Possibility of converting indigenous Salvadora persica L. seed oil into biodiesel in Pakistan

In this research study, biodiesel has been successfully produced from vegetable seed oil of an indigenous plant Salvadora persica L. that meets the international biodiesel standard (ASTM D6751). The biodiesel yield was 1.57 g/5 g (31.4% by weight) and the in-situ transesterification ester content conversion was 97.7%. The produced biodiesel density was 0.894 g/mL, its kinematic viscosity 5.51 mm²/s, HHV 35.26 MJ/kg, flash point 210°C, cetane no. 61, and sulfur content 0.0844%. Thermal analysis of the biodiesel showed that 97% weight loss was achieved at 595°C with total oxidation of the biodiesel. The production energy efficiency was 0.46% with a lab scale setup, assuming the volume fraction ratio (volume of the sample/total volume of the equipment used). The results revealed that single-step in-situ transesterification method is suitable for the production of biodiesel from S. persica seed oil.     

Transesterification of Pistacia chinensis seed oil using a porous cellulose-based magnetic heterogeneous catalyst

In the present work, a novel cellulose-based porous heterogeneous solid acid catalyst encapsulation of ferriferous oxide (Fe₃O₄) and sulfonated graphene (GO-SO₃H) into cellulose to form composite porous microspheres catalyst (GO-SO₃H/CM@Fe₃O₄)was synthesized and evaluated for biodiesel production from Pistacia chinensis seed oil. The SEM, EDS and FTIR analysis revealed that the catalyst GO-SO₃H/CM@Fe₃O₄ owned stronger active sites and GO-SO₃H dispersed well in porous surface and inside of cellulose support. Under the optimum conditions, microwave-assisted transesterification process was carried out with the best catalyst amount, i.e. 5 wt% GO-SO₃H/CM@Fe₃O₄ (weight ratio of GO-SO₃H/cellulose), and conversion yield reached 94%. The prepared catalyst could be easily separated from reaction solution by extra magnetic field and reclaimed at least five runs.     

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.     

Homogeneous catalysed biodiesel synthesis from Alexandrian Laurel (Calophyllum inophyllum L.) kernel oil using ortho-phosphoric acid as a pretreatment catalyst

In this study, a non-edible seed oil of Alexandrian Laurel (Calophyllum inophyllum L.) with higher free fatty acid content has been harnessed to produce biodiesel by transesterification process. The 20.2% free fatty acid (FFA) content was first reduced to 12.9% by using TOP degumming process. Ortho-phosphoric acid was used to esterify the refined kernel oil. Transesterification reaction was performed with NaOH as an alkaline catalyst and methanol as an analytical solvent. The effects of methanol to oil molar ratio (MR), catalyst concentration (CC), reaction temperature (TP), reaction time (TM), and stirrer speed (SS) on biodiesel conversion were studied to optimize the transesterification conditions using DOE- approach. The experimental study revealed that 9:1 MR, 0.8 wt.% CC, 60°C TP, 75 min TM and 1000 rpm SS were the optimal process control variables. The study indicated that CC was the most important control parameter in optimal methyl ester production. The optimal treatment combination yielded 97.14% of biodiesel. The profile of biodiesel was determined using gas chromatography-mass spectrometry. ¹H NMR spectrum of Calophyllum inophyllum methyl ester (CIME) has been reported. The properties of the biodiesel have been found within specifications of the ASTM D6751 and EN 14214 standards and hence could be considered as a suitable alternative to diesel fuel for sustainable circulation of carbon.     

Synthesis and use of a catalyst in the production of biodiesel from Pongamia pinnata seed oil with dimethyl carbonate

The preparation of sodium methoxide-treated algae catalysts and their activity in the transesterification of Pongamia pinnata seed oil by dimethyl carbonate were investigated. We also investigated the effect of the sodium methoxide-treated algae catalyst on the biodiesel yield. The development of sodium methoxide-treated algae catalysts can overcome most problems associated with dissolution in dimethyl carbonate. The products were analyzed using gas chromatography-mass spectroscopy to identify the fatty acid methyl esters in the biodiesel produced. The molar ratio of Pongamia pinnata seed oil to dimethyl carbonate in transesterification in the presence of the sodium methoxide-treated algae catalyst was observed to play a substantial role in this study, wherein the Pongamia pinnata seed oil conversion increased with increasing catalyst concentration. The highest percent conversion rate was 97%. With intense research focus and development, an ideal catalyst can indeed be developed for optimal biodiesel production that is both economically feasible and environmentally benign.     

Microalgae‐based biodiesel production in open raceway ponds using coal thermal flue gas: A case of West Bengal,India

India is one of the most populous countries and is the third largest greenhouse gas–emitting nation. Energy security is a serious issue for India as it relies heavily on fossil fuel imports. Biodiesel production using microalgae as feedstock can address both of these issues. In this study, the technical feasibility of microalgae‐based biodiesel production is carried out for a coal thermal power plant (i.e., Budge Budge Thermal Station) in the state of West Bengal, India, using a generic methodology. An oleaginous microalgae species that is tolerant toward flue gas was identified (i.e., Nannochloropsis sp). A 75‐acre open raceway microalgae production plant was designed keeping the costs, energy demand, and CO₂ emissions low. The open raceway pond can use 38 tons of CO₂, produce 19 tons of algal biomass, and treat 9320 m³ of wastewater per acre annually.     

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.