Tuesday, January 03, 2012

Cheap Cellulosic Sugars Re-Shape Future Fuels and Chemicals

Industrial sugars are important renewable resources for the chemical industry and can be used, for example, to produce biofuels or basic chemical products and intermediates by fermentative processes.The availability of industrial sugars in sufficient quantities and at favorable cost is therefore important for the competitiveness of the products. With this patented process, BASF notes, industrial sugar can be produced from lignocellulosic biomass (wood, cane trash or straw) in large quantities and at competitive cost from non-edible plant mass._GCC
Cheap industrial grade sugars from a wide range of biomass sources will re-write the economic equations for the production of biofuels, plastics, and chemicals from renewable sources.

Much of the "peak oil doom" angst arises from society's dependency on petroleum for the production of strategic chemicals, plastics, materials, and fuels. As chemists and plant geneticists become more clever about turning new, rapid-growth biomass into high value products, much of this angst -- at least in the more intelligent and informed community -- should subside.
There are three general approaches to breaking down biomass for use in renewable fuels and chemicals in the market today: enzymatic hydrolysis, acid hydrolysis, and gasification. Renmatix’ represents a new, fourth approach. Basic stages of the Plantrose process include:

Biomass—composed primarily of hemicellulose (C5 sugars), cellulose (C6 sugars), and lignin—which has undergone size reduction as necessary is mixed with water to form a slurry and pumped into a fractionation reactor.

In fractionation, less severe conditions first solubilize hemicellulose into a C5 sugar stream in a matter of minutes; the cellulose and lignin remain as solid particles.

A simple solid/liquid separation removes the remaining cellulose and lignin from the C5 sugar stream. The C5 stream is collected in one vessel and the solids are sent to cellulose hydrolysis.

In cellulose hydrolysis, more severe conditions solubilize the cellulose into a C6 sugar stream in a small number of seconds. The lignin remains as a solid particle. 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.

A simple solid/liquid separation removes the remaining lignin solid form the C6 sugar stream. The C6 stream is collected in one vessel and the lignin in another.

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

The Plantrose process is biomass agnostic. While the initial production facilities will use wood products as inputs, the initial step in Renmatix’s Plantrose Process can be modified to incorporate alternate inputs such as corn cobs and stover, miscanthus, switch grass, and bagasse. _GCC
This process would clearly benefit from cheap nuclear reactor process heat.

Cheap natural gas could facilitate this process, but since methane is an important feedstock for many of the same chemical and fuels-producing pathways, it makes far less sense to use natural gas as a heat source here. Methane might very well serve as a hydrogen source.

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