Effect of alkali catalyst on biodiesel production in South Korea from mixtures of fresh soybean oil and waste cooking oil

Biodiesel from waste cooking oil (WCO) and soybean oil (SO) mixture was produced by changing the alkali catalyst (NaOH) content and the WCO to SO ratio in the feedstock. All the prepared biodiesel samples satisfied the standard requirement in terms of free glycerol, density, and acid value. The minimum catalyst content and the highest WCO composition to get biodiesel from the WCO/SO mixture feedstock without ruining the biodiesel properties were 1.0 and 60 wt %, respectively. This conclusion implies that the waste cooking oil mixture, which contains 40 wt % fresh soybean oil, could be treated like the fresh soybean oil to produce biodiesel, and that this behavior would be helpful to reduce the biodiesel production cost when waste cooking oil used as feedstock. The unsaturated methyl esters such as linoleic, and oleic acid were dominant (almost 80 % w/w) in the fresh soybean oil. However the saturated methyl ester was increased due to the double bond breaking during the frying process. These results may deteriorate the biodiesel quality by changing the methyl ester composition.     

Biodiesel production using waste frying oil

Waste sunflower frying oil is used in biodiesel production by transesterification using an enzyme as a catalyst in a batch reactor. Various microbial lipases have been used in transesterification reaction to select an optimum lipase. The effects of various parameters such as temperature, methanol:oil ratio, enzyme concentration and solvent on the conversion of methyl ester have been studied. The Pseudomonas fluorescens enzyme yielded the highest conversion. Using the P. fluorescens enzyme, the optimum conditions included a temperature of 45 °C, an enzyme concentration of 5% and a methanol:oil molar ratio 3:1. To avoid an inhibitory effect, the addition of methanol was performed in three stages. The conversion obtained after 24 h of reaction increased from 55.8% to 63.84% because of the stage-wise addition of methanol. The addition of a non-polar solvent result in a higher conversion compared to polar solvents. Transesterification of waste sunflower frying oil under the optimum conditions and single-stage methanol addition was compared to the refined sunflower oil.     

Application of Poly(styrene-co-divinylbenzene) Macroporous Microparticles as a Catalyst Support in the Enzymatic Synthesis of Biodiesel

Macroporous poly(styrene-co-divinylbenzene) microparticles, with three different structural characteristics, have been synthesized and used as supports in the immobilization of lipase from Burkholderia cepacia. The best immobilization yield was found upon using microparticles with 35 % of divinylbenzene and the immobilized lipase on this type of particles was used as a catalyst to obtain biodiesel from soybean oil and ethanol. From the experimental results of the transesterification reaction, an empirical model quantitatively relating the temperature, the concentration of the enzyme and the transesterification yield was obtained. Statistical analysis of this model indicated that within the range of values of the variables studied (35–47 °C and 231–788 U/mg respectively) only the enzyme concentration exerted a significant influence on the reaction yield. Additionally, the good fit of a Michaelis–Menten-type model to the experimental results suggests that the limiting step of the reaction was the formation of the enzyme-substrate complex.     

Biodiesel production from vegetable oil and waste animal fats in a pilot plant

In this study, corn oil as vegetable oil, chicken fat and fleshing oil as animal fats were used to produce methyl ester in a biodiesel pilot plant. The FFA level of the corn oil was below 1% while those of animal fats were too high to produce biodiesel via base catalyst. Therefore, it was needed to perform pretreatment reaction for the animal fats. For this aim, sulfuric acid was used as catalyst and methanol was used as alcohol in the pretreatment reactions. After reducing the FFA level of the animal fats to less than 1%, the transesterification reaction was completed with alkaline catalyst. Due to low FFA content of corn oil, it was directly subjected to transesterification. Potassium hydroxide was used as catalyst and methanol was used as alcohol for transesterification reactions. The fuel properties of methyl esters produced in the biodiesel pilot plant were characterized and compared to EN 14214 and ASTM D6751 biodiesel standards. According to the results, ester yield values of animal fat methyl esters were slightly lower than that of the corn oil methyl ester (COME). The production cost of COME was higher than those of animal fat methyl esters due to being high cost biodiesel feedstock. The fuel properties of produced methyl esters were close to each other. Especially, the sulfur content and cold flow properties of the COME were lower than those of animal fat methyl esters. The measured fuel properties of all produced methyl esters met ASTM D6751 (S500) biodiesel fuel standards.     

Transesterification of waste vegetable oil under pulse sonication using ethanol,methanol and ethanol–methanol mixtures

This study reports on the effects of direct pulse sonication and the type of alcohol (methanol and ethanol) on the transesterification reaction of waste vegetable oil without any external heating or mechanical mixing. Biodiesel yields and optimum process conditions for the transesterification reaction involving ethanol, methanol, and ethanol–methanol mixtures were evaluated. The effects of ultrasonic power densities (by varying sample volumes), power output rates (in W), and ultrasonic intensities (by varying the reactor size) were studied for transesterification reaction with ethanol, methanol and ethanol–methanol (50%-50%) mixtures. The optimum process conditions for ethanol or methanol based transesterification reaction of waste vegetable oil were determined as: 9:1 alcohol to oil ratio, 1% wt. catalyst amount, 1–2 min reaction time at a power output rate between 75 and 150 W. It was shown that the transesterification reactions using ethanol–methanol mixtures resulted in biodiesel yields as high as >99% at lower power density and ultrasound intensity when compared to ethanol or methanol based transesterification reactions.     

Optimization of two-step catalyzed biodiesel production from soybean waste cooking oil

An acid–base-catalyst-based two-step biodiesel production experiment from soybean waste cooking oil was carried out to identify which parameter is the most influential among the experimental parameters by using the Taguchi method. Heterogeneous catalysts were used to avoid a water-consuming homogeneous catalyst removal process. Ferric sulfate and calcium oxide were used as acid and base catalysts, respectively, for the heterogeneous reaction. Reaction time and methanol-to-triglyceride mole ratio were significant factors. The optimum parameters for step 1 (acid esterification) were 4 h of reaction time, 4 wt. % of ferric sulfate amount, a 16:1 methanol to triglyceride mole ratio, and 400 rpm of mixing speed, respectively. For the transesterification step, the most influential factor was reaction time, and CaO amount was significant as well. On the other hand, the mole ratio of methanol and oil was relatively less significant. Optimum parameters were 3 h of reaction time, 2 wt. % of CaO, and a 12:1 methanol to triglyceride mole ratio with mixing speed at 400 rpm in this experimental range. Under the optimum conditions, waste cooking oil with 5.27 mg KOH/g of acid value was converted into crude biodiesel by a two-step process with fatty acid methyl ester content reaching 89.8 % without any further post-purification.     

Life cycle assessment of biodiesel fuel production from waste cooking oil in Okayama City

A life cycle assessment (LCA) is performed to make clear of the actual environment impacts from conversation of waste cooking oil (WCO) to biodiesel fuel (BDF) in Okayama. A scenario analysis is carried out based on different participation rate of residents who separate WCO from general waste, corresponding to different BDF utilisation rate in transportation system. Sub scenarios complying with different gas emission standards regarding vehicles are designed as well. Afterwards, life cycle impact assessment is conducted to focus on global warming, acidification, and urban air pollution. Overall improvement of almost all kinds of life cycle inventories is significant when diesel is replaced with BDF, demonstrating that a shift from WCO-to-incineration to WCO-to-BDF is more beneficial. Under carbon neutral, compared to base scenario (S0), about 746.05 ton CO₂ emission will be reduced annually in the scenario with 100 % BDF utilisation in vehicles (S4). Meanwhile, total external cost in three environmental impacts (EI) sharply reduces by 51.90 %, showing much economic sustainability in S4. Moreover, the manufacturing cost for producing one litter WCO-to-BDF is 97.32 Yen. Sensitivity analysis shows that the gas emission standard regarding vehicles had much bigger effect on EI than BDF manufacturing process in this research.     

酶法合成生物柴油的研究进展

生物柴油是一种清洁可再生的生物能源,是石油燃料的理想替代物。酶法合成生物柴油具有提取简单、反应条件温和、醇用量小、甘油易回收和无废物产生等优点。综述了脂肪酶与固定化脂肪酶、全细胞生物催化剂在生物柴油生产中应用的新进展,并对我国生物柴油产业的发展提出了建议。     

Sequential production of pyrolytic oil and biodiesel from oil-bearing biomass

Oil extraction from the oil-bearing biomass and waste materials has been considered as one of the biggest challenges in the biodiesel production process because it has been considered as the most energy- and cost-demanding step. This work provides a promising approach for the direct transformation without oil extraction from calcined montmorillonite clay (CMC) and microalgae by means of the non-catalytic thermo-chemical process in conjunction with the real continuous flow system. The introduced method showed the high tolerance of water, impurities, and free fatty acids (FFAs), which enable the combination of the esterification of FFAs and transesterification of triglycerides into a single step without the lipid extraction. For example, this study showed that the maximum achievable yield of biodiesel via the introduced methodology was 97 ± 0.5 % at the temperature regime of 380–480 °C and this biodiesel yield was enhanced in the presence of CO₂. Thus, the introduced methodology for producing biodiesel could be an alternative way of the methanol liquefaction and transesterification under supercritical conditions.     

The effect of biodiesel on the rate of removal and weathering characteristics of crude oil within artificial sand columns

The physical and chemical properties of crude oils differ greatly, and these properties change significantly once oil is spilled into the marine environment as a result of a number of weathering processes. Quantitative information on the weathering of spilled crude is a fundamental requirement for a fuller understanding of the fate and behaviour of oil in the environment. Additionally, such data are also essential for estimating windows-of-opportunities, where specific response methods, technologies, equipment or products are most effective in clean-up operations. In this study, the effects of a relatively low toxicity compound, biodiesel (rape seed oil methyl ester) on the rate of removal and weathering characteristics of crude oil within artificial sand columns are thoroughly investigated using GC/MS techniques. In the absence of the biodiesel, the crude oil exhibits low mobility and a slow rate of microbial degradation within the sediment and as a result, a high degree of persistance. Brent crude oil was subject to a progressive loss of the low molecular weight n-alkanes with respect to time through evaporation and a preferential migration of these fractions through the sediment to depth. The addition of the biodiesel led to greater recovery of oil from the sediment if applied to relatively unweathered crude oil. This was as the result of the crude oil dissolving within the more mobile biodiesel. The negligible concentration of the n-C₁₀ to n-C₂₁ fraction in surface sediment samples suggests a greater solubility of these fractions within the biodiesel and that their subsequent adsorption onto subsurface sediment particles was responsible for their absence from water flushed through the sands. These results suggest that biodiesel may have an active role in the beach clean-up of spilt crude oil.     

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.     

Extrication of biodiesel feedstock from early stage of food waste liquefaction

Biodiesel is commonly produced from vegetable oils, mostly edible and more expensive than petroleum diesel. By considering the cost of the conversion processes, cheap feedstock such as triglycerides and fatty acids (FA) extracted from early stage of food waste liquefaction has become a better choice than vegetable oils, as it could provide high yield of biodiesel without any compromise to food supply and other resources. In this study, FA from early stage of food waste liquefaction was extracted and tested for use as feedstock for biodiesel synthesis. The raw material was not pretreated but extraction was done by dry and wet methods. It was found that wet method could minimized the lost of short and medium-chained FA as well as reducing the number of steps required, thus, yielding higher amount of FA as feedstock. The effects of mixing, methanol ratio, reaction time and catalyst content were investigated for the acid-catalyzed esterification. The maximum biodiesel conversion obtained was 97.4 %.     

Removal of Oil from Water by Calcium Alginate Hydrogel Modified with Maleic Anhydride

Calcium alginate hydrogel was prepared and used as a biosorbent for the removal of oil from aqueous solutions. Calcium alginate hydrogel was further chemically modified by esterification with maleic anhydride. The changes in the physicochemical properties of maleic anhydride modified calcium alginate were investigated via multiple techniques (FTIR, SEM, BET and DSC/TGA). Adsorption batch experiments were carried out to compare the oil adsorption capacities of native and modified calcium alginates. Adsorption experiments were carried out as a function of solution pH, temperature and ionic strength to determine the optimal conditions for the adsorption of oil. Equilibrium and kinetic studies were conducted for the modified alginate. Results revealed that the maleic anhydride modification of calcium alginate improved its adsorption capacity towards oil. Higher adsorption capacities of modified alginate were attained at lower temperatures (20 °C), higher ionic strengths (1.0 M NaCl) and within the pH range of 5–9. The oil adsorption data obtained for modified alginate could be better described by the first order kinetic model (R²?=?0.981) and the BET equilibrium isotherm (R²?=?0.984). The maximum monolayer adsorption capacity predicted by the BET model for the modified calcium alginate was found to be 143.0 mg/g.     

Reaction Kinetic Model For Optimal Pyrolysis Of Plastic Waste Mixtures

Reaction kinetics at various temperatures for pyrolysis of mixtures of plastic waste [polyethylene(PE) and polystyrene(PS)] are modelled in terms of five types of pyrolysis reaction. The model development is based on the assumption that as plastic wastes are heated in a non-reactive environment they are decomposed homogeneously to various products of gas, oil and char by a first-order rate, irreversible reaction and isothermal condition. Among the five models, the type II model in which the activated polymer exists as an intermediate product is the most accurate in predicting the pyrolysis products of pure PE or pure PS. Also, for mixtures of plastics both type II and IV models can be used to explain the composition of pyrolysis products. Furthermore, from the analysis of variance (ANOVA), the mixing ratio and temperature are shown to be the parameters that have the greatest effect on the pyrolysis reaction of polymer waste mixture. The pyrolysis reaction time for the maximum oil production from PE-PS mixtures is shorter than for PE alone and approaches that of PS alone. Oil production increases with increase of PS content. The optimal temperature for maximum oil production is 600°C for the pyrolysis of 2:8, 5:5 and 1:0 mixtures (w/w) of PE and PS. Oil production for PS alone is constant when the pyrolysis is above 600°C.     

A bibliometric analysis of biodiesel research during 1991–2015

A bibliometric analysis based on the Science Citation Index Expanded (SCI-EXPANDED) from the Web of Science was carried out to provide insights into research activities and tendencies of the global biodiesel from 1991 to 2015. The document type and language, characteristics of publication outputs, Web of Science categories, journals, countries, institutions, author keyword and most cited articles were emphasized. The results indicated that annual output of the related scientific articles increased steadily. The top six categories focus on different aspects of biodiesel research. Bioresource Technology and Fuel were the two most frequent journals in the field of biodiesel research. The USA took a leading position and had the highest h-index (108) out of 122 countries/territories, followed by China and Brazil. Finally, author keywords and most cited articles were analyzed, indicating that microalgae, Jatropha curcas, vegetable oil and waste cooking oil are the most general raw materials for biodiesel production.     

Development of a catalytic dehalogenation (Cl,Br) process for municipal waste plastic-derived oil

Dehalogenation is a key technology in the feedstock recycling of mixed halogenated waste plastics. In this study, two different methods were used to clarify the effectiveness of our proposed catalytic dehalogenation process using various carbon composites of iron oxides and calcium carbonate as the catalyst/sorbent. The first approach (a two-step process) was to develop a process for the thermal degradation of mixed halogenated waste plastics, and also develop dehalogenation catalysts for the catalytic dehydrochlorination of organic chlorine compounds from mixed plastic-derived oil containing polyvinyl chloride (PVC) using a fixed-bed flow-type reactor. The second approach (a single-step process) was the simultaneous degradation and dehalogenation of chlorinated (PVC) and brominated (plastic containing brominated flame retardant, HIPS–Br) mixed plastics into halogen-free liquid products. We report on a catalytic dehalogenation process for the chlorinated and brominated organic compounds formed by the pyrolysis of PVC and brominated flame retardant (HIPS–Br) mixed waste plastics [(polyethylene (PE), polypropylene (PP), and polystyrene (PS)], and also other plastics. During dehydrohalogenation, the iron- and calcium-based catalysts were transformed into their corresponding halides, which are also very active in the dehydrohalogenation of organic halogenated compounds. The halogen-free plastic-derived oil (PDO) can be used as a fuel oil or feedstock in refineries.     

Soybean Oil-Based Photo-Crosslinked Polymer Networks

Novel soybean oil-based crosslinked polymer networks were prepared by UV photopolymerization and their mechanical properties were evaluated. Poly(ethylene glycol) diacrylate (PEGDA) and biodegradable poly(ε-caprolactone) diacrylate (PCLDA) were synthesized and used as crosslinking agent to form crosslinked polymer networks by UV-initiated free-radical polymerization with acrylated epoxidized soybean oil (AESO). The synthesis of acrylate end-capped macromers was confirmed using FT-IR and ¹H NMR spectroscopic techniques. Photopolymerization time, the composition of reaction mixture, and the type and length of crosslinking agent were changed to obtain crosslinked polymer networks with various mechanical properties. Polymers prepared from AESO and PCL degraded 6% of the initial weight in 24 days in phosphate buffer solution (pH 7.2) containing lipase enzyme. These potentially biodegradable and biocompatible polymers can be used as ecofriendly materials for biomedical and other applications to replace the existing petroleum-based polymers currently used.     

Production of biodiesel from waste frying oils

Waste frying oils transesterification was studied with the purpose of achieving the best conditions for biodiesel production. Transesterification reactions were carried out for 1 h using waste frying oils (WFOs), methanol, and sodium hydroxide as catalyst. In order to determine the best conditions for biodiesel production, a series of experiments were carried out, using methanol/WFO molar ratios between 3.6 and 5.4 and catalyst/WFO weight ratios between 0.2% and 1.0%. For oils with an acid value of 0.42 mg KOH/g, results show that a methanol/WFO ratio of 4.8 and a catalyst/WFO ratio of 0.6% gives the highest yield of methyl esters. Furthermore, an increase in the amount of methanol or catalyst quantity seems to simplify the separation/purification of the methyl esters phase, as showed by a viscosity reduction and an increasing purity to values higher than 98% for methyl esters phase.     

纳米Al_2O_3固定化红平红球菌菌球的制备及其对苯酚的降解

以海藻酸铝为主要包埋材料、纳米Al_2O_3为添加剂,包埋固定红平红球菌,制得纳米Al_2O_3固定化红平红球菌菌球,并将其用于苯酚的降解。表征结果显示:菌球内部包含丰富的菌丝体;内部孔径以中孔居多。实验结果表明:菌球的最优制备方案为0.05 g纳米Al_2O_3加入3 m L海藻酸钠溶液中、海藻酸钠质量分数6%、微生物包埋量0.5 m L/m L(以海藻酸钠溶液计)、Al_2(SO_4)_3质量分数3%;在初始苯酚质量浓度为400 mg/L、反应时间为24h、菌球加入量为8 g/L、反应p H为8.0、反应温度为30℃的条件下,菌球首次使用时可使苯酚完全降解,使用5次后的苯酚降解率仍达93%以上,具有良好的循环使用性。     

Biodiesel production from waste frying oils and its quality control

The use of biodiesel as fuel from alternative sources has increased considerably over recent years, affording numerous environmental benefits. Biodiesel an alternative fuel for diesel engines is produced from renewable sources such as vegetable oils or animal fats. However, the high costs implicated in marketing biodiesel constitute a major obstacle. To this regard therefore, the use of waste frying oils (WFO) should produce a marked reduction in the cost of biodiesel due to the ready availability of WFO at a relatively low price.In the present study waste frying oils collected from several McDonald’s restaurants in Istanbul, were used to produce biodiesel. Biodiesel from WFO was prepared by means of three different transesterification processes: a one-step base-catalyzed, a two-step base-catalyzed and a two-step acid-catalyzed transesterification followed by base transesterification. No detailed previous studies providing information for a two-step acid-catalyzed transesterification followed by a base (CH₃ONa) transesterification are present in literature. Each reaction was allowed to take place with and without tetrahydrofuran added as a co-solvent. Following production, three different procedures; washing with distilled water, dry wash with magnesol and using ion-exchange resin were applied to purify biodiesel and the best outcome determined. The biodiesel obtained to verify compliance with the European Standard 14214 (EN 14214), which also corresponds to Turkish Biodiesel Standards.