Techno-economics of carbon preserving butanol production using a combined fermentative and catalytic approach.

This paper presents a novel process for n-butanol production which combines a fermentation consuming carbon dioxide (succinic acid fermentation) with subsequent catalytic reduction steps to add hydrogen to form butanol. Process simulations in Aspen Plus have been the basis for the techno-economic analyses performed. The overall economy for the novel process cannot be justified, as production of succinic acid by fermentation is too costly. Though, succinic acid price is expected to drop drastically in a near future. By fully integrating the succinic acid fermentation with the catalytic conversion the need for costly recovery operations could be reduced. The hybrid process would need 22% less raw material than the butanol fermentation at a succinic acid fermentation yield of 0.7g/g substrate. Additionally, a carbon dioxide fixation of up to 13ktonnes could be achieved at a plant with an annual butanol production of 10ktonnes.

A novel process for recovery of fermentation-derived succinic acid: process design and economic analysis.

Recovery and purification of organic acids produced in fermentation constitutes a significant fraction of total production cost. In this paper, the design and economic analysis of a process to recover succinic acid (SA) via dissolution and acidification of succinate salts in ethanol, followed by reactive distillation to form succinate esters, is presented. Process simulation was performed for a range of plant capacities (13-55 million kg/yr SA) and SA fermentation titers (50-100 kg/m(3)). Economics were evaluated for a recovery system installed within an existing fermentation facility producing succinate salts at a cost of $0.66/kg SA. For a SA processing capacity of 54.9 million kg/yr and a titer of 100 kg/m(3) SA, the model predicts a capital investment of $75 million and a net processing cost of $1.85 per kg SA. Required selling price of diethyl succinate for a 30% annual return on investment is $1.57 per kg.

Today's and tomorrow's bio-based bulk chemicals from white biotechnology: a techno-economic analysis.

Little information is yet available on the economic viability of the production of bio-based bulk chemicals and intermediates from white biotechnology (WB). This paper details a methodology to systematically evaluate the techno-economic prospects of present and future production routes of bio-based bulk chemicals produced with WB. Current and future technology routes are evaluated for 15 products assuming prices of fermentable sugar between 70 euro/t and 400 euro/t and crude oil prices of US $25/barrel and US $50/barrel. The results are compared to current technology routes of petrochemical equivalents. For current state-of-the-art WB processes and a crude oil price of US $25/barrel, WB-based ethanol, 1,3-propanediol, polytrimethylene terephthalate and succinic acid are economically viable. Only three WB products are economically not viable for future technology: acetic acid, ethylene and PLA. Future-technology ethylene and PLA become economically viable for a higher crude oil price (US $50/barrel). Production costs plus profits of WB products decrease by 20-50% when changing from current to future technology for a crude oil price of US $25 per barrel and across all sugar prices. Technological progress in WB can thus contribute significantly to improved economic viability of WB products. A large-scale introduction of WB-based production of economically viable bulk chemicals would therefore be desirable if the environmental impacts are smaller than those of current petrochemical production routes.