On the cycloaddition reaction of propylene with cumene hydroperoxide to produce propylene oxide and dimethylbenzyl alcohol
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Currently, I am working on the cyclization reaction of propylene and CMHP using molecular sieve catalysts; this reaction yields propylene oxide and dimethylbenzyl alcohol. As of now, there are no industrial plants in China that utilize this production route, and I believe this is likely due to the limitations associated with molecular sieve catalysts. In China, most efforts are focused on the hydrogen peroxide method. Those who are interested can discuss CMHP and the corresponding catalysts further.
Is the molecular sieve you are using a titania-silica molecular sieve? Are you using Ti-HMS or TS-1?
Hello, I use titanium-silica molecular sieves. The TS-1 type is not suitable; it belongs to the category of microporous catalysts, while CMHP molecules are large and require a mesoporous structure :)
It seems to be Ti-HMS.
The carrier for molecular sieves is not fixed; the cyclization effect after loading titanium needs to be evaluated specifically.
Haha, it seems you have some knowledge about preparing PO using the CMHP method:D
This post was last edited by Guderian on 2017-3-23 at 11:06. The literature mentions that amorphous titanosilicate materials, Ti-MCM-41, and Ti-HMS are all acceptable; of course, Ti-MCM-41 and Ti-HMS are essentially also amorphous titanosilicate materials. The main drawback of amorphous titanium-silicon materials is that their framework is too fragile.
Yes, we also deal with titanium-silica molecular sieves, ammonia oximation, and epoxidation. Why not use the direct method (HPPO)? The CMHP process is too complex; it also requires the use of oxygen and hydrogen, so its costs are not necessarily lower than those of the HPPO method.
MCM-41 and HSM-48 are both acceptable; what remains to be considered are factors such as the specific titanium loading, specific surface area, and structure. The HPPO method requires a high-concentration hydrogen peroxide system, whereas the CMHP method can use air for oxidation. The process is shorter than the co-oxidation method. Titanium-silica molecular sieves are a promising catalyst in the future.
Are your titanium-silica molecular sieves also used for olefin cyclization? Is there any practical application now?
HPPO does not necessarily require high-concentration hydrogen peroxide; the 27.5% and 35% hydrogen peroxide solutions that we are using work just fine. The production of 27.5% and 35% hydrogen peroxide is already a well-established technology in China. In fact, the epoxidation reaction itself is a one-step process; the CHP reaction produces dimethylbenzyl alcohol, and it’s somewhat troublesome to recycle this substance. The problem with HPPO is the energy consumption for evaporating methanol. The molecular sieve production technology we developed has enabled the construction of two production lines in collaboration with Shandong and Luxi Group Catalyst Company: one for titanium silicalite molecular sieves and another for ZSM-5 molecular sieves.