Guidelines and cost analysis for catalyst production in biocatalytic processes

Biocatalysis is an emerging area of technology, and to date few reports have documented the economics of such processes. As it is a relatively new technology, many processes do not immediately fulfill the economic requirements for commercial operation. Hence, early-stage economic assessment could be a powerful tool to guide research and development activities in order to achieve commercial potential. This study discusses the cost contribution of the biocatalyst in processes that use isolated enzymes, immobilized enzymes, or whole cells to catalyze reactions leading to the production of chemicals. A methodology for rapidly estimating the production cost of the biocatalyst is presented, and examples of how the cost of the biocatalyst is affected by different parameters are given. In particular, it is seen that the fermentation yield in terms of final achievable cell concentration and expression level as well as the production scale are crucial for decreasing the total cost contribution of the biocatalyst. Moreover, it is clear that, based on initial process performance, the potential to reduce production costs by several orders of magnitude is possible. Guideline minimum productivities for a feasible process are suggested for different types of processes and products, based on typical values of biocatalyst and product costs. Such guidelines are dependent on the format of the biocatalyst (whole-cell, soluble enzyme, immobilized enzyme), as well as product market size and value. For example commodity chemicals require productivities in the range 2000−10000 kg product/kg immobilized enzyme, while pharmaceutical products only require productivities around 50−100 kg product/kg immobilized enzyme.