Biomass resources plants

Wood is one of our most important renewable biomass resources. Unlike most biomass sources, wood is available year round and is more stable on storage than other agricultural residues. In the United States, wood residues from iadustrial by-products totaled 60.8 x 10 metric tons ia 1993 (73). Increasiagly, residues are iacorporated iato manufactured wood products and are used as a fuel, replacing petroleum, especially at wood-iadustry plants (73) some is converted to charcoal but most is used ia the pulp and paper iadustry. Residues are also available for manufacturiag chemicals, generally at a cost equivalent to their fuel value (see Fuels frombiomass Fuels fromwaste). 

Chemurgy is defined as that branch of appHed chemistry devoted to industrial utilization of organic raw materials, especially from farm products. A more modem and general definition for chemurgy is the use of renewable resources particularly biomass, usually plant or microbial material, for materials and energy (see Fuels frombiomass Fuels fromwaste). 

These products can be fairly easily processed into high-quality diesel and jet fuel in theory, any source of carbon can be used to generate synthesis gas. These facts along with the growing need for petroleum alternatives have renewed interest in FT synthesis. During the twentieth century, the FT process was used to produce fuels from coal in large and costly reactors. Recently, this megasize approach has been applied to world-scale GTL plants in Qatar. However, to tap abundant biomass resources and stranded natural gas reserves, a smaller scale, yet economically viable, FT process is needed. 

The physical, chemical, and thermodynamic characteristics of biomass resources vary widely. This variation can occur among different samples of what would nominally seem to be the same resource. Also, variations could occur from one region to another, especially for waste products. This wide variation sometimes makes it difficult to identify a typical value to use when designing a gasification plant. 

Biomass resources are a major component of strategies to mitigate global climate change. Plant growth recycles C02 from the atmosphere, and the use of biomass resources for energy and chemicals results in low net emissions of carbon dioxide. Since the emissions of NOx and SOx from biomass facilities are also typically low, it is a technology that helps to reduce acid rain. 

While this reaction is substantially exothermic (6), it provides an intriguing approach to the production of fuels from renewable resources, as the required acids (including acetic acid, butyric acid, and a variety of other simple aliphatic carboxylic acids) can be produced in abundant yields by the enzymatic fermentation of simple sugars which are, in turn, available from the microbiological hydrolysis of cellulosic biomass materials ( ] ) These considerations have led us to suggest the concept of a "tandem" photoelectrolysis system, in which a solar photoelectrolysis device for the production of fuels via the photo-Kolbe reaction might derive its acid-rich aqueous feedstock from a biomass conversion plant for the hydrolysis and fermentation of crop wastes or other cellulosic materials (4). 

Biomass is any material that is directly or indirectly derived from plant life and that is renewable in time periods of less than about 100 years. More conventional energy resources such as oil and coal are also derived from plant life but are not considered renewable. Typical biomass resources are energy crops, farm and agricultural wastes, and municipal wastes. Animal wastes are also biomass materials in that they are derived, either directly or via the food chain, from plants that have been consumed as food. 

Nitrogen plays a major role in controlling the dynamics of marsh plants and plant communities. Two excellent reviews on the physiological ecology and effects of N-enrichment on intertidal marsh plants include Haines and Dunn (1985) and Morris (1991). Supply of N affects (1) plant production and biomass, (2) plant architecture, resource allocation, and tissue N content, (3) plant species composition, and (4) marsh community structure. 

This entry is organized into three major parts. The first identifies the biomass resources in the form of conventional forestry, agricultural crops and residue, and oil-bearing plants, among others. The second describes the conversion processes of bioresources into biofuels, and it is followed by the end product usage of biofuels in producing electricity in power plants. 

Municipal waste Residential, commercial, and institutional postconsumer wastes contain a significant proportion of plant-derived organic material that constitutes a renewable energy resource. Waste paper, cardboard, wood waste, and yard wastes are examples of biomass resources in municipal wastes. 

For the feedstock, there are logistical and sustainability concerns. Each potential biorefinery concept has specific coproduct and waste issues to consider. Transport is a general issue in this discussion. The biomass resource has to be transported to the refinery subsequently the products have to be transported to the downsdeam industry and/or the consumer. Of interest is the approach of the company Nature-Works LLC that currently operates the largest biorefinery in the United States in Blair, Nebraska. The nameplate capacity of the polymer production plant is 140,000 tons of polymer per year. Corn is the basis for the production of the bioplastic polylactic acid (PLA) in a complex multistage process. Sixty percent of its com feedstock is obtained from the local area (producers, located less than 40 kilometers from the plant). Several companies in an emergent network are now active on the Blair biorefinery campus (Wells and Zapata, 2012) reducing transportation from one industrial branch to the next one. 

Replacing the petro/fossil carbon with biobased carbon derived from plant/biomass resources offers the value proposition of a zero material carbon footprint. This arises from the fact that the rate and timescale of carbon cycling is in balance and sustainable using plant/biomass resources as shown in Figure 16.4. 

Carhon in the environment is sequestered by plants/biomass in a 1-10 year time frame by photosynthesis using sunlight as the energy source - one year if agricultural crops are used and 10+ years for tree plantations. This is in balance with the rate and timescale of use of the plant/biomass resources to make chemicals and products, and ultimate disposal with release of carbon back to the environment. In contrast, the rate and timescale of carhon sequestration to fossil resources (oil, coal, natural gas) is millions of years, whereas the use and ultimate disposal is in the 1-10 year time frame. This makes the use of fossil carbon resources out of balance and unsustainable. This represents the fundamental, intrinsic value proposition for using biobased carbon from plant/biomass, agricultural crops/residues and algae as opposed to fossil carbon resources. 

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