Cost-effective Biodiesel Production Research Articles

Production of microbial lipids utilizing volatile fatty acids derived from wastepaper: A biorefinery approach for biodiesel production

Volatile fatty acids (VFAs) derived from organic wastes are being considered as low-cost feedstock for microbial lipid production as a valuable alternative to plant derived oils/biodiesel. In this study, VFAs were produced from anaerobic open culture fermentation of wastepaper and subsequently, used as a feedstock for lipid production by Cryptococcus curvatus. Total VFAs, yield and productivity achieved from waste office paper (WOP) and waste newspaper (WNP) were 17.3 and 10.2 g/L, 0.17 and 0.10 g/g TS, and 0.86 and 0.51 g/L/day, respectively. Biomass, lipid content and productivity achieved utilizing VFAs derived from WOP and WNP were 4.3 and 2.9 g/L, 41.2 and 27.7% DCW, and 0.037 and 0.033 g/L/h, respectively. The dominance of fatty acids such as oleic, palmitic, stearic and linoleic acid in the lipids suggests a high level of similarity with plant/vegetable oils used for biodiesel production. Therefore, VFAs derived from wastepaper could be potentially used as feedstock to produce microbial lipids towards cost-effective production of biodiesel.

Production of Biodiesel from Castor Oil: A Review

An attractive alternative to the use of fossil fuels is biodiesel, which can be obtained from a variety of feedstock through different transesterification systems such as ultrasound, microwave, biological, chemical, among others. The efficient and cost-effective biodiesel production depends on several parameters such as free fatty acid content in the feedstock, transesterification reaction efficiency, alcohol:oil ratio, catalysts type, and several parameters during the production process. However, biodiesel production from vegetable oils is under development, causing the final price of biodiesel to be higher than diesel derived from petroleum. An alternative to decrease the production costs will be the use of economical feedstocks and simple production processes. Castor oil is an excellent raw material in terms of price and quality, but especially this non-edible vegetable oil does not have any issues or compromise food security. Recently, the use of castor oil has attracted attention for producing and optimizing biodiesel production, due to high content of ricinoleic fatty acid and the possibility to esterify with only methanol, which assures low production costs. Additionally, biodiesel from castor oil has different advantages over conventional diesel. Some of them are biodegradable, non-toxic, renewable, they can be used alone, low greenhouse gas emission, among others. This review discusses and analyzes different transesterification processes, technologies, as well as different technical aspects during biodiesel production using castor oil as a feedstock.

Strategies for enhanced lipid production of Desmodesmus sp. mutated by atmospheric and room temperature plasma with a new efficient screening method

This research provides a promising method to rapidly select optimal mutants for high-lipid production. The green microalgae Desmodesmus sp. was mutated using atmospheric and room temperature plasma (ARTP) to develop high lipid-producing mutants via radiation breeding for cost effective production of biodiesel. A new screening method was developed and was applied to obtain an optimal mutant strain that was designated as AT60-15. Genetic stability of the optimal strains was measured using three-generation reproduction testing. The highest triglyceride (TAG) production was 325.83 ± 3.02 mg L−1, which was 2.34-fold higher than that of the control group. Furthermore, compared with the original strain, the mutant strains showed rapid lipid accumulation but low levels of protein and carbohydrate production. In addition, AT60-15 displayed a lower actual quantum yield Y(II) and suffered more stress from ARTP than the original strain as evaluated by maximum quantum yield Fv/Fm. Analysis of the real-time quantitative PCR showed that mutant strains had a higher expression of lipid genes, including accD, me6562, pepc6833, and dgat7566. The ITS gene fragments showed that AT60-15 mutagen belonged to Desmodesmus.

Highly efficient renewable heterogeneous base catalyst derived from waste Sesamum indicum plant for synthesis of biodiesel

Waste Sesamum indicum plant derived heterogeneous catalyst was utilized for the first time for biodiesel synthesis from sunflower oil. The derived catalyst was characterized by using Powder XRD, FT-IR, BET, TGA, XRF, AAS, XPS, SEM-EDX and TEM, and the characterization revealed the presence of Na, K, Ca, Mg, Fe, Mn, Zn, Si, Sr and Cl with high percentage of K (29.64 wt %) and Ca (33.80 wt %) as oxides and carbonates. The catalyst with a moderate surface area of 3.66 m2 g−1 exhibited excellent catalytic activity producing a yield of 98.9% biodiesel under the optimized conditions of 12:1 methanol to oil molar ratio and catalyst loading of 7 wt % at the reaction temperature of 65 °C in a short reaction time of only 40 min. The catalyst could be reused up to the 3rd cycle of reaction with the yield of 94.2% biodiesel. The characterization of biodiesel was done by using FT-IR, NMR, and GC-MS techniques. The fuel property of produced biodiesel meets the prescribed limits of international standard. The prepared catalyst is easy to handle, reusable, and found to be highly efficient green catalyst that could help in reduction of biodiesel cost. Thus, the catalyst can be recommended as a potential candidate for cost-effective biodiesel production at a large scale.

Kinetic Modelling of Heterogeneous Methanolysis Catalysed by Iron Induced on Microporous Carbon Supported Catalyst

The investigation describes detailed kinetic modelling of biodiesel synthesis catalysed by waste derived carbonaceous catalyst in a batch reactor. The modelling is conducted via three approaches i.e. power law equation, Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) mechanism. Reversible and irreversible pathways with respect to triglycerides (TG) and fatty acid methyl esters (FAME) for first and second order reactions were considered for developing model equations. The kinetics of heterogeneous catalysis is studied using E–R and L–H mechanism to assess the exact rate controlling step by considering all the possible resistances offered by solid catalyst. The rate expressions for adsorption and desorption of individual reactant and product and surface chemical reaction were also developed. The influence of diffusional resistance offered by solid catalyst on conversion is also determined. The best fitted model is identified from calculated regression coefficients. The results revealed that glycerol desorption from catalyst surface given by E–R and L–H mechanisms is controlling the biodiesel synthesis process. The best suited model equation is considered for evaluating the kinetic parameters of the transesterification process. Thus, the study gives exact rate controlling step for heterogeneous catalysis to be used for reactor design and cost-effective production of biodiesel.

Utilization of Clarified Butter Sediment Waste as a Feedstock for Cost-Effective Production of Biodiesel.

The rising demand and cost of fossil fuels (diesel and gasoline), together with the need for sustainable, alternative, and renewable energy sources have increased the interest for biomass-based fuels such as biodiesel. Among renewable sources of biofuels, biodiesel is particularly attractive as it can be used in conventional diesel engines without any modification. Oleaginous yeasts are excellent oil producers that can grow easily on various types of hydrophilic and hydrophobic waste streams that are used as feedstock for single cell oils and subsequently biodiesel production. In this study, cultivation of Rhodosporidium kratochvilovae on a hydrophobic waste (clarified butter sediment waste medium (CBM)) resulted in considerably high lipid accumulation (70.74% w/w). Maximum cell dry weight and total lipid production were 15.52 g/L and 10.98 g/L, respectively, following cultivation in CBM for 144 h. Neutral lipids were found to accumulate in the lipid bodies of cells, as visualized by BODIPY staining and fluorescence microscopy. Cells grown in CBM showed large and dispersed lipid droplets in the intracellular compartment. The fatty acid profile of biodiesel obtained after transesterification was analyzed by gas chromatography-mass spectrometry (GC–MS), while its quality was determined to comply with ASTM 6751 and EN 14214 international standards. Hence, clarified sediment waste can be exploited as a cost-effective renewable feedstock for biodiesel production.

Comparative study on biodiesel production from Jatropha Curcas oil by supercritical and chemical catalytic method: a mathematical approach

ABSTRACTJatropha curcas oil is a renewable raw material which has been widely used for the production of biodiesel (BD) using various processes. This research article presents a study about BD production via chemical catalytic transesterification reaction method, supercritical methanol (SCM) method, and SCM with stirrer method. On this viewpoint, mathematical models of transesterification reaction process are formulated. The model systems are solved mathematically as well as numerically and the optimum value of important parameters, including reaction temperature, stirrer speed, and the molar ratio of methanol to oil, are found out. A comparative mathematical study has been made among these three processes with respect to product efficiency, reaction conditions, and mass transfer. Furthermore, control theoretic approach is applied in mixing intensity through supercritical process for cost-effective production of BD from Jatropha curcas oil. The optimum conditions were found to be 323K temperature, 6:1 mol/mol for methanol to oil ratio, and 561 rpm for stirrer speed. It may be concluded that SCM with stirrer is a promising alternative to produce BD from Jatropha curcas oil due to its economical benefit, high productivity, and good quality of the product. The validity of the models is established by experimental results available in literature.

Engineering a malic enzyme to enhance lipid accumulation in Chlorella protothecoides and direct production of biodiesel from the microalgal biomass

Genetic engineering of the eukaryotic microalga Chlorella protothecoides remains in the early stages of development. There is also an urgent need to develop cost-effective biodiesel production processes from wet and lipid-rich C. protothecoides. Malic enzyme is a potential key enzyme responsible for a rate-limiting step associated with lipid accumulation in some microorganisms. In this study, we genetically engineered C. protothecoides by overexpressing a key malic enzyme to improve lipid accumulation for direct biodiesel production from microalgal biomass. An open reading frame encoding 509 amino acid residues of a putative malic enzyme was obtained and identified. Cloning and overexpression of the malic enzyme gene allowed genetic engineering of C. protothecoides for lipid accumulation and further direct production of biodiesel without the need for lipid extraction steps. The total lipid accumulation in genetically engineered C. protothecoides increased 2.8-fold compared to the wild type. A dehydration step using methanol pretreatment coupled with H2SO4 or lipase catalyzed biodiesel production enabled 93–98% biodiesel yields directly from microalgal biomass without extraction of lipid under optimal conditions. The efficient direct dehydration and chemical and enzymatic transformation processes could significantly reduce the overall cost of biodiesel production from wet and lipid-rich microalgal feedstocks.

Enhancing algal biomass and lipid production by phycospheric bacterial volatiles and possible growth enhancing factor

The concept of sustainable biodiesel production using microalgae has attracted a lot of attention as an emerging green energy technology. However, low algal biomass and lipid productivity hinder cost-effective biodiesel production. To overcome these problems, this study examined the effect of bacterial volatile compounds (VCs) on the growth and lipid production of microalga Chlorella vulgaris OW-01. The VCs of phycospheric bacteria including Hyphomonas sp., Rhizobium sp., and Sphingomonas sp. efficiently augmented algal biomass in a newly developed VCs experimental apparatus. Moreover, an apparent increase in total lipid content along with a 2.34-fold increase in productivity was observed in Hyphomonas sp. VCs–exposed algal biomass. Fatty acid methyl esters (FAME) composition also demonstrated that the algal biodiesel properties were somewhat modified by exposure to bacterial VCs. A LiOH filter-inducing CO2-removed bacterial VCs (CRBVCs) also enhanced daily growth of microalgae, as compared to the control culture (aeration), indicating that CRBVC included growth-promoting volatiles. Of those factors, volatile indole was identified as a possible algal growth enhancing factor, and it showed a higher growth-promoting effect than dimethyl disulfide and dimethyl trisulfide. Based on these results, it is speculated that the use of bacterial VCs for algal cultivation is a promising future bioprocess for the algal biomass and biodiesel production.

Cost-effective biodiesel production from wet microalgal biomass by a novel two-step enzymatic process

In this study, a novel two-step enzymatic process was firstly established to produce microalgae biodiesel using wet Chlorella biomass. In the first hydrolysis step, to reduce energy consumption and effectively disrupt microalgal cell wall, among cellulase, hemicellulase, papain, lysozyme and pectinase, the highest hydrolysis efficiency (67.52%) was obtained by cellulase at pH 5.0 with enzyme dosage of 200 U/g dry biomass at 40 °C for 12 h. In the second transesterification step, compared with liquid CAL-A/B from Candida antarctica and PLA from Aspergillus oryzae, liquid lipase TL from Thermomyces lanuginosus achieved the highest biodiesel conversion at 81.15:1 (v/w) ethanol/g TFAs ratio in 78–83% water content with 100 PLU/g TFAs lipase loading at 25 °C for 48 h. Moreover, similar results were obtained with three Chlorella species by this process. Overall, this two-step enzymatic process was a green, low-energy and efficient method for cost-effective biodiesel production using wet microalgal biomass.

Synthesis of sulfonated carbon catalyst from waste orange peel for cost effective biodiesel production

The present research work deals with the bio-waste valorisation approach for the catalyst development and then its use in the low cost biodiesel production. The sulfonated carbon catalyst, a solid acid is prepared from waste orange peels (WOP) through carbonization followed by sulfonation treatment. WOP is one of the bio-wastes of food industries. The developed catalyst was characterized using elemental, spectral and thermal analysis. Surface area and pore volume is measured using Brunauer, Emmett and Teller (BET) surface area analysis. The synthesized catalyst exhibits 44 m2/g surface area and 1.57 mmol/g acid density. To demonstrate the catalytic performance, the sulfonated carbon catalyst was used to esterify corn acid oil (CAO), a low cost feed stock containing 127.21 mg KOH/g acid value, to generate cost effective biodiesel. 91.68% biodiesel conversion is obtained under optimized conditions using Box-Behnken Design (BBD).

Biodiesel production from date seed oil (Phoenix dactylifera L.) via egg shell derived heterogeneous catalyst

This work explains the preparation of an efficient catalyst from waste chicken egg shells for exploring environment-friendly and cost-effective biodiesel production process for socio-economic growth. XRD, BET, TGA, and TPD-CO2 analysis were employed to evaluate the physicochemical properties of the prepared catalysts. The catalytic performance of the synthesized catalysts was tested in biodiesel production via transesterification from date seed oil under different reaction conditions. It was found that catalyst prepared at 900°C exhibited excellent transesterification activity and provided maximum yield of fatty acid methyl esters up to 93.5% under optimal reaction conditions, i.e. reaction time of 1.5h, methanol–oil molar ratio of 12:1, and catalyst amount of 5wt.%. In addition, the catalyst exhibited substantial stability and reusability during biodiesel conversion.

Nano-Immobilized Biocatalysts for Biodiesel Production from Renewable and Sustainable Resources

The cost of biodiesel production relies on feedstock cost. Edible oil is unfavorable as a biodiesel feedstock because of its expensive price. Thus, non-edible crop oil, waste oil, and microalgae oil have been considered as alternative resources. Non-edible crop oil and waste cooking oil are more suitable for enzymatic transesterification because they include a large amount of free fatty acids. Recently, enzymes have been integrated with nanomaterials as immobilization carriers. Nanomaterials can increase biocatalytic efficiency. The development of a nano-immobilized enzyme is one of the key factors for cost-effective biodiesel production. This paper presents the technology development of nanomaterials, including nanoparticles (magnetic and non-magnetic), carbon nanotubes, and nanofibers, and their application to the nano-immobilization of biocatalysts. The current status of biodiesel production using a variety of nano-immobilized lipase is also discussed.

Boosting TAG Accumulation with Improved Biodiesel Production from Novel Oleaginous Microalgae Scenedesmus sp. IITRIND2 Utilizing Waste Sugarcane Bagasse Aqueous Extract (SBAE).

This investigation utilized sugarcane bagasse aqueous extract (SBAE), a nontoxic, cost-effective medium to boost triacylglycerol (TAG) accumulation in novel fresh water microalgal isolate Scenedesmus sp. IITRIND2. Maximum lipid productivity of 112 ± 5.2mg/L/day was recorded in microalgae grown in SBAE compared to modified BBM (26 ± 3%). Carotenoid to chlorophyll ratio was 12.5 ± 2% higher than in photoautotrophic control, indicating an increase in photosystem II activity, thereby increasing growth rate. Fatty acid methyl ester (FAME) profile revealed presence of C14:0 (2.29%), C16:0 (15.99%), C16:2 (4.05%), C18:0 (3.41%), C18:1 (41.55%), C18:2 (12.41), and C20:0 (1.21%) as the major fatty acids. Cetane number (64.03), cold filter plugging property (-1.05°C), and oxidative stability (12.03h) indicated quality biodiesel abiding by ASTM D6751 and EN 14214 fuel standards. Results consolidate the candidature of novel freshwater microalgal isolate Scenedesmus sp. IITRIND2 cultivated in SBAE, aqueous extract made from copious, agricultural waste sugarcane bagasse to increase the lipid productivity, and could further be utilized for cost-effective biodiesel production.

Studies on biodiesel production from Jatropha Curcas oil using chemical and biochemical methods – A mathematical approach

As fossil fuel declining worldwide, attention is grown up to develop a cost effective process for biodiesel production from renewable sources such as Jatropha Curcas Plant. Biodiesel can be produced by transesterification of Jatropha Curcas oil using chemical catalyst or biocatalyst. In this research article, we formulate and analyze two mathematical models of transesterification reaction with respect to chemical catalyst and enzyme catalyst respectively. The model systems are solved numerically by Runge–Kutta method. A comparative mathematical study has been made between these two processes with respect to product efficiency, reaction conditions and mass transfer. We also apply control theoretic approach in mixing intensity through biocatalytic process for cost effective production of biodiesel from Jatropha Curcas oil. The validity of both the models is established by experimental results available in literatures.

Cultivation of Chlorella protothecoides in anaerobically treated brewery wastewater for cost-effective biodiesel production.

The use of wastewater has been investigated to overcome the economic challenge involved with a production of microalgae-based biodiesel. In this study, to achieve economical biodiesel production along with effective wastewater treatment at the same time, anaerobically treated brewery wastewater (ABWW) was utilized as a low-cost nutrient source, in the cultivation of Chlorella protothecoides. About 96 and 90% of total nitrogen and phosphorus in ABWW were removed, respectively, while C. protothecoides was accumulating 1.88gL(-1) of biomass. The C. protothecoides grown in ABWW showed increases in cell size and cell aggregation, resulting in a near 80% enhanced harvesting efficiency within 20min, as compared with only 4% in BG-11. In addition, the total fatty acid content of the C. protothecoides grown in ABWW increased by 1.84-fold (35.94±1.54% of its dry cell weight), relative to that of BG-11.

Sodium zirconate (Na2ZrO3) as a catalyst in a soybean oil transesterification reaction for biodiesel production

Sodium zirconate (Na2ZrO3) was tested as a basic catalyst for the production of biodiesel using a soybean oil transesterification reaction. Initially, Na2ZrO3 was synthesized via a solid-state reaction. The structure and microstructure of the catalyst were characterized using X-ray diffraction, scanning electron microscopy and N2 adsorption. Various transesterification reactions were then conducted using soybean oil and methanol under differing reaction conditions. The influence of some parameters, such as the reactant concentrations (molar ratios), catalyst percentage, reaction time, temperature and re-use of the catalyst, on the transesterification process in the presence of Na2ZrO3 was investigated. The maximum FAME conversion efficiency was 98.3% at 3h of reaction time and 3% of catalyst. Additionally, the produced biodiesel was characterized using infrared spectroscopy, gas chromatography coupled to mass spectrometry and proton nuclear magnetic resonance. The resulting biodiesel showed good purity, composition and degree of unsaturation in comparison to previous reports. According to these results, Na2ZrO3 could become an alternative solid base catalyst for scalable and cost-effective biodiesel production.

Lipase‐catalyzed process for biodiesel production: Protein engineering and lipase production

Biodiesel is an environment-friendly and renewable fuel produced by transesterification of various feedstocks. Although the lipase-catalyzed biodiesel production has many advantages over the conventional alkali catalyzed process, its industrial applications have been limited by high-cost and low-stability of lipase enzymes. This review provides a general overview of the recent advances in lipase engineering, including both protein modification and production. Recent advances in biotechnology such as in protein engineering, recombinant methods and metabolic engineering have been employed but are yet to impact lipase engineering for cost-effective production of biodiesel. A summary of the current challenges and perspectives for potential solutions are also provided.

Effect of high ferric ion concentrations on total lipids and lipid characteristics of Tetraselmis subcordiformis, Nannochloropsis oculata and Pavlova viridis

Microalgae as sources for biodiesel production have been widely investigated. Microalgae biomass, lipid content and fatty acid profiles of microalgae are limiting factors for the cost-effective production of biodiesel. In this paper, the effects of high ferric ion concentrations on three species of microalgae (Tetraselmis subcordiformis, Nannochloropsis oculata and Pavlova viridis) were studied. The microalgae were cultured in different concentrations (1.2 × 10−2, 1.2 × 10−1, 1.2 and 12 mmol L−1) of ferric ion. The growth, lipid content and fatty acid profiles of the three microalgae were analysed. When algae were cultured in 1.2 mmol L−1 ferric ion for 10 days, the final cell density and specific growth rates of T. subcordiformis, N. oculata and P. viridis decreased significantly (p < 0.05), and the total lipid contents of the microalgae, 33.72, 37.34 and 29.48 % (dry mass) in T. subcordiformis, N. oculata and P. viridis, respectively, were higher than those at other concentrations. The neutral lipid/total lipid ratios of the three microalgae species increased with increasing ferric ion concentration. Neutral lipids accounted for 50.75, 48.37 and 46.59 % of the total lipid in T. subcordiformis, N. oculata and P. viridis, respectively, when cultured in 12 mmol L−1 ferric ion. The proportions of saturated fatty acids in all three species cultured in 12 mmol L−1 ferric ion were significantly higher than those cultured in lower ferric ion concentrations. An optimum ferric ion concentration can improve the properties of T. subcordiformis, N. oculata and P. viridis as sources for biodiesel.

An updated comprehensive techno-economic analysis of algae biodiesel

Algae biodiesel is a promising but expensive alternative fuel to petro-diesel. To overcome cost barriers, detailed cost analyses are needed. A decade-old cost analysis by the U.S. National Renewable Energy Laboratory indicated that the costs of algae biodiesel were in the range of $0.53-0.85/L (2012 USD values). However, the cost of land and transesterification were just roughly estimated. In this study, an updated comprehensive techno-economic analysis was conducted with optimized processes and improved cost estimations. Latest process improvement, quotes from vendors, government databases, and other relevant data sources were used to calculate the updated algal biodiesel costs, and the final costs of biodiesel are in the range of $0.42-0.97/L. Additional improvements on cost-effective biodiesel production around the globe to cultivate algae was also recommended. Overall, the calculated costs seem promising, suggesting that a single step biodiesel production process is close to commercial reality.