Integrating biomass gasification with pulp and paper production – systems analysis of economic performance and CO2 emissions

Biomass gasification offers several advantages; primarily the potential for higher electrical efficiency and the possibility to synthesise for example biofuels for transportation. Gasification based processes have a considerable surplus of heat that can be used in other processes in order to raise the overall efficiency. In this paper we study system aspects of integrating biomass gasification with a pulp and paper mill having a steam deficit, thus creating a biorefinery. Two different gasification concepts are considered: BIGCC (electricity production in biomass integrated gasification combined cycle) and BIGDME (biomass integrated gasification production of dimethyl ether, DME, for use as transportation fuel). Heat from the gasification processes replaces boiler steam in the pulp and paper mill. The systems analysis is made with respect to economic performance and global fossil CO2 emissions. As reference cases, BIGCC and BIGDME integrated with a district heating network are considered. The results show that in particular BIGCC can be economically profitable for the pulp and paper mill, with a calculated investment opportunity of 120-150 MEUR, but that the results are highly dependent on the assumed level of certificates promoting green electricity. For the BIGDME case the policy tools are of even larger importance. When strong policies promoting biofuels are assumed the investment opportunity is estimated at 300-330 MEUR, while there is no investment opportunity if no policies are in place. If BIGCC or BIGDME technologies are integrated instead with a district heating network, the investments only become profitable if the heat price is high and the annual heat delivery time is long (8000 hours). Biomass gasification has a larger CO2 reduction potential when integrated with a pulp and paper mill than when the mill and the gasification plant operate separately. The potential for the mill to implement biomass gasification as a means to reduce CO2 emissions is, however, uncertain and strongly dependent on the surrounding system