Catalytic cracking propylene assistant and preparation method thereof

Abstract

The invention discloses a catalytic cracking assistant for increasing the yield of propylene. Based on the total weight of the assistant, the assistant comprises 20-60% of HZSM-5 molecular sieve, 5-25% of phosphorus / aluminum oxide, 6-12% of silica-alumina gel carrier and the balance of kaolin, wherein the SiO2 / Al2O3 mol ratio of the HZSM-5 molecular sieve is (25-500):1; the phosphorus / aluminum oxide is aluminum phosphate; and the silica-alumina gel carrier is silica-alumina gel. The catalytic cracking assistant disclosed by the invention is used in the catalytic cracking process of petroleum hydrocarbon; and the yield of propylene is increased, the octane number of gasoline is increased, and the loss of the main product catalytic gasoline component can be obviously reduced.

Description

technical field [0001] The invention relates to an auxiliary agent for increasing the production of propylene in a catalytic cracking unit of a refinery and a preparation method thereof. Background technique [0002] Propylene is an important basic chemical raw material. With the development of the national economy, the market demand for propylene is getting stronger and stronger, and the demand gap is getting bigger and bigger. In recent years, the annual growth rate of global demand has exceeded 6.3%, and the growth rate is much faster than that of ethylene. Although 66% of the propylene is mainly from the co-production of steam cracking to ethylene, it is limited by raw material cost, processing capacity, investment scale, etc.; while the catalytic cracking process (FCCU) produces about 32% of the propylene by-product, and can also use heavy oil As a raw material, propylene can be produced through deep cracking. Especially in recent years, China's oil refining industry ...

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Problems solved by technology

[0007] CN101474573A ZSM-5 phosphoraluminum glue modification, kaolin carrier, adding rare earth, wherein the aluminum source is pseudoboehmite; CN102049284A phosphoraluminum glue plus kaolin carrier, wherein the aluminum source is aluminum sol; CN102049284A phosphoraluminum glue carrier, wherein the aluminum source It is pseudo-boehmite; CN102188992A Modification of phosphorus oxide and metal oxide, using alumina, silicon oxide dry powder plus acidic silica sol or aluminum sol as binder, because silicon and aluminum sol are used as binder, propylene aids The agent bulk density is higher than 0.80, and the specific surface area is lower than 64m 2 / g, and the amount of ZSM-5 is also high, more than 50%; CN102872902A adds alkali metal oxide CaO, rare earth oxide and non-metal oxide B in the preparation process of auxiliary agent 2 o 3 To increase the concentration of propylene in liquefied gas without increasing the yield of liquefied gas, but the amount of ZSM-5 molecular sieve is very high, reaching 50-75%, and the preparation cost is high

[0008] The catalytic cracking catalysts or additives for increasing the production of propylene disclosed in the prior art increase the selectivity of molecular sieves to light olefins through the modification of ZSM-5, and the propylene yield increases, but it also makes the gasoline yield significantly decrease. In terms of carrier , mainly use kaolin as filler, phosphoraluminum glue as binder, or add some oxides such as pseudoboehmite, aluminum sol, and silica sol, etc., the additives or density are high, the specific surface is low or the molecular sieve content high cost