Adsorptive removal of residual catalyst from palm biodiesel: Application of response surface methodology

In this work, the residual potassium hydroxide catalyst was removed from palm oil-based methyl esters using an adsorption technique. The produced biodiesel was initially purified through a water washing process. To produce a biodiesel with a better quality and also to meet standard specifications (EN 14214 and ASTM D6751), batch adsorption on palm shell activated carbon was used for further catalyst removal. The Central Composite Design (CCD) of the Response Surface Methodology (RSM) was used to study the influence of adsorbent amount, time and temperature on the adsorption of potassium species. The maximum catalyst removal was achieved at 40°C using 0.9 g activated carbon for 20 h adsorption time. The results from the Response Surface Methodology are in a good agreement with the measured values. The absolute error in prediction at the optimum condition was 3.7%, which is reasonably accurate. This study proves that adsorption post-treatment techniques can be successfully employed to improve the quality of biodiesel fuel for its effective use on diesel engines and to minimize the usage of water

Treatment of industrial low grade palm oil via esterification reaction using sonoreactor

In this study, the reduction of free fatty acid (FFA) in low grade palm oil (LGPO) was conducted at various sonication times, ranging from 30 to 300 min. Screening of various acids was reported and selected acid was considered for further study. The results found that strong acids such as sulfuric acid to be superior to other acids. The FFA content of LGPO decreased from 20% to less than 3%, using sulfuric acid at optimum conditions. Treated LGPO can be used as a new type of fuel for various applications such as biodiesel production

Utilizing ultrasonic energy for reduction of free fatty acids in crude palm oil

Recently, biodiesel production from abundant bio-sources has drawn the attention of the academic and the industrial community. In this study, crude palm oil (CPO) containing 8.7% free fatty acid content (FFA) was used as raw material. Different common types of acid catalysts (sulfuric acid, methanesulfonic acid and hydrochloric acid) were optimized to investigate the catalytic activity of each acid in the pre-treatment of CPO by the esterification process. Ultrasonic energy was used for the reduction of FFA in CPO. FFA content was measured at different sonication intervals, and the optimum time was determined. Hydrochloric acid showed the highest catalytic activity in the reduction of FFA content in CPO, as well as in converting FFA to fatty acid methyl ester (FAME). From this work, it is reasonable to conclude that there is significant enhancement in the pre-treatment of oils by applying ultrasonic energy using long sonication time

Esterification of sludge palm oil using trifluoromethanesulfonic acid for preparation of biodiesel fuel

Trifluoromethanesulfonic acid (TFMSA) was used to reduce the high free fatty acids (FFA) content in sludge palm oil (SPO). The FFA content of SPO was converted to fatty acid methyl ester (FAME) via esterification reaction. The treated sludge palm oil was used as a raw material for biodiesel production by transesterification process. Several working parameters were optimized, such as dosage of catalyst, molar ratio, reaction temperature and time. Less than 2% of the FFA content was the targeted value. The results showed that the FFA content of SPO was reduced from 16% to less than 2% using the optimum conditions. The yield of the final product after the alkaline transesterification was 84% with 0.07% FFA and the ester content was 96.7%. All other properties met the international standard specifications for biodiesel quality such as EN 14214 and ASTM D6751

Assessment of cytotoxicity and toxicity for phosphonium-based deep eutectic solvents

In this work, the cytotoxicity and toxicity of phosphonium-based deep eutectic solvents (DESs) with three hydrogen bond donors, namely glycerine, ethylene glycol, and triethylene glycol were investigated. The cytotoxicity effect was tested using brine shrimp (Artemia salina). The toxicity was investigated using the two Gram positive bacteria Bacillus subtilis and Staphylococcus aureus, and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The cytotoxicity of tested DESs was much higher than that of their individual components, indicating their toxicological behavior was different. It was also found that there was toxic effect on the studied bacteria, indicating their potential application as anti-bacterial agents. To the best of our knowledge, this is the first time the cytotoxicity and toxicity of phosphoniumbased DESs were studied

Are deep eutectic solvents benign or toxic?

In continuation of investigation for environmentally benign protocol for new solvents termed deep eutectic solvents (DESs), it is herein reported results concerning the toxicity and cytotoxicity of choline chloride (ChCl) based DESs with four hydrogen bond donors including glycerine, ethylene glycol, triethylene glycol and urea. The toxicity was investigated using two Gram positive bacteria Bacillus subtilis and Staphylococcus aureus, and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The cytotoxicity effect was tested using the Artemia salina leach. It was found that there was no toxic effect for the tested DESs on all of the studied bacteria confirming their benign effects on these bacteria. Nevertheless, it was found that the cytotoxicity of DESs was much higher than their individual components (e.g. glycerine, ChCl) indicating that their toxicological behavior is different. For our best knowledge this is the first time that toxicity and cytotoxicity of DESs were studied. The toxicity and cytotoxicity of DESs varied depending on the structure of components. Careful usage of the terms non-toxicity and biodegradability must be considered. More investigation on this matter is required

Treatment of acidic palm oil for fatty acid methyl esters production

Acidic crude palm oil (ACPO) produced from palm oil mills with an acid value of 18 mg g−1 was considered to be a possible feedstock for biodiesel production. Due to its high acidity, conventional transesterification cannot be applied directly for biodiesel production. Methane sulphonic acid (MSA, CH3SO3H) is used to reduce the acidity prior to the alkaline transesterification reaction. The laboratory-scale experiments involved an MSA to ACPO dosage of 0.25–3.5 %, a molar ratio (methanol to ACPO) from 4: 1 to 20: 1, reaction temperature of 40–80°C, reaction time of 3–150 min, and stirrer speed of 100–500 min−1. The optimum esterification reaction conditions were 1 % of catalyst to ACPO, with a molar ratio of methanol to ACPO of 8: 1, a stirring speed of 300 min−1, for 30 min and at 60°C. Under these conditions, the FFA content was reduced from 18 mg g−1 to less than 1 mg g−1 and with a yield of 96 %. The biodiesel produced met the EN14214 standard specifications. MSA was recycled for three times without losing its activity. The biodiesel produced in a two-stage process has a low acid value (0.14 mg g−1)

Regression Parameters for viscosity and conductivity of polyol-based DESs.

<p>Regression Parameters for viscosity and conductivity of polyol-based DESs.</p

(a) Dependence of specific conductivity (<i>σ</i>) on temperature for the DESs; (b) Arrhenius plot of specific conductivity (<i>σ</i>) for the polyol based DESs; and (c) VTF plot of ionic conducticity for DES1 and DES2.

<p>(a) Dependence of specific conductivity (<i>σ</i>) on temperature for the DESs; (b) Arrhenius plot of specific conductivity (<i>σ</i>) for the polyol based DESs; and (c) VTF plot of ionic conducticity for DES1 and DES2.</p