Measurement of Emission Factors for Cotton Gin Trash Piles

The process of ginning creates a significant amount of trash and dust. Particulate matter (PM) is the term applied to dust and other small particles that are emitted from agricultural operations and may be suspended in the air. The Environmental Protection Agency (EPA) regulates PM as a pollutant because it can cause health problems when inhaled.

The results of recent testing have overcome the primary issues surrounding particulate matter regulations for cotton gins including the over-prediction of current dispersion models and the effects of sampler errors. Some dispersion models over-estimated PM concentrations by as much as 10x. Sampler errors accounted for PM10 oversampling rate of 181% for cotton gin.

Cotton gins have received extremely low EPA total particulate emission factor ratings due to the collection of data from a limited, single geographical region. Therefore, a recent study focused on the collection of additional PM2.5, PM10 and total particulates and established new PM2.5 emission factors at seven cotton gins located across the cotton belt using EPA-Method 17 (CFR 1978) approved stack sampling methodology to sample all of the processing systems at each gin. The cotton gins were selected based on 1) facility location, 2) production capacity, 3) processing systems and 4) abatement technologies. A full set of emission factors have been collected for all of the emission points, covering PM, PM10, and PM2.5. It should be noted that the mote trash fan is separate from the trash stacker. The main trash fan typically discharges into the stacker, but that emission rate is really unrelated to the stacker emission rate.

This presentation focuses on the emission factors for gin trash piles that contain the PM, sticks, leaves, etc. that are removed in the ginning process. The trash piles would be an area source and are usually left outside the gin.