Patent ID: 6638432
Filing Date: 2003-10-28
Classification: B01D,Y10S

Abstract:
A method of removing heavy metals contained in exhaust gas generated by burning a waste liquid containing the heavy metals discharged in a process of producing organic compounds, wherein the waste liquid includes waste water and/or waste oil discharged from a process of producing (meth)acrylic acids and/or esters thereof, comprising the steps in the order of:(a) a combustion step of burning the waste liquid to produce exhaust gas; (b) a gas-liquid contact step of rendering a liquid containing an alkali compound in contact with the exhaust gas to precipitate the heavy metals in bottoms of the liquid, wherein, in the gas-liquid contact step, the amount of the alkali compound in the liquid is regulated to keep pH of the bottoms in the range of 4 to 10; and (c) a coagulating step of adding a coagulant to the bottoms to coagulate the heavy metals in the bottoms for removal of the heavy metals.