Utah Chemists evaluate the ash formation rates of various biofuels.

[NNadir]

Yesterday I discussed and excerpted an article on the liquifaction of various biofuels:

http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x59526

Today I would like to do the same for an article in the current issue of Energy and Fuels discussing the ash depostion rates of several solid biofuels. Yesterday's article gave a rough idea about the financial costs associated with biomass. Noting however that liquifaction is both expensive and involves an energy cost, we should expect that in the future, the direct burning of solid biomass will be increasingly important. In evaluating the environmental impact of such decisions, it is useful to keep in mind studies like this.

Coal, a major fossil fuel, represents the most substantial energy reserve in the United States and contributes more than half of the electric power generation in many developed
countries. Important challenges to coal combustion include deposition and corrosion in boilers, pollutant emissions, and greenhouse gas emissions to the atmosphere.1-5 Carbon dioxide and NOx are two of the most problematic products of coalfired power plants. Progress has been made to reduce NOx emissions through low NOx burner design and prudent fuel selection, and catalysts can be used to achieve acceptable NOx control where necessary, but technologies to reduce CO2 from coal combustion are yet to be proven. Biomass is a renewable fuel that can be used in existing combustion facilities and provides an energy source with essentially zero (95% CO2 closure) CO2 emission.6 It has been shown that biomass combustion closes the CO2 cycle when combined with the photosynthesis process during plant growth. With this inherent advantage of biomass fuels, technologies are developed for coal biomass co-firing and dedicated biomass combustion as a potential solution for greenhouse gas formation.7-12 Unfortunately, the use of biomass in combustion systems has introduced added operating difficulties mainly related to ash deposition and corrosion. Because biomass sources vary, so do the ash content and composition of these fuels.11,13-17 The alkali salts present in biomass ashes play an important role in deposition due to their ability to bind fly ash particles by sintering. The outcomes of coal-biomass co-firing have been the motivation for investigating how the wide variation in ash content and composition of biofuels can be used to reduce ash deposition rates.18-23...

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Abstract here: http://pubs.acs.org/cgi-bin/abstract.cgi/enfuem/2006/20/i03/abs/ef050410e.html