OLEOCHEMICALS
Despite the potential advantages of enzymatic processing in manufacturing oleochemicals, the process has not yet broken through into mainstream production. Chemical processing is the wellestablished route for oleochemical production globally and has proven its technical and economic feasibility on a large scale. However, the main drawback of chemical processing is its high energy consumption. The temperature of esterification/transesterification reactions, for example, ranges from 180-200°C. Such high temperatures darken the intermediate products and produce many unwanted by-products, so that many downstream treatment process steps are needed. Due to this, chemical technology has a high capital investment cost compared to an enzymatic-based plant. Enzymatic technology uses a mild temperature of about 60°C and allows a selective mechanism, which reduces the need for downstream process steps. As a result, the capital investment cost is lower. However, an existing manufacturer who already has a well-established conventional chemical process that works highly efficiently may not wish to convert existing conventional units. Working with enzymes requires special equipment and a different industrial set-up. Enzymatic 28 OFI – MARCH/APRIL 2022
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The enzymatic route Enzymatic technology offers a ‘green’ route to producing oleochemicals, with several companies already utilising the technology or on the verge of demonstration-scale production Ahmad Mustafa technology is therefore more attractive for new start-ups at the design and decision stage as the plant-based process costs about two-and-half times less than the chemical route. Another challenge associated with enzymatic production is the high cost of commercial enzymes and their deactivation if not treated correctly. The enzymatic process would be more profitable if the operational stability of enzymes is maintained for as long as possible. A minimum of two tonnes of product per 1kg of enzyme would maintain process profitability. However, even with improved enzyme operational stability, the cost of enzymes can never compare favourably with the cost of a chemical catalyst such as sodium hydroxide. The enzymatic process manufacturing cost will always be higher than the chemical process. Consequently, the higher manufacturing cost of the final product is reflected in the final product price. The question that needs to be asked is:
are customers ready to pay a premium for a ‘green’ product?
Green credentials
Recently, manufacturers have started publicising their utilisation of enzymatic technology to market their products. One such company is Evonik Industries, the first global manufacturer of biotechnologically-produced emollient esters. The company has been making myristyl myristate, decyl cocoate, cetyl ricinoleate and isocetyl palmitate using bioprocess enzymatic technology since 2008. Evonik emphasises the effectiveness and profitability of using this green technology in practical large-scale applications. These products are highly priced with high profit margins, meaning the cost of enzymes do not negatively affect profits. In addition, Evonik has dealt with the challenge of the high cost of enzymes by using a fixed-bed reactor with a circulation loop, through which the reaction charge u
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22/03/2022 09:33:43
