Preliminary Design of Bioethanol Process Plants

Anne Grydgaard and Camilla Berg. Department of Chemical and Biochemical Engineering, Technical University of Denmark, Soeltofts Plads, Building 229, Lyngby, DK-2800, Denmark

Lately the demand for ethanol utilized as a petrol additive for combustion engines has increased due to the escalating crude oil prices. It is thus desirable to produce ethanol from alternative renewable sources of raw materials such as corn, cereal and sugar or waste materials such as wood chips, straw, bagasse, manure. Organic matter provides a source of trapped and unutilized energy which can be exploited to supply the ever-increasing energy demand in the world.

The objective of this presentation proposal is to summarize the preliminary designs of process plants for production of bioethanol with a purity of 99 % or higher. The preliminary designs were carried out as part of a process design course at the Technical University of Denmark (DTU) in the spring 2008. The design project covers all aspects of the process design procedure from initial considerations regarding qualitative aspects of the flow sheet to detailed process simulations and economic evaluations. Base case designs were developed systematically using several known design models and procedures. Heat and mass integration and environmental impact analysis were performed in order to optimize the design. Feasible process flow sheets with unit operations were generated based on decisions made through design tools, which were later verified using commercial process simulators. Optimisation and derivation of heat recovery networks for the final processes are of importance for the design project and had a great influence on the economic feasibility of the final design. Specific features of interest regarding the development procedure will be highlighted in the presentation.