Towards continuous enzyme-catalysed processes for the production of biodiesel

The application of lipases in the production of biodiesel can find several roles: in pretreating high FFA oils via esterification, transesterification for converting oil to biodiesel and polishing via esterification to ensure the product is within specification. In all these cases the potential size of the process plants, suggest that continuous operation would be highly beneficial due to the economies of scale.

To investigate this, we have examined both oil pretreatment via esterification and biodiesel production via transesterification in batch stirred tank reactors (BSTRs), continuous stirred tank reactors (CSTRs) and continuous packed bed reactors (CPBRs). In addition comparisons have been made between the use of liquid enzyme (in CSTR and BSTR) and immobilized enzyme (in BSTR, CSTR and CPBR) in transesterification reactions.

In this presentation an evaluation will be given of the alternative modes of operation based on experimental and modeled data from laboratory scale studies. Implications for scale-up will be discussed, together with guidelines for the implementation of continuous processes for enzymatic reactions.