Biomass energy, use

Bhattacharya SC, Salam PA, Sharma M. Emissions from biomass energy use in some selected Asian countries. Energy 2000 25(2) 169—88. 

Zheng YH, et al. Anaerobic fermentation technology increases biomass energy use efficiency in crop residue utilization and biogas production. Renew Sustain Energy Rev 2012 16(7) 4588-96. 

Distribution of Carbon. Estimation of the amount of biomass carbon on the earth s surface is a problem in global statistical analysis. Although reasonable projections have been made using the best available data, maps, surveys, and a host of assumptions, the vaHdity of the results is impossible to support with hard data because of the nature of the problem. Nevertheless, such analyses must be performed to assess the feasibiHty of biomass energy systems and the gross types of biomass available for energy appHcations. 

A projection of biomass energy consumption in the United States for the years 2000, 2010, 2020, and 2030 is shown in Table 6 by end use sector (12). This analysis is based on a National Premiums Scenario which assumes that specific market incentives are appHed to aU. new renewable energy technology deployment. The scenario depends on the enactment of federal legislation equivalent to a fossil fuel consumption tax. Any incentives over and above those in place (ca 1992) for use of renewable energy will have a significant impact on biomass energy consumption. 

The market penetration of synthetic fuels from biomass and wastes in the United States depends on several basic factors, eg, demand, price, performance, competitive feedstock uses, government incentives, whether estabUshed fuel is replaced by a chemically identical fuel or a different product, and cost and availabiUty of other fuels such as oil and natural gas. Detailed analyses have been performed to predict the market penetration of biomass energy well into the twenty-first century. A range of from 3 to about 21 EJ seems to characterize the results of most of these studies. 

Several important generalizations can be made. The first is that fossil fuel prices are primary competition for biomass energy. Table 28 summarizes 1990 U.S. tabulations of average, consumption-weighted, deflvered fossil fuel prices by end-use sector (90). The deflvered price of a given fossil fuel is not the same to each end user ie, the residential sector normally pays more for fuels than the other sectors, and large end users pay less. 

Another factor is the potential economic benefit that may be realized due to possible future environmental regulations from utilizing both waste and virgin biomass as energy resources. Carbon taxes imposed on the use of fossil fuels in the United States to help reduce undesirable automobile and power plant emissions to the atmosphere would provide additional economic incentives to stimulate development of new biomass energy systems. Certain tax credits and subsidies are already available for commercial use of specific types of biomass energy systems (93). 

Location of the system boundaries also is important in the net energy analysis of integrated biomass energy systems. Thus tractors may be used to plant and harvest biomass. The fuel requirements of the tractors are certainly part of E, but is the energy expended in manufacturing the tractors also part of E Some analysts beheve that a complete study should trace all materials of constmction and fossil fuels used back to their original locations in the ground. 

Gasification. Conversion of biomass to gaseous fuels can be accompHshed by several methods only two are used by the biomass energy industry (ca 1992). One is thermal gasification in which LHV gas, ie, producer gas, is produced. The other process is anaerobic digestion, which yields an MHVgas. 

There are four principal ways ia which biomass is used as a reaewable eaergy resource. The first, and most common, is as a fuel used directiy for space and process heat and for cooking. The second is as a fuel for electric power generation. The third is by gasification iato a fuel used oa the site. The fourth is by coaversioa iato a Hquid fuel that provides the portabiUty aeeded for transportatioa and other mobile appHcations of energy. Figure 7 shows the varied pathways which can be followed to convert biomass feedstocks to useful fuels or electricity. 

At the low end is the United States, where biomass energy accounted for only about 3 percent (2.7 quadrillion Btus) of the total energy consumption in 1997. However, biomass use had been rising over the previous five years at an average rate of about 1 to 2 percent per year, but fell in 1997 due to a warmer-than-average heating season. Bioenergy produced in the United States is primarily from wood and wood waste and municipal solid waste. 

In the United States, where clean and convenient natural gas, propane, and electricity are widely available and affordable, biomass use has limited potential. Nevenheless, U.S. biomass energy production has been increasing because of technological advances for new and improved biomass applications for electricity generation, gasification, and liquid fuels. 

Wright, L. L., and Hughes, E. E. (1993). "U.S. Carbon Offset Potential Using Biomass Energy Systems. Water, Air, and Soil Pollution 70 483-497. 

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