A new heterogeneous acid catalyst system for esterification of free fatty acids into methyl esters (original) (raw)
Related papers
Alginate-derived solid acid catalyst for esterification of low-cost palm fatty acid distillate
Aluminum alginate (Al-A), a bio-based solid acid catalyst derived from natural brown algae extracted algin (polysaccharide) was studied for its physicochemical properties and catalytic activity as an acid catalyst via esterification of palm fatty acid distillate (PFAD). Based on the results, the presence of Al phases in the alginate system has successfully lowered crystallinity with winkled surface of bead form structure, which created large Lewis acid sites for the esterification process. Besides, the optimization study (RSM-CCD) showed that the methanol:PFAD ratio rendered the most significant effect on the PFAD conversion, followed by catalyst amount. The highest PFAD conversion of 92% was achieved at reaction conditions of 10 wt.% of catalyst concentration, 20:1 of methanol:PFAD molar ratio and reaction time of 230 min. High recovery of biodiesel was obtained for 2 consecutive cycles with PFAD conversion >80% under the optimized reaction conditions in the reusability test. The synthesized PFAD-derived biodiesel has complied with international biodiesel standards EN14214 and ASTM D6751.
Recent studies have successfully synthesized polyol ester of vegetable oil origin for the application of biolubriant, which though biodegradable, met with the challenge of food chain disruption. Therefore, biomass-derived bio oil is a potential alternative for the production of polyol ester in the application of biolubricant production. Due to its high oxygen content and low storage stability, further upgrading process such as esterification is necessary before bio oil is ready to be used as biolubricant. Acetic acid (AcA), a major component found in bio oil was used for the catalytic esterification with neopentyl glycol (NPG) in the presence of bio-polymer acid catalyst, aluminium alginate (Al-A) and ferric alginate (Fe-A). Surface morphological study reveals Al-A has higher surface area as the surface is rough and wrinkled as compared to the more compact surface of Fe-A. TPD-NH 3 shows acidity of Al-A is 1.5 times higher than Fe-A. Catalytic activity screening test showed that Al-A catalyzed ester-ification renders highest polyol ester yield of 100% (monoester: 40.2% and diester: 59.8%) under 15 wt% of catalyst, 6 h, 0.5:1 molar ratio of NPG:AcA and 100 • C, as compared to Fe-A catalyst. The presence of Lewis acid site from Al 3+ ion played a major role in esterification process. In additional, the Al-A catalyst rendered significant reusability up to 3 consecutive cycles with ester yield above 85%.
Application of Ferric Sulfate Loaded on Activated Carbon as Solid Catalyst for Biodiesel Production
2008
The production of fatty acid methyl ester (FAME) from palm fatty acid distillate (PFAD) having high free fatty acid (FFA) by using esterifacation reaction was investigated. The esterification experiments were carried out in a batch reactor with temperature at 95oC. The four parameters were varying as follows; molar ratio of PFAD to methanol from 1:1 to 1:14, reaction time 0.5 to 10 h, an activated carbon loaded with 10, 20 and 30 wt% of ferric sulfate as a solid acid catalyst and quantity of catalyst from 8 to 48 %(wt/wt of PFAD). The optimum condition for this process was observed at 1:12 molar ratio of PFAD to methanol, reaction time 6 h, activated carbon loaded with 20 wt% of ferric sulfate at 40 %(wt/wt of PFAD). The convertion of FFA average was 98.22%.The final FAME product met with the ASTM D6751-02
Bioresource Technology, 2008
In the present study, such carbohydrate-derived catalysts have been prepared from various carbohydrates such as d-glucose, sucrose, cellulose and starch. The catalytic and textural properties of the prepared catalysts have been investigated in detail and it was found that the starch-derived catalyst had the best catalytic performance. The carbohydrate-derived catalysts exhibited substantially higher catalytic activities for both esterification and transesterification compared to the two typical solid acid catalysts (sulphated zirconia and Niobic acid), and gave markedly enhanced yield of methyl esters in converting waste cooking oils containing 27.8 wt% high free fatty acids (FFAs) to biodiesel. In addition, under the optimized reaction conditions, the starch-derived catalyst retained a remarkably high proportion (about 93%) of its original catalytic activity even after 50 cycles of successive re-use and thus displayed very excellent operational stability. Our results clearly indicate that the carbohydrate-derived catalysts, especially the starch-derived catalyst, are highly effective, recyclable, eco-friendly and promising solid acid catalysts that are highly suited to the production of biodiesel from waste oils containing high FFAs.
The waste cooking oil (WCO) is a promising feed stock for the synthesis of biodiesel. In this study, the WCO used for biodiesel production has a very high acid value (>13 mg KOH/g) so a simple base transesterification process was not suitable, which resulted in soap formation. Here we reported a two step process for biodiesel production from WCO, acid catalyzed esterification followed by base catalyzed transesterification. In the first step, the acid value of WCO was reduced below 1 mg KOH/g by homogeneous acid catalysis and in the second step, acid catalyzed WCO was transformed to biodiesel in the presence of NaOH as homogeneous base catalyst. GC/MS analysis was done to determine the chemical composition of WCO biodiesel. Five FAMEs, methyl dodecanoate (C12:0), methyl tetradecanoate (C14:0), methyl hexadecanoate (C16:0), methyl octadecanoate (C18:0) and methyl 9-octadecenoate (C18:1) were identified. The synthesized FAMEs were confirmed by FTIR and NMR (1H and 13C). The 1H NMR was also used to determine the percentage conversion of triglyceride to methyl esters which was 97.89%. The prepared biodiesel was investigated for fuel properties using ASTM standards methods.