Modeling and optimization of two-step shea butter oil biodiesel synthesis using snail shell as a heterogeneous base catalyst

Shea butter oil (SBO) is underutilized in the biodiesel production industry in Nigeria because of its high free fatty acid (FFA) which reduces its biodiesel yield. This research aimed at...

Optimization of In-situ Transesterification Process for Biodiesel Production from High Free Fatty Acid Feedstock by Semi-continuous Column Reactor

An in-situ transesterification (in-situ TE) process can reduce the multiple steps of biodiesel production by merging vegetable oil extraction and biodiesel synthesis into a single step. However, high free fatty acid, generally found in waste feedstock, dramatically reduce both yield and quality of biodiesel. In this work the new concept of a semi-continuous column reactor was introduced to mitigate the negative effect of high free fatty acid found in spent coffee grounds (SCGs). The potassium methoxide solution, as reactive solvent, was pumped through the series of column reactors. At the beginning of process free fatty acid in SCGs was promptly extracted in form of soap as a pretreatment fraction. Then, the residual mono-, di- and triglyceride in SCGs matrix were covert to fatty acid methyl ester (FAME) biodiesel and simultaneously extracted. A liquid fraction analysis was conducted to distinguish the pretreatment fraction from biodiesel. A central composited rotatable design was applied to determine optimal process conditions of potassium methoxide concentration and solid retention time at 30°C. Under the optimal conditions, up to 88% FAME yield was observed. The residual triglyceride in defatted SCGs was less than 1.5%mass. Compared to batch reactor type, the semi-continuous column reactor used only half of the required methanol for in-situ TE by recirculating the reagent in the series of reactors. This could dramatically reduce the energy usage and environmental impact of FAME production from high free fatty acid feedstock via in-situ TE.

D-optimal Design Optimization for the Separation of Oleic Acid from Malaysian High Free Fatty Acid Crude Palm Oil Fatty Acids Mixture Using Urea Complex Fractionation

Oleic acid (OA) rich vegetable oils is important for the daily essential dietary oils intake but restrict to particular oil such as olive oil. However OA enrichment to other vegetable oil such as palm oil is always possible. OA can be obtained from cheap resources such as high free fatty acid crude palm oil (HFFA-CPO). OA concentrate from HFFA-CPO fatty acids mixture requires efficient and low cost technique. Urea complex crystallization fractionation is a classic method for fractionating saturated and monounsaturated fatty acids from polyunsaturated fatty acids of many vegetable oils. In this work, the separation and purification of oleic acid (OA) from unsaturated fatty acids mixture fraction (USFA) of HFFA-CPO fatty acids mixture by urea complex fractionation (UCF) was studied. The crystallization reaction conditions of urea inclusion for the non-urea complex fraction (NUCF) were optimized using the response surface methodology (RSM) and the optimal model was developed. The results showed high content of OA (88%) in urea complex fraction (UCF) with 86% yield at optimal conditions of urea-to-USFAs ratio of 4.62 : 1 (w/w), crystallization temperature at –10°C and crystallization time of 24 h. The results have demonstrated that urea complex crystallization fractionation method is a very effective with low cost, stable, obtainable, and comparatively ease to recover of OA from polyunsaturated fatty acids (PUFA) of an oil fatty acids mixture. Pure OA is plausible to be used back for the OA enrichment modification into palm oil for new dietary oil.

Efficiency Evaluation on the Influence of Washing Methods for Biodiesel Produced from High Free Fatty Acid Waste Vegetable Oils through Selected Quality Parameters

The increasing use of alternative energy sources has brought benefits like the recycling of waste vegetable oils (WVO) for biodiesel production; however, this practice presents challenges derived from a highly variable raw matter. Our research focused on the washing techniques usually employed by small to medium scale producers which may lack the infrastructure to perform high-grade purification and often relay on the employment of “artisanal” technology. We report biodiesel production from pure canola oil (C1) and a mix of soybean/canola oil (C2) as well as WVO from sample C2 with high free fatty acid content (2.7 FFA %) oil. We selected seven quality tests: pH determination, cloud, pour and flash point, acid number (AN), water/sediments and soap content considering the most commonly failed checkpoints in biodiesel production. From the use of four washing techniques, we determined that the sawdust filtration had the highest recovering yield with 89%. The majority of the washed biodiesel met the America Society of Testing Material (ASTM) standard limits for the tests selected. Biodiesel stability was tested from week 0 to week 6, determining a shelf life of three weeks in optimal conditions without the addition of antioxidants or specific storage conditions.