Location: Cotton Ginning Research
Title: The Environmental Cost of Reducing Agricultural Fine Particulate (PM2.5) Dust Emissions Author
Submitted to: ASABE Annual International Meeting
Publication Type: Proceedings
Publication Acceptance Date: April 27, 2010
Publication Date: June 23, 2010
Citation: Funk, P.A. 2010. THE ENVIRONMENTAL COST OF REDUCING AGRICULTURAL FINE PARTICULATE (PM2.5) DUST EMISSIONS. Proceedings of the American Society of Agricultural and Biological Engineers (ASABE) 2010 Annual International Meeting. June 20-24,2010, Pittsburgh, PA. Paper No. 1008749. Interpretive Summary: The US Environmental Protection Agency changed parts of the Clean Air Act, lowering the amount of fine dust that will be considered acceptable in the air during a day or year; states with higher than acceptable levels in any region are required to implement measures to reduce fine dust emissions. The reported research was conducted to aid state and regional air pollution control bodies tasked with drafting State Implementation Plans in formulating regulations that will actually achieve their and EPA’s objectives. This paper looks at adding emissions control technology to an agricultural processing facility in four different regions. It compares the fine dust emissions reduced thereby to the fine dust and other emissions increased through generating electricity to power the added controls. Translating increased demand for electric power into increased emissions was done using published emission factors and emissions inventories. It was shown that emissions reductions at the agricultural processing facility could be more than offset by increases in emissions at the power plant. On average, for one unit of agricultural fine dust not emitted by additional controls, emissions from generating additional power to operate those controls were as much as two units of fine dust, 70 units of criteria (toxic) pollutants, and 13,000 units of greenhouse gasses at the point where electricity was produced. This paper cautions that if regulations designed to reduce fine dust emissions increase electrical power consumption, the unintended net effect will be a substantial increase in emissions of multiple types, resulting in a greater and more serious threat to public health and the environment.
Technical Abstract: Revisions to the National Ambient Air Quality Standards (NAAQS) were promulgated by the US Environmental Protection Agency (EPA) in 2006, reducing acceptable fine particulate (PM2.5) levels. Non-attainment findings are scheduled for release in 2010. State environmental protection agencies in states with non-attainment areas are required to draft State Implementation Plans (SIP) detailing measures to reduce regional PM2.5 levels by reducing PM2.5 and PM2.5 precursor emissions. This paper shows how important it is for SIP authors to consider the energy requirements of control technologies. Regulations that require the operation of control technologies to reduce PM2.5 emissions will cause increased emissions where the electricity that powers those control devices is generated. This resulting increase in power plant emissions may be greater or more harmful than the avoided PM2.5 emissions. The cotton ginning industry was modeled. Cyclones are the most common emissions control device used by agricultural processing facilities. Potential PM2.5 emissions reductions realized by adding a second set of cyclones to cotton gins were estimated for each cotton growing region. Increases in energy consumption were calculated based on cyclone air pressure drop. Additional energy required was translated into increased emissions using published emission factors and state emissions inventories. Reductions in gin emissions were compared to increases in emissions at the power plant. Because of the electrical energy required, reducing one unit of agricultural PM2.5 emissions at a cotton gin may result in emitting 0.11 to 2.67 units of direct PM2.5, 1.39 to 69.1 units of PM2.5 precursors, 1.70 to 76.8 units of criteria pollutants, and 692 to 15,400 units of greenhouse gasses at the point where electricity is produced. If regulations designed to reduce rural PM2.5 emissions increase electrical power consumption, the unintended net effect may be more emissions, increased environmental damage and a greater risk to public health.