Biomass 101

Biomass energy or Bioenergy refers to energy produced from organic matter. Biomass is primarily found in the form of living or recently living plants as well as waste. The term feedstock is used to refer to whatever type of organic material will be used to produce energy. Different feedstock will have different physical compositions. But generally, all feedstocks include varying amounts of carbon, water, or organic volatile. For energy production, a feedstock must be converted using one of many conversion processes. Some common biomass conversion processes include Combustion, Gasification, Pyrolysis, Anaerobic digestion, Fermentation.

Combustion- the process where feedstock is burned in the presence of air to release heat. The same thing happens when someone starts a small campfire with wood. Combustion can be used to heat steam for electricity generation as well.

Gasification- the process of using heat, pressure, and partial combustion to convert feedstock into a combustible gas mixture called syngas. Syngas can then be used in place of natural gas for heating electricity and other uses.

Pyrolysis- the process of heating feedstock at high temperatures in the absence of oxygen. Since no oxygen is present, the organic material does not combust instead the chemical compounds decompose into three forms- a liquid called bio-oil, a solid called biochar, and the syngas.

Anaerobic digestion or bio-digestion- a process where bacteria breaks down organic material in the absence of air to create biogas which can be captured and burned to produce energy. The remaining byproduct is called digestate and makes a great fertilizer.

Fermentation- the process of converting a plant's glucose into an alcohol called ethanol through the use of yeast. The ethanol is a liquid fuel that can be used as an automotive fuel.

It is important to note that certain feedstocks are more conducive for some biomass conversion processes over others. The determination of which feedstock and process will be used is determined largely by the availability of the resource is in the desired end form of energy. Prior to the industrial revolution, biomass was the primary source of energy. Biomass now makes up only a small percentage of total world energy use. However, for approximately 2.5 billion people it remains a primary source of energy for cooking and heating. The use of biomass is highly contextual to the region in which these are used. Availability of resources, availability of technology, and economic viability are all drivers of biomass use. The environmental benefits and costs are highly contextual depending on the technology and feedstocks used. While some biomass processes such as waste to energy are touted for their lower carbon dioxide emissions, some processes such as combustion release carbon dioxide and particulate matter that are a significant concern for human health. The world's most energy-poor peoples and regions still rely on biomass for the majority of their energy needs. The lack of appropriate ventilation mechanisms for burning biomass is a major health concern and contributes to short life expectancies in much of the developing world. Concerns associated with biomass also go beyond human health. Depending upon the source of biomass used, deforestation, cropland degradation, and land-use alteration can all be relevant issues associated with biomass.

Reference: https://studentenergy.org/map/