A process model to estimate the cost of industrial scale biodiesel production from waste cooking oil by supercritical transesterification

This paper describes the conceptual design of a production process in which waste cooking oil is converted via supercritical transesterification with methanol to methyl esters (biodiesel).Since waste cooking oil contains water and free fatty acids, supercritical transesterification offers great advantage to eliminate the pre-treatment capital and operating cost.A supercritical transesterification process for biodiesel continuous production from waste cooking oil has been studied for three plant capacities (125,000; 80,000 and 8000 tonnes biodiesel/year). It can be concluded that biodiesel by supercritical transesterification can be scaled up resulting high purity of methyl esters (99.8%) and almost pure glycerol (96.4%) attained as by-product.The economic assessment of the biodiesel plant shows that biodiesel can be sold at US$ 0.17/l (125,000 tonnes/year), US$ 0.24/l (80,000 tonnes/year) and US$ 0.52/l for the smallest capacity (8000 tonnes/year).The sensitive key factors for the economic feasibility of the plant are: raw material price, plant capacity, glycerol price and capital cost.Overall conclusion is that the process can compete with the existing alkali and acid catalyzed processes.Especially for the conversion of waste cooking oil to biodiesel, the supercritical process is an interesting technical and economical alternative.     

Ferric-manganese doped sulphated zirconia nanoparticles catalyst for single-step biodiesel production from waste cooking oil: Characterization and optimization

Biodiesel of waste cooking oil origin is gaining attention as a replacement for current fossil fuels, as its low-priced, recycled feedstock shall prevent food source competition, which is estimated to happen with current biodiesel production processes. As a result, waste cooking oil has been claimed to be a highly potential feedstock for biodiesel production. In the present research work, Fe-Mn doped sulphated zirconia catalyst was synthesized and used in simultaneous esterification and transesterification of waste cooking oil to biodiesel synthesis. The catalyst was prepared through the impregnation method and characterized by using XRD, TPD-NH_3, FT-IR, BET, and TEM. Response surface methodology (RSM) in conjunction with the central composite design (CCD) was applied to statistically evaluate and optimize the biodiesel preparation process. It was found that the synthesis of biodiesel achieved an optimum level of 97.2% waste cooking oil methyl ester’s (WCOME’s) yield at the following reaction conditions: methanol/oil molar ratio: 10:1, catalyst concentration: 3.0 wt %, and reaction temperature: 160 °C. The extremely high WCOME’s yield of 97.2% was proved to be due to high acidity, surface area, and large pore diameter; reactants can easily diffuse into the interior pore of the catalyst and allow them to be in contact with active sites that enhance catalytic activity.     

An investigation of engine and fuel system performance in a diesel engine operating on waste cooking oil

Waste cooking oil (WCO) was experimentally examined to determine whether it can be used as an alternative fuel in a 3-cylinder, 4-stroke, direct injection, 48 kW power tractor engine. The test engine was operated under full load conditions using diesel fuel and waste vegetable oil from the 2400 to 1100 rpm and performance values were recorded. Tests were performed in two stages to evaluate the effect of the waste oils on the engine life cycle. When the test engine was operated with diesel fuel and waste cooking oil; engine torque decreased between at ratio of 0.09 % and 3% according to the engine speed. While no significant difference occurs in the diesel fuel tests at the end of 100 hours of operation, an important reduction was observed in the engine torque of the WCO engine between 4.21% and 14.48% according to the engine speed, and an increase in average smoke opacity ratio was also observed. In accordance with the results obtained from the studies, it was determined that the engine performance values of waste cooking oil show similar properties with diesel fuel, but in long-term usage, performance losses increased. In the SEM analysis performed on the fuel system, there were dark deposits at the nozzle tip and stem. According to an EDX analysis at the nozzle tips, the detected elements point to engine oil ash in the combustion chamber and show coking products (C and O). The other elements (Na, S, Ca, P, Cl, and K) point to used WCO.     

Promotional effect of transition metal doping on the properties of KF/CaO catalyst for biodiesel synthesis

A series of heterogeneous KF/CaO catalysts modified with transition metals (lanthanum, cerium, and zirconium) were prepared via wet impregnation method and applied to the trsansesterification process of waste cooking oil (WCO) as feedstock with methanol to biodiesel production. The structure, performance of the solid catalysts was characterized by X-ray diffraction (XRD), temperature programmed desorption of CO₂ (CO₂-TPD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The effect of methanol/oil molar ratio, ¹reaction time, reaction temperature, catalyst amount, and stability was investigated. The results showed that 10 wt% of lanthanum, cerium, and zirconium improved the catalytic activity of KF/CaO catalyst. The maximum catalytic activity using the lanthanum doping of 10wt% on KF/CaO catalyst was reached 98.7% under the optimal reaction condition of methanol/oil molar ratio of 12:1, reaction for 1 h at reaction temperature of 65°C, and 4% (wt/wt oil) catalyst amount. In addition, the FAME yield of KF/CaO/La catalyst remained higher than 95% after 10 cycles. The promotional effect of lanthanum doping could be attributed to the enhancement of the basicity strength of KF/CaO catalyst and block the leach of Ca²⁺ in the transesterification reaction.     

Rice bran: A prospective resource for biodiesel production in Bangladesh

The increasing demand of renewable energy sources has pressed the need to search for biofuels. The world is not only thrusting for potential sources of biofuels but also surveilling not to hamper the food supply, particularly in the Third World countries, such as Bangladesh. Rice bran oil is a prominent source of biofuels. Rice, the main cereal in Bangladesh, is cultivated all the year round. Rice hull containing bran is mostly wasted and merely used as feedstock for cattle and for cooking purposes. This study considered rice bran as a prospective source of biodiesel in Bangladesh. The properties of oil collected from rice bran were investigated to ensure the production of biodiesel by transesterification. An economic analysis relative to Bangladesh was conducted, and the production rate of biodiesel under different percentage of catalyst was investigated.     

Emission study of a diesel engine fueled with higher alcohol-biodiesel blended fuels

This work examines the effect of butanol (higher alcohol) on the emission pattern of neat neem oil biodiesel (NBD100) fueled diesel engine. Single-cylinder, 4-stroke, research diesel engine was employed to conduct the trial. Blends comprising the mixture of biodiesel and higher alcohol were prepared by employing an ultrasonic agitator. Four test fuels such as neat neem oil biodiesel, diesel, and two blends of higher alcohol/neem oil biodiesel: 10% and 20% (by volume). Experimental result showed that increasing alcohol content to biodiesel brought down the various emissions such as Smoke, NO_x, HC, and CO by 6.8%, 10.4%, 8.6%, and 5.9%, respectively, at all loads. It was also concluded from the trail that a 20% higher alcohol/neem oil biodiesel blends show the promising signs in reducing all the emissions associated with biodiesel fuelled diesel engine.     

A comprehensive review on biodiesel production using Moringa oleifera oil

Biodiesel has emerged as one of the most promising renewable energy to substitute existing petroleum-derived diesel fuel being used in transportation sectors. Among the various feedstocks reported for biodiesel production, Moringa oleifera oil is becoming a promising replacement for conventional diesel fuel. Therefore, this work provides a comprehensive overview of the recent progress in biodiesel production from Moringa oleifera oil. The physicochemical properties, fatty acid composition of oil and methyl esters, oil extraction methods, esterification, and transesterification process, and purification methods employed in the biodiesel production have been discussed.     

Facilitating access to the algal economy: Mapping waste resources to identify suitable locations for algal farms in Queensland

Algae offer a multiple-benefit opportunity as the products that can result from algal cultivation are numerous and diverse. However, commercial production of algal-derived materials is scarce and in Queensland Australia is virtually non-existent, partly due to challenges around readily available resources. In this work, the potential to regionally recycle waste nitrogen (N), phosphorus (P) and CO₂ to support algal production is considered. A feature of the work is mapping the availability of the three resources for algal cultivation (N, P and CO₂) together with climatic and land use considerations. Mapping resolution is defined by the boundaries of Queensland's (Australia) regional authorities. Layering the maps enables identification of regional hotspots for growing algae. Waste resources are shown to be most abundant in Mackay, Burdekin, Toowoomba, Cassowary and Bundaberg; regions which also have favourable eco-climatic conditions. Waste nitrogen is the limiting waste stream, in these and most other regions however additional requirements can be fixed atmospherically, whereas waste CO₂ is shown to be abundant relative to waste nutrients. It is found that, based on the availability of waste phosphorus, the top 5 most suitable regions have sufficient resources to produce around 1.1 million t/y of algal biomass. This could potentially produce 309 ML of biodiesel which is 5% of Queensland's 2011 diesel oil sales. The outcomes of this work highlight new opportunities for industrial ecology in non-urban regions.     

Application of TiO2 nanoparticles for eco-friendly biodiesel production from waste olive oil

An environmentally benign, simple, and efficient process has been developed for biodiesel production from waste olive oil in the presence of a catalytic amount of TiO₂ nanoparticles at 120°C with a conversion of 91.2% within 4 h. The present method affords nontoxic and noncorrosive medium, high yield of biodiesel, clean reaction, and simple experimental and isolation procedures. The catalyst can be recycled by simple filtration and reused without any significant reduction in its activity.     

The Kinetics of Interesterfication on Waste Cooking Oil (Sunflower Oil) for the Production of Fatty Acid Alkyl Esters using a Whole Cell Biocatalyst (Rhizopus oryzae) and Pure Lipase Enzyme

Recent research and technology have provided promising outcomes to rely on biodiesel as the alternative and conventional source of fuel. The use of renewable sources constitutes the main stream of research. Waste Cooking Oil (WCO) was used for biodiesel production in this study. Lipase enzyme producing fungi Rhizopus oryzae 262 and commercially available pure lipase enzyme were used for comparative study in the production of FAAE. The whole cell biocatalyst and pure enzyme were immobilized using calcium alginate beads. It was prepared by optimizing with different molar ratios of calcium chloride and different percent sodium alginate. Entrapment immobilization was done for whole cell biocatalyst. PE was also immobilized by entrapment for the transesterification reaction. Four different solvents methanol, ethanol, n-propanol, n-butanol were used as the acyl acceptors. The reaction parameters like temperature, molar ratio, reaction time, and amount of enzyme to be used were also optimized for methanol alone. The same parameters were adopted for the other acyl acceptors too. Among the different acyl acceptors, methanol whose reaction parameters were optimized showed maximum conversion of triglycerides to FAAE - 94% with PE and 84% with WCB. On the whole, PE showed better catalytic converting ability with all the acyl acceptor compared to WCB, further study, it was observed that three consecutive and reversible reactions occurred in the interesterification of triglycerides. So, a kinetic model based on Michaelis-Menten equation with competitive substrate inhibition was used to find the maximum reaction rate V_i for the four solvents using pure enzyme and WCB.     

From waste to value-added products: A review of opportunities for fish waste valorization

The fishing industry is responsible for generating large amounts of organic waste rich in compounds of commercial interest. This review aimed to present the state of the art about the possibilities of using solid waste to obtain value-added products. Skins, fins, and scales have been used to obtain gelatin and collagen, a promising compound for use as an additive in yogurts and creams, as well as for the synthesis of biodegradable packaging that, if applicable, can reduce the environmental impact caused by petroleum packaging. Other parts, such as the head and the viscera, contain polyunsaturated fatty acids and other fat-soluble vitamins that have been studied for the production of omega-3 capsules for the pharmaceutical industry, but when the extracted oil does not fit the feeding parameters, it can be applied for the production of biodiesel. Furthermore, fishes are a promising source of astaxanthin, a carotenoid with high antioxidant properties. The use of combined techniques such as chemical and enzymatic methods can increase the extraction yield and favor the obtaining of more purified compounds, in addition to promoting the reduction of chemicals that are aggressive to the environment. In general, conscious production in the fishing industry through the valorization of waste generated for use as inputs for other value chains encompasses aspects of the circular economy, which can positively impact several Sustainable Development Goals.     

Characteristics of stable biodiesel emulsion fuel with the aid of lipophilic surfactant,polyglycerol polyricinoleate (PGPR)

ABSTRACT

Biodiesel emulsion fuel is reported as one of the most feasible options capable of generating lower NOx emission than that from fossil fuels. However, oil and water in the emulsion fuel are easily separated and unstable. The aim of the present study is to consider the production and stability of biodiesel emulsion fuel by using tetraglycerin ester (CR-310), i.e., one of lipophilic surfactant, polyglycerol polyricinoleate (PGPR) and biodiesel, i.e., Waste cooking Oil Methyl Ester (WOME) produced based on waste cooking oil. The corresponding heat rate, water content, and viscosity are measured. Emphasis is placed on the effects of water content and surfactant on biodiesel emulsions. It is found that: (i) stable emulsion fuel is obtained by adding at least 2.0% of CR-310 and is maintained over 1 month, (ii) there is no effect of water content on stable emulsion fuel if CR-310 is used over 2.0%, and (iii) the viscosity of emulsion fuels is higher than that of the biodiesel fuel and is gradually increased with an increase in the water content.     

Evaluating the potential of biodiesel (via recycled cooking oil) use in Singapore,an urban city

Singapore has pledged to attain 7–11% Business-As-Usual carbon emissions reduction by 2020. About 19% of CO₂ contribution stemmed from road transport in 2005. Commercial vehicles, which uses mainly diesel, consumed 695 million litres diesel in 2012. An estimated 115,585 tonnes or 127 million litres cooking oils (derived from seeds/fruits) were consumed in 2010, in which the bulk of used cooking oil is re-incorporated into the food preparation process while only a small amount is being recycled into biodiesel or disposed into the sewerage. Nevertheless, the present research reveals that biodiesel derived from spent cooking oil has potential to be a viable fuel supplement. Surveys were carried out involving three market segments – suppliers, processors and end-users – to identify the barriers and obstacles in mass production of biodiesel. A key enabler of biodiesel as a fuel supplement towards a greener environment lies in government mandate/policies in promoting greater biodiesel usage.     

Enzyme catalyzed biodiesel production from rubber seed oil containing high free fatty acid

Unrefined rubber seed oil contains high levels of free fatty acids and moisture, which make the conventional chemical catalyzed transesterification unsuitable. The method of enzyme catalyzed transesterification is well suited for biodiesel production from rubber seed oil as the enzymes are insensitive to the free fatty acids. In the present work, rubber seed oil was extracted from preserved rubber seed cake by mechanical means. The extraction process was designed and optimized through 2⁴ full factorial design. Extracted oil was subjected to enzymatic transesterification using four different lipases to identify the best one for the purpose. Transesterification process was optimized by considering three influencing variables for biodiesel production viz. methanol/oil molar ratio, catalyst concentration (% w/v) and solvent content (% v/v). A 2³ full factorial design was applied to design the experiments and optimize the biodiesel production. The interactive effects of the independent variables on biodiesel yield were analyzed and regression models were developed for each set of enzyme reactions. Among the four lipases, Thermomysis Lanugonosus Lipase was found to be the most suitable for the transesterification of rubber seed oil with a biodiesel conversion of 92.83% at a molar ratio of 4% and 5% (w/v) enzyme concentration in solvent free reaction medium.     

Clam shell catalyst for continuous production of biodiesel

Continuous flow transesterification of waste frying oil (WFO) with methanol for the biodiesel production was tested in a laboratory scale jacketed reactive distillation (RD) unit packed with clam shell based CaO as solid catalyst. The physiochemical properties of the clam shell catalysts were characterized by X-ray Diffraction (XRD), Brunauer–Emmett–Teller (BET), Scanning Electron Microscopy (SEM), and Energy Dispersive Atomic X-ray Spectrometry (EDAX). The effects of the reactant flow rate, methanol-to-oil ratio, and catalyst bed height were studied to obtain the maximum methyl ester conversion. Reboiler temperature of 65°C was maintained throughout the process for product purification and the system reached the steady state at 7 hr. The experimental results revealed that the jacketed RD system packed with clam shell based CaO showed high catalytic activity for continuous production of biodiesel and a maximum methyl ester conversion of 94.41% was obtained at a reactant flow rate of 0.2 mL/min, methanol/oil ratio of 6:1, and catalyst bed height of 180 mm.     

Sulfonated tea waste: A low-cost adsorbent for purification of biodiesel

In the present work, the crude biodiesel produced from spent fish frying oil through alkaline catalyzed transesterification was purified using a low-cost adsorbent viz. sulfonated tea waste. After separating the glycerol, the crude biodiesel was purified using the suggested adsorbent. Various methods of purification using the said adsorbent were applied such as purification using adsorption column chromatography and shaking methods. The results showed that purification using adsorption column chromatography exhibited the bst result. Properties of the purified fuels were determined and found conformed to those specified by the ASTM standards. For the sake of comparison, purification using zeolite and water washing method was also investigated. The result indicated that the suggested adsorbent was more successful on purification of the crude biodiesel compared to other methods.     

Application of response surface methodology for the optimization of biodiesel production from yellow mustard (Sinapis alba L.) seed oil

In the present study, response surface methodology (RSM) involving central composite design (CCD) was applied to optimize the reaction parameters of biodiesel production from yellow mustard (Sinapis alba L.) seed oil during the single-step transesterification process. A total of 30 experiments were designed and performed to determine under the effects of variables on the biodiesel yield such as methanol to oil molar ratio (2:1–10:1), catalyst concentration (0.2–1.0 wt.% NaOH), reaction temperature (50–70°C), and reaction time (30–90 min). The second order polynomial model was used to predict the biodiesel yield and coefficient of determination (R²) was found to be at 0.9818. The optimum biodiesel yield was calculated as 96.695% from the model with the following reaction conditions: 7.41:1 of methanol to oil molar ratio, 0.63 wt. % NaOH of catalyst concentration, 61.84°C of reaction temperature, and 62.12 min of reaction time. It is seen that the regression model results were in agreement with the experimental data. The results showed that RSM is a suitable statistical technique for optimizing the reaction parameters in the transesterification process in order to maximize the biodiesel yield.     

Prospect of castor oil biodiesel in Bangladesh: Process development and optimization study

In this study, castor oil (CO) has been investigated as a potential source for biodiesel production in Bangladesh. Castor oil has been extracted from the seeds by mechanical press and the Soxhlet extraction method. Maximum oil content of 55.7% has been found by the Soxhlet extraction method. The physicochemical properties such as free fatty acid (FFA) content, kinematic viscosity, saponification value, and density of the oil have been measured by different standard methods. The FFA content and viscosity have been found considerably higher such as 33.5% and 253 mm²/s, respectively. Biodiesel has been prepared using a three-step method comprising of saponification of oil followed by acidification of the soap and esterification of FFA. The overall yield of FFA from CO is found to be around 89.2%. The final step is esterification that produces fatty acid methyl ester (FAME) and a maximum 97.4% conversion of FFA to biodiesel has been observed. The effect of the oil to methanol molar ratio, catalyst concentration, reaction temperature, and time has been investigated for esterification reaction and optimized using the response surface methodology. ¹H NMR of crude castor oil and castor oil methyl ester (COME) was studied and analyzed that confirms the complete conversion of castor oil to biodiesel. Finally, the biodiesel, produced under optimum conditions, was characterized using the various standard method and found comparable with petro-diesel and biodiesel standard.     

Biodiesel production from a free fatty acid containing Karanja oil by a single-step heterogeneously catalyzed process

Karanja oil, containing 6.2% free fatty acids (FFAs), was considered for biodiesel production using a single-step solid-phase acid catalyzed process. Different types of zeolites and Amberlyst15 catalysts were tested and biodiesel was produced. Under similar conditions, the highest biodiesel yield was achieved using an Amberlyst15 catalyst, which contained 3–5% of moisture. The effects of operating parameters of the reaction such as reaction temperature, catalyst amount, and methanol-to-oil ratio were studied. An increase of methanol:oil ratio revealed a non-monotonic increase in biodiesel yields. Similar non-monotonic behavior was observed when Jatropha oil was used. Leaching and catalyst reusability were also considered. No significant effects of leaching were observed and catalyst reusability appeared to be affected by methanol interactions. The presence of a co-solvent, Tetrahydrofuran (THF), increased the biodiesel yield. Furthermore, an optimum amount of THF (THF:methanol volume ratio of 1:2) gave rise to the highest biodiesel yield. A biodiesel yield of 93% was achieved at 120 °C using a single-step process with Amberlyst15 as a catalyst, THF as a co-solvent, and a methanol:oil ratio of 30:1.     

Economy wide impacts of ethanol and biodiesel policy in Canada: An input–output analysis

The Government of Canada has committed that Canada’s total greenhouse gas (GHG) emissions be reduced by 17% from 2005 levels by 2020. The new Renewable Fuels Regulations required 2% renewable content in diesel fuel and heating distillate oil and 5% for gasoline. This represents approximately 2.1 billion liters of ethanol and 600 million liters of biodiesel requirement per year, which would reduce GHG emissions by more than four million tones. Canada is expected to consume more fuel ethanol compared to its production capacity. The above mandates as well as the gap in consumption and production of biofuel will have enormous impact on the Canadian economy. In this backdrop, an input–output model of the Canadian economy is developed to estimate the macroeconomic impact of the ethanol and biodiesel production in Canada. The impacts on sectoral prices have also been calculated. Simulation exercises have been attempted to reach the mandates using modified Leontief model. Results show that agriculture sector is affected because of feedstock use in the biofuel sector. Mining and manufacturing industries also show a considerable impact. In addition, the impact on commodity prices cannot be ignored. Finally, to meet the target of Copenhagen commitment, the nation needs to revise the blending capacity of ethanol and biodiesel.