What is biomass conversion? In the context of Industrial Biotechnology (IB) biomass is a feedstock used to supply sugars or other chemicals which are used for energy to drive fermentation processes or as feedstocks for biochemical transformations. The biomass should be of low value so that the manufacturing processes are economic and the products will be commercially attractive and have a higher value. Examples of biomass that attracts interest for IB are waste agricultural biomass, such as corn stover, barley straw, rice stalks, grain husks, and corn cobs; energy crops such as switchgrass and elephant grass; or forestry products such as forestry thinnings, sawdust, and pulp from the paper industry. To be accessible for the IB process the biomass must be broken down into usable components. This means that the key plant polymers –cellulose, hemicellulose, and lignin – need to be separated, and then these polymers must be broken down into their component parts. For cellulose, this is glucose used as a fermentation substrate or to make chemicals such as HMF; for hemicellulose, this is a range of sugars including xylose and arabinose and small molecules including acetic acid; and for lignin, the products are a range of aromatic chemicals, humans, etc. that can be used as building blocks for various products including monomers for bioplastics.
Converting biomass to the component parts is not an easy task – plants have evolved for millennia to avoid being broken down by the environment or compromised by pests. Typically the process has three stages – mechanical, thermochemical, and enzymatic.
- Mechanical processing: This gets the biomass into a form that makes it more susceptible to breakdown, especially by increasing the surface area. Mechanical processing includes milling or cutting to reduce particle size, typically to 0.5-2mm lengths of plant material. In the case of wood, using standard forest product equipment developed in the paper industry has proved successful.
- Thermochemical processing: Combinations of heat, pressure, and chemicals are employed separately for the three types of plant polymers. A wide range of different processes have been developed and deployed, including steam explosion, mild acid treatments; concentrated acid treatments; supercritical water; solvent applications; alkaline treatments such as AFEX. The output of thermochemical processing is:
o Hemicellulose solubilized into component parts which can be separated and used for subsequent processing.
o Lignin solubilized and partially converted into monomers so that it can be separated and used for subsequent processing.
o Cellulose is released from the lignin and hemicellulose so that it can be separated and further processed.
- Enzymatic processing: the cellulose, which is the main component of biomass, is released during thermochemical processing but is not typically broken down. The release of glucose from the cellulose requires enzymatic treatment involving incubation for 48-72 hours with a cocktail of enzymes to break down the fibers and the glucose backbones to produce the resulting fermentable glucose. Enzymes may also be used in further processing of the lignin and hemicellulose components to obtain more usable or valuable feedstocks for fermentation or biochemical processing.
The best renewable energy and biochemical consulting firms have experts in a wide variety of bioeconomy specialties, including biomass conversion and all types of alternative energy and energy consultants. These firms should also have experts in renewable fuels like ethanol fuel and diesel biodiesel, synthetic diesel, renewable chemicals, renewable electricity, biomass energy, feedstocks, biomass technologies, bioproducts, and all areas of sustainability, synthetic biology, emerging technologies, and waste management, as well as even more specialized things like algae biofuel, agitation systems, agricultural waste, bio-oils, bio-jet fuel, carbon accreditation, carbon capture, carbon credits, climate change analysis, emerging technologies, environmental permitting, enzyme technologies, feedstock due diligence, financial due diligence, and glycerin related matters. They should have teams of experts for all types of clean energy, green energy, renewable energy finance, and renewables and should be able to provide expertise for projects and be available to serve as expert witnesses in matters within the bioeconomy.
With over 150 consultants worldwide, Lee Enterprises Consulting has the diverse experts and geographical reach to assist in virtually any bioeconomy project, including biomass conversion. Our highly qualified teams bring a unique integration of technical, scientific, regulatory, and hands-on experience to any project. Look at our experts and the services we provide. Most of our experts are also available to advise and serve as expert witnesses in bioeconomy litigation matters. For the larger projects, we specialize in putting together full-service, interdisciplinary teams with one point of contact. See a video about LEC here. Call us at 1+ (501) 833-8511 or email us for more information.