catalysts have been introduced for biodiesel synthesis. Recently, the use of bio-derived catalysts has attracted more interest due to their high catalytic activity and ecofriendly properties. These catalysts include alkali catalysts, acid catalysts, and enzymes (biocatalysts), which are (bio)synthesized from various natural sources. This review summarizes the latest findings on these bio-derived catalysts, as well as their source and catalytic activity. The advantages and disadvantages of these catalysts are also discussed. These bio-based catalysts show a promising future and can be further used as a renewable catalyst for sustainable biodiesel production.

Comparative analysis of the application of artificial neural network-genetic algorithm and response surface methods-desirability function for predicting the optimal conditions for biodiesel synthesis from chrysophyllum albidum seed oil

Efficient and sustainable commercial production of biodiesel requires process optimization and modeling using artificial intelligence techniques. Artificial neural network-genetic algorithm (ANN-GA) and response surface methodology (RSM) were used to predict the optimal process conditions for biodiesel synthesis from novel chrysophyllium albidum seed oil. Application of Levenberg -Marquardt algorithm and full factorial central composite design-desirability function analysis were carried out for ANN and RSM respectively. The biodiesel obtained at the optimum conditions was characterized using gas chromatography-mass spectrophotometer (GC–MS), Fourier transform infrared (FTIR), AOAC and ASTM D standard methods. The ANN and RSM correlation coefficients were 0.98 and 0.95 respectively. The best RSM fitted model was second order polynomial while the ANN best architecture topology consists of three layers: input layer with four input variables, hidden layer with ten hidden neurons and an output layer with single output variable. Optimization of the process shows that: RSM optimum conditions for biodiesel yield of 85.91wt% validated at 86.85wt% were 65.62 °C, 2.14wt% catalyst concentration, 62.04 min and 5.88 methanol: oil molar ratio with overall desirability of 1.00. ANN-GA gave 9.40% faster reaction time and required 15.88% less energy, 3.76% more alcohol and 16.82% less catalyst with 1.86wt% more biodiesel yield than RSM optimized conditions. Ascertained fuel properties, GC–MS and FTIR characterizations confirmed unsaturation and good cold-flow qualities of the biodiesel. Overall results presented ANN-GA as better than RSM and a reliable modeling and optimization technique for viable and sustainable production of biodiesel from chrysophyllum albidum seed.

Valorization of de-oiled microalgal biomass as a carbon-based heterogeneous catalyst for a sustainable biodiesel production

In this study, a novel carbon-based solid acid catalyst was synthesized by carbonization of de-oiled microalgal biomass followed by sulfonation. The effect of catalyst synthesis conditions such as carbonization temperature, sulfonation time, and H2SO4 concentration on the surface acidity of the catalyst and free fatty acid conversion was determined. The de-oiled microalgal biomass-based solid acid (DMB) catalyst was predominantly composed of carboxylic, phenolic, and sulfonic groups as indicated by the FTIR analysis and supported by the XPS analysis. The catalyst was further characterized by various methods to determine its physiochemical properties. A maximum fatty acid methyl ester (FAME) yield of 94.23% for microalgal oil (AO) and 96.25% for waste cooking oil (WCO) was obtained under optimized transesterification conditions. The catalyst exhibited high catalytic activity (FAME yield >90%) until the fourth cycle. Most of the biodiesel properties were within the permissible limit of EN 14,212 and ASTM D6751 standards.

Production and utilization aspects of waste cooking oil based biodiesel in Pakistan

Excessive fuel demand thrusts the Pakistani government to import large volumes of fuel from foreign sources, creating adverse effects on the country’s economy. Therefore, exploring an alternative to fossil fuels is unavoidable. The option of environmentally friendly fuel like biodiesel produced from indigenous waste is an additional bonus for the populous developing country like Pakistan where likelihood of waste generation is huge. There exists a potential option for sustainable biodiesel production utilizing excessive waste cooking oil available in the country which otherwise is an ecological burden. The present work is focused to sturdily vindicate the appropriateness of waste cooking oil-based biodiesel generation and utilization in Pakistan through SWOT-AHP, TOWS and PESTLE analysis. The prioritization of SWOT through AHP in view of experts’ perception displayed the strengths and opportunities in highest group priority values (Strengths: 0.51, Opportunities: 0.29). Furthermore, TOWS analysis suggests promising strategies for the sustainable implementation of commercial aspect of waste oil-based biodiesel in Pakistan. Political, Economic, Social, Technological, Legal and Environmental (PESTLE) analysis favors the strengths and opportunities factors of SWOT and TOWS strategies for the application of waste cooking oil based biodiesel in country. At the end, regional recommendations have been provided for the implementation of biodiesel production scenario in country.

Synthesis of fuel bioadditive by esterification of glycerol with acetic acid over hydrophobic polymer-based solid acid

The transformation of glycerol into high value-added derivatives has been of critical importance from the viewpoint of sustainable production of biodiesel. Among the reported processes, selective esterification of glycerol with acetic acid to a fuel bioadditive, including glycerol diacetate (DAG) and glycerol triacetate (TAG), is a research hot topic in both academic research and industrial application. In this work, a series of polydivinylbenzene-based solid acids (PDS) with different structural performances were prepared by a hydrothermal synthesis method and employed as catalysts for the acetylation of glycerol with acetic acid to DAG and TAG. The effects of PDS structure properties on the catalytic performance are discussed in detail with the help of various characterizations. PDS-THF prepared in tetrahydrofuran solvent was proven to be the most active catalyst among all the tested samples. In addition, glycerol could be almost completely converted into glyceryl acetates in the presence of PDS-THF, with a combined selectivity to DAG and TAG of 88.6% at its optimization condition. No obvious deactivation can be observed for PDS-THF after five runs, and the synergism of abundant acidic sites, suitable acidic site density and super hydrophobicity can account for its superior catalytic performance.

Biomass generation and biodiesel production from macroalgae grown in the irrigation canal wastewater.

The wastewater concentration is commonly acceptable for macroalgae growth; this process consumes water and is applicable for bioremediation. This study evaluated biodiesel's potential production from freshwater macroalga, Nitella sp., using batch experiment. Algae were collected from wastewater saturated from irrigation canals. Water quality and algae growth environment characteristics were monitored and analyzed. COD and BOD values were 18.67 ± 4.62 mg/L and 5.40 ± 0.30 mg/L, respectively. The chemical composition contents were high, demonstrating that water quality and sufficient nutrients could support algae growth. Oil extraction was estimated by the room temperature and heat extraction methods. The biodiesel in room temperature treatment was 0.0383 ± 0.014%, and in heat, extraction treatment was 0.0723 ± 0.029%. Results confirmed that the heat extraction treatment gave a high amount of oil and biodiesel yield. Gas chromatography/mass spectrometry (GC/MS) was used to analyze fatty acid methyl esters (FAME). Results revealed that 9-octadecane was a major portion of the substance. The obtained results confirmed that the wastewater contains many elements that can be utilized for dual-mode, like bioremediation and enhanced macroalgae growth for biodiesel production. Therefore, macroalgae grown in canal wastewater were highly feasible for use in sustainable biodiesel production.

Sustainable biodiesel production from waste cooking oil: ANN modeling and environmental factor assessment

Biodiesel, the most suitable diesel fuel alternative, is currently gaining popularity due to its advantages and potential environmental protection. Besides, one of the environmental sustainability approaches in biodiesel production process would be the reuse of biomass waste. In this regard, this work focuses on sustainability and environmental factor assessment of waste cooking oil biodiesel production and the application of artificial neural networks to predict the biodiesel yield and its engine characteristics. The artificial neural network model was developed to predict the biodiesel yield, engine performance, and emission characteristics. It was observed that biodiesel production with 1% (wt/wt) catalyst concentration, 9:1 methanol to waste cooking oil molar ratio, 60 min reaction time with 500 rpm mixing intensity generates lesser wastes, and the process exhibits positive environmental impacts. In the process of predicting the biodiesel yield, the overall regression coefficient was calculated as 0.98. Moreover, in case of biodiesel fueled engine characteristics, the overall regression coefficient was computed as 0.99. It is disclosed from the analysis that artificial neural networks are excellent tools to simulate and predict the biodiesel produced from waste cooking oil and its engine characteristics.

Fe3O4-poly(AGE-DVB-GMA) composites immobilized with guanidine as a magnetically recyclable catalyst for enhanced biodiesel production

This present research aims at developing an efficient and reusable base catalyst to improve the biodiesel production for the need of green chemistry and sustainable development. To achieve this, the copolymer, namely poly(allylglycidyl ether-divinylbenzene-glycidyl methacrylate) (poly(AGE-DVB-GMA)), was firstly incorporated in the Fe3O4 nanoparticles forming magnetic Fe3O4-poly(AGE-DVB-GMA) composites, and then organic guanidine was bound on the magnetic matrices via covalent bonds with active epoxy groups. The characterization of the as-made magnetic copolymer support and solid base catalysts was performed by several techniques, and the results revealed that the guanidine base was successfully tethered on the magnetic copolymer support. This developed solid catalyst possessed large surface basicity of 2.45 mmol/g and highly magnetic responsiveness with saturation magnetization value of 18.13 emu/g, displaying good activity to the transesterification of soybean oil to biodiesel in a heterogeneous manner. Under the transesterification conditions of methanol/oil molar ratio of 20:1, catalyst dosage of 7 wt%, reaction temperature of 65 °C, reaction duration of 8 h, the biodiesel yield of 92.6% was attained over the guanidine-based solid catalyst. Moreover, the catalyst could be easily separated under an external magnetic field, and showed satisfactory catalytic activity even after four reuse cycles, thus posing considerable potential for the sustainable and clean production of biodiesel.