All plant cells comprise cellulose, hemicellulose, and lignin as their core structural components, and all plant cells contain sugars in varying concentrations. Conventional approaches to biofuels production have focused on converting the sugars and starches found in the fruit-bearing portion of plants into ethanol by way of fermentation and distillation. Consequently, crops, such as sugarcane, beet, and corn, have become the preferred feedstocks for biofuels production. The challenge with this approach is that the "fruit" portion of a plant is often the smallest part. When harvested, these conventional feedstocks result in the bulk of the plant material becoming waste. This waste is known as ligno-cellulosic material and consists of cellulose, hemicellulose, and lignin. Conversion of these materials into biofuels holds the promise of ultimately displacing much of the current demand for fossil fuels.

Of these ligno-cellulosic materials, cellulose is relatively simple to convert into glucose. Glucose is a "C6" sugar (i.e., it contains a six-carbon ring) that can be converted into ethanol via fermentation. By comparison, hemicellulose contains predominantly "C5" sugars (i.e., five-carbon rings) and cannot be converted into ethanol by conventional means. However, these C5 sugars have the potential to become the raw materials for producing other biofuels. Likewise, lignin is a highly complex molecule with the potential for use as raw material for producing high-value chemicals, engineering polymers, and other materials.

To date, conversion of ligno-cellulosic feedstocks into biofuels has followed two different approaches. The first, known as acid hydrolysis, focuses on releasing the cellulose from the plant structure and converting it to glucose, ready for fermenting and distilling into pure ethanol. While there are variations on this approach, all are limited to some extent by the fact that hemicellulose and lignin are easily degraded, making it difficult to separate their components for processing into higher value materials. As a result, acid hydrolysis approaches typically generate large amounts of secondary waste (up to 40 percent).

The second approach to converting ligno-cellulosic feedstocks into biofuels involves the use of enzymes to convert some or all of the C5 sugars into ethanol to complement the yield from C6 sugars. Most of these approaches are in early stages of development and face serious challenges, including scalability and feedstock sensitivity. By contrast, RedOx's proprietary MMR technology uses an electrochemical synthesis process to sequentially process the separate components of ligno-cellulosic materials, using fully recycled reagents that created little or no secondary waste, and requiring no chemical pretreatment of feedstocks.

Diagram of RedOx MMR Process [Click to enlarge]

RedOx’s MMR technology (pictured above) can be used to convert a range of ligno-cellulosic materials into ethanol and other high performing fuels and chemicals for the automotive, aerospace, and motorsport industries.