FROM KRAFT MILLS TO FOREST BIOREFINERY: AN ENERGY AND WATER PERSPECTIVE. I. METHODOLOGY

摘要

The conversion of a Kraft mill into a forest biorefinery increases the demands for water and energy, while the optimization of such utility systems is of paramount importance for the profitability of a Kraft-based biorefinery. This paper is the first part of a more extensive work undertaken to evaluate the energy impacts of a Kraft pulp mill conversion into a biorefinery. Thus, Part I presents the methodology developed to identify the complex interactions between steam and water systems, and the process for determining their impacts on the implementation of energy efficiency measures. This methodology has been illustrated by its application to an operating Kraft mill situated in Eastern Canada. Several energy enhancing techniques, such as internal heat recovery, water reutilization, elimination of non-isothermal mixing and energy upgrading and conversion have been considered. The steam and water savings achieved will allow the conversion of the mill into a green biorefinery requiring no substantial increments of the energy demand and no fossil fuel. In Part II, the process of hemicellulose extraction and conversion for the production of furfural, xylitol and ethanol is presented.