This activity provided the client with all technical, economic, mass balance and energy balance concerning biological conversion of plant materials (biomass) to ethanol for use as fuel. It was part of a larger project that also considered thermochemical conversion of biomass to liquid fuels. The model consisted of a series of modules that included raw materials, process description, processing costs, equipment costs, mass and energy flows through a series of steps, with outputs of one step becoming inputs of subsequent steps. These steps covered the production and fermentation of sugar solutions as well as the recovery of ethanol by distillation.

The processes modelled for production of sugar (hexose) solutions were diffusion of sugar beet, enzymatic hydrolysis of starch from wheat and both acid and enzyme (cellulase) hydrolysis of wood chips and straw. Fermentation processes included simple batch, cascade and cell recycle systems, based on brewers' yeast, with recovery using a three column still, with cyclohexane as entrainer in the dehydration step. Process design and equipment costs were based on commercial activities where possible. For lignocellulose hydrolysis they were based on proposals for full scale plant. By-products were variously given a positive value (animal feed, biogas) or a negative (disposal cost).