Biodiesel Production from Acidic Crude Palm Oil ...

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ScienceDirect Energy Procedia 61 (2014) 2745 – 2749

The 6th International Conference on Applied Energy – ICAE2014

Biodiesel Production from Acidic Crude Palm Oil Using Perchloric Acid Adeeb Hayyana,b*,Mohd Ali Hashima,b, Maan Hayyana,c, Khor Gui Qingb a

University of Malaya Centre for Ionic Liquids (UMCiL), University of Malaya, Kuala Lumpur 50603, Malaysia b Department of Chemical Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia c Department of Civil Engineering, University of Malaya, Kuala Lumpur 50603, Malaysia

Abstract

Perchloric acid was used as a catalyst for the treatment of free fatty acid (FFA) in acidic crude palm o il (ACPO). Perch loric acid shows reduced the FFA content fro m 8.8% to 1% using 1% of acid to ACPO and the conversion of FFA to fatty acid methyl ester (FAME) was 88%. The produced biodiesel from treated ACPO meets international biod iesel standards such as EN 14214 and ASTM D6751. Perchlo ric acid shows high catalytic activ ity for the conversion of FFA to FAME and can be used to treat a wide range of acidic oils and fats. © 2014 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license © 2014 The Authors. Published by Elsevier Ltd. (http://creativecommons.org/licenses/by-nc-nd/3.0/). Selection and/or peer-review under responsibility of ICAE Peer-review under responsibility of the Organizing Committee of ICAE2014

Keywords: Acidic crude palm oil; biodiesel; esterification; perchloric acid; free fatty acid.

1. Introduction Biodiesel is an alternative renewable fuel and can be produced from animal fats and vegetable oils. The typical process to produce biodiesel fuel is trasesterification [1]. For high acidity raw materials it is required to undergo a pre -treat ment process before trasesterification to convert the FFA to fatty acid methyl ester (FAME) [2]. In Malaysia, at p resent, mo re than 2.8 million hectares of land are under o il palm cult ivation. It is reported that in 1995, there were some 281 palm o il mills. Fro m these mills, non edible industrial o ils such as acidic crude palm oil (ACPO) are being produced [3]. Low grade palm oil, which is usually rejected fro m palm oil refineries due to high free fatty acid (FFA) content of over 5% [4]. Pre-treat ment process for the reduction of the FFA, i.e. esterificat ion, is essential before transesterification [5]. Sulfuric acid and p -toulenesulfonic acid (PTSA) are the co mmon ho mogenous acid used for the

* Corresponding author. Tel.: +60-123002949; E-mail address: [email protected].

1876-6102 © 2014 Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Peer-review under responsibility of the Organizing Committee of ICAE2014 doi:10.1016/j.egypro.2014.12.295

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Adeeb Hayyan et al. / Energy Procedia 61 (2014) 2745 – 2749

esterification reaction [6,7]. While the common heterogeneous acids are ferric sulfate [8]. So lid Brønsted acid of amorphous carbon bearing SO3 H, COOH and phenolic OH groups [9]. New types of homogenous acids are introduced and used for biodiesel production such as ethanesulfonic acid and chromosulfuric acid [1, 10]. A super acid such as trifluoro methanesulfonic acid was us ed for biodiesel production fro m sludge palm oil (SPO) [11]. Perchlo ric acid is also considered as superacid and a relatively stable acid compared to hydrochloric acid and trifluoro methanesulfonic acid. There is no reported work on the application of perchloric acid for the reduction of FFA in an acidic raw material such as ACPO, therefore this study aimed to study the catalytic activity of this acid as well as reporting the optimum conditions. 2. Materials and chemicals ACPO was acquired fro m a local mill in the state of Selangor in Malaysia. Methanol, perch loric acid and potassium hydroxide (KOH) pellets all of laboratory grades were purchased fro m R&M Chemicals (Malaysia). 3. Methodol ogy In the present work, different dosages of perchloric acid were invest igated and a single factor optimization of the esterification experiments was observed. To facilitate ease of handling, the ACPO was heated in an oven at a temperature 70o C for one hour. The preheated ACPO was then transferred into a batch multi-un it reactor system with reflu x condenser for the esterification reaction using perchloric acid catalyst after which transesterification reaction using potassium hydro xide was carried out. The characteristics of ACPO were determined according to the Malaysian Palm O il Board (MPOB) Test Methods [12] wh ile the FFA co mposition was determined using GC/MS (Agilent Technologies 7890A gas chromatograph equipped with 5975C mass spectrometer). 4. Results and discussion Figure 1 shows the fatty acid compositions of ACPO, whereb y the saturated fatty acids is higher than that of unsaturated fatty. The fatty acid profile was almost similar to profile of crude palm o il reported by Hashim et al., (2010). The physical p roperties of ACPO are illustrated in Table 1, indicat ing that the oil is non-edible. The effect of the catalyst in any chemical reaction (e.g. esterificat ion reaction), is one of the most impo rtant factors that affect the efficiency of FFA conversion to FAME. The effect of perchlo ric acid in the reduction of the FFA content in ACPO is well illustrated in Figure 2. The acid has a good catalytic activity, rapid ly reducing FFA to 2.92% with only 0.25% catalyst. Perch loric acid has slightly lower catalytic act ivity co mpared to sulphuric acid and it is more stable co mpared to hydrochloric acid. In terms of cost perchloric acid is more expensive compared to sulphuric acid and hydrochloric acid due to limited industrial applications of perchloric acid. Figure 2 also shows that the optimu m catalyst dosage is 1%, and at this poin t, FFA can be reduced to 1.03% wh ile the FFA conversion remains almost constant. Theoretically, methylation requires one mole of methanol for each mole of FFA (Ding et al., 2012). Practically, mo re than 1 mo le is needed for an esterification reaction for FFA reduction in acidic oils such as ACPO. Figure 3 shows the effect of mo lar ratio on the reduction of FFA and conversion of FFA to FAME. Loading of 10:1 methanol to oil was enough to reduce the FFA content to 1%. Figure 4 clearly shows that the optimu m reaction temperature (60 o C) for the treat ment of A CPO. Figure 5 illustrated the effect of reaction time on the reduction of FFA and conversion of FFA to FAME. Results of Figure 5 indicated that that perchloric acid has high catalytic activity because 30 min was sufficient to reduce the FFA content to less that 1%. Hence, 30 min was selected as optimum reaction time for esterification reaction using perchloric acid.

Fatty acid content (%)


Fig.1. Fatty acid profile of ACPO Table 1: ACPO Characterization Parameters Free fatty acid, FFA (%)

ACPO 8.8

Peroxide value (ml mol/kg)

7.9

Moisture content (%)

1. 4

Iodine value, IV

52.5

Impurities (%)

0.06

Saponification value (mg KOH/g oil)

191

Ash (%)

0.015

Fig.2. Effect of perchloric dosage on the reduction of FFA and conversion of FFA to FAME

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Fig.3. Effect of molar ratio on the reduction of FFA and conversion of FFA to FAME

Fig.4. Effect of reaction temperature on the reduction of FFA and conversion of FFA to FAME

Fig.5. Effect of reaction time on the reduction of FFA and conversion of FFA to FAME


5. Conclusion The optimu m conditions for the pre -treat ment process were 1% (w/w) dosage of perchloric acid to ACPO, 10:1 M ratio, 60 o C temperature, 30 min reaction time and 300 rp m stirrer speed. The h ighest yield of biodiesel after transesterification and purificat ion processes was 76.62%, with 0.07% FFA and 96% ester content. The results showed that the FFA content of ACPO was reduced fro m 8.8% to 1% under the optimu m conditions, and the final product met the biodiesel international standard specifications, such as EN 14214 and ASTM D6751. Acknowledgements The authors would like exp ress their thanks to the University of Malaya HIR-M OHE (D000003-16001), Centre fo r Ion ic Liquids (UM CiL) and the Bright Sparks Program at the University of Malaya for their support of this research. References [1] Hayyan A, Mjalli FS, Hashim MA, Hayyan M, AlNashef IM. Conversion of free fatty acids in low grade crude palm oil to methyl esters for biodiesel production using chromosulfuric acid. Bulg Chem Commun 2013; 45: 394 – 399. [2] Hayyan A, Hashim MA, Hayyan M Mjalli FS, AlNashef IM. A novel ammonium based eutectic solvent for the treatment of free fatty acid and synthesis of biodiesel fuel. Ind Crops Products 2013;46:392–398. [3] Chuah, T. G., Wan Azlina A. G. K., Robiah Y., Omar R. Biomass as the renewable energy sources in Malaysia: An overview. Int J Green Energy 2006; 3:323–46. [4] Hayyan A, Mjalli FS, Hashim MA, Hayyan M, AlNashef IM, Al-Wahaibi T , Al-Wahaibi YM. A solid organic acid catalyst for the pretreatment of low-grade crude palm oil and biodiesel production. Int J Green Energy; 11: 129–140. [5] Canakci M. The potential of restaurant waste lipids as biodiesel feedstocks. Bioresour Technol 2007; 98 : 183–190. [6] Atadashi IM, Aroua MK, Abdul Aziz AR, Sulaiman NMN. The effects of catalysts in biodiesel production: A review. J Ind Eng Chem 2013; 19: 14-26. [7] Di Serio M, Tesser R, Pengmei L, Santacesaria E. Heterogenous catalyst for biodiesel product ion. Energy Fuels 2008; 22: 207– 217. [8] Mengyu GAN, Deng PAN, Li MA, En YUE, Jianbing HONG. The kinetics of the esterification of free fatty acids in waste cooking oil using Fe2(SO4)3/C Catalyst. Chinese J Chem Eng 2009; 17: 83-87. [9] Hara M. Biodiesel production by amorphous carbon bearing SO 3H, COOH and phenolic OH groups, a solid brønsted acid catalyst. Top Catal 2010; 53: 805–810. [10] Hayyan A, Mjalli FS, Hashim MA, Hayyan M, AlNashef IM, Al-Zahrani SM, Al-Saadi MA. Ethanesulfonic acid-based esterification of industrial acidic crude palm oil for biodiesel production. Bioresour T echnol 2011; 102: 9564 –9570. [11] Hayyan A, Hashim, MA, Mirghani MES, Hayyan M, AlNashef IM. Esterification of sludge palm oil using trifluoromethanesulfonic acid for preparation of biodiesel fuel. Korean J Chem Eng 2013; 30:1229-1234. [12] Kuntom A, Lin SW, Ai TY, Idris NA, Yusof M, Sue TT, Ibrahim NA. Malaysian Palm Oil Board (MPOB) Test Methods. MPOB, Bangi, Malaysia 2005.

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