Effect of the Post‐Treatment of HZSM‐5 on Catalytic Performance for Methanol to Aromatics

Abstract

The preparation of aromatic by methanol was the most effective way for rational utilization of resources. However, the catalyst for MTA reaction has not yet been successfully studied. Therefore, highly active and shape‐selective HZSM‐5 zeolite‐based catalysts were designed and synthesized by post‐treatments of desilication, dealumination, surface‐passivation and hydrothermal treatment tuning pore structure and acid amount and acid concentration of catalysts. XRD, SEM, TEM, BET, NH3‐TPD and Py‐IR were used for research and analysis the structure‐activity relationship between the catalysts and MTA reaction. The results showed that the total acid amount of catalyst shown a significant role in increasing the BTX selectivity. The selectivity of aromatics increased from 33 % to 58.1 % after hydrothermal treatment compared to the parent HZSM‐5 zeolite due to the decreased of total acid amount. Nevertheless the weak acid sites were crucial in increasing the p‐xylene selectivity. The selectivity of p‐xylene reached 63.8 % and 70.1 % after hydrothermal treatment and surface‐passivation due to the increased of weak acid sites, respectively. Modified HZSM‐5 zeolite‐base catalysts showed good application prospects in producing aromatics from methanol.

Selective Formation of Para-Xylene by Methanol Aromatization over Phosphorous Modified ZSM-5 Zeolites

“…However, it is imperative to develop new technologies because of the depletion of oil. The conversion of methanol to hydrocarbons over acidic zeolite catalysts is now considered an important and feasible non-petroleum route to obtain valuable chemicals [10][11][12][13][14][15][16][17][18]. Therefore, it is a significative work to design a shape selectivity catalyst for high PX selectivity in methanol to aromatics conversion (MTA).…”

Renewable p-Xylene Production by Catalytic Conversion of Crude Bioglycerol (GTA-pX Process)

“…Aromatic compounds, which include benzene, toluene, and xylenes (BTX), are the potential building blocks for a wide variety of products, such as plastics, resins, solvents, and pharmaceuticals, and the demand for BTX is progressively growing due to the rapid development of these applications. , Among them, para -xylene ( p -X) is considered to be a special aromatic building unit used for the production of terephthalic acid and dimethyl-terephthalate, essential monomers for the synthesis of a variety of end products such as poly­(ethylene terephthalate) (PET) bottles, fibers, resins, plastics, etc. , Terephthalic acid was mainly produced by an AMOCO process that involves aerobic catalytic oxidation of p -xylene in an acid medium using cobalt, manganese, and bromide catalysts . It was estimated that the global market for p -X has consistently grown by ∼10% annually over the last several years and reached 45 million tons in 2016 .…”

CFD-PBE Simulation of para-Xylene Crystallization Behavior and Process Amplification under Different Operating Conditions

“…para -Xylene (PX) is an organic compound in which two hydrogen atoms at the para position on the benzene ring are swapped for methyl groups. It is one of the most significant aromatic hydrocarbon compounds and the primary raw material for many petrochemical products. − In the industrial production, high-purity p -xylene is obtained from mixed xylene by adsorption or crystallization. , If the mother liquor's PX concentration is low, the adsorption technique will be more efficient. Otherwise, using the crystallization technique is more advantageous.…”