One of Virent’s key differentiators is our ability to use a wide variety of feedstocks in the BioForming® process. Our patented catalytic process can effectively convert both conventional and cellulosic feedstocks as described below.
Bagasse is the fibrous residue remaining after sugarcane or sweet sorghum stalks are crushed to extract their juice. Historically, bagasse has been a waste by-product of the sugarcane production process. Bagasse is indigenous to Asia, but today Brazil is by far the largest producer, with about one-third of world production. Because of the short life-cycle and fast growth of the sugarcane plant, bagasse is viewed as an annually renewable resource. In addition, its connection to sugar make it a very logical cellulosic choice for companies currently working with cane or sorghum.
Corn stover consists of the leaves, husks, cobs and stalks of maize plants left in a field after harvest. Stover makes up about half the yield of a corn crop and is similar to straw, having low water content and bulk density. Historically unused, corn stover is growing in popularity as a feedstock for biofuels production. It is abundant and freely accessible in the United States, with obvious proximity to corn, and because of its short life cycle and fast growth, corn stover (like corn) is considered an annually renewable resource.
Diverse mixtures of native prairie plant species have emerged as suitable biomass for biofuels production. Grasses such as elephant grass, hybrid poplar, hybrid willow, miscanthus and switchgrass can grow in a wide variety of soils and are naturally drought and wind tolerant. All parts of the plant above ground are usable. The practice of using degraded land to grow mixed prairie grasses for biofuels could provide stable production of energy and have additional benefits, such as renewed soil fertility, cleaner ground and surface waters, preservation of wildlife habitats, and recreational opportunities.
Using the cellulosic biomass resulting from forest management practices is gaining popularity in the effort to reduce the use of fossil fuels and address climate change. Woody biomass suitable for biofuels production is sourced through collecting residual biomass following timber harvest and the periodic harvesting of understory woody vegetation. Today the most commonly used forest harvest residuals are pine species, due to the soft nature of the wood, the comparatively short growth cycle, and their abundance due to association with timber harvesting for building materials.
High Biomass Sorghum
“Sorghum” is a term given to numerous species of grasses, which can be used as feedstock to produce biofuels and biochemicals. The plants are cultivated in warmer climates worldwide, and are native to tropical and subtropical regions of all continents. High Biomass Sorghum, as shown here to the left, is a very tall cellulosic crop, having less “free” sugar than its conventional relative, Sweet Sorghum.
As seen in the pictures above, these feedstocks are fibrous and tough, and the plant cellulose will need to be digested or deconstructed before it can be converted into fuels and chemicals. Once the pretreatment of cellulosic biomass is complete, the broken-down plant matter is mixed with water to form what is called a hydrolysate mixture.
- Read about our DOE award to convert corn stover into jet fuel.
- Read an update about our work with HCL CleanTech in converting pine
waste to gasoline.