Course: SAT 170 Introductory Biotechnology

Unit 12 Learning Module

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Biomass

Notice the plumes of leaving this petrochemical refinery. These emissions carry large amounts of greenhouse gases into the atmosphere.
Biomass is defined as biological materials collected from living or recently dead organisms, and it is an essential component of industrial biotechnology. In contrast to biomass, fossil fuels such as coal, petroleum, and natural gas represent materials from organisms that have been dead for millions of years. Unlike biomass, fossil fuels are considered to be non-renewable resources because of the length of time it takes them to form. Another major problem with the use of fossil fuels is the large amount of carbon dioxide emitted from their refinement and use. Carbon dioxide is one of the major greenhouse gases present in Earth’s atmosphere. The effects of such greenhouse gases in the atmosphere are to trap heat to the Earth’s surface that would otherwise be able to escape back into space. There is wide speculation that the rapid accumulation of greenhouse gases, has led to rapid climate change. Climate change is described as a significant and sometimes drastic change to the expected weather patterns. This is a topic that we are going to investigate in much more detail in unit 14. Living biomass can take in carbon as it grows so it has the potential to mitigate or neutralize the carbon emissions that are released from its use. One of the primary uses of fossil fuels is for the production of petrochemicals, or petroleum based chemicals that are used as feedstock for industrial production. These conversions from the raw fossil fuels like oil and gas to these desired petrochemicals occurs in petrochemical refineries. Biomass can be employed as feedstock for industrial processes and it can also be used as a form of fuel or energy that can help to overcome some of these problems associated with fossil fuels.

Feedstock is a term used to describe bulk raw materials or fuels that serve as the input for industrial processes. Biomass feedstock could be used to replace many of the raw materials that are currently used for industrial purposes. There are many types of biomass feedstock currently used for industrial purposes including crops such as sugar cane, corn, and wheat. Many agricultural residues (such as the straw that is left over from harvesting wheat and rice) and food wastes can also be used as biomass feedstock. Other potential sources of biomass feedstock include municipal solid wastes, lawn wastes and wastewater.The use of biomass as a form of energy such as biofuel is another promising, although somewhat controversial topic. First, we should clarify that although the terms bioenergy and biofuel are often used synonymously, they do have different meanings. Bioenergy is used to describe any energy source that is derived from biomass, while biofuel is more specifically a liquid form of bioenergy often used for transportation and to power equipment. Some of the same materials that are used as biomass feedstock can also be used for bioenergy. However, the use of biomass for energy often requires the cultivation of low maintenance and low cost crops; such crops are often referred to as energy crops. Common examples of energy crops include woody plants and temperate grasses. Algae are also a common source for biofuel.  The conversion of biomass to useful energy can occur via a few different mechanisms including: thermal conversion, chemical conversion and biochemical conversion. As its name indicates, thermal conversion largely employs the use of heat to break down biomass materials into more readily useable forms. Chemical conversion on the other hand, accomplishes this using a variety of chemicals. Finally, biochemical processing takes advantage of the fact that many microorganisms have the enzymes needed to break down the biomass material.
This diagram illustrates the effect that greenhouse gases have on the atmosphere as they absorb and trap radiation to the Earth’s atmosphere that would otherwise escape into space.
Pictured here is an example of a quick growing grass that can be used as an energy crop.
Some of the concerns over replacing the materials that are currently widely used for feedstock and energy include: the need for more land to produce the biomass, the potential problems and pollution that result from processing biomass for energy purposes, and the allotment of crops for non-food purposes. The argument that the need for more land for growing fuel crops may lead to deforestation and may also have impacts on biodiversity is one that needs to be seriously considered when making plans to incorporate the usage and production of biofuels. Practices to harvest the bioenergy materials from biomass while limiting the amount of carbon emissions and water pollutants must also be worked out to make bioenergy a more attractive and sustainable practice. The food vs. fuel debate addresses the risks of allocating farm lands to the production of biofuels rather than food crops.

The transition to the wide-spread and possibly the exclusive use of biofuels will require many more biofuel pumps such as the one shown here.
The woody materials here represent agricultural waste that can be used as a sourse of biomass for fuel and feedstock.
The structure of a supply chain is illustrated in the diagram shown here. | Another factor that needs to be addressed is the undeveloped infrastructure and market for such biomass products. The concept of a value chain is one that is important for understanding this problem. A value chain is considered to be groups of organizations, people and practices that help to convert raw materials to final products and establish a market for such products. A value chain includes a what is referred to as a supply chain as well as other aspects of the operations not accounted for in the supply chain such as the marketing of a particular product, and the research and development of products. The goal of a value chain is to deliver products with maximum value at the lowest cost, and thus meet the demands of the consumer. A supply chain is a group of organizations, people and practices that link the production, pre-processing, conversion and consumption of products from supplier to consumer. A biomass supply chain for the production of bioenergy needs to incorporate expertise in cultivating, growing, harvesting, transporting, aggregating, pre-processing (when necessary) and converting the biomass. One of the major hurdles facing the biomass supply chain is the lack of developed biomass markets, including few biorefineries. A biorefinery is a facility which houses equipment and personnel that are able to convert biomass into usable products such as fuels and chemicals. Bioenergy is a relatively new trend and the infrastructure including processing plants is not well established. | Notice how the value chain encompasses components, such as marketing, that are not necessarily a part of the supply chain itself.