Ethanol from lignocellulosics: A review of the economy

The present study is a review of published investigations regarding the economy of ethanol production from lignocellulosic material. The objective is to present relations between and tendencies observed in different cost estimates. The influence of plant capacity and overall product yield on the ethanol production cost is investigated, as well as variations in capital costs in the different processes. The underlying technical and economic assumptions show a large variation between the various studies published. The variation in the ethanol production cost is large, from 18 to 151 US¢/l. The most important factor for the economic outcome is the overall ethanol yield. Other important parameters are the feedstock cost, which was found to vary between 22 and 61 US$/dry metric ton, and the plant capacity, which influences the capital cost. It is shown that there is a tendency towards a decrease in ethanol production cost with an increase in plant capacity for the enzymatic processes. A high yield also results in a decrease in production cost for the enzymatic and dilute acid processes in the papers reviewed.