Efficient Biodiesel Production Research Articles

Periodic mesoporous organosilica functionalized sulfonic acids as highly efficient and recyclable catalysts in biodiesel production

Novel water tolerant sulfonic acid based Periodic Mesoporous Organosilicas (PMOs) having either phenylene (1a) or ethyl (1b) as bridge and methylpropyl sulfonic acid as functionalized group have been developed. The materials have been then employed in efficient biodiesel production via direct transesterification of sunflower oil, canola oil, corn oil, refined olive oil, and extracted oil from olive sludge with methanol. By comparing the catalytic performance of these acids with well-known SBA-15-PrSO3H, it was revealed that catalyst 1b bearing an ethyl bridging group is a more reactive catalytic system in biodiesel production. On the other hand, while the water adsorption experiment shows that among the described PMO functionalized acids, 1a shows more hydrophobic character, in contrast, we interestingly found that 1b consistently exhibited higher catalytic performance in biodiesel formation, which relies on a balance between hydrophobic-hydrophilic- and pore size of the mesochannels in this catalyst.

Use of colloid chemistry principles to improve efficiency in biodiesel production

The principles of colloid chemistry have been employed to improve the efficiency of biodiesel production. Potential sources of material loss caused by colloid chemistry were linked to specific steps in the sequence of unit operations, and literature reviewed for possible solutions. Liquid-liquid equilibrium and trans-esterification experiments with high oleic sunflower and rapeseed oils were conducted using apolar and polar solvents. The kinetics of trans-esterification were improved by both through the modification of interfacial resistance but the shift to final chemical equilibrium was only possible with apolar solvents. The use of an apolar solvent is beneficial in synthesis and product refining alike, though the removal of interfacial resistance between reaction partners, by shifting the reversible trans-esterification to close to complete conversion in a single step, and by reducing losses in material and profit. The results can be used to design and operate leaner, more efficient biodiesel production s ystems.

Double the biodiesel yield: Rearing black soldier fly larvae, Hermetia illucens, on solid residual fraction of restaurant waste after grease extraction for biodiesel production

Biodiesel is a promising alternative diesel fuel which has increased worldwide public interest in a number of countries including China. But the high cost of producing biodiesel from feedstock, predominately food grade oils, limited its economic feasibility. An alternative of using grease extracted from restaurant waste to produce biodiesel is a potential low cost approach. However, this approach generates a significant large quantity of solid residual fraction which required proper disposal. This study was conducted to evaluate the potential of a secondary biodiesel production from the solid residual fraction of restaurant waste after typical grease extraction (SRF) employing a high fat containing insect, black soldier fly, Hermetia illucens. The SRF was sampled and fed to black soldier fly larvae. The resulting larval biomass was used for crude grease extraction by petroleum ether. The extracted crude grease was then converted into biodiesel by acid-catalyzed (1% H 2SO 4) esterification and alkaline-catalyzed (0.8% NaOH) transesterification. About 23.6 g larval grease-based biodiesel was produced from approximately 1000 larvae grown on 1 kg of SRF. The weight of SRF was reduced by about 61.8% after being fed by the black soldier fly larvae for 7 days. The amount of biodiesel yield from restaurant waste was nearly doubled (original restaurant waste grease, 2.7%; larval grease, 2.4%). The major methyl ester components of the biodiesel derived from black soldier fly larvae fed on SRF were oleinic acid methyl ester (27.1%), lauric acid methyl ester (23.4%), and palmitic acid methyl ester (18.2%). Most of the properties of this biodiesel met the specifications of the standard EN 14214, including density (860 kg/m 3), viscosity (4.9 mm 2/s), flash point (128 °C), cetane number (58) and ester contents (96.9%). These results indicated that black soldier fly larval biomass obtained from larvae reared on SRF could potentially be used as a non-food feedstock for biodiesel production. This approach not only enhances the efficiency of biodiesel production from restaurant waste, it also helps to better manage and significantly reduce the large quantity of solid residual fraction produced during the process of biodiesel production using restaurant waste.

Biodiesel production from crude canola oil by two-step enzymatic processes

Crude canola oil (CCO) contains about 100–300 ppm of phospholipids, which have shown negative effects on biodiesel/buffer solution phase separation, resulting in low biodiesel production yield. Therefore, phospholipids should be removed before transesterification by a degumming process for efficient production of biodiesel. In this study, two-step enzymatic processes (degumming and transesterification) were carried out for the production of biodiesel from CCO. Degumming of CCO was performed using phospholipase A2 as a degumming reagent. The initial phospholipid content was reduced to less than 5 ppm by enzymatic degumming. The effects of three formulations of enzyme catalyst on the efficiency of transesterification were investigated. As a result, conversion rates of degummed CCO to fatty acid methyl esters (FAME) were 68.56%, 70.15%, and 84.25%, respectively. Lipase formulation composed of a 1:1 (vol:vol) enzyme mixture of Rhizopus oryzae and Candida rugosa showed the best performance among those tested. In order to recover and reuse the lipase catalyst efficiently, a 1:1 enzyme mixture of R. oryzae and C. rugosa was immobilized on silica gel. The immobilized lipase was used in subsequent transesterification optimization experiments. Optimization of transesterification was performed by response surface methodology (RSM). A total of 20 experiments based on RSM were carried out, and the optimal reaction conditions appeared to be 24.4% (w/w) immobilized catalyst, 13.5% (w/w) buffer solution, and 15.8% (w/w) methanol based on oil mass. Conversion rate of degummed CCO to FAME was determined to be 88.9% under optimal conditions.

Continuous biodiesel production using in situ glycerol separation by membrane bioreactor system

Biodiesel is one of the most promising renewable fuel sources. Candida antarctica lipase B (CalB) has been used for biodiesel production because of its high activity and stability. However, CalB can only be utilized in industrial biodiesel production if the enzyme deactivation by methanol and the negative effects of glycerol can be mitigated. Methanol inhibition can be avoided by utilizing a stepwise addition of methanol, but there is no suitable method to reduce the glycerol effect. This study aims to use a membrane bioreactor system to remove glycerol during biodiesel production. In addition, methanol inhibition can be reduced by continuously feeding methanol through the membrane system. This continuous membrane bioreactor system can be used for efficient biodiesel production.

Development of an Aspergillus oryzae whole-cell biocatalyst coexpressing triglyceride and partial glyceride lipases for biodiesel production

An Aspergillus oryzae whole-cell biocatalyst which coexpresses Fusarium heterosporum lipase ( FHL) and mono- and di-acylglycerol lipase B ( mdlB) in the same cell has been developed to improve biodiesel production. By screening a number of transformants, the best strain was obtained when FHL gene was integrated into A. oryzae chromosome using sC selection marker while mdlB was integrated using niaD selection marker. The reaction system using the lipase-coexpressing whole-cells was found to be superior in biodiesel production to others such as lipase-mixing and two-step reactions, affording the highest reaction rate and the highest ME content (98%). Moreover, an ME content of more than 90% was maintained during 10 repeated batch cycles. The whole-cell biocatalyst developed in this work would be promising biocatalysts for efficient biodiesel production.

Highly efficient biodiesel production by a whole-cell biocatalyst employing a system with high lipase expression in Aspergillus oryzae

In the present study, a system with high lipase expression in Aspergillus oryzae was developed using an improved enolase promoter (P-enoA124) and the 5' untranslated region of a heat-shock protein (Hsp-UTR). P-enoA142 enhanced the transcriptional level of a heterologous lipase gene and Hsp-UTR improved its translational efficiency. Fusarium heterosporum lipase (FHL) was inserted into a pSENSU-FHL expression vector harboring P-enoA142 and Hsp-UTR and was transformed into an A. oryzae NS4 strain. Transformants possessing pSENSU-FHL in single (pSENSU-FHL#1) and double copies (pSENSU-FHL#2) were selected to evaluate the lipase activity of the whole-cell biocatalyst. The two strains, pSENSU-FHL#1 and #2, showed excellent lipase activity in hydrolysis compared with the strain transformed with conventional expression vector pNAN8142-FHL. Furthermore, by using pSENSU-FHL#2, methanolysis could proceed much more effectively without deactivation, which allowed a swift addition of methanol to the reaction mixture, thereby reducing reaction time.

An efficient activity ionic liquid-enzyme system for biodiesel production

The efficient production of biodiesel in hydrophobic ionic liquids using immobilized lipase was demonstrated. The use of ionic liquids containing long alkyl chains on the cation has the important advantage of producing homogeneous systems at the start of the reaction but, when the reaction is complete, a three-phase system is created that allows selective extraction of the products using straightforward separation techniques, while the ionic liquid and the enzyme can be reused. Fifteen ionic liquids based on different alkyl chain length of the methyl imidazolium cation ([C10MIM], [C12MIM], [C14MIM], [C16MIM] and [C18MIM]) combined with [BF4], [PF6] or [NTf2] anions were assayed as reaction media for two immobilized lipases (Candida antarcticalipase B and Pseudomonas fluorescenslipase AK) for biodiesel production. The highest synthetic activity was obtained in [C16MIM] [NTf2] using Novozym 435 (immobilized Candida antarcticalipase with 245.13 U g−1IME), its activity being more than three times higher than in a solvent-free system. Additionally, in this IL the fatty acid methyl esters production was 90.29% after 3 h, while in the solvent-free system it was 27.3%. The influence of several reaction parameters, such as temperature, methanol-to-oil molar ratio, alkyl-chain length of the alcohols, IL : substrate volume ratios, amount of enzyme, and oils feedstock were studied and optimized.

The Role of Synthetic Biology in the Design of Microbial Cell Factories for Biofuel Production

Insecurity in the supply of fossil fuels, volatile fuel prices, and major concerns regarding climate change have sparked renewed interest in the production of fuels from renewable resources. Because of this, the use of biodiesel has grown dramatically during the last few years and is expected to increase even further in the future. Biodiesel production through the use of microbial systems has marked a turning point in the field of biofuels since it is emerging as an attractive alternative to conventional technology. Recent progress in synthetic biology has accelerated the ability to analyze, construct, and/or redesign microbial metabolic pathways with unprecedented precision, in order to permit biofuel production that is amenable to industrial applications. The review presented here focuses specifically on the role of synthetic biology in the design of microbial cell factories for efficient production of biodiesel.

Fast biodiesel production from beef tallow with radio frequency heating

Efficient biodiesel production from beef tallow was achieved with radio frequency (RF) heating. A conversion rate of 96.3 ± 0.5% was obtained with a NaOH concentration of 0.6% (based on tallow), an RF heating for 5 min, and a methanol/tallow molar ratio of 9:1. Response surface methodology was employed to evaluate the influence of NaOH dose, RF heating time, and methanol/tallow ratio. The alkaline concentration showed the largest positive impact on the conversion rate. Similar fast conversion from canola oil to biodiesel was achieved in our previous work, indicating that RF heating, as an accelerating technique for biodiesel production, had a large applying area. Viscosities of biodiesel products from beef tallow and canola oil were measured as 5.23 ± 0.01 and 4.86 ± 0.01 mm 2 s −1, respectively, both meeting the specification in ASTM D6751 (1.9–6.0 mm 2 s −1).

Biodiesel production by a mixture of Candida rugosa and Rhizopus oryzae lipases using a supercritical carbon dioxide process

In this study, various factors, such as temperature, pressure, agitation speed, water content, and the concentration and ratio of immobilized ROL and CRL were investigated for the efficient enzymatic production of biodiesel using a supercritical carbon dioxide process. Furthermore, a stepwise reaction method for the maintenance of immobilized lipase activity was optimized. Optimal conditions for biodiesel production were determined to be as follows: 130 bar pressure, 45 °C temperature, 250 rpm agitation speed, 10% water content, and 20% immobilized ROL and CRL (1:1). When batch process was performed under optimal conditions, the biodiesel conversion yield was 99.13% at 3 h. Biodiesel conversion yield was 99.99% at 2 h when 90 mmol methanol was used in a stepwise reaction. Moreover, the conversion yield of biodiesel produced by the repeated recycling of immobilized lipase in the stepwise reactions was 85% after 20 reuses.

Parametric Study of Jatropha Seeds for Biodiesel Production by Reactive Extraction

AbstractThe purpose of the present study was to reduce the cost and increase the efficiency of biodiesel production by reactive extraction (in situ) of Jatropha seeds. Oil from the seeds was extracted and reacted in a single step. Experimental studies have been carried out to maximize the yield of biodiesel by varying the reaction parameters viz. seed size (<0.85 mm to >2.46 mm), seed/solvent ratio (w/w) (1:2.6–1:7.8) and catalyst concentration (0.05–0.1 M). Under the optimized conditions: seed size (>2.46 mm), seed/solvent ratio (w/w) (1:7.8), catalyst concentration (0.1 M) and reaction time 1 h, approximately 98% conversion to biodiesel was achieved meeting International (ASTM) as well as National (BIS) specifications. The results were supported by HPLC analysis.

Effect of Canola Oil Quality on Biodiesel Conversion Efficiency and Properties

Many small-scale biodiesel producers use feedstocks in their operations that vary in quality and degree of refining, ranging from crude to degummed to highly refined oils. There have been claims that mechanically extracted oil makes better biodiesel as compared to that from hexane extracted oil. However, there is no comprehensive study evaluating the effects of oilseed extraction and refining techniques on biodiesel production efficiency and properties, specifically products derived from canola. This study examined biodiesel conversion efficiency of canola oil obtained by both hexane and mechanical extraction methods. Hexane extracted crude, degummed, and refined-bleached-deodorized and mechanically extracted crude canola oils were converted to biodiesel using a conventional transesterification method. Material balances for conversion of hexane and mechanically extracted oils to biodiesel were calculated. Physical and chemical properties for both oil and biodiesel samples were analyzed. Quality parameters of the biodiesel samples were compared to both ASTM and European standards. This study demonstrated that degummed canola oil produces biodiesel with acceptable yield and quality.

Sulfated tin oxide as solid superacid catalyst for transesterification of waste cooking oil: An optimization study

Biodiesel is a renewable, biodegradable and non-toxic fuel which can be easily produced through transesterification reaction. However, current commercial usage of refined vegetable oils for biodiesel production is impractical and uneconomical due to high feedstock cost and priority as food resources. Low-grade oil, typically waste cooking oil can be a better alternative; however, the high free fatty acids (FFA) content in waste cooking oil does not allow efficient production of biodiesel via current commercial homogeneous transesterification process. Therefore in the present study, superacid sulfated tin oxide catalyst, SO42−/SnO2 has been prepared using impregnation method for biodiesel production via heterogeneous tranesterification process. The bi-metallic effect of the catalyst was also studied, in which SnO2 was mixed with SiO2 and Al2O3, respectively, at different weight ratios in order to enhance the catalytic activity of SnO2. The effect of different reaction parameters such as calcination temperature and period of the catalyst, reaction temperature, catalyst loading, methanol-to-oil ratio and reaction time were studied to optimize the reaction conditions. It was found that SO42−/SnO2-SiO2 with weight ratio 3 exhibited an exceptional high activity with an optimum yield of 92.3% at reaction temperature 150°C, catalyst loading 3wt%, methanol-to-oil ratio 15 and reaction time 3h. The physical and chemical properties of the catalysts were also characterized using XRD analysis and FT-IR imaging.

A First Law Thermodynamic Analysis of Biodiesel Production From Soybean

A proper First Law energy balance of the soybean biodiesel cycle shows that the overall efficiency of biodiesel production is 0.18, i.e., only 1 in 5 parts of the solar energy sequestered as soya beans, plus the fossil energy inputs, becomes biodiesel. Soybean meal is produced with an overall energetic efficiency of 0.38, but it is not a fossil fuel. If both biodiesel and soybean meal were treated as finished fossil fuels, the overall energy efficiency of their production would be 0.56, ∼ 40% higher than the average overall efficiency, 0.4, of producing ethanol and DDGS from corn patzek 2006z, patzek 2007a. This difference is caused by the high energy efficiency of producing soybean meal, which is 57% of soya beans by mass. Production of corn ethanol alone, with the average overall efficiency of 0.25, is more energy-efficient than production of biodiesel from soybeans with the overall efficiency of 0.18. The results of the current analysis are compared with those by NREL 1998 and Hill et al. 2006.

Catalytic properties of a lipase from Photobacterium lipolyticum for biodiesel production containing a high methanol concentration

Biodiesel, an alternative fuel, is generated via the transesterification reaction of vegetable oil or animal oil with alcohol. Currently, many reports have noted that microbial lipases might be utilized for the production of biodiesel. Among them, immobilized Candida antarctica lipase B (Novozym435) is frequently utilized for its biocatalytic efficiency and availability. However, as the enzyme is unstable in a medium containing high concentrations of methanol, a multi-stepwise methanol supply is required for the efficient production of biodiesel. Photobacterium lipolyticum lipase (M37) was determined to be quite stable in a medium containing a high concentration of methanol. The enzyme activity was maintained for longer than 48 h without any loss at a methanol concentration of 10%. In an effort to evaluate enzyme performance in the production of biodiesel, we have compared M37 lipase and Novozym435 in the biodiesel production reaction using fresh or waste oil and methanol. In the 3-stepwise methanol feeding method generally conducted for Novozym435 in biodiesel production, the M37 lipase showed a similar or superior conversion yield to Novozym435. However, the M37 lipase evidenced significantly higher conversion yields in the 2 and 1 step methanol feeding reactions. Particularly in the 1 step process using 10% of methanol where almost no conversion was detected by Novozym435, the biodiesel yield achieved with M37 lipase reached a level of up to 70% of the possible maximum yield. Consequently, this methanol-tolerant lipase, M37, has been shown to be a suitable enzyme for use in the biodiesel production process.

Nanosized and reusable SiO2/ZrO2 catalyst for highly efficient biodiesel production by soybean transesterification

Nanosized SiO2/ZrO2 catalyst with high surface area (131.50 ± 14 m2 g-1) was prepared by the sol-gel method. The material presented highly homogeneous particles with an average diameter of 250 nm according to SEM images. It was applied in the transesterification of soybean oil for biodiesel production. The biodiesel conversion reached a yield of 96.2 ± 1.4 % after 3 h of transesterification reaction catalised by SiO2/ZrO2 (SiZr). The catalyst was recovered and reused six times, maintaining a catalytic efficiency of about 84.1 %.

Efficient production of biodiesel from high free fatty acid-containing waste oils using various carbohydrate-derived solid acid catalysts

In the present study, such carbohydrate-derived catalysts have been prepared from various carbohydrates such as d-glucose, sucrose, cellulose and starch. The catalytic and textural properties of the prepared catalysts have been investigated in detail and it was found that the starch-derived catalyst had the best catalytic performance. The carbohydrate-derived catalysts exhibited substantially higher catalytic activities for both esterification and transesterification compared to the two typical solid acid catalysts (sulphated zirconia and Niobic acid), and gave markedly enhanced yield of methyl esters in converting waste cooking oils containing 27.8 wt% high free fatty acids (FFAs) to biodiesel. In addition, under the optimized reaction conditions, the starch-derived catalyst retained a remarkably high proportion (about 93%) of its original catalytic activity even after 50 cycles of successive re-use and thus displayed very excellent operational stability. Our results clearly indicate that the carbohydrate-derived catalysts, especially the starch-derived catalyst, are highly effective, recyclable, eco-friendly and promising solid acid catalysts that are highly suited to the production of biodiesel from waste oils containing high FFAs.

Improved Method for Efficient Production of Biodiesel from Palm Oil

Biodiesel (methyl esters of long-chain fatty acids) can be produced by methanolysis of vegetable oils using lipase as a biocatalyst. However, the lipase, such as immobilized Candida antarctica lipase B (Novozym 435), is poisoned as a result of the contact with insoluble methanol, reducing the lipase activity. To minimize the problem, a salt-solution-based controlled release system for methanol is developed. The developed method can easily minimize the problem by dissolving methanol in the salt solution and keeping an acceptable methanol concentration in vegetable oil, thereby increasing the lipase activity. The results of methanolysis of palm oil in the salt-solution-based methanol release system are compared to those in a salt-solution-free system, where methanol is added by the traditional method of three successive additions of methanol. The maximum biodiesel yields in both systems are the same (97%), but methanolysis in the developed method progresses 4-fold faster than that in the traditional method. It is found that a LiCl-saturated solution stabilizes Novozym 435 against heat-induced inactivation. The results suggest that the salt-solution-based methanol release system can be an acceptable substitution for the traditional method and provides an efficient method for biodiesel production.

Preparation of a sugar catalyst and its use for highly efficient production of biodiesel

Novel solid acid catalysts for esterification have recently been described that are made by incomplete carbonization of carbohydrates followed by sulfonation. Herein, such a ‘sugar catalyst’ is prepared from D-glucose and its catalytic properties and structure are investigated in detail. This type of sugar catalyst is, for the first time, applied for the effective production of biodiesel from waste oils. Our results indicate that sugar catalysts are highly effective, minimally polluting and re-usable catalysts that are highly suited to the production of biodiesel from waste oils with a high acid value.