Volume 17, No. 1, January 2017, Pages 209-217 PDF(1.58 MB)
A Survey of VOC Emissions from Rendering Plants
Fernanda D. Guerra1,4, Gary Douglas Smith, Jr.2, Frank Alexis1,5, Daniel C. Whitehead3
1 Department of Bioengineering, Clemson University, Clemson, SC 29634, USA
2 Vice President for Research and Development, Baker Commodities, Inc., Vernon, CA 90058, USA
3 Department of Chemistry, Clemson University, Clemson, SC 29634, USA
4 CAPES Foundation, Ministry of Education of Brazil, Brasília - DF 70040-020, Brazil
5 Institute of Biological Interfaces of Engineering, Department of Bioengineering, Clemson University, Clemson, SC 29634, USA
- Ambient air samples collected at two rendering facilities in California, USA.
- Samples were collected over two site visits in Winter and Summer.
- A number of VOCs were detected associated with potential malodors.
Rendering is a global industry that recycles by-products resulting from butchering operations, which process billions of animals per year. About 50% of the weight of livestock is not consumed by humans and must be processed by rendering operations, which cook and separate the material into its protein and fat components. These products serve as a sustainable food source for livestock, feedstocks for oleochemicals, and raw material for biodiesel refineries. Due to the scale and nature of the raw materials and the cooking process, rendering operations emit a significant, but as yet poorly quantified, VOC load. Assessing this VOC load is important in order to calibrate the industry’s contribution to global VOC emissions, and to help address nuisance odor problems. We conducted VOC air sampling of two facilities in California, USA during the winter and summer seasons. VOC and reduced sulfur analyses were conducted using 8 h ambient air samples. Analyses for amines, ammonia, aldehydes/ketones, and volatile fatty acids were conducted using sampling pumps. These analyses detected 43 compounds at the facilities, and the number and concentration of detectable compounds were seasonally dependent. The compounds present at the highest concentrations included: ammonia (1600–2800 ppb, i.e., winter–summer levels), acetic acid (80–320 ppb, along with twelve other fatty acids ranging from ~0.5–140 ppb), acetone (55–241 ppb, along with nine other aldehyde/ketone products ranging from 0.4–60 ppb), and ethanol (15–81 ppb). These constituents have low odor thresholds and thus contribute to nuisance odor problems. Further, the overall VOC contribution arising from rendering facilities on a global scale is as yet very poorly characterized. This analysis will be useful to guide the development of new odor abatement strategies and strategies for the reduction of VOC emissions associated with this critical industry.
Rendering; VOCs; Sulfur; Amines; Volatile fatty acids; Carbonyls; Environmental sampling.