Vegetable Oils For Biodiesel Production Research Articles

Biodiesel production feedstocks: current state in Algeria

Research and development of affordable, sustainable, and low-carbon energy sources capable of reducing dependence on fossil fuels, contributing to social and economic development, and improving environmental and health skills have become a global priority. In recent decades, biodiesel produced from oilseeds has received significant attention as an alternative biofuel. However, the use of first-generation oilseed crops has sparked controversy, and the use of local non-edible feedstocks is considered a promising alternative. The motivation behind this review is to provide an alternative and enlightening perspective on the use of non-edible vegetable oils for biodiesel production, with a particular focus on the current state of biodiesel production in Algeria. The objective is to assess the conditions under which this production could be sustainable and environmentally friendly while maintaining a balance between energy needs, economic stability, and environmental impact.

An Evolved Strain of the Oleaginous Yeast Rhodotorula toruloides, Multi-Tolerant to the Major Inhibitors Present in Lignocellulosic Hydrolysates, Exhibits an Altered Cell Envelope.

The presence of toxic compounds in lignocellulosic hydrolysates (LCH) is among the main barriers affecting the efficiency of lignocellulose-based fermentation processes, in particular, to produce biofuels, hindering the production of intracellular lipids by oleaginous yeasts. These microbial oils are promising sustainable alternatives to vegetable oils for biodiesel production. In this study, we explored adaptive laboratory evolution (ALE), under methanol- and high glycerol concentration-induced selective pressures, to improve the robustness of a Rhodotorula toruloides strain, previously selected to produce lipids from sugar beet hydrolysates by completely using the major C (carbon) sources present. An evolved strain, multi-tolerant not only to methanol but to four major inhibitors present in LCH (acetic acid, formic acid, hydroxymethylfurfural, and furfural) was isolated and the mechanisms underlying such multi-tolerance were examined, at the cellular envelope level. Results indicate that the evolved multi-tolerant strain has a cell wall that is less susceptible to zymolyase and a decreased permeability, based on the propidium iodide fluorescent probe, in the absence or presence of those inhibitors. The improved performance of this multi-tolerant strain for lipid production from a synthetic lignocellulosic hydrolysate medium, supplemented with those inhibitors, was confirmed.

Impact of ultrasonic mixing on virgin and waste vegetable oils for biodiesel production

This paper investigates the use of waste vegetable oil (WVO) for production of biodiesel. The study explores the improvement of biodiesel production using ultrasonic mixing to achieve high yields. Different oil streams, including virgin canola oil and WVO, were used as the raw material for the transesterification processes. These oils had different fatty acid contents as a result of environmental or previous processing conditions. The impact of free fatty acid (FFA) content on the resulting yield was assessed. It was demonstrated that the yield was influenced by production parameters such as reaction time, reaction temperature, molar/volume ratios of oil to alcohol, catalyst amount, and mechanical mixing. This was accomplished by automating the biodiesel production from WVO, thereby achieving improved processing and requiring minimal direct human involvement. A biodiesel production apparatus was developed with a Raspberry Pi 3 microcomputer to control the process. The particular choice of these process parameters depended on the particular oil type. This research used mixtures of virgin and waste vegetable oils at different volume ratios (oil to alcohol) of 4:1, 6:1, and 8:1, which was determined by the FFA content of the oil. In addition to mechanical mixing, ultrasonication rated at 500 W, 20 kHz was used to enhance mixing by adding 450 kJ to the process, thereby reducing both the processing time and the amount of methoxide needed to perform a base-catalyzed transesterification. This research demonstrated that optimal yield depends on temperature, catalyst concentration, FFA content of the oil, and the energy introduced by sonication.

Various Pre-Treatment Methods to Reduce Free Fatty Acid Content in Non-Edible Vegetable Oils for Biodiesel Production

In this work, the efforts were made to reduce high free fatty acid (FFA) content in non-edible karanja and jatropha vegetable oils below 1 mg KOH/g. The process was optimized in terms of amount of sulphuric acid used in pre-treatment of the studied non-edible oils. Various adsorbents like activated carbon, alumina, alumina-silica, calcined alumina and calcined alumina-silica exhibited significant removal of FFA in a single-stage filtration process. Pre-treatment of test oil with calcined alumina-silica as adsorbent was found to be the most appropriate for the removal of free fatty acids. Ultraviolet-visible spectroscopy (UV) analysis showed that the original composition of test oil was not changed after the pre-treatment process.

A comprehensive review on non-edible woody oil-based biodiesel: composition, production, properties and emissions

With the continuous increase of world’s population, rapid development of industrialization and urbanization, and rapid growth of economy, the fossil fuel consumption is also increasing continuously to meet growing energy demand. The unsustainability of fossil fuels and the issues of national energy security make it very urgent to develop the appropriate and sustainable replacement for fossil fuels. Biodiesel is one of appropriate alternatives for diesel engine due to its renewable and eco-friendly nature. This greener fuel has been used in many countries across the continents in a blending range up to 20% with petrodiesel. However, the high biodiesel production cost is still a major obstacle to market acceptance. Non-edible woody oils can be considered as low-cost substitutions for traditional edible vegetable oils for biodiesel production. In order to make biodiesel into reality in much wider scope, a growing number of relevant researches focused on: (1) evaluating the biodiesel properties; (2) optimizing the production process; and (3) assessing the environmental impact. This article reviews these three aspects in order to reflect the research status and development potential of non-edible woody oil-based biodiesel.

Biofuel, Bioenergy and Feed Valorization of By-Products and Residues from Hevea brasiliensis Cultivation to Enhance Sustainability

In the latex production chain, rubber tree seeds (Hevea brasiliensis) represent an underutilized fraction with high potentialities, which can increase the sustainability of the whole process if rightly valorized. In the present study, the quality of all the fractions obtained from the rubber fruit were evaluated, with the aim to identify possible applications for their valorization with a circular economy perspective. Seeds from five different varieties of rubber tree were analyzed. Furthermore, a whole mass and energy balance was defined, which has allowed us to define hypothetical production scenarios. The obtained results show negligible differences among varieties. Shells and capsules have shown a composition similar to woody biomass, with high heating values (more than 16.5 MJ kg−1), low nitrogen content (below 0.5% on weight basis (w/w)) and reduced ash content (0.51% w/w and 1.90% w/w, respectively). Kernels were chemically extracted comparing two different solvents: n-hexane and ethanol. Both solvents showed similar extraction yields, i.e., 49% w/w and 46% w/w for n-hexane and ethanol, respectively. The resulting extraction flour was characterized by a high protein content (around 40% w/w) making it suitable for animal feeding. The rubber seed oil could be used in blends of different vegetable oils for biodiesel production. All this information is useful for improving the sustainability of the latex production chain and to assess the sustainability of possible bioenergy value chains.

Oleaginous yeasts isolated from traditional fermented foods and beverages of Manipur and Mizoram, India, as a potent source of microbial lipids for biodiesel production

PurposeOleaginous yeasts can accumulate intracellular lipid bodies or triacylglycerides (TAGs) under nutrient limiting conditions. TAGs derived from those yeast strains are considered as an alternative to conventional plant-based oils for biodiesel production. In this study, we attempt to isolate and characterize yeast strains from selected traditional fermented foods of Manipur and Mizoram, India, and study their oleaginous attributes for biodiesel production.MethodFourteen potential oleaginous yeasts were isolated from fermented food samples of Manipur and Mizoram, India. The isolates were identified by 5.8S internal transcribed spacer (ITS) rRNA gene sequencing. Intracellular TAG accumulation by yeast cells were confirmed by Nile red fluorescence microscopy and spectrometry technique. The most promising isolates were evaluated for lipid accumulation having different initial carbon to nitrogen (C/N) ratios and also the full kinetic studies (depicting the glucose consumption, biomass, and lipid production) using optimum C/N ratio were estimated. Fatty acid methyl esters (FAME) profile of the transesterified lipids were analyzed by GC-MS.ResultsThe identified yeast isolates belonged to seven different genera viz. Rhodotorula, Pichia, Candida, Saturnispora, Wickerhamomyces, Zygoascus, and Saccharomyces. Under nitrogen-limiting conditions, maximum biomass concentration of 5.66 ± 0.03 g/L and 4.713 ± 0.03 g/L was produced by Wickerhamomyces anomalus FK09 and Pichia kudriavzevii FK02, respectively. The highest lipid concentration (g lipid/L fermentation broth) of 0.58 g/L was attained by Rhodotorula mucilaginosa R2, followed by Wickerhamomyces anomalus FK09 (0.51 g/L), and Zygoascus hellenicus FC10 (0.41 g/L). Rhodotorula mucilaginosa R2 exhibited the maximum lipid content (% lipid/g dry cell weight) of (21.63 ± 0.1%) after 96 h of growth. The C/N ratio of 40 and 20 was found to be optimum for R. mucilaginosa R2 and W. anomalus FK09 with a lipid content of 22.21 ± 0.4% and 12.83 ± 0.08% respectively.ConclusionNewly isolated yeast strains were obtained from traditional fermented food samples of Manipur and Mizoram, India. FAME analysis of the transesterified lipid extracts suggested the potential use of yeast-derived oil as an alternative to vegetable oil for biodiesel production.

Biodiesel Production Processes and Sustainable Raw Materials

Energy security and environmental concerns, related to the increasing carbon emissions, have prompted in the last years the search for renewable and sustainable fuels. Biodiesel, a mixture of fatty acids alkyl esters shows properties, which make it a feasible substitute for fossil diesel. Biodiesel can be produced using different processes and different raw materials. The most common, first generation, biodiesel is produced by methanolysis of vegetable oils using basic or acid homogeneous catalysts. The use of vegetable oils for biodiesel production raises serious questions about biodiesel sustainability. Used cooking oils and animal fats can replace the vegetable oils in biodiesel production thus allowing to produce a more sustainable biofuel. Moreover, methanol can be replaced by ethanol being totally renewable since it can be produced by biomass fermentation. The substitution of homogeneous catalyzed processes, nowadays used in the biodiesel industry, by heterogeneous ones can contribute to improve the biodiesel sustainability with simultaneous cost reduction. From the existing literature on biodiesel production, it stands out that several strategies can be adopted to improve the sustainability of biodiesel. A literature review is presented to underline the strategies allowing to improve the biodiesel sustainability.

CaO Nanocatalyst for Transesterification Reaction of Palm Oil to Biodiesel: Effect of Precursor’s Concentration on the Catalyst Behavior

Depletion of fossil fuel sources in a few decades due to industrialization and motorization has led to a keen interest in the production of alternative fuels like biodiesel. Research on the development and improvement of more efficient transesterification process for biodiesel production has attain great attention in the last decade. The using of low cost catalyst is one of the main focuses on the biodiesel production. As a basic heterogeneous catalyst, CaO has been examined in the transesterification of vegetable oils for biodiesel production. In this research, calcium oxide (CaO-X) catalysts were prepared by sol-gel method at different Ca2+ precursor concentration (X = 1.0, 1.5, 2.0 M). The crystalline structure and morphology of the synthesized catalysts were characterized by means of x-ray diffraction (XRD) and N2 adsorption-desorption analysis. All the synthesized catalysts were then applied to transesterification reaction of palm oil to produce biodiesel. The characterization by x-ray diffraction demonstrate CaO-1.0 was partially hydrated due to the incomplete reaction during synthesis. As a matter of fact, formation of H2O on the surface of CaO causes lower basic strength of the catalysts, thus responsible in lowering the catalytic activity. It is demonstrated that CaO-2.0 exhibits mesoporous structure with least chemisorb amount of H2O on the catalysts surface has a very active catalytic activity. It was found that 2.0M of calcium precursor has high catalytic activity and 81% FAME yield was obtained within 3h reaction.

Fungal diversity in oil palm leaves showing symptoms of Fatal Yellowing disease.

Oil palm (Elaeis guineensis Jacq.) is an excellent source of vegetable oil for biodiesel production; however, there are still some limitations for its cultivation in Brazil such as Fatal Yellowing (FY) disease. FY has been studied for many years, but its causal agent has never been determined. In Colombia and nearby countries, it was reported that the causal agent of Fatal Yellowing (Pudrición del Cogollo) is the oomycete Phytophthora palmivora, however, several authors claim that Fatal Yellowing and Pudrición del Cogollo (PC) are different diseases. The major aims of this work were to test, using molecular biology tools, Brazilian oil palm trees for the co-occurrence of the oomycete Phytophthora and FY symptoms, and to characterize the fungal diversity in FY diseased and healthy leaves by next generation sequencing. Investigation with specific primers for the genus Phytophthora showed amplification in only one of the samples. Analysis of the fungal ITS region demonstrated that, at the genus level, different groups predominated in all symptomatic samples, while Pyrenochaetopsis and unclassified fungi predominated in all asymptomatic samples. Our results show that fungal communities were not the same between samples at the same stage of the disease or among all the symptomatic samples. This is the first study that describes the evolution of the microbial community in the course of plant disease and also the first work to use high throughput next generation sequencing to evaluate the fungal community associated with leaves of oil palm trees with and without symptoms of FY.

A sustainable use of low-cost raw substrates for biodiesel production by the oleaginous yeast Wickerhamomyces anomalus.

Over the past decade, the increasing demand of vegetable oils for biodiesel production has highlighted the need for alternative oil feedstocks that do not compete with food production. In this context, the combined use of agro-industrial wastes and oleaginous microorganisms could be a promising strategy for sustainable biodiesel production. The present investigation involves the performance of the oleaginous yeast Wickerhamomyces anomalus strain EC28 to produce lipids from different agro-industrial wastewaters (i.e., deproteinized cheese whey, olive mill wastewater, and wastewaters from confectionary industries) and waste frying oils (i.e., waste oil from frying fish, waste oil from frying potato and waste oil from frying meat). Results indicated that this strain can adequately grow on agro-industrial wastewater-based media and produce substantial amounts of lipids [up to 24%, wt/wt in deproteinized cheese whey-based medium and olive mill wastewater-based medium (75%, v/v in water)] of similar fatty acid composition to that of the most commonly used vegetable oils in the biodiesel industry. However, the addition of frying oils to the culture media resulted in a significant decrease in total lipid content, probably due to excess of available nitrogen released from meat, fish, and potato into the frying oil. The estimated properties of the resulting biodiesels, such as SV (190.69-203.13), IV (61.77-88.32), CN (53.45-59.32), and CFPP (-0.54 to 10.4), are reported, for the first time, for W. anomalus and correlate well with specified standards. In conclusion, W. anomalus strain EC28, for which there is very limited amount of available information, might be regarded as a promising candidate for biodiesel production and additional efforts for process improvement should be envisaged.

An overview of transesterification methods for producing biodiesel from waste vegetable oils

ABSTRACT Compared to petroleum diesel, biodiesel is biodegradable and non-toxic. The use of edible vegetable oils for biodiesel production competes with the need for foodstuff. The continuously rising price of edible vegetable oils makes them uneconomical as a long-term biodiesel source. Waste vegetable oils are considered environmental pollution, despite being a potential raw material for biodiesel production, as well as cheap and readily available. Transesterification of vegetable oil is carried out to produce biodiesel in the presence of a catalyst. The catalyst can be homogeneous, heterogeneous, nanoparticles, or enzymatic. Homogeneous catalysts are considered more effective compared to their heterogeneous counterparts, because of reduced mass transfer limitations and high conversion. However, the challenges of separation and purification of biodiesel produced from homogeneously acid/base-catalyzed transesterification of vegetable oils has shifted attention to non-catalytic supercritical methanol/ethanol. It has been reported that at a reaction temperature of 350°C, with a methanol/oil molar ratio of 42, and in the short time of 400 s, 95% conversion is achievable under supercritical methanol. This study explores and presents the advantages and disadvantages of the biodiesel production processes in addition to the effect of the process variable, and also shows the key data set not presently available that would enhance commercialization and economics and improve biodiesel production.

Investigation of silicates as a catalyst in biodiesel production: A review

Summary Hiking of crude oil prices and diesel fuel shortage is incentive for the researchers to develop bioenergy sources. Biodiesel has environmental beneficial attributes, and its production processes are worthy of continued studies. Many biodiesel production processes are available but, most of them are not on a commercial scale. Biodiesel production using solid catalysts involved fewer unit operations compared with homogeneous catalyzed processes. Many heterogeneous catalysts have been extensively investigated in the recent years and well established. Researchers' focus is how to obtain active and more stable silicates catalyst that can be recycled for several times in the process. Silicates catalyst activity and stability are critically discussed in this work to assess their industrial application, as excessive purification steps could be avoided. This review provides a brief overview on semi-novel heterogeneous catalyst types ‘silicates’ used in the transesterification of vegetable oils for biodiesel production. Process conditions and leaching out of catalyst active sites are also highlighted. Product quality analysis is presented, in addition to concluded remarks regarding silicates as a selected catalyst. A preliminary economic assessment of biodiesel production catalyzed by the suggested catalyst ‘silicates’ compared with potassium hydroxide (KOH) and lime (CaO) is performed. Copyright © 2016 John Wiley & Sons, Ltd.

Tomato seed oil for biodiesel production

The use of vegetable oil for biodiesel production as a renewable energy source can have five main goals: the reduction of dependence on fossil energy, the reduction of wastes, the increase of the economic value of fruits, the increase of the economic value of vegetable oils, and the reduction of total CO2 emissions. Tomato seeds could be used for biodiesel production. The influence of the hot break and cold break treatments together with the harvest year effect on the physicochemical properties of the tomato seed oil were studied. Relative density was within 928 ± 0.33, acid value ranged from 0.48 ± 0.07 to 2.50 ± 0.03. The oil stability index measured at 110°C was always above 6 h. Kinematic viscosity decreased with the increase of the temperature from 30 to 50°C, being similar to the value indicated by the DIN 51605 for rapeseed oil at 40°C (35.17 ± 020–41.35 ± 0.56 mm2/s). Eleven fatty acid were detected: myristic acid, palmitic acid, palmitoleic acid, margaric acid, margaroleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidic acid, and eicosenoic acid. Linoleic acid prevailed on all fatty acid methyl esters (mono‐alkyl esters) (49.61–57.89%) followed by oleic acid (18.79–21.82%). In the large part of cases, the iodine value was within the maximum of DIN 51605. Cetane number, calcium, and magnesium were out of the limit. International standards for biodiesel and vegetable oil quality standard were discussed.Practical applications: This study is related to the possibility of using an unusual vegetable oil as a source for biodiesel production. In this way, one can monetize a waste product (tomato seeds) and at the same time obtain a vegetable oil useful for biodiesel production. It is noteworthy that, at present, tomato seed oil is not used in the food industry so its use for biodiesel will not increase its price.In the tomato seed oil, the sum C18:1 + C18:2 is similar to an olive oil. All biodiesels produced by the studied TSOs have a CN well above 51.0 and 47.0 stated by the European and USA regulations for a biodiesel.

Esterification of Free Fatty Acid on Palm Fatty Acid Distillate using Activated Carbon Catalysts Generated from Coconut Shell

In the last few years, biodiesel has emerged as one of the most potential renewable energy to replace current petrol-derived diesel. It is a renewable, biodegradable and non-toxic fuel which can be easily produced through esterification of triglycerides (vegetable oils or animal fats) or esterification of free fatty acids (FFAs) with methanol. 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, can be a better alternative; however, the high free fatty acids (FFA) content has become the main drawback for this potential feedstock. Solid acid catalysts offer significant advantages of eliminating separation, corrosion, toxicity and environmental problems. Recently, a new strategy of preparing novel carbon-based solid acids has been developed. In this research, the esterification reactions of Palm Fatty Acid Disttillate (PFAD) with methanol, using carbon based solid catalyst from coconut shell activated carbon as catalyst, were studied. The ester preparation involved an esterification reaction, followed by purification. In this study, the activated carbon catalyst catalysts were synthesized by sulfonating the activated carbon using concentrated H2SO4. The physico-characteristics and acid site densities were analyzed by Nitrogen gas adsorption, FT-IR, X-ray fluorescent (XRF), and acid-base back titration methods. The effects of the molar ratio of methanol to oil (6:1 to 12:1), the amount of catalyst (1-10%), and the reaction temperature (40, 50 and 60oC) were studied for the conversion of FFA to optimize the reaction conditions. The optimal conditions were an methanol/PFAD molar ratio of 12:1, the amount of catalyst of 10%wt., and reaction temperature of 60oC.

Potassium fluoride impregnated CaO/NiO: An efficient heterogeneous catalyst for transesterification of waste cottonseed oil

Potassium fluoride impregnated CaO/NiO has been prepared by wet impregnation method in nano particle form as supported by powder XRD, scanning electron microscopy, and transmission electron microscopy studies. Brunauer–Emmett–Teller surface area and basic sites measurement studies have been performed to establish the effect of potassium fluoride impregnation on catalyst surface morphology and basic strength. CaO/NiO impregnated with 20 wt% potassium fluoride was used as solid catalyst for the transesterification of waste cottonseed oil having up to 5.8 wt% free fatty acid content. The variables used for the transesterification were, KF impregnated on CaO/NiO, catalyst concentration, reaction temperature, and methanol to oil molar ratio. Reaction parameters have been optimized to achieve the least reaction period for the completion of the reaction. Complete transesterification (>99% FAMEs yield) of waste cottonseed oil with methanol (1:15 molar ratio) required 4 h in the presence of 5 wt% catalyst (with respect to oil) at 65°C. Reusability study suggests that catalyst could be recycled for four successive runs without significant loss in activity. A pseudo first order kinetic equation was applied to evaluate the kinetic parameters and under optimized conditions first order rate constant and activation energy was found to be 0.023 min−1 and 41.2 kJ/mol, respectively. Few physicochemical properties of the prepared biodiesel sample have also been studied and compared with standard values.Practical applications: In India, application of edible vegetable oils for biodiesel production is prohibited to avoid food versus fuel situation. Application of waste cottonseed oil (WCO) for biodiesel production could circumvent this problem. However, homogeneous alkali catalyst could not be employed due to the presence of high free fatty acid contents in such feedstock. In this context present study demonstrates the impregnation preparation of KF impregnated CaO/NiO and its application as reusable solid catalyst for the transesterification of WCO.

<i>In Situ</i> Transesterification of Vegetable Oil for Biodiesel Production via Ultrasound Clamp on Tubular Reactor as an Environment Sustainable Manufacturing Process

Biodiesel is defines as monoalkyl fatty acid ester has represents a promising alternative to be substituted as an alternative fuel for the use of diesel engines and it is produced by chemically reacting the vegetable oil with an alcohol in a process called the transesterification process. The reaction usually requires a catalyst such as sodium hydroxide (NaOH) or potassium hydroxide (KOH) and methanol to obtain chemical compound called methyl esters which will then be known as biodiesel. The approach of this research is to enhance the yielding of Fatty Acid Methyl Esters, FAME by using ultrasound clamp on tubular reactor. With the assistance of the ultrasound clamp, immiscible liquids such as the vegetable oil and methanol will be able to emulsify together in a short period of time comparing to the conventional method which is by stirring the mixture leading to a longer period of time to emulsify and to achieve the desired yield of FAME. The use of ultrasonic energy will eventually cause the rapid movement of the mixture hence creating cavities where the liquids will breaks down and cavitation bubbles is produced. The optimum results for biodiesel production using ultrasound clamp assisted on the tubular reactor is 1 minute with the conversion of esters 94 % as compared to the previous researcher which achieve 98 % of esters conversion within 5 minutes. Higher esters conversion was achieved through the presence of methanol to oil molar ratio of 9:1 and 12:1, catalyst concentration of 0.75 Wt. % , 1.00 Wt. % and reaction temperature at 64 oC is being studied.

Recovery of different waste vegetable oils for biodiesel production: A pilot experience in Bahia State, Brazil

In Brazil, and mainly in the State of Bahia, crude vegetable oils are widely used in the preparation of food. Street stalls, restaurants and canteens make a great use of palm oil and soybean oil. There is also some use of castor oil, which is widely cultivated in the Sertão Region (within the State of Bahia), and widely applied in industry. This massive use in food preparation leads to a huge amount of waste oil of different types, which needs either to be properly disposed of, or recovered. At the Laboratorio Energia e Gas-LEN (Energy & Gas lab.) of the Universidade Federal da Bahia, a cycle of experiments were carried out to evaluate the recovery of waste oils for biodiesel production. The experiences were carried out on a laboratory scale and, in a semi-industrial pilot plant using waste oils of different qualities. In the transesterification process, applied waste vegetable oils were reacted with methanol with the support of a basic catalyst, such as NaOH or KOH. The conversion rate settled at between 81% and 85% (in weight). The most suitable molar ratio of waste oils to alcohol was 1:6, and the amount of catalyst required was 0.5% (of the weight of the incoming oil), in the case of NaOH, and 1%, in case of KOH.The quality of the biodiesel produced was tested to determine the final product quality. The parameters analyzed were the acid value, kinematic viscosity, monoglycerides, diglycerides, triglycerides, free glycerine, total glycerine, clearness; the conversion yield of the process was also evaluated.

Improvement of Hydraulic Press for Vegetable Oil Expression in Rural Areas

Cultivation of oil producing crops especially Jatropha and croton as source of vegetable oil for biodiesel production is being encouraged in rural areas. To recover oil from seed, manual press is the feasible method in rural areas where there is no electricity. Research was conducted to improve hydraulic oil press machine for rural application. Factorsaffecting oil recovery were found to be: moisture content of seeds, operating pressure, seed oil content, and the amount of seeds pressed per batch. Percentage oil recovery was improved by reducing diameter of press cylinder, hence increasing expression pressure, and either reducing amount of seed processed per batch or placing disk within the seeds to improve oil flow. The maximum vegetable oil recovered from Jatropha seeds at a pressure of 20.8 MPa after improvement was 57.5% of the total oil in seeds. There was no significant difference in terms of oil recovery between pressing whole seeds or milled seeds. Suggested further improvement includes: higher pressure than 20.8 MPa, reduced radial distance travelled by oil and replacement of hydraulic jack with a self retracting double acting hydraulic power cylinder to reduce batch cycle.

Biodiesel from lignocellulosic biomass – Prospects and challenges

Biodiesel can be a potential alternative to petroleum diesel, but its high production cost has impeded its commercialization in most parts of the world. One of the main drivers for the generation and use of biodiesel is energy security, because this fuel can be produced from locally available resources, thereby reducing the dependence on imported oil. Many countries are now trying to produce biodiesel from plant or vegetable oils. However, the consumption of large amounts of vegetable oils for biodiesel production could result in a shortage in edible oils and cause food prices to soar. Alternatively, the use of animal fat, used frying oils, and waste oils from restaurants as feedstock could be a good strategy to reduce the cost. However, these limited resources might not meet the increasing demand for clean, renewable fuels. Therefore, recent research has been focused the use of residual materials as renewable feedstock in order to lower the cost of producing biodiesel. Microbial oils or single cell oils (SCOs), produced by oleaginous microorganisms have been studied as promising alternatives to vegetable or seed oils. Various types of agro-industrial residues have been suggested as prospective nutritional sources for microbial cultures. Since the most abundant residue from agricultural crops is lignocellulosic biomass (LCB), this byproduct has been given top-priority consideration as a source of biomass for producing biodiesel. But the biological transformation of lignocellulosic materials is complicated due to their crystalline structure. So, pretreatment is required before they can be converted into fermentable sugar. This article compares and scrutinizes the extent to which various microbes can accumulate high levels of lipids as functions of the starting materials and the fermentation conditions. Also, the obstacles associated with the use of LCB are described, along with a potentially viable approach for overcoming the obstacles that currently preclude the commercial production of biodiesel from agricultural biomass.