Enzymatic Process for Biodiesel and High Value-Added Products

George Chou

Abstract An enzymatic biodiesel process can not only overcome the challenges faced by conventional chemical processes but also pave the way for versatile products to be coproduced from the same feedstock source. However, this is only possible and cost-effective through the right enzymatic process. This paper intro­duces a patented process that can meet these criteria, the ET Process®. Unlike before, biodiesel can now be produced in a very environmentally friendly manner. However, in order to maintain competitive commodity pricing without subsidies, oil feedstock cost should be lowered, i. e., allowing the direct use of oil with high free fatty acid content, and the process should be integrated so that different high value — added co-products can be produced. To be sustainable and profitable, optimal utili­zation of feedstock source should be taken into account. New processing configurations are illustrated using crude palm oil and coconut oil as examples.

Keywords Biodiesel • Free fatty acids • Feedstock • Enzymes

11.1 Introduction

Although the biodiesel industry has developed into a major pillar for liquid biofuel commodity, it still relies on commercial chemical approaches, such as those using acid and base catalyses, which are not entirely efficient or cost-effective. These types of technologies are known to face many process and environmental problems. For example, the free fatty acid (FFA) content allowable in the feedstock cannot exceed 1 wt% and the moisture level is likewise restricted to low levels. If the FFA level is high, such as the case with low-quality feedstock, then it needs to be removed or the system is preceded by an acid process to reduce FFA level enough for it to be

G. Chou (H)

Sunho Biodiesel Corporation, Taipei, Taiwan e-mail: gc@sunhobiodiesel. com

R. Pogaku and R. Hj. Sarbatly (eds.), Advances in Biofuels, 179

DOI 10.1007/978-1-4614-6249-1_11, © Springer Science+Business Media New York 2013

processed by base catalysis. Refining or addition of an acid process both contribute to increased final product cost. Because it is a slow process, a separate acid catalysis system is not economically feasible to set up given the high capital investment needed to convert, say, only 10-25% FFA in the feedstock. Other related problems are the significant amount of wastewater produced, chemical disposal and low qual­ity of glycerol co-product. The result is an unavoidably high product cost, with which it cannot survive unless subsidies are present. A more long-term solution is therefore necessary.

From a business point of view, the biodiesel industry has two options to increase survival: one is to cut costs and the other is to increase profits through co-production. It is not as easy to achieve either of these using the conventional chemical approach. This is due to the very nature of the chemical approach itself. In contrast, an enzy­matic approach has specific and clean reactions that could address the issues mentioned.

Biodiesel is primarily a commodity product and must therefore maintain low or competitive pricing. Normally, the biodiesel market competes with diesel derived from crude oil. To lower costs, it is necessary to use a low-cost feedstock, which generally pertains to feedstock with high FFA content. Alternatively, depending on the feedstock used, price can be balanced off by profit from co-products. To increase profit from a biodiesel plant, the system design can be integrated to develop multi­ple products, including high value-added ones, technical or pharmaceutical grade glycerol, phytochemicals and nutrients. It allows the biodiesel plant to produce maximum profit at the lowest cost possible.