(1) 25% ammoniacal liquor of 937kg10 DEG C is put into amidation reaction still, 1000kg phthalic anhydride is dropped into amidation reaction still, ammoniacal liquor and phthalic anhydride react in the environment below 30 DEG C and generate o-formamide benzoic acid amine, reaction Time 2.5h. The 25% ammonia water that actually participated in the amidation reaction was 892.3 kg, and 937 kg of 25% ammonia water was added to make the amidation reaction more complete and complete.
(2) after amidation reaction, put 879kg30% sodium hydroxide solution into amidation reaction kettle, o-formamide benzoic acid amine and sodium hydroxide generate displacement reaction to generate o-formamide sodium benzoate, then amidation reaction kettle The temperature inside rises to 50°C, the ammonia molecules in the mixed solution are evaporated, and the evaporated ammonia gas is led to the secondary series water absorption tower by the induced draft fan to absorb the water to obtain ammonia water, and the ammonia water is sent to the ammonia water storage tank, and the ammonia water is sent to the ammonia water storage tank. Liquid ammonia is added into it, and it is made into 25% ammonia water for reuse.
(3) the solution in the amidation reactor is pushed into the esterification reactor, put into the methanol solution of 1561kg75% and the sodium hypochlorite solution of 3451kg14% in the reactor, keep the temperature in the esterification reactor is 10 ℃, the reaction A paste-like Methyl Methyl Anthranilate was generated, and the reaction time was 3 hours. After the reaction was completed, the temperature in the esterification reaction kettle was raised to 50°C. After the paste Methyl Methyl Anthranilate was dissolved, 1000kg of hot water was added to the esterification reaction kettle.
(4) the solution in the esterification reaction kettle is sent into the methyl ester settling tank to stand and divide, the solution of the upper stratum is pumped into the methanol recovery operation, the solution of the lower stratum obtains the filtrate through the jet vacuum pump suction filtration, and the filtrate passes through the secondary After standing, the solution of the upper layer was pumped into the methanol recovery process, and the filtrate of the lower layer was pumped into the still, and distilled in an environment with a pressure of 2.00Kpa and a temperature of 135.5°C to obtain the finished product.
The solution sent to the methanol recovery process is pumped into the methanol rectification tower. Using the different boiling points of the components in the solution, the methanol in the solution is first evaporated, the methanol vapor is condensed to obtain a methanol solution, and the remaining solution is cooled and crystallized. It is sent to a centrifuge and can be sold as industrial salt after centrifugation.