Chemical scrubbing of odorous gas emitted from feed-drying processes
In this study, three chemical scrubbing processes were investigated to test their performances for removing odorous compounds in waste gases emitted from feed-drying operations.
A gas chromatography with a flame ionization detector (GC/FID) and gas detector tubes were used for the identification of odorous species and their concentrations in the waste gases. Results indicate that toluene, ethyl benzene, xylenes, and styrene could be detected while their concentrations were all below the detection limits. However, trimethylamine, amine, mercaptans, ammonia, hydrogen sulfide, and acetic acid could be detected with the detector tubes.
A two-stage scrubbing system with a gas flow rate of 10 L/min was used to test its performance for the odor removal. Results demonstrate that an ¡§acidic chlorination-alkaline sulfite scrubbing¡¨ process was effective. The pertinent operating conditions were found to be: (1) a pH of 6.4-6.6 and total residual chlorine of 55-85 mg/L for the acidic-chlorination solution, and (2) a pH of 8.0-8.5 for the alkaline sulfite solution with a sulfite concentration of 10,000 mg/L (as SO2). By the conditions, ammonia, trimethylamine, and amine in the odorous gas could be completely removed. A sensory measurement indicates that the odor concentration could be reduced from 17,378 to 232 after scrubbing. Cost estimation indicates that it required a chemical cost of NT$ 5.74 for removing the odors from 1,000 m3 of the gas.
This study has successfully developed an economical and effective chemical scrubbing technology for the removal of odorous gas emitted from feed-drying operations. It could be applied to the treatment of odorous gases emitted from the manufacture of feeds, seafood, and other related operations.
Advisor:Mei-J. Syu; Ming-Shean Chou; Chu-Chin Hsieh
School:National Sun Yat-Sen University
School Location:China - Taiwan
Source Type:Master's Thesis
Keywords:odorous chemical scrubbing feed
Date of Publication:08/30/2005