연구홍보포털

논문 초록 (Abstract)

Swine excreta were dried by boiling via immersion in hot oil. In this method, moisture in the excreta is replaced with oil or evaporated by turbulent heat transfer in high-temperature oil. The dried excreta ca n be used in an incinerator like low-rank coal or solid fuel. Refined waste oil and B-C heavy oil were used for drying. Drying for 8 min at 150 degrees C reduced thewater content of raw excreta from 78.90 wt.% to 1.56 wt.% (refined waste oil) or 1.62 wt.% (B-C heavy oil) and that of digested excreta from 79.58 wt.% to 3.40 wt.% (refined waste o il) or 3.48 wt.% (B-C heavy oil). The low heating values of the raw and digested excreta were 422 kJ/kg and -2,713 kJ/kg, respectively, before drying and 27,842-28,169 kJ/kg and 14,394-14,905 kJ/kg, respect ively, after drying. A heavy metal analysis did not detect Hg, Pb, Cd, As, and Cr in the dried excreta, but Al, Cu, and Zn, which occur in the feed formula, were detected. Thermogravimetric analysis before and a fter drying revealed that emission of volatiles and combustion of vo latiles and fixed carbon occurred at temperatures of 250-500 degrees C when air wasused as the transfer gas. (C) 2012 The Institution of Chem ical Engineers. Published by Elsevier BM. All rights reserved.