Sustainability Metrics Applied to the Cephalexin Processes

Alongside the development of technology and sustainability assessments as presented above, the assessments of the green process routes to Cephalexin were evaluated. Throughout the development of the enzymatic process, the projected advantages in costs for chemicals and environmental factors were confirmed. Major breakthroughs during the overall development period of 6-8 years were achieved in productivity and stability of the required biocatalysts, allowing space-time yields (kg/l/hr) equal or better than the traditional, fully optimized stoichiometric processes. In more general terms, the advantages of catalysis over stoichiometric processes were fully confirmed. Approval for the required investments, millions of dollars for the enzy­matic coupling and tens of million dollars for the direct biosynthesis of 7-ADCA, were in fact the most difficult hurdle. Given the stiff international competition, mainly stemming from India and China, short payback times for all investments were crucial. The bio-routes were implemented at plant scale in the period 1996-2001 and assessed for sustainability at their stable and robust performance in 2003. A compar­ison was made with the traditional routes at their top performance between 1990 and 1996. Data were taken from running plants in Europe and projected to a single site in The Netherlands, thus excluding transport costs. Assessments were done from ‘cradle to gate’, i. e. starting from the most basic sources for energy and materials and up to the drum of bulk active ingredient Cephalexin leaving the factory on its way to the customer for formulation and further distribution. To prevent any DSM bias, all assessments were done with the well-known independent Oko Institute for LCA (life cycle analysis) in Germany.

The spider’s web diagram in Figure 19.7 shows a clear picture of the profound advantages of biocatalysis over traditional stoichiometric chemistry. Improvements of over a factor 2 are achieved at every parameter, all related to the production of 1 kg of Cephalexin. Parameters are briefly discussed below. All parameters are normalized according to existing LCA standards (Oeko, 2004).

Sustainability Metrics Applied to the Cephalexin Processes

Energy consumption

Resources

consumption

Area use

Emissions

Toxicity potential

Risk potential

Figure 19.7 Sustainability assessment of Cephalexin processes: bio-based route vs stoichiometric chemistry as reference

Updated: December 18, 2015 — 7:59 am