Total site heat and mass integration and optimisation using P-graph: A biorefinery case study

Abstract

The aim of this paper is to solve total site heat and mass integration and optimisation using P-graph framework, with a biorefinery case study. Total site heat and mass integration is important for the selection of biorefinery processes because it must achieve high material and energy efficiency to be economically competitive. This paper considers co-location of simultaneous scarification and co-fermentation of wood, hydrothermal liquefaction of forest residues and gasification of black liquor with an existing Kraft pulp mill in Central North Island of New Zealand. Result shows that the Kraft pulp mill is the most profitable biorefinery option, followed by hydrothermal liquefaction. However, an increment in the price of bio-oil by 5 % puts hydrothermal liquefaction in the optimal network with Kraft pulp mill.