Waste Management and Renmatix to explore conversion of urban waste to low-cost cellulosic sugar via supercritical hydrolysis

23 August 2012

Waste Management, Inc. and Renmatix, a manufacturer of biobased sugar intermediates for global chemical and fuel markets, have entered into a joint development agreement (JDA) to explore the feasibility of converting post-consumer waste into affordable, sufficient-quality sugars for manufacturing biobased materials using Renmatix’ supercritical hydrolysis technology. (Earlier post.)

The strategic investment and alliance aims to expand the feedstock flexibility of Renmatix’s proprietary Plantrose process beyond rural biomass to include materials derived from cost-effective and readily available urban waste material such as that managed by Waste Management. The JDA aims to determine how these materials can be reduced to sugar and leveraged for production of renewable chemicals and fuels.

This deal is the first-of-its-kind for Renmatix and is anticipated to generate immediate revenue for the company as it investigates viability of these new feedstocks. Under the agreement, Renmatix will explore multiple waste streams currently collected and processed by Waste Management and its service subsidiaries, including: source-separated recyclables, food scraps, construction and demolition debris, and pulp and paper waste.

The water-based Plantrose Process consists of two core steps:

• Fractionation of biomass and separation of the remaining solids which contain cellulose and lignin. The biomass first undergoes size reduction, as necessary, and is then conveyed to a storage silo. The stored solids are slurried with water and pumped and heated to reaction temperature and then fed to the fractionation reactor where the reaction takes place. The products from the fractionation reactor are then sent to solid/liquid filtration and stored.

• Cellulose hydrolysis of the pretreated solids under more severe conditions utilizing supercritical water as the primary solvent. The solids from the fractionation process consist predominantly of cellulose and lignin. These solids are sent to a blend tank where they are re-slurried by mixing with water and then pumped into the system at pressure and preheated. The preheated slurry is further treated with hot compressed water and undergoes a rapid reaction. The products from this reaction are then cooled and filtered. Remaining solids are clean, odorless, lignin.

Renmatix says that the relative ease of hydrolysis of the hemicelluloses compared to the recalcitrant cellulose necessitates this two-step process in order to preserve the C₅ sugars that would be rapidly destroyed under the more severe conditions necessary for cellulose dissolution.

Where necessary, the separate C₅ and C₆ soluble oligomer streams are transformed to monomers through a catalytic process. Renmatix has also developed processes to concentrate its produced sugars as necessary to meet specifications of different partners.

Renmatix’s demonstration facility in Kennesaw, Georgia can convert three dry tons of woody biomass to sugars daily.

One of the core cost advantages of Renmatix’s water-based process is its feedstock flexibility. Using very little consumables in rapid reactions, Renmatix can convert a variety of non-food biomass into sugars.