Catalytic Performance Of Nano-ZSM-5 Zeolite In The Reaction Of Aromatization And Cyclamination

In this paper, we focus on the catalytic performance of nano-ZSM-5 Zeolite in the reaction of aromatization and cyclamination which are as follows:(1) Use C₄LPG to produce high octane number gasoline with low content of sulfur and alkene.(2)Use cheaper monoethanolamine(MEA) to produce triethylenediamine(TEDA) with high additional value under the condition of atmospheric pressure and without carrier gas.The effects of crystal size, reaction conditions, and modification on catalytic performance of HZSM-5 catalysts are comparatively studied. The catalytic performance of the catalyst which is used in the reaction of MEA cyclaminating to TEDA after 4 rounds deactivation-regeneration is estimated, and furthermore, the effect of recycling the seperated mother liquor on the reaction of cyclamination of MEA is investigated.Results show that, nano-sized HZSM-5 catalyst possesses high tolerance ability for coke and favorable catalytic performance due to its smaller size and shorter channel of micropore. Stability is improved and better activity is preserved when the pores of the nano-sized catalyst is enlarged pore with acid after hydrothermal treatment. When modified with appropriate metal at suitable loading the activity of ZSM-5 catalyst is improved effectively.In the aromatization of C₄LPG, high coking speed of the catalyst is seen when pressure is too low, and the activity of aromatization is depressed when pressure is too high. When improper WHSV_lpg condition is used, negative influence on the aromatization activity of the catalyst is obvious.Increasing temperature increases the conversion of MEA and the selectivity of TEDA. The conversion of MEA and the selectivity of TEDA are depressed obviously when the WHSV of mixed feed is increased excessively. The catalytic performance of nano-ZSM-5 catalyst can be kept well after 4 times deactivation-regeneration. On the distribution of product, the activity, the selectivity, and the stability of the catalyst, the effect of seperated mother liquor reclamation instead of ammonia is unconspicuous.