【正文】 The second step is to absorb liquid acetic acid ethylene ketone anhydride generating, by distillation and purification to obtain the product of acetic anhydride, vinyl ketone conversion rate of about 100%. Reaction equation: CH3COOH+CH2 = C = O ( CH3CO ) 2O+ / mol. 2 The production process is a German Wacher chemical pany to develop a success, and in 1936 achieved industrialization. Two existing production process: One, as the tower process. Using 4 packed tower for synthesis and separation. The consumption of per ton of acetic anhydride as catalyst, acetic acid , 100160kg, ammonia, acetic acid recovery. Secondly, as the liquid ring pump flow. The liquid ring pump for reaction and absorption equipment. The process is simple, being replaced by tower process. Per ton of products consumption quota for acetic acid cracking rate, T, 75%, the yield of synthesis of 96%. The production process is as follows: The first step is to acetone in 700800 C, atmospheric pressure, no catalyst under the conditions of the cleavage reaction. Reaction equation: CH3COCH3 CH2 = C = O+ kJ / mol. The second step is to absorb the liquid acetic acid ethylene ketone anhydride generating. Reaction equation: CH2 = C = O+CH3COOH ( CH3CO ) 2O+ / mol. But in the same scale, acetone and acetic acid, acetone method requires larger cracking furnace, absorption tower and the washing tower, and an increase in cyclic acetone water distillation separation and other auxiliary equipment, the project construction cost is high. At the same time, the production cost is also higher acetone method. Ketene process relative acetaldehyde oxidation and carbonylation of methyl acetate to the process, the process is plex, a lot of side reactions, high energy consumption, low profit. Due to the production technology is mature, abroad in the early construction device using this method, in our country is still widely used. In 1973, Halcon Scientific Development Corporation obtained the carbonylation of methyl acetate to acetic anhydride production of patent. In 1983, the pany cooperates with American EastmanKodak pany built up the first set of the carbonylation synthesis of acetic anhydride production device. Celanese pany also has this technology. The production process is as follows: the first is the methanol and acetic 3 acid in sulfuric acid under the action of catalyst to generate methyl acetate, the reaction pressure is normal pressure, reaction temperature of 6585 C, the acetic acid conversion rate of about 100%. Then, methyl acetate and methanol and carbon monoxide in the methyl iodide and rhodium catalyst or nickel catalysts ( for rhodium catalyst catalytic activity of Ni catalyst is 10 times, so the industrial use of rhodium catalyst ) presence, for carbonylation reaction of acetic anhydride and acetic acid, cogeneration. The reaction pressure is about MPa, reaction temperature 180 degrees celsius. The acetic acid / acetic acid ratio can be adjusted according to the requirement. Reaction equation: CH3COOH+CH3OH CH3COOCH3+H2O。 CH3OH+CO CH3COOH