Biomass emission factors

Oros DR, Simoneit BRT, Identification and emission factors of molecular tracers in organic aerosols from biomass burning Part 1. Temperate climate conifers, Applied Geochem 16 1513—1544, 2001. 

Three areas of uncertainty in this present inventory of natural sulfur emissions which need further work include natural variability in complicated wetland regions, differences in emission rates in the corrected SURE data and those reported by Lamb et al. (1) and Goldan et al. (21) for inland soil sites, and biomass emissions for which only a very limited data base easts. The current difficulty in determining the sources of variability emphasizes the need to better understand natural sulfur release mechanisms. At present, it may be useful to consider the emission rates based on the corrected SURE data as an upper bound to natural emissions and use the emission rates based on data described by Lamb et al. (1) as a more conservative estimate of natural sulfur emissions. However, this still leaves a factor of 22 difference between the suggested upper bound and our best current estimate. 

All estimates for particle production due to forest fires and biomass burnings are based on experimental emission factors combined with statistical data for the global consumption rates for the materials involved. The most detailed study has been made by Seiler and Crutzen (1980). They deduced a particle production rate from forest fires alone of 100 Tg/yr. Including agricultural biomass burnings raises the rate to about 200 Tg/yr, a value approaching that for mineral dust emissions. This is much higher than all earlier estimates. 

Biomass. Wood and peat are studied in several countries as a potential fuel for power generation. In a study of a small 2 MW hot water boiler, the combustion of wood and peat gave emission factors of 2 mg and 15 mg PAH per kg fuel, respectively (34). 

Table 2.44 Emission factors for biomass burning (after Andreae and Merlot 2001, Rander-son et al. 2007), in g kg (note that uncertainties are large and not given in this Table).

Table 2.45 Comparison between emission factors for biomass burning, in g kg . ...

In a later study investigating biomass emissions from controlled laboratory fires it was again concluded that PTR-MS measurements underestimated the concentration of HCN, and in this study by roughly a factor of 5 in comparison to values determined by FTIR spectroscopy [17]. From the collected field data, it was found that the HCHO ratios between PTR-MS and FTIR measurements varied significantly with ambient atmospheric humidity, ranging from 0.2 at the lowest humidity to 0.05 at the highest humidity. It was concluded that the addition of water from the hollow cathode discharge ion source into the drift tube needs to be taken into account in addition to the humidity of the inlet air if HCN and HCHO concentrations are to be accurately determined. 

Akagi, S. K., Yokelson, R. J., Wiedinmyer, C. et al. (2011) Emission factors for open and domestic biomass burning for use in atmospheric models. Atmos. Chem. Phys. 11,4039. 

Default IPCC emission factors, taken from the 2006 IPCC Inventory Guidelines or subsequent updates of these Guidelines, shall be used unless activity-specific emission factors identified by independent accredited laboratories using accepted analytical methods are more accurate. The emission factor for biomass shall be zero. A separate calculation will be made for each flight and for each fuel. ... 

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). 

For soybean-based biodiesel at this concentration, the estimated emission impacts for percent change in emissions of NO,, particular matter (PM), HC, and CO were +20%, -10.1%, -21.1%, and -11.0%, respectively (EPA, 2002). The use of blends of biodiesel and diesel oil are preferred in engines in order to avoid some problems related to the decrease of power and torque, and to the increase of NO, emissions (a contributing factor in the localized formation of smog and ozone) that occurs with an increase in the content of pure biodiesel in a blend. Emissions of all pollutants except NO appear to decrease when biodiesel is used. The use of biodiesel in a conventional diesel engine dramatically reduces the emissions of unbumed hydrocarbons, carbon dioxide, carbon monoxide, sulfates, polycyclic aromatic hydrocarbons, nitrated polycyclic aromatic hydrocarbons, ozone-forming hydrocarbons, and particulate matter. The net contribution of carbon dioxide from biomass combustion is small. 

By using renewable carbon from biomass, an improvement in the CO2 balance can be achieved. However, significant effects beyond the impacts on greenhouse gas emissions are possible, e.g., soil modification, eutrophication, impact on biodiversity, land requirements and water consumption. These aspects depend on different factors like feedstock type, scale of production, cultivation and land-management practices, location and downstream processing routes. The environmental implications of agriculture are sometimes difficult to assess by the LCA methodology and require further research. 

Reinhardt, T., and D. E. Ward, Factors Affecting Methyl Chloride Emissions from Forest Biomass Combustion, Enriron. Sci. Techno , 29, 825-832 (1995). 

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