Chemrec’s pulp mill-integrated BioDME (dimethyl ether) biorefinery demonstration plant project will break ground in September in Pitea, Sweden, with expected biofuel production by mid-2010, according to Chemrec CEO Richard J. LeBlanc
The project will demonstrate the production of an advanced diesel fuel, DME, from forest biomass over the black liquor route and will also demonstrate the use of this fuel in heavy vehicles in commercial service. This demonstration plant is a continuation of demonstration-scale plants designed by Chemrec to yield green fuels and green chemicals.
In June, Chemrec announced that its DP-1 black liquor gasification development plant, also in Pitea, had reached 10,000 accumulated operating hours. This plant is the only gasification plant in the world producing high-quality synthesis gas, from which DME and other biofuels can be produced, based totally on renewable woody biomass feedstock.
“The Chemrec BioDME project will not only be a technical demonstration but will also showcase the opportunity for the pulp and paper industry to play a major role in the production of high-value, high-performance biofuels from low quality forest and agricultural residues,” LeBlanc said.
“It is the proven capability of the Chemrec process and its advantages to the paper industry that has attracted the attention of mill owners, investors and state governments in the U.S. and who want to bring this technology to their states,” LeBlanc added.
Around the world DME is becoming widely recognized as a superior ultra-clean biofuel, and its global production capacity based on fossil feedstock is rapidly expanding. The primary use of DME today is as a liquefied petroleum gas (LPG) substitute, yet DME use as an advanced diesel fuel is also being developed. With a high cetane number (the measure of combustion of diesel fuel under compression) and with no particle formation during combustion, DME provides the opportunity to very cost-efficiently meet stringent exhaust emission targets.
Unlike convention DME produced from fossil-based feedstocks, the Chemrec BioDME is produced from residual forestry biomass over the black liquor gasification route. BioDME offers a very high reduction of fossil carbon dioxide emissions — around 95% — compared to conventional diesel fuel, and it can be produced with very high conversion efficiency at relatively moderate capital cost. Several diesel truck and bus manufacturers have operated DME-fueled prototype vehicles, and pre-series production is imminent.
Swedish truck manufacturer AB Volvo, in a biofuels study, showed that the production of DME from harvest forestry woody biomass using the black liquor gasification process yields the highest miles per acre per year than biofuels produced by most other processes. Other studies show that the technology also yields the highest well-to-wheel greenhouse gas reduction and energy efficiency.
The Chemrec gasification process in the BioDME demonstration plant will combine two objectives — production of green liquor from black liquor and upgrade of the organic part of the black liquor to synthesis gas. Also primary gas cleaning and cooling takes place here. The Chemrec DP-1 gasifier plant will be used for this service. Carbon conversion and sulfate reduction in this process is near 100%. Syngas tar and methane content is very low, eliminating in biomass gasification the common need for secondary tar and methane reforming.
Another advantage of this process over conventional DME processes is the flexible distillation system. The separation process in the BioDME pilot contains more separation columns than the commercially available DME separation schemes. This feature comes at a cost but also gives DME with a higher purity and allows the co-production of methanol if desired.
The gas treatment step of the plant rejects carbon dioxide at high concentration. The process is therefore also very suitable to combine with carbon capture and sequestration (CCS). With renewable feedstock the produced biofuel will then have a carbon footprint less than zero.
“The potential of our technology to transform pulp mills into biorefineries is good news for the paper industry, which is struggling today against foreign competitors and the overall reduction in demand for paper products,” LeBlanc said. “Biorefinery mills not only will continue to produce pulp but will have a second revenue stream — high value, renewable green fuels and green chemicals for which the demand is steadily growing.”
To facilitate its ability to ramp-up commercial scale black liquor gasification biorefineries at U.S. pulp mills, Chemrec is actively pursuing federal and state grants and loan guarantees.