Efficient Biodiesel Production Research Articles

Rapid biodiesel production using wet microalgae via microwave irradiation

The major challenges for industrial commercialized biodiesel production from microalgae are the high cost of downstream processing such as dewatering and drying, utilization of large volumes of solvent and laborious extraction processes. In order to address these issues the microwave irradiation method was used to produce biodiesel directly from wet microalgae biomass. This alternative method of biodiesel production from wet microalgae biomass is compared with the conventional water bath-assisted solvent extraction. The microwave irradiation extracted more lipids and high biodiesel conversion was obtained compared to the water bath-assisted extraction method due to the high cell disruption achieved and rapid transesterification. The total content of lipid extracted from microwave irradiation and water bath-assisted extraction were 38.31% and 23.01% respectively. The biodiesel produced using microwave irradiation was higher (86.41%) compared to the conventional method. Thus microwave irradiation is an attractive and promising technology to be used in the extraction and transesterification process for efficient biodiesel production.

Biodiesel production and Environmental CO2 cleanup using Oleaginous Microorganisms from Al-Hassa area in Saudi Arabia

AbstractBiodiesel production is rapidly moving towards the mainstream as an alternative source of energy. Algae oil is one of the viable feed stocks among others to produce Biodiesel. However the difficulties in efficient biodiesel production from algae lie not in the extraction of the oil, but in finding an algal strain with a high lipid content and fast growth rate. This paper presents an experimental work performed to study the production of biodiesel from local algae strains in Al-Hassa territory of the eastern province in Saudi Arabia which was found to contain high lipid contents and show rapid growth. The collected results predict that those types of desert algae are promising and are considered to be a potential feedstock for biofuels.

Continuous harvest of marine microalgae using electrolysis: effect of pulse waveform of polarity exchange

Advances in harvesting of microalgae are needed for the efficient and economical production of microalgal biodiesel. In addition to improvements in recovery efficiency, developments in harvest technology should focus on reducing the adverse impact of subsequent processes, and should also allow water recycling. We investigated a continuous electrochemical approach for microalgal biodiesel production. Instead of conventional DC, pulsed DC was applied as a method of polarity exchange and its performance was analyzed in terms of recovery efficiency, electricity consumption, and residual Al concentration. Under optimized pulsed-DC conditions, 32 % less electricity was required and 7 % less Al was remained after continuous harvesting and there was no decrease in recovery efficiency compared to the continuous harvesting by conventional DC. We also examined the effect of this new protocol on biodiesel quality and water reusability. There were no differences in the microalgal oil composition before and after electrolytic harvesting. In addition, the harvested oil quality, based on four key parameters, was superior to that produced by other terrestrial crops. Lastly, there was no retardation of growth in recycled medium relative to that in fresh medium.

Cultivation of Chlorella vulgaris in Dairy Wastewater Pretreated by UV Irradiation and Sodium Hypochlorite

There is potential in the utilization of microalgae for the purification of wastewater as well as recycling the resource in the wastewater to produce biodiesel. The large-scale cultivation of microalgae requires pretreatment of the wastewater to eliminate bacteria and protozoa. This procedure is costly and complex. In this study, two methods of pretreatment, UV irradiation, and sodium hypochlorite (NaClO), in various doses and concentrations, were tested in the dairy wastewater. Combining the efficiency of biodiesel production, we proposed to treat the dairy wastewater with NaClO in the concentration of 30ppm. In this condition, The highest biomass productivity and lipid productivity of Chlorella vulgaris reached 0.450g L(-1) day(-1) and 51mg L(-1) day(-1) after a 4-day cultivation in the dairy wastewater, respectively.

Optimization of oleic acid esterification catalyzed by ionic liquid for green biodiesel synthesis

In order to improve the efficiency of biodiesel production from esterification of free fatty acids, an alternative to sulfuric acid has been explored. In this study, esterification of oleic acid was performed using 1-butyl-3-methylimidazolium hydrogen sulfate ([BMIM][HSO4]) ionic liquid for green biodiesel production. Response surface methodology (RSM) based on central composite design (CCD) was employed to study the effect of independent parameters on the process and also for single-objective optimization, while artificial neural network–genetic algorithm (ANN–GA) was utilized to simultaneously optimize the responses of the reaction (methyl oleate yield and oleic acid conversion). From the results, the predicted mathematical models for both methyl oleate yield and oleic acid conversion covered more than 80% of the variability in the experimental data. Furthermore, the linear temperature coefficient was identified as the most influential coefficient towards both responses. Higher responses were predicted for multi-objective optimization using ANN–GA compared to single-objective optimization using RSM. The optimum responses predicted using multi-objective optimization were 81.2% and 80.6% for methyl oleate yield and oleic acid conversion, respectively. The conditions to achieve optimum response were methanol–oleic acid molar ratio of 9:1, catalyst loading (0.06mol), reaction temperature (87°C), and reaction time (5.2h). Furthermore, there was only small decrease in the catalytic activity of the IL after being recycled for five successive runs.

Biodiesel Reactor Design with Glycerol Separation to Increase Biodiesel Production Yield

The study consisted of reactor design used for transesterification process, effect of glycerol separation ontransesterification reaction, determination of biodiesel quality, and mass balance analysis. The reactor was designed byintegrating circulated pump/stirrer, static mixer, and sprayer that intensify the reaction in the outer tank reactor. The objective was to reduce the use of methanol in excess and to shorten the processing time. The results showed that thereactor that applied the glycerol separation was able to compensate for the decreased use of the reactant methanol from 6:1 to 5:1 molar ratio, and changed the mass balance in the product, including: (i) the increase of biodiesel productionfrom 42.37% to 49.34%, and (ii) the reduction of methanol in excess from 42.37% to 32.89%. The results suggested that the efficiency of biodiesel production could be increased with the glycerol separation engineering.

English

  In the current study, biodiesel production efficiency of Chlorella vulgaris, Rhizoclonium hieroglyphicum and mixed algae culture was measured by transesterification process. Growth rate of algal species was measured on the basis of increase in their dry matter in various media. Protein, carbohydrates and lipids in all selected algae were measured on dry matter basis. Extracted oil was analyzed for water contents, iodine value, saponification value, acid number and fatty acid composition. Transesterification of algal oil was performed by using sodium methoxide as a catalyst. Yield of biodiesel from extracted oil was calculated for C. vulgaris (95%), R. hieroglyphicum (91%) and mixed algae culture (92%). Produced biodiesel was analyzed for kinematic viscosity (4.9, 5.0 and 4.7 mm2/s), flash point (160, 156 and 155°C), specific gravity (0.91, 0.914 and 0.912 g/ml), cetain number (51, 49 and 47 min), iodine value (47, 53 and 49 mg/g), acid number (0.49, 0.5 and 0.46 mg.KOH/g), carbon residue (0.01, 0.02 and 0.01 mass%), sulfated ash (0.007, 0.003 and 0.004 mass%), sulphur (0.013, 0.012 and 0.01 wt%) and water contents (15, 23 and 17 mg/kg) for C. vulgaris, R. hieroglyphicum andmixed algae culture, respectively. Properties of biodiesel were compared with ASTM standards and it was found with high quality biodiesel.   Key words:  Biodiesel, oil extraction, algae, transesterification.    

Preliminary evaluation of the effectiveness of moisture removal and energy usage in pretreatment module of waste cooking oil for biodiesel production

Waste Cooking Oil (WCO) is a plausible low cost biodiesel feedstock but it exhibits few unfavorable parameters for conversion into biodiesel. One of the parameter is the presence of high moisture content which will inhibit or retard catalyst during the acid esterification or base transesterification causing lower purity and yield of biodiesel. This will effect the post processing and escalate production cost making WCO a not favorable biodiesel feedstock. Therefore, it is important to have an effective moisture removal method to reduce the moisture content below 0.05%wt or 500 ppm in WCO for an efficient biodiesel production. In this work, the effectiveness of moisture removal and the energy usage of a newly develop innovative pretreatment module has been evaluated and reported. Results show that the pretreatment module is able to reduce up to 85% to effectively reduce the moisture content to below 500ppm of the initial moisture content of WCO and only consume 157 Wh/l energy compared to conventional heating that consume 386 Wh/l and only remove 67.6% moisture in 2 hours.

A robust whole-cell biocatalyst that introduces a thermo- and solvent-tolerant lipase into Aspergillus oryzae cells: Characterization and application to enzymatic biodiesel production

To develop a robust whole-cell biocatalyst that works well at moderately high temperature (40–50°C) with organic solvents, a thermostable lipase from Geobacillus thermocatenulatus (BTL2) was introduced into an Aspergillus oryzae whole-cell biocatalyst. The lipase-hydrolytic activity of the immobilized A. oryzae (r-BTL) was highest at 50°C and was maintained even after an incubation of 24-h at 60°C. In addition, r-BTL was highly tolerant to 30% (v/v) organic solvents (dimethyl carbonate, ethanol, methanol, 2-propanol or acetone). The attractive characteristics of r-BTL also worked efficiently on palm oil methanolysis, resulting in a nearly 100% conversion at elevated temperature from 40 to 50°C. Moreover, r-BTL catalyzed methanolysis at a high methanol concentration without a significant loss of lipase activity. In particular, when 2 molar equivalents of methanol were added 2 times, a methyl ester content of more than 90% was achieved; the yield was higher than those of conventional whole-cell biocatalyst and commercial Candida antarctica lipase (Novozym 435). On the basis of the results regarding the excellent lipase characteristics and efficient biodiesel production, the developed whole-cell biocatalyst would be a promising biocatalyst in a broad range of applications including biodiesel production.

Efficient Production of Biodiesel from Rapeseed Oil Deodorizer Distillate: One-Pot Esterification and Transesterfication with Compound Lipases

A novel concept and efficient method for producing biodiesel from rapeseed oil deodorizer distillate (RODD) was developed by using compound lipases for one-pot esterification of FFA and transesterification of triglyceride with methanol in a solvent-free system. Compound lipases Novozyme435 and immobilized Pseudomonas cepacia G63 at 1:1(wt/wt) gave FAME about 96% yield under optimal conditions, being better than that with single lipase or other compound lipases. Besides, the loss rate of vitamin E was 18% much lower than that of using chemical catalyst, which shows that the compound lipases Novozyme435 and immobilized P. cepacia G63 can be ideal catalysts for biodiesel production from rapeseed oil deodorizer distillate.

Design and performance study on polypropylene biodiesel pilot plant for non-edible oils

A cost-effective, efficient biodiesel production plant that conforms to the decentralized feed stock processing program in vogue in villages of tropical countries of Asia and Africa is the concern of the present study. A 50 L/batch capacity biodiesel reactor has been designed and fabricated using polypropylene consisting of reaction vessel, catalyst tank, settling and washing chamber, evaporation chamber, and methanol recovery system. The performance of the reactor has been studied using pongamia oil, jatropha oil, and waste vegetable oil using transesterification process. The biodiesel yield achieved were 93.75–96 % (v/v) for pongamia, 92.5–95 % (v/v) for jatropha, and 94–95.5 % (v/v) for waste vegetable oil. The biodiesel samples have acceptable fuel standards as per ASTM D-6751 and BIS (ISO15607) specifications.

Efficient transformation of grease to biodiesel using highly active and easily recyclable magnetic nanobiocatalyst aggregates

Green and efficient production of biodiesel (FAME) from waste grease containing high amount of free fatty acid (FFA) was achieved by using novel magnetic nanobiocatalyst aggregates (MNA). Thermomyces lanuginosus Lipase (TLL) and Candida antarctica Lipase B (CALB) were covalently immobilized on core-shell structured iron oxide magnetic nanoparticle (80 nm), respectively, followed by freeze-dry to give MNA (13-17 μm) with high yield (80-89%) and high enzyme loading (61 mg TLL or 22 mg CALB per gram MNA). MNA TL showed the best performance among immobilized enzymes known thus for the production of FAME from grease (17 wt.% FFA) with methanol, giving 99% yield in 12 h (3.3 wt.% catalyst). MNA TL was easily separated under magnetic field and reused, retaining 88% productivity in 11th cycle. MNA CA converted >97% FFA in grease (17 wt.% FFA) to FAME in 12 h (0.45 wt.% catalyst), being useful in two-step transformation of grease to biodiesel.

Combined utilization of lipase-displaying Pichia pastoris whole-cell biocatalysts to improve biodiesel production in co-solvent media

Lipase-displaying whole cells appear to be efficient biocatalysts because of their low preparation costs and simple recycling procedure. The combined utilization of Candida antarctica lipase B (CALB) and Rhizomucor miehei lipase (RML), separately displayed on Pichia pastoris whole cells, to produce biodiesel in co-solvent media was investigated. A response surface methodology incorporating a D-optimal design was employed to obtain the optimum reaction conditions for methyl ester (ME) synthesis. The synergistic effect of the two displayed lipases and the use of tert-butanol and isooctane as the co-solvent media were found to significantly improve the transesterification reaction. Scaled-up reactions using various types of feedstock were carried out in a 0.5–l stirred reactor under optimum conditions, affording ME yields over 90% in 12h. Moreover, the ME yields remained above 85% after 20 repeated batch cycles. In conclusion, this biocatalyst affords a promising route to efficient biodiesel production.

Efficient production of biodiesel from waste grease: One-pot esterification and transesterification with tandem lipases

A novel concept and efficient method for producing biodiesel (FAME) from grease (15–40wt% free fatty acid, FFA) were developed by using tandem lipases for one-pot esterification of FFA and transesterification of triglyceride with methanol in a solvent-free system. Combining immobilized Candida antarctica lipase B (CALB) (Novozyme 435) favoring the esterification and immobilized Thermomyces lanuginosus lipase (TLL) (Lipozyme TLIM) preferring the transesterification at 2:8 (wt/wt) gave FAME in 80% yield, being better than that with Novozyme 435 or Lipozyme TLIM. Recombinant Escherichia coli (Calb/Tll) co-expressing CALB and TLL was engineered as a more efficient tandem-lipases system. Using wet or dry cells (4wt%) gave FAME in 87% or 95% yield, which is much better than that with E. coli cells expressing either CALB or TLL alone. Cells of E. coli (Calb/Tll) were recycled for five times and retained 75% productivity, thus being practical for producing biodiesel from grease.

Enzymatic production of biodiesel from waste cooking oil in a packed-bed reactor: An engineering approach to separation of hydrophilic impurities

An engineering approach was applied to an efficient biodiesel production from waste cooking oil. In this work, an enzymatic packed-bed reactor (PBR) was integrated with a glycerol-separating system and used successfully for methanolysis, yielding a methyl ester content of 94.3% and glycerol removal of 99.7%. In the glycerol-separating system with enhanced retention time, the effluent contained lesser amounts of glycerol and methanol than those in the unmodified system, suggesting its promising ability to remove hydrophilic impurities from the oil layer. The PBR system was also applied to oils with high acid values, in which fatty acids could be esterified and the large amount of water was extracted using the glycerol-separating system. The long-term operation demonstrated the high lipase stability affording less than 0.2% residual triglyceride in 22 batches. Therefore, the PBR system, which facilitates the separation of hydrophilic impurities, is applicable to the enzymatic biodiesel production from waste cooking oil.

Whole-cell based solvent-free system for one-pot production of biodiesel from waste grease

A whole-cell based solvent-free system was developed for efficient conversion of waste grease to biodiesel via one-pot esterification and transesterification. By isolation and screening of lipase-producing strains from soil, Serratia marcescens YXJ-1002 was discovered for the biotransformation of grease to biodiesel. The lipase (SML) from this strain was cloned and expressed in Escherichia coli as an intracellular enzyme, showing 6 times higher whole-cell based hydrolysis activity than that of wild type strain. The recombinant cells were used for biodiesel production from waste grease in one-pot reactions containing no solvent with the addition of methanol in several small portions, and 97% yield of biodiesel (FAME) was achieved under optimized conditions. In addition, the whole-cell biocatalysts showed excellent reusability, retaining 74% productivity after 4 cycles. The developed system, biocatalyst, and process enable the efficient, low-cost, and green production of biodiesel from waste grease, providing with a potential industrial application.

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.