Turning a pulp mill into a biorefinery - a possible outcome from the 2nd black liquor gasification program
Rikard Gebart
Luleå University of Technology ETC, Piteå
Abstract
The modern pulp mill has the potential to be transformed into a biorefinery that produces electrical power, fuels and valuable chemicals at competitive prices in addition to pulp and paper. Estimates that have been made for Sweden indicate that about 25% of the current use of gasoline and diesel can be replaced by synthetic fuels made from black liquor. Black liquor is a mixture of lignin and spent cooking chemicals and can be considered a "green" fuel since the lignin, and other organics in it, originate from biomass (wood), and all the cooking chemicals are recycled to the pulping process.
The key to these exciting new possibilities is pressurized black liquor gasification (PBLG). Techno-economical studies at Princeton and in Sweden have shown that both the power and transportation fuels production alternatives are economically competitive with current technologies, including fossil fuel based technology. Motivated by this potential, black liquor gasification is under intense development both in the US and in Sweden.
In Sweden a national research program on black liquor gasification, led by ETC, was started in 2001 and was expanded and extended first in 2004 and then again in 2007. The program is focusing on computer modeling of the process, detailed studies of the kinetics of carbon conversion and inorganic reactions, on corrosion of materials and finally on integration of the gasification process with the pulping process. In parallel with the research program a development plant with a 20 ton ds/day Chemrec gasifier has been built in Piteå, Sweden. The development plant is used for technical development and for long time testing of the process to make assessments of process reliability and material behaviour possible. The development plant is also used by the research program for full scale experiments and validation of computer models.
In 2008 a new EU-sponsored project, BioDME, was started. In this project the syngas from the Chemrec gasifier will be converted into 4 ton per day of DME and this fuel will be used by Volvo for long time testing of 14 heavy trucks that have been specially built for the BioDME project. The goal of this project is to demonstrate for the first time the whole chain from black liquor gasification to operation of heavy duty trucks on a synthetic "green" fuel.
Created 2009-02-23 12:06:18 by Mats Holmström Last changed 2009-02-23 20:36:56 by Mats Holmström
