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

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%.