Utilization of Scallop Waste Shell for Biodiesel Production from Palm ...

Available online at www.sciencedirect.com

ScienceDirect APCBEE Procedia 8 (2014) 216 – 221

2013 4th International Conference on Agriculture and Animal Science (CAAS 2013) 2013 3rd International Conference on Asia Agriculture and Animal (ICAAA 2013)

Utilization of Scallop Waste Shell for Biodiesel Production from Palm Oil - Optimization Using Taguchi Method Achanai Buasri,, Phatsakon Worawanitchaphong, Sarinthip Trongyong, Vorrada Loryuenyong Department of Materials Science and Engineering, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom 73000, Thailand

Abstract The optimization of experimental parameters, such as reaction time, reaction temperature, methanol/oil molar ratio and catalyst loading, on the transesterification for the production of biodiesel has been studied. A Taguchi L9 (34) orthogonal array was used to evaluate the factors affecting the conversion of palm oil to fatty acid methyl ester (FAME). The scallop waste shell was calcined at 1,000 flC for 4 h and catalyst characterizations were carried out by XRD, XRF, SEM, and BET surface area measurements. Under the optimal reaction conditions of 10 wt.% of catalyst, 9:1 methanol/oil molar ratio and at a temperature of 65 flC, the FAME conversion was 95.44% and it was achieved in 3 h. It was found that the scallop waste shell catalyst shows high catalytic activity and ecologically friendly properties, having the potential opportunity to be used in biodiesel production process as heterogeneous base catalyst. © Authors. Published by Elsevier B.V. This and/or is an open access articleunder under responsibility the CC BY-NC-ND license © 2014 2013The Published by Elsevier B.V. Selection peer review of Asia-Pacific (http://creativecommons.org/licenses/by-nc-nd/3.0/). Chemical, Biological & Environmental Engineering Society Selection and peer review under responsibility of Asia-Pacific Chemical, Biological & Environmental Engineering Society Keywords: Biodiesel, Scallop Waste Shell, Renewable Catalyst, Transesterification, Taguchi Method

1. Introduction Depleting supplies of fossil fuel and increasing environmental concerns have stimulated the intense search for alternative renewable fuels that are capable of fulfilling an increasing energy demand [1]. Biodiesel is receiving increasing attention as an environmentally friendly and renewable alternative for the petroleum , Corresponding author. Tel.: 66 34 219363; fax: 66 34 219363. E-mail address: [email protected].

2212-6708 © 2014 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/). Selection and peer review under responsibility of Asia-Pacific Chemical, Biological & Environmental Engineering Society doi:10.1016/j.apcbee.2014.03.030

Achanai Buasri et al. / APCBEE Procedia 8 (2014) 216 – 221

based diesel fuel [2]. Biodiesel is chemically a fatty acid methyl ester (FAME) and can be produced from a direct transesterification of vegetable oils and animal fats, where the corresponding triglycerides (TG) react with methanol in the presence of a catalyst forming glycerol as a by-product [3]. The cetane number, flash point and lubricity of biodiesel are better than those of petroleum diesel [4]. The transesterification for the production of biodiesel using homogeneous catalysts requires several refining processes such as neutralization with acids. The formation of soap leads to difficulties in separating of the FAME from the reaction mixture [5]. The homogeneous catalytic process provides some disadvantages, such as, a huge production of wastewater from washing process of catalyst residues and nonreusability of the catalysts [6]. Heterogeneous catalysts have their own advantages: reusability, simpler operational procedures, easier catalyst, product separation, reduction in the amount of wastewater produced, and they are not very sensitive to water [7]. Extensive research has been carried out throughout the years in order to find the most cost-effective and sustainable heterogeneous catalyst. Calcium oxide (CaO) is one of the catalysts that are widely accepted as an excellent source of heterogeneous based catalyst [8]. However, the utilization of waste materials as heterogeneous catalysts has been of recent interest in the search for a sustainable process [9]. Along the seashore of Thailand, many marine product manufacturers and a large number of restaurants discharge scallop shell as a waste and pay for the treatment of the waste. Most of them are dumped into landfill [10]. A large amount of scallop waste shells, with main composition of approximately 98 wt.% CaCO3, 0.79 wt.% MgCO3 and 0.15 wt.% SrCO3, are discarded in the eastern and southern Thailand regions [11]. The objective of this paper is to demonstrate that the calcined scallop waste shell can be used as a catalyst in the production of biodiesel from palm oil. The Taguchi method was adopted as the experimental design methodology, which was adequate for understanding the effects of the control parameters and to optimize the experimental conditions from a limited number of experiments [12]. The effects of reaction time, reaction temperature, methanol/oil molar ratio and catalyst loading were systematically investigated. 2. Experimental 2.1. Materials Scallop waste shell (5 kg) was collected from university cafeterias in Nakhon Pathom, western Thailand. All reagents were reagent grade and used as received. Palm oil was purchased from Morakot Industries Public Company Limited (Thailand). The molecular weight and density of the oil were measured to be 851.06 g/mole and 0.868 g/cm3, respectively. 2.2. Catalyst Preparation and Characterization The scallop waste shell was cleaned by washing thoroughly with warm water several times. Then it was dried overnight in an oven at 80 flC. Crushed and powdered shells were then sieved (38-75 om) before being subjected to heat treatment in a furnace [9]. The dried waste shell was calcined at 1,000 flC in air atmosphere with a heating rate of 10 flC/min for 4 h. Fig. 1 illustrated the preparation process of scallop waste shellderived catalyst. The X-ray diffraction (XRD) characterization of the scallop waste shell-derived catalyst was performed on a Rigaku (MiniFlex II, England) based generator X-ray diffractometer using CuKα radiation over a 2θ range from 25fl to 125fl with a step size of 0.04fl at a scanning speed of 3fl/min. The elemental chemical compositions of the material were analyzed by X-ray fluorescence spectroscopy (XRF - Oxford, ED-2000, England) under energy dispersive mode for precise measurement of both light and heavy elements [13]. The microstructure of the calcined waste shell was observed by a scanning electron microscope (SEM). The SEM

217

218


image of the representative sample was obtained from a Camscan-MX 2000 (England) equipped with an energy dispersive spectroscope (EDS). To evaluate the surface area, mean pore diameter and pore volume, adsorption-desorption of nitrogen (N2) at 77 K was carried out by a Quantachrome Instrument (Autosorb-1 Model No. ASIMP.VP4, USA). The surface area was calculated using the Brunauer-Emmett-Teller (BET) equation and the mean pore diameter and pore volume was obtained by applying the Barret-Joyner-Halenda (BJH) method on the desorption branch [14].

Methanol

Palm oil

Scallop shell

Calcined shell

CaO catalyst

1,000 qC

4h

Catalyst Fig. 1. Preparation of CaO catalyst derived from scallop waste shell (1,000 flC)

2.3. Reaction Procedure and Taguchi Method Transesterification was carried out in laboratory scale in a 500 mL round bottom three neck flask equipped with a water cooled condenser and a constant temperature magnetic stirrer with hot plate. After the reaction, the catalyst was separated from the biodiesel product by centrifugation and the excessive amount of methanol was evaporated under reduced pressure in a rotary evaporator [15]. The design of experiment used a statistical technique to investigate the effects of various parameters included in experimental study and to determine their optimal combination. The design of the experiment via the Taguchi method uses a set of orthogonal arrays for performing of the fewest experiments [12]. The Taguchi approach is used for the process optimization of transesterification. Taguchi’s method has become increasingly popular for developing engineered products [16]. A Taguchi L9 (34) orthogonal array was used to evaluate the factors affecting the conversion of TG to FAME [17]. The main effects of four factors were investigated: reaction time, reaction temperature, methanol/oil molar ratio and catalyst loading. The three levels selected for each of the factors were 3, 4 and 5 h for reaction time; 60, 65 and 70 flC for reaction temperature; 6, 9 and 12 for methanol/oil molar ratio and 8, 10 and 12 wt.% for catalyst loading. 3. Results and Discussion The peaks for calcined waste shell at 1,000 °C appeared at 2θ = 32.26, 37.34, 53.80, 64.40, 67.65, 78.56, 90.11, 92.43, 104.58 and 111.82 in Fig. 2, which were the characteristic peaks for CaO. This confirmed the formation of CaO at a calcination temperature of 800-1,000 °C [15]. In addition, with the increase in activation temperature, CaCO3 completely transforms to CaO by evolving the CO2 [9]. The calcined waste shells were irregular in shape, and some of them bonded together as aggregates. However, the smaller size of the grains and aggregates could provide higher specific surface areas [6]. The chemical compositions of the catalyst were characterized by XRF. The major mineralogical component is CaO. The scallop waste shell-


Intensity

derived catalyst has concentration of 97.53 wt.% CaO, 1.57 wt.% SO3 and 0.57 wt.% Na2O. The CaO catalyst had a large surface area (74.96 m2/g), pore volume (0.097 cm3/g) and mean pore diameter 30.55 (A°), and presented a uniform pore size. It can be seen that the heterogeneous catalyst resulted in a strong increase in the active sites [2].

10

20

30

40

50

60

70

80

90

2-Theta (degree)

Fig. 2. XRD pattern and SEM image of scallop waste shell calcined at 1,000 flC

Reaction time (t), reaction temperature (T), catalyst loading (C) and methanol/oil molar ratio (R) were selected as independent variables [17]. The levels of independent variables determined from preliminary experiments are given in Table 1. With a three-level-four-factor array, L9 (34), nine experiments were required as shown in Table 2. The conditions of experiment were chosen as the optimal conditions for biodiesel production process [18]. Table 1. Independent variables and levels of L9 (34) for Taguchi method Parameters

Symbol

Reaction time (h) Reaction temperature (oC) Catalyst loading (wt.%) Methanol/oil molar ratio

t T C R

1 3 60 8 6

Level 2 4 65 10 9

3 5 70 12 12

Table 2. Taguchi experiments for determining the optimal conditions for biodiesel production process No. 1 2 3 4 5 6 7 8 9

t 1 1 1 2 2 2 3 3 3

T 1 2 3 1 2 3 1 2 3

C 1 2 3 2 3 1 3 1 2

R 1 2 3 2 1 3 2 3 1

Conversion (%) 88.56 95.44 96.41 88.79 90.94 89.83 87.14 93.37 93.97

4. Conclusion The conversion of TG was 95.44%, at the reaction time of 3 h, reaction temperature of 65 °C, CaO catalyst amount of 10 wt.% and methanol/oil molar ratio 9. A range of conditions were established that would produce a high-quality product of considered to be a more economic solution. The catalyst performed equally well as

219

220


the laboratory-grade CaO. Scallop waste shell is therefore a useful raw material for the production of a cheap catalyst for transesterification. Calcination of the catalyst derived from the waste shell resulted in an increase in surface area, leading to better catalytic activity. The final product is a light brown material, meeting the requirements of the Thai biodiesel standard.

Acknowledgements The authors acknowledge sincerely the Department of Materials Science and Engineering (MATSE), Faculty of Engineering and Industrial Technology, Silpakorn University (SU) for supporting and encouraging this investigation.

References [1] Yang L, Zhang A, Zheng X. Shrimp shell catalyst for biodiesel production. Energy Fuels 2009;23:3859–65. [2] Buasri A, Chaiyut N, Loryuenyong V, Rodklum C, Chaikwan T, Kumphan N, Jadee K, Klinklom P, Wittayarounayut W. Transesterification of waste frying oil for synthesizing biodiesel by KOH supported on coconut shell activated carbon in packed bed reactor. Sci. Asia 2012;38:283–8. [3] Roschat W, Kacha M, Yoosuk B, Sudyoadsuk T, Promarak V. Biodiesel production based on heterogeneous process catalyzed by solid waste coral fragment. Fuel 2012;98:194–202. [4] Buasri A, Ksapabutr B, Panapoy M, Chaiyut N. Biodiesel production from waste cooking palm oil using calcium oxide supported on activated carbon as catalyst in a fixed bed reactor. Korean J. Chem. Eng. 2012;29:1708–12. [5] Obadiah A, Swaroopa GA, Kumar SV, Jeganathan KR, Ramasubbu A. Biodiesel production from Palm oil using calcined waste animal bone as catalyst. Bioresour. Technol. 2012;116:512–6. [6] Viriya-empikul N, Krasae P, Nualpaeng W, Yoosuk B, Faungnawakij K. Biodiesel production over Ca-based solid catalysts derived from industrial wastes. Fuel 2012;92:239–44. [7] Boey PL, Maniam GP, Hamid SA. Biodiesel production via transesterification of palm olein using waste mud crab (Scylla serrata) shell as a heterogeneous catalyst. Bioresour. Technol. 2009;100:6362–8. [8] Boey PL, Ganesan S, Maniam GP, Khairuddean M. Catalysts derived from waste sources in the production of biodiesel using waste cooking oil. Catal. Today 2012;190:117–21. [9] Boey PL, Maniam GP, Hamid SA, Ali DMH. Utilization of waste cockle shell (Anadara granosa) in biodiesel production from palm olein: Optimization using response surface methodology. Fuel 2011;90:2353–8. [10] Yeom SH, Jung KY. Recycling wasted scallop shell as an adsorbent for the removal of phosphate. J. Ind. Eng. Chem. 2009;15:40–4. [11] Guan G, Chen G, Kasai Y, Lim EWC, Hao X, Kaewpanha M, Abuliti A, Fushimi C, Tsutsumi A. Catalytic steam reforming of biomass tar over iron- or nickel-based catalyst supported on calcined scallop shell. Appl. Catal., B. 2012;115–6:159– 68. [12] Kim S, Yim B, Park Y. Application of Taguchi experimental design for the optimization of effective parameters on the rapeseed methyl ester production. Environ. Eng. Res. 2010;15(3):129–34. [13] Buasri A, Chaiyut N, Loryuenyong V, Wongweang C, Khamsrisuk S. Application of eggshell wastes as a heterogeneous catalyst for biodiesel production. Sust. Energ. 2013;1(2):7–13. [14] Alba-Rubio AC, Vila F, Alonso DM, Ojeda M, Mariscal R, Granados ML. Deactivation of organosulfonic acid functionalized silica catalysts during biodiesel synthesis. Appl. Catal., B. 2010;95:279–87. [15] Boro J, Thakur AJ, Deka D. Solid oxide derived from waste shells of Turbonilla striatula as a renewable catalyst for biodiesel production. Fuel Process. Technol. 2011;92:2061–7. [16] Karabas H. Biodiesel production from crude acorn (Quercus frainetto L.) kernel oil: An optimisation process using the Taguchi method. Renew. Energy 2010;35:283–7.


[17] Buasri A, Chaiyut N, Ketlekha P, Mongkolwatee W, Boonrawd S. Biodiesel production from crude palm oil with a high content of free fatty acids and fuel properties. CMU J. Nat. Sci. 2009;8:115–24. [18] Chongkhong S, Tongurai C, Chetpattananondh P, Bunyakan C. Biodiesel production by esterification of palm fatty acid distillate. Biomass Bioenerg. 2007;31:563–8.

221