Optimization of Pyrolysis Operating Condition for Deriving Corn Starch Heterogeneous Acid Catalyst for Biodiesel Production

Herry Santoso,Maria Inggrid,Hillman Wira,Christ Michael

doi:10.5539/mas.v9n7p61

Abstract

Biodiesel can be produced from various oils and fats. Due to possibility of diversion of edible oils from feedstocks to raw materials for biodiesel production, which may lead to food crisis, it is preferable to choosenon-edible oils as raw material for biodiesel production. As a country rich in natural resources, Indonesia has avast amount and variety of non-edible fatty-oil production plants. However, non-edible oils usually have highfree fatty acid (FFA) contents. Oils with high FFA contents cannot be converted directly to biodiesel using aconventional alkaline catalyzed process due to saponification problem. To avoid this problem, the high FFAcontents in the oils must be reduced via esterification process using acid catalyst. The use of homogeneous acidcatalyst in this process can be very corrosive and not environmentally friendly while the use of commerciallyavailable heterogeneous acid catalyst can be very expensive. In this research, a heterogeneous acid catalystsuitable for biodiesel production will be derived from corn starch through pyrolysis followed by sulphonationprocesses. The purpose of this research is to study the effects of pyrolysis temperature and time to the aciddensity of the catalyst and the activity of the catalyst in the esterification of oleic acid using a 22 factorial designwith 3 center points experimental design. It is found that the catalyst obtained from pyrolysis at 400°C for 15hours has the optimum–HSO3 content of 5.9% which corresponds to the highest average conversion of theesterification of oleic acid of 97.45%.

Highlights

Biodiesel is an alternative fuel for diesel engine that can be produced by transesterification reaction of various plant and animal oils and fats with short-chain alcohols in the presence of a catalyst (Marchetti et al, 2007; Ibeto et al, 2011)
From the esterification reaction test, it is found that the catalyst obtained from pyrolysis at 400°C for 15 hours has the optimum –SO3H content of 5.9% which corresponds to the highest average conversion of the esterification of oleic acid of 97.45%
At a lower pyrolysis temperature, the carbonized material tends to form a soft aggregate of small polycyclic aromatic carbon with –SO3H group

Summary

Introduction

Biodiesel is an alternative fuel for diesel engine that can be produced by transesterification reaction of various plant and animal oils and fats with short-chain alcohols in the presence of a catalyst (Marchetti et al, 2007; Ibeto et al, 2011). As a country rich in natural resources, Indonesia has a vast amount and variety of non-edible fatty-oil production plants. Non-edible oils usually have high free fatty acid (FFA) contents (Mathiyazhagan et al, 2011). Oils with high FFA contents cannot be converted directly to biodiesel using a conventional alkaline catalyzed process due to saponification problem (Guo and Leung, 2003). To avoid this problem, the high FFA contents in the oils must be reduced via esterification process using acid catalyst (Wang et al, 2007;Van Gerpen and Knothe, 2005; Zhang et al, 2003)

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Conclusion