Revised October, 2018.
Biomass is commonly cited as a renewable energy source. The term also is used by biologists and ecologists to describe living and dead carbon-based biological material that is part of the environment’s carbon cycle. Biomass is the renewable, living and recently dead plant matter whose cellulose, sugars and proteins can be directly combusted; or biologically, physically or chemically changed into an industrial chemical or fuel. Industrial biomass is processed into a “bio-product.” Energy-related biomass is processed into a “bio-fuel.” It should be noted that coal, oil and other fossil fuels were once biomass, but over time, that biomass was chemically and physically changed by geologic processes. This material is not considered biomass, since it is nonrenewable and (unless combusted) no longer part of the environment’s carbon cycle.
Organic matter can be farmed or collected for biomass crops. This can be as simple as collecting corn, soy or wheat stalks, or collecting yard waste or industrial or recycled wood waste. It can be as complex as creating specialized aquatic environments for the production of algae or higher aquatic plants.
Any biomass-production strategy has several important hurdles to overcome. First and foremost are the simple economics of the system. An energy audit is necessary. This should look at the energy or product gained and the energy consumed by all aspects of collection, transportation and processing of the material, including any depletion due to storage issues, and all associated costs and values. A comprehensive engineering study, overall feasibility study and business plan should describe the markets, material supply, seasonality of production, agronomic and economic threats to the system, and similar issues.
When considering any biomass-utilization project of larger scope and scale, two points usually are limiting factors or at least important considerations: The immediate availability of material, and the material and transportation cost. For example, limited acres of seasonally-harvested switchgrass will not reliably support continuous power generation for a municipality. Additionally, if the municipality must bear handling and transportation costs that are in excess of the value of the returned energy, even a free material source will not be economically viable as a generation facility fuel. A good way to identify potential problems is to carefully look at the total infrastructure necessary to implement any biomass utilization strategy; then develop risk-avoidance and risk-management plans that cover problem areas.
Currently, there is considerable research in many promising areas of biomass utilization from renewable “green” biodegradable solid and fibrous plastics, paints and coatings to various fuels and high-value chemicals. Much of this biomass is derived from tree and grass species, as well as the “woody” (cellulosic) waste streams from construction, farm and industrial production.