| Resorcinol, an important fine organic intermediate, has been widely used for many fields such as agriculture, dyestuff, dope, medicine, adhesive and latex. As the rapid development of automobile industry, the output of tyres will be enlarged so much that the output of resorcinol produced at home can't meet the demand in the market. In another case, the technics for resorcinol at home gives low resorcinol yield but too many pollutants polluting the environment seriously. With a higher requirement for quality of resorcinol and the more focus on environmental protection, the research on new technics of resorcinol having better environmental effects is very needed.The traditional technics for resorcinol with sulfuric acid was firstly improved. The results show that the operation conditions were too atrocious and it gave out so many pollutants to pollute the environment seriously. Furthermore the equipments were greatly eroded since lots of acids and alkalis were used. It gave low resorcinol yield but high subsidiary products yield. And it can hardly be continued to improved and its developing potential is too low.A process for the preparation of resorcinol from diisopropylbenzene (DIPB) has been mainly introduced in this paper. And a feasible technics was proposed as the followings: Firstly, DIPB was oxidized for about 20~25 hours to the diisopropyl- benzene dihydroperoxide (DHP) or diisopropylbenzene hydroxyhydroperoxide (HHP) under anhydrous, non-alkaline conditions with oxygen at 85℃ and the remaining unreacted DIPB was recycled to the feed stream for further hydroperoxidation. Secondly, the hydroperoxidation products were extracted with 4%NaOH and stripped with methyl isobutyl ketone (MIBK) at about 80℃. The extracts were pretreated with hydrogen peroxide. Lastly, the product drying with 4A sieves was decomposed at 50℃ for about 20 minutes in the presence of a catalyst boron trifluoride, and the rude resorcinol was gained by aether extracted. In a single process, 20% resorcinol yield was achieved and about 40% yield was finally achieved with recycle processes. The results show that the presence of water will bring out more subsidiary reactions and the control on temperature is important in the course of experiment because DHP is very unstable on heat. Besides, it is propitious to improve the yield to carry out the pretreat process since it will convert HHP to DHP. Water will decrease the activity of boron trifluoride so the m-DHP fraction must be dried best with 4A sieves before decomposition with boron trifluoride. Some contrasts have been studied between the technics with DIPB and with sulfuric acid. And the results show that the technics with DIPB is very new, which can offer us a better environmental effect, fewer pollutants, a higher material using ratio and a larger market for subsidiary productions. It can be concluded that the technics with DIPB will be a perfect substitute for that with sulfuric acid. And some proposes were put forward on its further study according to the results of the technics for preparation of resorcinol from DIPB in this paper. |
