Biofuel Synthesis Research Articles

Synthesis of biofuel via catalytic fast pyrolysis of wood-plastic composite over low-cost catalysts

Thermogravimetric (TG) and pyrolyzer-gas chromatography/mass spectrometry (Py-GC/MS) analyses were performed to know the feasibility of low cost catalysts, γ-Al2O3, spent fluid catalytic cracking (FCC) catalyst, natural zeolite, to the pyrolysis of wood-plastic composite (WPC). Notably, the respective decomposition temperature of polyethylene and polypropylene in WPC was lowered with the use of low-cost catalysts during the catalytic fast pyrolysis (CFP). Furthermore, the lowest activation energy (Ea) of the CFP, obtained by the Ozawa method, was with the use of natural zeolite (127.5 kJ/mol), followed by the ones with the use of spent FCC catalyst (133.3 kJ/mol) and γ-Al2O3 (145.0 kJ/mol), respectively. In addition, the CFP over natural zeolite was less effective in terms of decreasing the production of low-quality hydrocarbons, paraffins and olefins having a wide carbon number distribution, and oxygenates compared to that over spent FCC catalyst and γ-Al2O3, respectively, due to the small pore size of natural zeolite. However, the largest amount of value-added aromatic hydrocarbons was produced in the CFP over natural zeolite among all the catalysts due to the high and strong acidity of natural zeolite.

Moving towards the Application of Biocatalysis in Food Waste Biorefinery

Waste valorization is an important strategy to reduce environmental pollution and dependency on petroleum-based fuels. In this regard, utilization of food waste as a versatile and low-cost resource is important. Several advanced catalytic methods for the valorization of food waste have been widely investigated for the production of liquid biofuels. Along this line, chemical catalysts have been explored for the synthesis of liquid biofuels. Chemo-catalysis is mainly metal based, which requires harsh process conditions. Alternatively, biocatalysts are currently being investigated as a result of several advantages such as mild reaction conditions, recyclability, selectivity and biodegradability. In this work, recent biocatalytic technologies for the preparation of liquid biofuels through food waste valorization are discussed thoroughly. Lipases are employed for the synthesis of biodiesel and the upgradation of bio-oil, whereas methane mono-oxygenases could be explored for the production of methanol via the oxidation of methane generated from food wastes. Industrial production of ethanol from food waste using bioconversion technologies is a success story. To date, there has been no specific report on the use of food waste for propanol preparation using enzymes. The ABE process (Acetone–Butanol–Ethanol) (using suitable microorganisms) is used for butanol preparation, where the vacuum stripping system is integrated to remove butanol from the broth and circumvent inhibition. The synthesis of hydrocarbon fuels from fatty acids and triglycerides can be carried out using enzymes, such as carboxylic acid reductase and fatty acid photodecarboxylase (an algal photoenzyme). Both carboxylic acid reductase and fatty acid photodecarboxylase have not yet been applied in the direct valorization of food wastes. Furthermore, limitations of the reported methods, societal and economic aspects and a fresh perspective on the subject, along with important examples, are described.

Control in Advanced Biofuels Synthesis via Alcohol Upgrading: Catalyst Selectivity to n‐Butanol, sec‐Butanol or Isobutanol

AbstractRuthenium complexes with tetradentate PNNP donor ligands demonstrate a marked change in selectivity compared to analogous bis bidentate PN complexes in Guerbet catalysis, producing mixtures of n‐butanol (17 %), sec‐butanol (14 %) and ethyl acetate (66 %) rather than the usual 90 %+ selectivity to n‐butanol. Tridentate PNP ruthenium complexes such as [Ru(H)(Cl)(CO)(Ph2PCH2CH2NHCH2CH2PPh2)] also produce sec‐butanol and, in optimized conditions (120 °C, 10 mol% NaOEt base), achieve 71 % selectivity to this butanol isomer. The same tri‐ and tetradentate complexes are efficient catalysts for the conversion of methanol/ethanol mixtures to isobutanol (up to 97 % selectivity). In this way, judicious choice of ligand within this general catalyst family allows selectivity to three butanol isomers of interest as fuel molecules.

Promoting Electrolysis of Carbon Monoxide toward Acetate and 1-Propanol in Flow Electrolyzer

Acetic acid/acetate is an important precursor for many chemical manufacturing sectors, as well as a feedstock for the microbial synthesis of value-added biofuel and biomass products. As the downstream reaction in tandem with the carbon dioxide reduction reaction, carbon monoxide electrolysis has a unique advantage over direct carbon dioxide reduction, boosting the selectivity for multicarbon products. However, highly selective and high-current-throughput acetate and 1-propanol production from CO electrolysis is yet to be explored. Herein, we present practical approaches for improving acetate and 1-propanol selectivity and yield from CO electrolysis using a commercial copper catalyst. Acetate showed a strong pH dependence with an optimum performance at 90% Faradaic efficiency and 128 mA cm–2 current density. In addition, 1-propanol showed a strong catalyst loading dependence, achieving 20% Faradaic efficiency under high-catalyst-loading conditions. In situ Raman and Multiphysics modeling further demonstrated the mechanism of the improvements.

An Overview of Green Bioprocessing of Algae-Derived Biochar and Biopolymers: Synthesis, Preparation, and Potential Applications

Algae have the potential to be used as a feedstock for the synthesis of valuable compounds and biofuels. In addition, algal waste can be further transformed into biofuel, biogas, and biochar using different thermochemical processes such as microwave pyrolysis, pyrolysis, torrefaction, and hydrothermal conversion. Due to its high specific surface area, rapid electron transport, and graphitic carbon structure, algal biochar carbonized at high temperatures has shown outstanding performance for applications as CO2 adsorbents, supercapacitors, and persulfate activation. Due to the combination of various functional groups and porous structures, the algae biomass pyrolysis at a moderate temperature produced high-quality biochar that shows high performance in terms of pollutant removal, while low-temperature pyrolysis produces coal fuel from algae via torrefaction. Over time, there have been exponentially more petroleum-based polymers created that have harmful impacts on both humans and the environment. As a result, researchers are becoming more interested in algae-based biopolymers as a potential alternative strategy for establishing a sustainable circular economy globally. The advantages of microalgal biopolymer over other feedstocks are its capacity to compost, which provides greenhouse gas credits, its quick growth ability with flexibility in a variety of settings, and its ability to minimize greenhouse gas emissions.

Optimization of mevalonate production using acetate by precursor balancing and flux redistribution in Escherichia coli

Mevalonate is an important organic acid that can be used to synthesize bioplastics and is utilized as a key precursor for the synthesis of terpenoids and biofuels. To develop economically feasible microbial fermentation, the use of acetate, which is an inexpensive and non-edible feedstock, as the substrate is advantageous. However, a previous study that used acetate as a carbon source reported low levels of mevalonate production, which was caused by a precursor imbalance and insufficient acetyl-CoA. Mevalonate production was substantially improved by simultaneously regulating the expression levels of mvaE and mvaS to balance the precursors. Then, the excess carbon flux for cell growth was redirected to mevalonate by repressing gltA, which encodes citrate synthase, resulting in efficient production. The optimized strain produced a yield of 0.41 g mevalonate/g acetate (72% of the theoretical maximum yield). Finally, repeated feeding resulted in the highest reported mevalonate titer (7.9 g/L) among all reported studies using acetate. These results show that precise regulation of the expression levels of mvaE, mvaS, and gltA is a powerful strategy for mevalonate production. Moreover, this strategy can be widely applied to the production of mevalonate using other substrates.

Synthesis of Biofuel Using Organic-Inorganic Perovskite Solar Cell Material Based on Nanocomposite

Synthesis of Biofuel Using Organic-Inorganic Perovskite Solar Cell Material Based on Nanocomposite

Novel Challenges on the Catalytic Synthesis of 5-Hydroxymethylfurfural (HMF) from Real Feedstocks

The depletion of fossil resources makes the transition towards renewable ones more urgent. For this purpose, the synthesis of strategic platform-chemicals, such as 5-hydroxymethylfurfural (HMF), represents a fundamental challenge for the development of a feasible bio-refinery. HMF perfectly deals with this necessity, because it can be obtained from the hexose fraction of biomass. Thanks to its high reactivity, it can be exploited for the synthesis of renewable monomers, solvents, and bio-fuels. Sustainable HMF synthesis requires the use of waste biomasses, rather than model compounds such as monosaccharides or polysaccharides, making its production more economically advantageous from an industrial perspective. However, the production of HMF from real feedstocks generally suffers from scarce selectivity, due to their complex chemical composition and HMF instability. On this basis, different strategies have been adopted to maximize the HMF yield. Under this perspective, the properties of the catalytic system, as well as the choice of a suitable solvent and the addition of an eventual pretreatment of the biomass, represent key aspects of the optimization of HMF synthesis. On this basis, the present review summarizes and critically discusses the most recent and attractive strategies for HMF production from real feedstocks, focusing on the smartest catalytic systems and the overall sustainability of the adopted reaction conditions.

An Overview of Nano-Catalysts in Biodiesel Production

Energy consumption and dependence on non-renewable resources is increasing over the years. The combustion of fossil fuels resulting in the emission of substantial amounts of CO2, NOX, SOX and some greenhouse gases. Biofuels are evolving as the primary alternatives to fossil fuels since they can be readily synthesised from discarded bioresources and yield lesser emission during the combustion process. However, the extraction of biofuels has thrown up new challenges that have widened the scope of the use of nano-particles in the synthesis of biofuels. From the literature, distinct findings concerning the use of nano-particles as a catalyst and process reactant during biodiesel production have been identified; this is majorly attributed to the fact that nano-catalysts enhance thermophysical properties, reaction speed and mass transport properties. Henceforth, the present paper aims to review, summarise and provide an insight into the research findings of effectively using nanocatalysts in biofuel production and consider the significance and its relevance for further researchers in the domain of biofuels.

Coal fly ash supported ZnO catalyzed transesterification of Jatropha curcas oil: Optimization by response surface methodology

• Biodiesel was produced via transesterification of JCO by Coal fly ash supported ZnO (ZnO-CFA). • Activity of ZnO-CFA catalyst was enhanced by calcination at 400 o C. • Under the optimal transesterification conditions, maximum biodiesel yield was 91.08 ± 0.06%. • Physicochemical properties of produced biodiesel agreed with ASTM D6751 and EN 14214 . Herein, a zinc oxide based coal fly ash (ZnO-CFA) composite as heterogeneous catalyst was formulated and explored for transesterification of non-edible oil (Jatropha curcas oil, JCO). The as-synthesized catalyst was analyzed to gain insights into its properties using various characterization techniques (EDX, FTIR, TEM, XRD and BET surface area). The solid catalyst’s ability to catalyze the methanolysis reaction was investigated and optimized at varying reaction temperature, methanol/JCO molar ratio and catalyst dosage using Box-Behnken design. Predicted value of biodiesel yield was found to be in excellent agreement with observed value with high coefficient of determination R 2 = 0.9759 a n d A d j . R 2 = 0.9449 . It was determined that optimum transesterification process conditions of 60.4 o C reaction temperature, 11.8:1 methanol/JCO molar ratio and 1.63 wt.% catalyst loading resulted in biodiesel yield and FAME content of 91.08 ± 0.06% and 97.22%, respectively. Additionally, the produced biodiesel at the optimum conditions was shown to be conformed to ASTM standard. The ZnO-CFA catalyst was simple to synthesize and handle, eliminating the need for costly aluminosilicate-based catalysts in biofuel synthesis. It was also simple to separate from the product stream and could be recycled up to four times.

Biomass oxy-CO2 gasification process for bio-methane production: an experimental and numerical activity

Biomass gasification is a thermochemical process in which the biomass is converted into a mixture of gases, called syngas, commonly utilised in thermal machines to produce electricity and heat. In the present research activity, the conventional air-gasification in downdraft gasifier is replaced by oxy-CO2 gasification technology. This strategy allows to obtain a nitrogen-free syngas, mainly composed by CO, H2, CO2 and CH4, which can be used into the synthesis of various bio-fuels like methanol or synthetic natural gas (SNG). Carbon dioxide is utilized as gasifying agent together with oxygen to mitigate the reactivity of the latter, which can lead to excessive reaction temperatures. In particular, the present work shows the preliminary results of an experimental campaign carried on utilizing a small scale downdraft gasifier (max thermal power of roughly 100 kW) fed with wood pellet and using a mixture of oxygen and CO2 as gasification agent. The experimental results have been utilized to calibrate a pseudo-kinetic model of the oxy-CO2 gasification process, implemented in Aspen Plus environment. To analyse the possibility to transform the produced syngas into methane, an additional numerical model of a methanation plant was then utilised. As a whole, the numerical analysis confirms its usefulness in predicting the performance of the gasifier, which can reach a cold gas efficiency of around 70%, while the methanation plant can achieve a production of roughly 20 kg of methane per 100 kg of gasified wood.

Synthesis and Characterization of Biofuel Using Waste Cooking Oil Obtained by the College Canteen

The enhanced environmental concerns, increasing energy demand, and dependence on non-renewable fossil fuels explore the need for sustainable and renewable substitute fuels. Biodiesel is one of the best alternatives. Also, the used cooking oils available in every part of the world are very harmful and a significant pollutant source. The present work focuses on a simple and user-friendly approach for converting waste cooking oil into biodiesel and further characterization of this synthesised biodiesel. For this, waste cooking oil has been procured from the college (BIT Sindri) canteen to synthesise biodiesel. Different fuel blends were prepared using diesel and kerosene oil. To characterise fuels and blends, physico-chemical properties were measured and compared with those of diesel fuel. Spectroscopy studies of fuel samples were performed using FTIR and GCMS, which are helpful to identify the different functional groups and compounds present in the fuel samples. FTIR interpretation of biodiesel and their blends shows that all the oil samples have some joint functional group as diesel to be used as a fuel on a diesel engine. The GCMS interpretation of synthesised biodiesel shows its highest percentage of fatty acids and methyl ester. It indicates that waste cooking oil has excellent potential for producing biodiesel.

Optimized conversion of wheat straw into single cell oils by Yarrowia lipolytica and Lipomyces tetrasporus and synthesis of advanced biofuels

This paper deals with the optimized conversion of undetoxified wheat straw hydrolysates into microbial lipids by two oleaginous yeasts, Yarrowia lipolytica and Lipomyces tetrasporus. Wheat straw were pretreated by steam explosion at 203 °C for 300 s and hydrolysed at 20% solid-to-liquid ratio by using an enzymatic loading of 15 FPU/g substrate. The mixed wheat straw hydrolysates (WHS) contained 86 gL-1 glucose and 22 gL-1 xylose, 2.3 gL-1 acetic acid, 0.9 gL-1 furanic compounds. The fermentation process was optimized in terms of the inoculum age and density, medium composition, and bioreactor feeding strategy. In particular, the different capacity of the two yeasts to overcome the toxic effect of the biomass degradation by-products, in different inoculum ages, was deeply investigated. Two hydrolysates concentration were tested: WSH containing 86 gL-1 glucose and 22 gL-1 xylose and the diluted medium containing 40 gL-1 glucose and 22 gL-1 xylose. The results indicated that both yeasts were able to detoxify WSH and grow on undetoxified hydrolysates as effect of the intrinsic capacity to metabolize the furan derivatives. Y. lipolytica was able to detoxify the medium in all the investigated set-ups, while L. tetrasporus was able to detoxify the medium only if inoculated in the stationary phase of growth. After the process optimization in shaken flasks, the production of Single Cell Oils (SCOs) by L. tetrasporus was carried out in a medium-scale bioreactor of 10L obtaining lipid yield and cell content of 21% and 62%, respectively. The extracted SCOs, with high oleic and palmitic acid content, were converted into biodiesel displaying overall features in accordance with international biodiesel standards, namely ASTM and EN 14214.

Zr-Based Metal-Organic Frameworks for Green Biodiesel Synthesis: A Minireview.

Metal-organic frameworks (MOFs) have widespread application prospects in the field of catalysis owing to their functionally adjustable metal sites and adjustable structure. In this minireview, we summarize the current advancements in zirconium-based metal-organic framework (Zr-based MOF) catalysts (including single Zr-based MOFs, modified Zr-based MOFs, and Zr-based MOF derivatives) for green biofuel synthesis. Additionally, the yields, conversions, and reusability of Zr-based MOF catalysts for the production of biodiesel are compared. Finally, the challenges and future prospects regarding Zr-based MOFs and their derivatives for catalytic application in the biorefinery field are highlighted.

Discovery of Oleaginous Yeast from Mountain Forest Soil in Thailand.

As an interesting alternative microbial platform for the sustainable synthesis of oleochemical building blocks and biofuels, oleaginous yeasts are increasing in both quantity and diversity. In this study, oleaginous yeast species from northern Thailand were discovered to add to the topology. A total of 127 yeast strains were isolated from 22 forest soil samples collected from mountainous areas. They were identified by an analysis of the D1/D2 domain of the large subunit rRNA (LSU rRNA) gene sequences to be 13 species. The most frequently isolated species were Lipomyces tetrasporus and Lipomyces starkeyi. Based on the cellular lipid content determination, 78 strains of ten yeast species, and two potential new yeast that which accumulated over 20% of dry biomass, were found to be oleaginous yeast strains. Among the oleaginous species detected, Papiliotrema terrestris and Papiliotrema flavescens have never been reported as oleaginous yeast before. In addition, none of the species in the genera Piskurozyma and Hannaella were found to be oleaginous yeast. L. tetrasporus SWU-NGP 2-5 accumulated the highest lipid content of 74.26% dry biomass, whereas Lipomyces mesembrius SWU-NGP 14-6 revealed the highest lipid quantity at 5.20 ± 0.03 g L−1. The fatty acid profiles of the selected oleaginous yeasts varied depending on the strain and suitability for biodiesel production.

Efficient application of newly synthesized green Bi2O3 nanoparticles for sustainable biodiesel production via membrane reactor

Introduction of waste and non-edible oil seeds coupled with green nanotechnology offered a pushover to sustainable and economical biofuels and bio refinery production globally. The current study encompasses the synthesis and application of novel green, highly reactive and recyclable bismuth oxide nanocatalyst derived from Euphorbia royealeana (Falc.) Boiss. leaves extract via biological method for sustainable biofuel synthesis from highly potent Cannabis sativa seed oil (34% w/w) via membrane reactors. Advanced techniques such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Diffraction X-Ray (EDX), and FT-IR were employed to illustrate the newly synthesized green bismuth oxide nanoparticles. 92% of FAMEs were produced under optimal reaction conditions such as a 1.5% w/w catalyst weight, 1:12 oil to methanol molar ratio, and a reaction temperature of 92 ⸰C for 3.5 h via membrane reactor. The synthesized Cannabis biodiesel was identified using the FT-IR and GC-MS techniques. The fuel properties of synthesized biofuels (acid number 0.203 mg KOH/g, density 0.8623 kg/L, kinematic viscosity 5.32 cSt, flash point 80 °C, pour point −11 °C, cloud point −11 °C, and Sulfur 0.00047 wt %, and carbon residues 0.2) were studied and established to be comparable with internationally set parameters. The experimental data (R2 = 0.997) shows that this reaction follow pseudo first-order kinetics. These findings affirm the application of green bismuth oxide nanoparticles as economical, highly reactive and eco-friendly candidate for industrial scale biodiesel production from non-edible oil seeds.

MCM-41 supported S-alkyl/aryl-substituted 2-mercaptobenzothiazolium-based ionic liquids: synthesis, characterization, and application in the fuel desulfurization

Supported ionic liquids (SILs), synthesized by immobilization of ionic liquids (ILs) onto solid support materials, have played an effective role in several applications like fuel desulfurization, organic catalysis, gas separations, biofuel synthesis, etc., in comparison to pure ILs which suffer from many drawbacks like difficult recovery, high cost, mass transfer issue owing to large viscosity, toxic nature, complications in product purifications and fixed bed reactor technology. In this study, a series of new SILs (MCM-41@[S-RBTh][Cl]; R = aryl/alkyl groups) were synthesized via immobilization of different S-alkyl/aryl-substituted 2-mercaptobenzothiazolium-based ILs onto MCM-41 silica support. Structure elucidation of SILs was achieved through SEM, EDS, SAXS, NMR, BET, and FT-IR spectroscopy. Further, the synthesized SILs and MCM-41 were investigated for the removal of sulfur-containing aromatic species from model gasoline and real gasoline. MCM-41@[S-BzBTh][Cl] (0.5 g) removed maximum sulfur content with the percentage of 57.5 % (at 35 °C), 58.7 % (at 40 °C), and 63.4 % (at 45 °C) of TS, TN, and DBT respectively, from model gasoline (5 g) of sulfur concentration of 200 ppm under shaking conditions for 140 min. The impact of the aryl group and different lengths of alkyl groups of supported benzothiazolium-based ILs on their adsorption performance was also studied.

Nanostructured coating, Agricultural Biomass, Organic Rankine Cycle.

The transformation and use of agricultural and agro-industrial biomass has been the focus of study in recent years, due to its treatment and use in value-added products such as liquid, solid and gaseous fuels. Molecules such as hydrogen, organic carbon, organic nitrogen, oxygen, and oxygenated compounds present in the liquid phase of biomass currently represent opportunities for synthesis of green fuels and inputs for the industry. In this work was discussed the main aspects for Animal Biomass transformations from a perspective based on Biooils composition obtained from different thermochemical methods, containing model molecules, useful for biofuels synthesis for transportation.

Pretreatment of lignocellulosic biomass from sugar bagasse under microwave assisted dilute acid hydrolysis for biobutanol production

Alternative renewable energy sources are the future potential energy that will benefit the country’s overall energy shortage and demand. The efficient biofuel production depends on the viability of the raw material used. The holistic approach of this study is to establish an integrated bioprocess from lignocellulosic material for biofuel synthesis. Sugar bagasse as one of the waste material, can be economically process for sugar extraction used in biofuel production. In this study, the optimum saccharification rate obtained was 43.62% when the biomass was pretreated at microwave temperature of 100 °C for 15 min with 2.5 g catalyst concentration. The results attained shows that hydrolysis time reduces to approximately 40–50% in compare with other traditional heating method. The sample was analyzed by using UV spectrophotometer and HPLC and computed by using Response Surface Method in MINITAB 17, whereas the structural changes of the residue was detected by using ATR-FTIR and ESEM.

Cyanobacteria as a Promising Alternative for Sustainable Environment: Synthesis of Biofuel and Biodegradable Plastics.

With the aim to alleviate the increasing plastic burden and carbon footprint on Earth, the role of certain microbes that are capable of capturing and sequestering excess carbon dioxide (CO2) generated by various anthropogenic means was studied. Cyanobacteria, which are photosynthetic prokaryotes, are promising alternative for carbon sequestration as well as biofuel and bioplastic production because of their minimal growth requirements, higher efficiency of photosynthesis and growth rates, presence of considerable amounts of lipids in thylakoid membranes, and cosmopolitan nature. These microbes could prove beneficial to future generations in achieving sustainable environmental goals. Their role in the production of polyhydroxyalkanoates (PHAs) as a source of intracellular energy and carbon sink is being utilized for bioplastic production. PHAs have emerged as well-suited alternatives for conventional plastics and are a parallel competitor to petrochemical-based plastics. Although a lot of studies have been conducted where plants and crops are used as sources of energy and bioplastics, cyanobacteria have been reported to have a more efficient photosynthetic process strongly responsible for increased production with limited land input along with an acceptable cost. The biodiesel production from cyanobacteria is an unconventional choice for a sustainable future as it curtails toxic sulfur release and checks the addition of aromatic hydrocarbons having efficient oxygen content, with promising combustion potential, thus making them a better choice. Here, we aim at reporting the application of cyanobacteria for biofuel production and their competent biotechnological potential, along with achievements and constraints in its pathway toward commercial benefits. This review article also highlights the role of various cyanobacterial species that are a source of green and clean energy along with their high potential in the production of biodegradable plastics.