Biodiesel By-product Research Articles

Renewable hydrogen production from chemical looping steam reforming of biodiesel byproduct glycerol by mesoporous oxygen carriers

Abstract The selection of metal oxides and supports to improve catalytic activity and stability of oxygen carriers (OCs) is crucial for chemical looping steam reforming (CLSR) to hydrogen production. In this study, the Ni-based MCM-41 and SBA-15 OCs with and without CeO2 promoter were prepared by direct synthesis and impregnation methods. The BET, XRD, TEM, ICP-AES, H2-TPR and DSC-TGA were used to analyze the synthesized OCs. Hydrogen production by CLSR using biodiesel byproduct glycerol was studied in a fixed-bed reactor with fuel and air stages. The DSC-TGA experiments were carried out to determine the thermal decomposition of biodiesel byproduct glycerol and the results indicated the exothermic and/or endothermic reactions as a result of secondary reactions and, the main degradation with the mass loss of 85.5 wt% occurred in the stages of 150–500 °C. The mesoporous OCs presented high specific surface area, large pore volume, and uniform pore size. It was found that the NiO and CeO2 in the mesoporous OCs were first reduced by fuels and the reduced OCs was responsible of steam reforming and water gas shift (WGS) to hydrogen production, and hydrogen selectivity was up to 90% using CeNiO/SBA-15. The mesoporous OCs with Ce promoter greatly shortened ‘dead time’ (the reduce time of OCs), and effectively suppressed carbon deposited on OCs. High loading of NiO and CeO2 on SBA-15 improved oxygen transfer and achieved excellent cyclic stability. These findings provide the fundamental understanding and principle of design on the conventional Ni-based OCs with room for further developments in chemical looping process.

Self-Pillared MFI-Type Zeolite Nanosheets as Selective Catalysts for Glycerol Dehydration to Acrolein

The surplus production of glycerol as a by-product of biodiesel has become a serious problem for the sustainability of the biodiesel industry. Glycerol dehydration over MFI zeolites offers a green route to acrolein production. However, conventional MFI zeolites suffer diffusion limitation, which inhibits accessibility to active sites and causes quick deactivation of catalysts because of severe coke deposition. In this study, self-pillared MFI nanosheet catalysts were prepared with different Si/Al ratios to catalyze glycerol dehydration. The nanosheets with interlayered meso-space possessing wide a,c-planes of ∼2 nm thickness in the b-axis provide a shortened diffusion pathway to easily access the active acid sites. In contrast to conventional MFI zeolites, the nanosheet morphology significantly enhanced the catalyst selectivity, activity, and stability; gave a high acrolein selectivity (92%) at a higher WHSV of 4 h–1; and remained stable after up to 100 h of the reaction of 5% glycerol in water.

Selective dehydration of glycerol on copper based catalysts

Glycerol is produced in large quantities as a byproduct of biodiesel, and among others hydroxyacetone (acetol) is an important commodity obtained from glycerol. Metallic Cu has been identified as active site for the dehydration of glycerol to hydroxyacetone and acid and metal sites are known to influence the catalytic performance. In this study, dehydration of glycerol over 5 wt.% copper supported on γ-Al2O3, ZrO2 and SiO2 was investigated. Catalysts were characterized by N2 physisorption, H2-TPR, NH3-TPD, N2O chemisorption, XPS, XRD, FTIR of pyridine adsorption. Cu/ZrO2 exhibited the highest hydroxyacetone yield at 20 % of glycerol conversion and the highest apparent reaction rate. The superior activity of Cu/ZrO2 was attributed to the highly acidic, both Lewis and Brönsted acidic, nature of the support and positive roles of the interfacial sites. The Weisz-Prater (WP) criterion was applied to confirm the absence of intraparticle diffusion limitations. It was assumed spherical particles and first order reaction. The WP value obtained in the worst scenario was less than 0.3 ensuring no diffusion limitation. Complementary DFT study indicates that both glycerol and hydroxyacetone interact significantly stronger on Cu/γ-Al2O3 and Cu/ZrO2 compared to metallic Cu, suggesting that the active sites are at the interface of Cu particles and the acidic support.

Simultaneous CO2 capture and thermochemical heat storage by modified carbide slag in coupled calcium looping and CaO/Ca(OH)2 cycles

• A process coupled calcium looping and CaO/Ca(OH) 2 heat storage is proposed. • Modified carbide slag with by-product of biodiesel is employed in coupled process. • Treatment of by-product of biodiesel improves heat storage capacity of carbide slag. • Heat storage capacity of modified carbide slag rises by introducing calcium looping. • CO 2 uptake of modified carbide slag is activated by introducing heat storage cycles. The simultaneous CO 2 capture and heat storage performances of the modified carbide slag with by-product of biodiesel were investigated in the process coupled calcium looping and CaO/Ca(OH) 2 thermochemical heat storage using air as the heat transfer fluid. The modified carbide slag with by-product of biodiesel exhibits superior CO 2 capture and heat storage capacities in the coupled calcium looping and heat storage cycles. The hydration conversion and heat storage density of the modified carbide slag after 30 heat storage cycles are 0.65 mol·mol −1 and 1.14 GJ·t −1 , respectively, which are 1.6 times as high as those of calcined carbide slag. The negative effect of CO 2 in air as the heat storage fluid on the heat storage capacity of the modified carbide slag is overcome by introducing CO 2 capture cycles. In addition, the CO 2 capture reactivity of the modified carbide slag after the multiple calcium looping cycles is enhanced by the introduction of heat storage cycles. By introducing 10 heat storage cycles after the 10th and 15th CO 2 capture cycles, the CO 2 capture capacities of the modified carbide slag are subsequently improved by 32% and 43%, respectively. The porous and loose structure of modified carbide slag reduces the diffusion resistances of CO 2 and steam in the material in the coupled process. The formed CaCO 3 in the modified carbide slag as a result of air as the heat transfer fluid in heat storage cycles decomposes to regenerate CaO in calcium looping cycles, which improves heat storage capacity. Therefore, the modified carbide slag with by-product of biodiesel seems promising in the coupled calcium looping and CaO/Ca(OH) 2 heat storage cycles.

Green synthesis of glycerol carbonate by transesterification of bio glycerol with dimethyl carbonate over Mg/ZnO: A highly efficient heterogeneous catalyst

Glycerol carbonate is one of the trending value added chemicals in biodiesel industry, which extensively used in pharmaceutical, cosmetic and food industries as well as green solvent in chemical industries. Depending upon the tremendous application of glycerol carbonate the synthesis of such compound from glycerol as by-product of biodiesel is the main focus of the researchers now a days. In this work, highly efficient heterogeneous Mg/ZnO base catalyst was designed through wet impregnation technique and used for transesterification of glycerol with dimethyl carbonate to produce glycerol carbonate. The synthesized catalysts were characterized by XRD, SEM -EDX, FT-IR, TGA-DSC, BET analyzer and XPS to find out the physico-chemical properties of catalyst. The conversion and validation of glycerol carbonate synthesis was confirmed by 1H and 13C NMR spectroscopy and gas chromatography also. It was observed at 80 °C the conversion of glycerol and GLC yield were to be obtained 98.4%, 96.57% respectively for the catalyst in 2 h time period. Finally, all the reaction parameters like temperature, molar ratio of DMC/Glycerol, catalyst loading, reaction time were optimized and the respective effects were examined.

Mixed glycerol and orange peel-based substrate for fed-batch microbial biodiesel production

The aqueous extraction of orange peel waste (OPW), the byproduct of the juice extraction process generated annually in massive amounts (21 Mton), yields a carbohydrate-rich liquid fraction, termed orange peel extract (OPE). Several studies highlight that the combination of glycerol, a biodiesel byproduct, with carbohydrate mixtures might boost microbial lipid production. This study performed first a shaken flask screening of 15 oleaginous yeast strains based on their growth and lipid-producing abilities on OPE- and glycerol-based media. This screening enabled the selection of R. toruloides NRRL 1091 for the assessment of the process transfer in a stirred tank reactor (STR). This assessment relied, in particular, on either single- and double-stage feeding fed-batch (SSF-FB and DSF-FB, respectively) processes where OPE served as the primary medium and nitrogen-containing glycerol-OPE mixtures as the feeding one. The continuous supply mode at low dilution rates (0.02 and 0.01 h−1 for SSF-FB and DSF-FB, respectively) starting from the end of the exponential growth of the initial batch phase enabled the temporal extension of biomass and lipid production. The SSF-FB and DSF-FB processes attained high biomass and lipid volumetric productions (LVP) and ensured significant lipid accumulation on a dry cell basis (YL/X). The SSF-FB process led to LVP of 20.6 g L−1 after 104 h with volumetric productivity (rL) of 0.20 g L−1 h−1 and YL/X of 0.80; the DSF-FB process yielded LVP, rL and YL/X values equal to 15.92 g L−1, 0.11 g L−1 h−1 and 0.65, respectively. The fatty acid profiles of lipids from both fed-batch processes were not significantly different and resembled that of Jatropha oil, a vastly used feedstock for biodiesel production. These results suggest that OPE constitutes an excellent basis for the fed-batch production of R. toruloides lipids, and this process might afford a further option in OPW-based biorefinery.

Advances in solid catalysts for selective hydrogenolysis of glycerol to 1,3-propanediol

ABSTRACT Glycerol is one of the top 12 platform chemicals obtained from biomass. Its surplus availability as a by-product of biodiesel, fat-splitting and soap manufacturing industries and affordable price lends significant opportunity for its valorization, using solid catalysts, into propanediols (PDOs), particularly to 1,3-propanediol (1,3-PDO), by selective hydrogenolysis. 1,3-PDO is an important chemical with wide applications including that as a precursor in polymers manufacturing. However, the synthesis of 1,3-PDO by selective cleavage of the secondary C-O bond of glycerol in the presence of hydrogen (instead of the primary C-O bond yielding 1,2-PDO) is highly challenging. Of late, supported Pt and Ir catalysts in combination with a reducible oxide (WOx or ReOx) were found selective for 1,3-PDO formation. Support, metals composition and additives (co-added metals) affect the performance of these catalysts. Detailed investigations revealed that metal dispersion, electronic connectivity between metal and metal oxide/support, hydrogen activation/spillover and Brönsted acidity are some parameters that influence the activity and selectivity of these bi-functional, metal-metal oxide catalysts. This review summarizes the latest advances in these solid catalysts for selective hydrogenolysis of glycerol to 1,3-PDO, a monomer for advanced polymers.

How sustainable are biopolymers? Findings from a life cycle assessment of polyhydroxyalkanoate production from rapeseed-oil derivatives

The main purpose of the article was to compare different scenarios of biopolymer production and their impacts on the environment using Life Cycle Assessment. Three alternative polyhydroxyalkanoates (PHA: amorphous PHA and poly(3-hydroxybutyrate), P(3HB)) production scenarios were considered to assess its environmental impact: Scenario A - Production of mcl-PHA/P(3HB) from crude vegetable oil; Scenario B - Production of P(3HB) with biodiesel by-product; Scenario C - Production of mcl-PHA/P(3HB) from used vegetable oil. Subject to the scenario considered, it was shown that the environmental efficiency of PHA production is highly dependent on carbon sources used, and it is strongly supporting production of mcl-PHA instead of P(3HB). As LCA study shows, due to low yield of P(3HB) in comparison to mcl-PHA production in considered processes, all the P(3HB) production scenarios have higher impacts than the production of mcl-PHA. Production processes based on bacterial fermentation had its impacts related mostly to the raw materials used and to its separation phase. Additionally, using secondary materials instead of raw ones, namely used oil instead of virgin oil, gives significant improvement with regard to environmental impact. The resource efficiency is also the identified as the key factor with sensitivity analysis that indicates the possible increase of biopolymer yield as the most beneficial factor. Biobased polymers have big environmental potential but still need significant improvement with regard to their manufacturing processes in order to become more economically benign. Preferably production of these microbial polymers should be integrated into biorefinery blocks, where such waste stream arises (e.g. biodiesel production plant).

Ni-Fe catalyst derived from mixed oxides Fe/Mg-bearing metallurgical waste for hydrogen production by steam reforming of biodiesel by-product: Investigation of catalyst synthesis parameters and temperature dependency of the reaction network

This study focuses on a thorough investigation of the effect of synthesis parameters (nickel content and preparation method) and operating temperature on the physiochemical properties and catalytic performance of Ni promoted Fe/Mg-bearing metallurgical waste catalyst (Ni-UGSO) for hydrogen production by glycerol steam reforming. The best results were achieved by incorporating 5 wt.% Ni by solid-state impregnation method (SSI-5%Ni-UGSO), leading to almost complete glycerol conversion to gaseous products. Higher H2 yield (80.7 %) and very low coke formation (0.59 mgcoke h−1(m2/gcat)−1) are the advantages of working at 580 °C by favouring the water-gas-shift (WGS) reaction, whereas increasing temperature to 730 °C allows to almost suppress coke formation (0.18 mgcoke h−1(m2/gcat)−1) mainly by limiting the Boudouard reaction, with the drawback of a lower hydrogen yield (59.4 %). This notable catalytic behavior was ascribed to the synergic cooperation between Ni and Fe/Mg containing species inside UGSO, through the formation of Ni-FexOy and Ni-MgO active sites.

Alternative Briquette Material Made from Palm Stem Biomass Mediated by Glycerol Crude of Biodiesel Byproducts as a Natural Adhesive

Recently, the global population has increased sharply, unfortunately, the availability of fossil fuel resources has significantly decreased. This phenomenon has become an attractive issue for many researchers in the world so that various studies in the context of finding renewable energy are developing continuously. Relating to this challenge, this research has been part of scientific work in the context of preparing an energy briquette employing palm oil stems and glycerol crude of biodiesel byproducts as inexpensive and green materials easily found in the Riau province, Indonesia. Technically, the palm oil stems are used for the production of charcoal particles and the glycerol crude as an adhesive compound in the production of energy briquettes. The heating value of palm oil stem is 17,180 kJ/kg, which can be increased to an even higher value through a carbonization process followed by a densification process so that it can be used as a potential matrix to produce energy briquettes. In detail, this study was designed to find out several parameters including the effect of sieve sizes consisting of 60, 80, and 100 mesh, respectively, which are used for the preparation of charcoal particles as the main matrix for the manufacture of the briquettes; the effect of charcoal-adhesive ratios (wt) of 60:40, 70:30, and 80:20; and the effect of varied pressures of 100, 110, and 120 kg/cm2 on the briquette quality. The quality of the obtained briquettes is analyzed through the observation of important properties which involve the heating value and the compressive strength using Response Surface Methodology (RSM). The results showed that the produced briquettes had an optimum heating value of 30,670 kJ/kg, while their loaded charcoal particles resulted from the mesh sieve of 80, in which there was a charcoal loading of 53 g and it pressed at 93.1821 bar, whereas, the compressive strength value of the briquette was 100,608 kg/cm2, which loaded charcoal particles from the mesh sieve of 100, the charcoal-adhesive ratio of 53:47 (wt) and the pressure of 93.1821 bar.

A scalable approach of using biomass derived glycerol to synthesize cathode materials for lithium-ion batteries

Glycerol, a main byproduct of biodiesel, was used as the fuel agent in a scalable flame-assisted spray pyrolysis approach to synthesize micron-size cathode materials. Single droplet combustion, particle morphology, and electrochemical performance were examined considering the effects of salt concentration, water addition, and post-annealing time on synthesizing Li(Ni1/3Co1/3Mn1/3)O2 (NCM111) cathode materials. Single droplet tests showed that a sufficient amount of water in the glycerol-based precursor could delay droplet inflation and ignition. Moreover, using a two-fluid atomization nozzle, spray tests demonstrated that adding water would result in less wrinkled and more uniform particles. Nevertheless, increasing water proportion in the precursor could reduce the reaction heat, resulting in that samples prepared with water addition needed longer post-annealing time to improve their electrochemical performance. Using the precursor without water, the best performed NCM111 cathode material was synthesized with only 2 h of post-annealing. It has a discharge capacity of 163.3 mAh/g at 0.1C and 85.5% capacity retention at 1C after 100 cycles. The current work confirmed the capability of using glycerol as a sustainable fuel agent to synthesize NCM111 cathode materials, and also provided basic conditions for the development of large-scale production in the future.

Valorization of Biodiesel Byproduct Crude Glycerol for the Production of Bioenergy and Biochemicals

The rapid growth of global biodiesel production requires simultaneous effective utilization of glycerol obtained as a by-product of the transesterification process. Accumulation of the byproduct glycerol from biodiesel industries can lead to considerable environment issues. Hence, there is extensive research focus on the transformation of crude glycerol into value-added products. This paper makes an overview of the nature of crude glycerol and ongoing research on its conversion to value-added products. Both chemical and biological routes of glycerol valorization will be presented. Details of crude glycerol conversion into microbial lipid and subsequent products will also be highlighted.

Investigation of fermentation conditions of biodiesel by-products for high production of β-farnesene by an engineered Escherichia coli.

Recently, the research on conversion of biodiesel by-products to high value-added products has received much attention, due to the adverse effects of large accumulations of biodiesel by-products caused by the rapid increase in biodiesel production. Herein, this study investigated the utilization of by-products crude glycerol (CG-1 and CG-2) from two different industrial methods of biodiesel production and the favorable fermentation conditions for the high yield of β-farnesene by an engineered Escherichia coli F4, which harbored an optimized mevalonate pathway. Through analyzing by-products' components and fermentation performance, we found that CG-2 did not contain harmful impurities such as methanol and black solid impurities, and the β-farnesene production was up to 2.7g/L from CG-2, which was similar to that from pure glycerol (2.5g/L) and higher than that (2.21g/L) from CG-1. Therefore, CG-2 was more suitable for β-farnesene production than CG-1, which might provide a reference for choosing a more suitable method on practical biodiesel production. Afterward, a variety of important fermentation conditions were explored using CG-2 as a substrate in shaken flasks. Under the optimal conditions (including induced cell density 1.0, initial cell density 0.25, temperature after induction 33°C, initial medium pH6.5), the yield of β-farnesene from CG-2 reached 10.31g/L in a 5-L bioreactor, which was 2.8-fold higher than initial conditions in shake flasks and was the highest yield of β-farnesene produced from biodiesel by-products by fermentation as well. The recommended fermentation conditions in this work will provide a valuable reference for the industrial production of β-farnesene utilizing biodiesel by-products.

Economical production of vitamin K2 using crude glycerol from the by-product of biodiesel

Industrial waste, such as crude glycerol, was used for vitamin K2 by B. subtilis Z-15. Crude glycerol could be used instead of pure glycerin for vitamin K2 production. The combination of soybean peptone and yeast extract was more conducive to the synthesis of vitamin K2. The optimal composition of medium was obtained by response surface methodology. The results indicated that the optimal medium was as follows: 6.3% crude glycerol, 3.0% soybean peptone concentration and 5.1 g/L yeast extract. Under the optimal culture medium, vitamin K2 production was increased to 45.11 ± 0.62 mg/L. The fermentor test further proved that the use of crude glycerol affected neither the synthesis of vitamin K2 nor the growth of B. subtilis. These investigations could lay a foundation for reducing the pollution of crude glycerol, exploring a late model for vitamin K2 cleaner production.

Structure–selectivity relationship of a zirconia-based heterogeneous acid catalyst in the production of green mono- and dioleate product

A novel catalytic technique is vital to produce mono- and dioleate (GMO and GDO) from bioglycerol: a renewable resource and by-product of biodiesel. The advantage of this invention is the direct production of GMO and GDO through catalytic approach compared to the conventional method that requires transesterification and distillation processes. In this paper, glycerol esterification with oleic acid using a catalyst was experimented. The process was carried out over a hydrophobic mesoporous zirconia–silica heterogeneous acid catalyst (ZrO2–SiO2–Me&Et–PhSO3H) with three types of sulphated zirconia catalysts (SO42−/ZrO2) to produce high-selectivity GMO and GDO products. The catalytic performance of the hydrophobic ZrO2–SiO2–Me&Et–PhSO3H catalyst was benchmarked with that of SO42−/ZrO2 which was developed from three zirconium precursors. Results showed that the pore volume and hydrophobicity of the designed catalyst greatly could influence the product selectivity, thus enabling smaller substrates GMO and GDO to be dominated in the synthesis. This finding was supported by characterisation data obtained through N2 adsorption–desorption, X-ray diffraction and scanning electron microscopy. In addition, a good correlation was found between pore volume (pore size) and product selectivity. High pore volume catalyst favoured GDO production under identical reaction conditions. Pore volume and size can be used to control product sensitivity. The hydrophobicity of the catalyst was found to improve the initial reaction rate effectively.

Engineering of glycerol utilization in Pseudomonas chlororaphis GP72 for enhancing phenazine-1-carboxylic acid production

Glycerol is a by-product of biodiesel, and it has a great application prospect to be transformed to synthesize high value-added compounds. Pseudomonas chlororaphis GP72 isolated from the green pepper rhizosphere is a plant growth promoting rhizobacteria that can utilize amount of glycerol to synthesize phenazine-1-carboxylic acid (PCA). PCA has been commercially registered as "Shenqinmycin" in China due to its characteristics of preventing pepper blight and rice sheath blight. The aim of this study was to engineer glycerol utilization pathway in P. chlororaphis GP72. First, the two genes glpF and glpK from the glycerol metabolism pathway were overexpressed in GP72ANO separately. Then, the two genes were co-expressed in GP72ANO, improving PCA production from 729.4mg/L to 993.4mg/L at 36h. Moreover, the shunt pathway was blocked to enhance glycerol utilization, resulting in 1493.3mg/L PCA production. Additionally, we confirmed the inhibition of glpR on glycerol metabolism pathway in P. chlororaphis GP72. This study provides a good example for improving the utilization of glycerol to synthesize high value-added compounds in Pseudomonas.

Ultrasound as pretreatment in biogas production from crude glycerol

Air pollution, acid precipitation, ozone depletion and the gaseous emissions to the atmosphere are associated to the petroleum derivate use, currently considered the main energy source used in the world. Renewable energy sources are expected to replace them in order to solve these environmental concerns. Biofuels as biodiesel and biogas are renewable energy produced from natural matter. Studies made suggest that using the principal by-product of biodiesel’s production process, crude glycerol, is possible to obtain biogas. Biogas can be produced from an anaerobic digestion process and enhanced by using pretreatment in substrate. This work tested ultrasound pretreatment on crude glycerol as a substrate in the biogas production. Different times of pretreatment (15 and 30 minutes) were examined, to determinate the best performance and compare it to the untreated substrate. The biogas production was daily measured directly from the reactors. The results showed that ultrasound pretreatment improved methane production. The best result was obtained by using 30 minutes of pretreatment on crude glycerol.

Utilization of waste crude glycerol for hydrogen production via steam reforming over Ni–La–Zr catalysts

The biodiesel industry generates crude glycerol (CG) at the rate of 10% of the amount of biodiesel produced. With the production of this biofuel increasing, a large amount of CG is produced each year. This results in low price for it and its final disposal becomes a significant problem. Herein, steam reforming represents a viable route to valorize this biodiesel by-product into hydrogen. The performance of Ni–La–Zr catalysts (15 wt%) for steam reforming of a CG without any purification treatment has been investigated at atmospheric pressure and at 500 °C and 650 °C. These materials were prepared using a coprecipitation method with oxalic acid. At 650 °C, the catalyst calcined at 850 °C presents higher catalytic activity and stability and displays better resistance to deactivation by carbon formation than the catalyst calcined at 700 °C. This behavior can be attributed to several causes: higher surface nickel content, higher catalyst reducibility and the presence of oxygen vacancies formed as a consequence of the partial substitution of nickel atoms into the pyrochlore structure during the formation of the biphasic system, which is related to mechanisms that act in the removal of carbon deposits on the catalyst.

Peanut meal and crude glycerin in lamb diets: Meat quality and fatty acid profile

Abstract This study aimed to evaluate the effects on lamb meat quality of replacing the soybean meal and corn diet with peanut meal and crude glycerin. A total of 40 lambs, with an initial body weight of 17.15 ± 1.56 kg, were divided into four biodiesel by-product treatment groups: a no-treatment control, peanut meal, crude glycerin, and peanut meal + crude glycerin. The roughage-to-concentrate ratio was 40:60 in all diets. Peanut meal, crude glycerin, and their combination had no effect on the physicochemical characteristics of the meat, except the fatty acid profile. The meat from animals fed the diets with crude glycerin and peanut meal + crude glycerin had higher proportions of oleic, pentadecanoic, heptadecanoic, and eicosapentaenoic fatty acids, lower proportions of palmitic acid, a lower atherogenicity index, a lower sum of hypercholesterolemic fatty acids, and stronger hypocholesterolemic:hypercholesterolemic relationships. When used as alternative sources of protein and energy in the diet of feedlot lambs, peanut meal and crude glycerin improve the lipid profile of the meat.

Exploring Pongamia seed cake hydrolysate as a medium for microbial lipid production by Aspergillus ochraceus

Abstract Biofuels and their production is the need of the hour considering the current fuel crisis. In this regard, ways of mitigating biodiesel production costs is being actively researched upon. With the same intention, in the present work, an investigation was carried out to test the capability of utilizing the hydrolysates of de-oiled Pongamia seed cake, a byproduct of biodiesel, for microbial lipid production using Aspergillus ochraceus. This is the first time A. ochraceus is being reported to be used to evaluate its oleaginous property. Also, Pongamia seed cake is the novel source being used for microbial lipid production. The different variants of the seed cake based medium proved acid hydrolysate of de-oiled seed cake to be the effective medium for lipid production. The values recorded for maximum biomass titer, lipid titer and lipid content were 3.065 ± 0.248 g/L, 0.849 ± 0.056 g/L and 28.93%, respectively, upon using acid hydrolysate of the seed cake. The fatty acid composition obtained by GC-MS analysis revealed the presence of linoleic, oleic, stearic and palmitic acids as the major fatty acid components in the lipids produced proving their similarity to the vegetable oils. The fuel properties of the lipids produced were found be in accordance with the standard specifications making them a very good source for biodiesel production. The findings from the current study reveal the effectiveness of Pongamia seed cake for microbial lipid production and simultaneous value addition to the biodiesel industry.