The Process Route Of 200 Ton/a 1- Bromopropane Production And Waste Acid Management

Based on the general method of taking the concentrated sulfuric acid to catalyse 1-propanol reacting with hydrobromic acid to produce 1-bromopropane, an improved process has been developed in consideration of the production rate, reaction time, sulfuric acid dosage and post-processing of by-products. The main results are as follows:(1)In the process, sulfuric acid was added dropwise and replenished into the reaction mixture, which can avoid the hydrogen bromide gas escaping caused by sulfuric acid one-time join, and the yield increased from 80%~90% to 95%~97%. In the process of heat preservation, reaction and distillation were carried out simultaneously, distilling the 1-bromopropane from the 1-propanol,promoting the balance to generate 1-bromopropane direction. The product was washed by water, acid, water and alkali successively, and rectified to get 1-bromopropane with a purety of more than 97%.(2)The improved process also recycled the sulfuric acid from the refined procedure, along with all the waste sulfuric acid to realize the zero discharge. The recovery sodium bisulfate was heated in 1-propanol to produce sulfuric acid and sodium sulfate. The sodium sulfate was collected as a by-product, and the sulfuric acid and 1-propanol in the filtrate were recovered and reused for the next run. The consumed sulfuric acid was transformed into sodium sulfate as a by-product.(3)The modified process was designed based on the annual output of 200 tons 1-bromopropane and waste acid treatment. Semi-continuous production was used to replace oringinal method. Aspen Plus was used to simulate the technical process material balance and heat balance of the whole process were calculated. The flow chart with control points and the material flow chart of reaction synthesis section, products refined section and waste acid treatment phase have been drawn by AutoCAD&PID. Combined with chemical engineering design and industrial production, the main equipments were also selected and designed according to the modified process.The improved process was simple, normol pressure reaction, safe and reliable with high yield and purity. The process realized the recycling of sulfuric acid, getting the by-product sodium sulfate at the same time, and no waste gas and waste acid discharged during the production. At the same time, the raw material and energy was saved, and the production cost was reduced.