Enzymatic synthesis of acrylates. Catalyst properties and development of process and product

• Main Author: Nordblad, Mathias
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Department of Biotechnology, Lund University 2008
• Subjects: Industrial Biotechnology; enzyme kinetics; process development; enzyme stability; enzyme immobilisation; acrylation; lipase; Endeavour; Antarc*; Antarctica
• Online Access: https://lup.lub.lu.se/record/1241035

The increasingly apparent environmental problems in our surroundings necessitate a quest for sustainable development in all areas of human endeavour. Within the field of chemistry and the production of chemicals, the focus is increasingly on the development of green chemistry. This discipline aims to reduce environmental impact by replacing petrochemical raw materials with renewable feedstock and also to increase the efficiency of chemical processes. The latter can be done by reducing energy use and by improving atom economy, i.e. to ensure that as much as possible of the used raw materials end up in the final product. Acrylates are highly reactive compounds, with applications in many areas. This work has focused on developing a process for the production of acrylates that can be used as UV-curing wood coatings, where these products have been shown to be highly efficient from an environmental point of view. The traditional process for making acrylates is relatively complex and requires lower reaction temperatures than are ideal for chemical catalysis. Enzymes, on the other hand, are ideally suited for such conditions. The use of lipases for acrylation reactions has previously been the subject of relatively little scientific research and a large part of this thesis has therefore been devoted to the catalytic function of the enzyme used in these reactions, Candida antarctica lipase B (CalB). It was found that because the chemical structure of acrylic compounds is different from that of ordinary fatty acids, they were relatively poor substrates for CalB. The results presented in this work indicate that the binding of acrylic substrates in the active site of the enzyme is inhibited both by linear alcohols (octanol) and by water present in the system. Furthermore, acrylic acid is shown to be a potent inhibitor of CalB, which makes this enzyme more suitable for transesterification reactions. Very high catalytic rates were achieved at dry, solvent-free conditions with ethyl acrylate in excess. CalB is commercially ...