American Process Incorporated (API) recently launched a waste-to-cellulosic ethanol biorefinery project in Alpena, Michigan. API is one of Michigan’s bioenergy Centers of Energy Excellence (COEE).
In November 2008, API, in partnership with San Antonio’s Valero Energy Corporation, received $4 million from the COEE program to establish a pilot scale biorefinery at the Decorative Panels International hardwood plant in Alpena. The biorefinery will convert the process waste effluent from the plant into cellulosic ethanol, sodium acetate and clean, warm water. The project has potential to be replicated across the state in other biorefineries, pulp and paper mills, and food and agricultural processing plants.
Michigan Technical University will contribute research to improve fermentation processes and also on the use of sodium acetate for novel de-icing applications.
The $4 million in COEE funding to API helped secure a US Department of Energy (DOE) grant for $17.9 million. API has invested $10 million in the project and estimates that replication across Michigan in existing industries alone could create annual economic value of $200 million within 10 years.
API developed a proprietary process—AVAP (American Value Added Pulping)—to co-produce pulp and ethanol from wood in an integrated biorefinery application. AVAP utilizes alcohol sulfite cooking liquor to fractionate softwood chips into three lignocellulosic components. An addition of alcohol speeds the pulping, while preserving the cellulose strength.
Volatile cooking chemicals are stripped and reused in the cooking process at a high recovery rate. Lignosulfonates are precipitated and burned to produce process energy. The remaining liquid fraction contains hydrolyzed hemicelluloses. The value of converted hemicelluloses is 4-5 times greater for society as ethanol than as presently burned, the company says. Biomass from the surrounding wood processing plants as well as logging residues can provide energy self-sufficiency for the mill.
Because ethanol processing occurs concurrently with pulping, the heat and chemical input are split between the two products, without sacrificing the yield on either product. Flexibility to swing yield between the two products provides financial stability over the market conditions, according to API. Additional biofuels and chemicals are obtainable from the process if the economics are favorable.
API’ GREEN POWER+ utilizes a module in front of the biomass boiler that utilizes steam extract hydrolyzate as feedstock and an ethanol extraction module. Dewatered solids are then returned to the biomass boiler. The process significantly increases overall profitability by converting low BTU hemicelluloses into high value ethanol.
The process enables cost-effective cellulosic ethanol production at a small scale of 10-20 MMUSG/year, with an ethanol production cost ~$1/USG, according to API.
Key success factors of this process are the cost effective treatment of the extract, being able to return consistent biomass composition to the boiler with uninterrupted operation, and an effective energy integration of ethanol production with biopower.
This technology is applicable not only in the pulp and paper industry, but also for biomass power stations in utilities and any industry employing biomass boilers for power production.