Process optimization for biodiesel production from Moringa oleifera oil using conch shells as heterogeneous catalyst

Abstract

The potential of conch shells (CSs) as a suitable heterogeneous basic catalyst for transesterification of high FFA content non‐edible Moringa oleifera oil (MOO) was investigated. Biodiesel was produced by a two‐step transesterification process. In the first step, high FFA content of the oil was reduced from 40.25 to 1.4% using reaction conditions of 1:2 v/v methanol to oil ratio, 1.5 vol% H2SO4 concentration, 2 h reaction time and 60°C reaction temperature. In the second step, the esterified oil was converted into biodiesel by reacting with methanol using calcined conch shells (CCSs) as a heterogeneous basic catalyst. The physiochemical characteristics of the CCS catalyst were studied by X‐ray diffraction (XRD), scanning electron microscopy, and energy dispersive X‐ray (SEM–EDAX), Fourier transform infrared spectroscopy (FTIR), and Brunauer–Emmett–Teller (BET) analysis. The characterization results revealed that calcium oxide (CaO) was the major phase of CCS. The effect of process variables on biodiesel conversion was investigated by response surface methodology using Box–Behnken design and the independent variables taken for study are catalyst concentration, methanol to oil ratio and reaction time. The optimum process conditions were found to be 8.02 wt % catalyst concentration, 8.66:1 methanol to oil molar ratio and 130 min reaction time. Under these experimental conditions, methyl ester conversion of 97.06% was obtained which was in reasonable agreement with the predicted value. The structure of Moringa oleifera methyl ester (MOME) was characterized by FTIR and methyl ester conversion was determined by proton nuclear magnetic resonance (1H‐NMR) spectroscopy. © 2018 American Institute of Chemical Engineers Environ Prog, 38:e13015, 2019

Non-Edible Moringa Oleifera Seeds for Environmentally Friendly Biodiesel – A Review

“…The manufacture of biodiesel from Moringa seed oil can also be made with a heterogeneous catalyst that utilizes eggshell and shellfish waste, by first doing the calcination process. After the calcination process, the catalyst particle size will decrease, thus increasing the catalyst surface area [3]. The yield of biodiesel obtained using a shellfish catalyst is 97.06%, which is quite high in biodiesel production Aziz et al [30] compared the use of catalysts from eggshell impregnated with potassium fluoride (KF /eggshell), eggshell, commercial CaO, and commercial CaO impregnated with potassium fluoride (KF /CaO).…”

“…This is because increasing the methanol content will prevent methanol from reacting with a catalyst which causes difficulty in separating methanol from biodiesel and glycerin. In accordance with the stoichiometric reaction, excess methanol will also push the reaction to the right and increase the conversion, but the use of excess methanol with a long reaction time can cause a glycerolysis reaction [3] and increase the amount of energy when refining biodiesel [28]. The glycerolysis reaction causes glycerol to react with biodiesel to re-form monoglycerides instead of methyl esters [9].…”

“…Palm oil, if used as a raw material in the manufacture of biodiesel, can compete with human food needs [2]. To overcome this problem and reduce the cost of biodiesel production, nonedible vegetable oil is used as a raw material for making biodiesel [3].…”

Technology News

“…Subramaniapillai Niju and his colleagues at the PSG College of Technology in India have now found just such a catalyst in the form of conch shells. 1 Other research groups have explored using various shells, including egg shells and oyster shells, as biodiesel catalysts. This is because shells are primarily made from calcium carbonate, and previous research has shown the calcium oxide makes an effective biodiesel catalyst.…”

“…By tailoring environmental conditions and adding a dash of electricity, Spanish scientists have shown that an unusual class of photosynthetic bacteria can convert the organic material in wastewater into useful biochemicals and hydrogen. 1 In normal photosynthesis, organisms such as plants and cyanobacteria use the energy from visible light to split water into oxygen and hydrogen. This releases electrons, which the organisms use to combine the hydrogen with carbon dioxide to produce various organic compounds.…”