MSU Technologies

Using Ammonia Treatment to Make Biomass Pellets

Introduction

Cellulosic biomass is not dense enough to be transported economically over long distances. The treated biomass must be compressed to increase its density. However, when compressed, the biomass tends not to bind sufficiently. Additionally, current additives used to increase binding characteristics of the biomass are expensive.

Description of Technology

Michigan State University’s invention allows for the inexpensive binding of cellulosic biomass. This invention adds value to the Gaseous Ammonia Pretreatment (GAP) process (090068) developed by the inventor. It allows GAP treated biomass to be conveniently made into pellets for transport, storage, and animal feed operations. The binding properties of the ammonia-treated biomass provide improved cohesion without the addition of external binding agents.

When the pressure is released in the GAP process, dissolved components such as lignin migrate to the surface of the biomass where they are deposited as the ammonia evaporates. Thus, a natural adhesive layer is produced that can bind with other biomass to form dense pellets useful for animal feed, biofuel production, or to bind other solids such as particles of coal for use as boiler fuels for the electric power industry.

Key Benefits

Less costly approach: The binding of treated biomass due to naturally occurring compounds such as lignin and hemicellulose saves the cost of adding external binding agents, which are required by other approaches and increase the cost of forming the biomass into pellets for various uses.
Improved storage and distribution of treated biomass: Biomass briquettes produced using this invention are stable, if kept dry, and should exhibit roughly the same storage and handling properties as corn grain. Therefore, much, if not all, of the existing infrastructure for corn grain storage and distribution should be useable for these briquettes.
Variety of potential applications: GAP treated biomass is likely to be a good ruminant animal feed, a good biofuel, and possibly could provide cheaper building materials.

Applications