MTP Reaction Research Articles

A self-supported SS-fiber@meso-HZSM-5 core–shell catalyst via caramel-assistant synthesis toward prolonged lifetime for the methanol-to-propylene reaction

Self-supported SS-fiber@meso-HZSM-5 core–shell catalyst prepared by caramel-assistant hydrothermal synthesis, delivered dramatically prolonged lifetime for MTP reaction due to its hierarchical design and favourably-tuned acidic properties.

F-assisted synthesis of a hierarchical ZSM-5 zeolite for methanol to propylene reaction: a b-oriented thinner dimensional morphology

A hierarchical ZSM-5 zeolite with a thinner dimension morphology has been synthesized in fluoride medium, and presents a superior performance in MTP reaction.

Methanol to Propylene Process in a Moving Bed Reactor with Byproducts Recycling: Kinetic Study and Reactor Simulation

A moving bed reactor concept was introduced to the methanol to propylene process. To implement this concept, a modified kinetic model of MTP reaction on a special HZSM-5 pellet catalyst was developed; a moving bed reactor model in propylene yield platform period was proposed. Applying these two models, a two-stage moving bed in series with methanol quenched between stages was investigated. Water and part of the byproducts were recycled to the first moving bed reactor. Simulation results showed that the recycle of byproducts could increase the yield of propylene to 70%. The roles of higher hydrocarbons in the two reactors were different since they acted as reactants in the first moving bed while as products in the second one.

Synthesis of highly accessible ZSM-5 coatings on SiC foam support for MTP reaction

Highly accessible porous ZSM-5 coating with high loading and high adherence was successfully grown on SiC foam support using a two-step coating and steam-assisted crystallization process. The zeolite precursor gel pre-coated on the SiC foam surface and existed in the upper mixed coating layer functioned as a binder to firmly bond the SiC support and the pre-coated zeolite crystals with the formation of a dense ZSM-5 transition layer. The high porosity was achieved from the pre-coated zeolite crystals. The ZSM-5/SiC foam composite catalyst prepared by the proposed method showed higher propylene selectivity and propylene to ethylene (P/E) ratio, lower C1–C4 saturated hydrocarbons and aromatics and as well as higher stability in comparison to that prepared by conventional in situ hydrothermal process in methanol to propylene reaction.

The joint reaction of methanol and i-butane over the HZSM-5 zeolite

The effects of i-butane addition to methanol in MTP reaction were investigated over an in-house prepared HZSM-5 catalyst. It was observed that, propylene yield would be enhanced when i-butane fed to the reactor along with methanol. The rising growth of the propylene yield continued to peak on till the balance in thermal condition established. Similar trends have been observed when water was added to the mixture. The effect of WHSV with fixed water composition on product distribution was also studied. The optimum point where the highest amount of propylene yielded was shown to be high depended upon the temperature and residence time.

Selective production of propylene from methanol: Mesoporosity development in high silica HZSM-5

The mesoporosity development in high silica HZSM-5 was carried out by alkaline desilication treatment and soft template method, and its relationship with the catalytic performance of the modified catalysts in methanol-to-propylene reaction was studied. High propylene selectivity (42.2%) and propylene/ethylene ratio (10.1) were observed on the high silica HZSM-5 catalyst modified by alkaline desilication. The enhanced catalytic performance can be attributed to the newly created open mesopores on the surface of the zeolite crystals together with the low Brønsted acidity. A greater amount of mesoporosity could be readily formed in HZSM-5 crystals via the soft template route. However, the mesopores formed in this method are randomly distributed in the zeolite crystals and play a minor role in the molecular transport of the reaction, so the improvement in propylene selectivity and propylene/ethylene ratio of the catalyst is less evident. The higher propylene selectivity and propylene/ethylene ratio on modified HZSM-5 (especially by alkaline treatment) than unmodified HZSM-5 could be also related to different contributions of the methylaromatics route and olefins methylation/cracking route in MTP reaction.