Process development for scum to biodiesel conversion

Chong-hao Bi; Min Min; Yong Nie; Qing-long Xie; Qian Lu; Xiang-yuan Deng; Erik Anderson; Dong Li; Paul Chen; Roger Ruan

doi:10.1016/j.biortech.2015.01.081

Process development for scum to biodiesel conversion

Bioresour Technol. 2015 Jun:185:185-93. doi: 10.1016/j.biortech.2015.01.081. Epub 2015 Feb 18.

Authors

Chong-hao Bi¹, Min Min², Yong Nie³, Qing-long Xie⁴, Qian Lu⁴, Xiang-yuan Deng⁴, Erik Anderson⁴, Dong Li⁵, Paul Chen⁴, Roger Ruan⁶

Affiliations

¹ College of Engineering, China Agricultural University, Beijing 100083, China; Center for Biorefining, and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA.
² Center for Biorefining, and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA. Electronic address: minxx039@umn.edu.
³ College of Chemical Engineering, Zhejiang University of Technology, Hangzhou 310014, China.
⁴ Center for Biorefining, and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA.
⁵ College of Engineering, China Agricultural University, Beijing 100083, China.
⁶ Center for Biorefining, and Department of Bioproducts and Biosystems Engineering, University of Minnesota, 1390 Eckles Avenue, St. Paul, MN 55108, USA. Electronic address: ruanx001@umn.edu.

PMID: 25770465
DOI: 10.1016/j.biortech.2015.01.081

Abstract

A novel process was developed for converting scum, a waste material from wastewater treatment facilities, to biodiesel. Scum is an oily waste that was skimmed from the surface of primary and secondary settling tanks in wastewater treatment plants. Currently scum is treated either by anaerobic digestion or landfilling which raised several environmental issues. The newly developed process used a six-step method to convert scum to biodiesel, a higher value product. A combination of acid washing and acid catalyzed esterification was developed to remove soap and impurities while converting free fatty acids to methyl esters. A glycerol washing was used to facilitate the separation of biodiesel and glycerin after base catalyzed transesterification. As a result, 70% of dried and filtered scum was converted to biodiesel which is equivalent to about 134,000 gallon biodiesel per year for the Saint Paul waste water treatment plant in Minnesota.

Keywords: Acid washing; Biodiesel; Glycerol washing; Scum; Wastewater treatment plant.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Acids / chemistry
Biofuels*
Conservation of Natural Resources / methods
Esterification
Fatty Acids, Nonesterified / chemistry*
Glycerol / chemistry*
Refuse Disposal / methods*
Wastewater / chemistry*
Water Pollutants, Chemical / chemistry*

Substances

Acids
Biofuels
Fatty Acids, Nonesterified
Waste Water
Water Pollutants, Chemical
Glycerol