Environmental assessment of enzyme use in industrial production – a literature review

Enzymatic processes have been implemented in a broad range of industries in recent decades because they are specific, fast in action and often save raw materials, energy, chemicals and/or water compared to conventional processes. A number of comparative environmental assessment studies have been conducted in the past 15 years to investigate whether these properties of enzymatic processes lead to environmental improvements and assess whether they could play a role in moving toward cleaner industrial production. The purpose of this review is to summarize and discuss the findings of these studies and to recommend further developments regarding environmental assessment and implementation of the technology. Life Cycle Assessment (LCA) has been widely used as an assessment tool, while use of the ‘carbon footprint’ concept and Environmental Impact Assessment (EIA) is limited to a few studies. Many studies have addressed global warming as an indicator and several studies have furthermore addressed other impact categories (acidification, eutrophication, photochemical ozone formation, energy and land use). The results show that implementing enzymatic processes in place of conventional processes generally results in a reduced contribution to global warming and also a reduced contribution to acidification, eutrophication, photochemical ozone formation and energy use to the extent that this has been investigated. Agricultural land has been addressed in few studies and land use savings appear to occur in industries where enzymatic processes save agricultural raw materials, whereas it becomes a trade-off in processes where only fossil fuels and/or inorganic chemicals are saved. Agricultural land use appears to be justified by other considerable environmental improvements in the latter cases, and the results of this review support the hypothesis that enzyme technology is a promising means of moving toward cleaner industrial production. LCA gives a more complete picture of the environmental properties of the processes considered than EIA and carbon footprint studies, and it is recommended that researchers move toward LCA in future studies. Tradition, lack of knowledge and bureaucracy are barriers to implementation of enzymatic processes in industry. Education and streamlining of public approval processes etc. are means of overcoming the barriers and accelerating the harvesting of the environmental benefits.