propylene catalytic cracking catalysts

Title: propylene catalytic cracking catalysts
　　Author: Geng-shan
　　Degree awarded: China University of Petroleum
　　Keywords: catalytic cracking;; propylene;; ZSM-5;; vermiculite
　　Summary:
　　Propylene is an important petrochemical basic raw materials. Two-stage riser catalytic cracking of propylene (TMP) technology, supporting catalyst LTB-2 in ZSM-5 as the active component, thermal stability and heavy oil into the water to poor. This paper from the molecular sieve and matrix, respectively, two aspects of the study to earth - phosphorus Neodymium Magnets modified ZSM-5 to improve the hydrothermal stability of mesoporous acidic materials in order to add the catalyst to improve heavy oil conversion capacity.
　　Study found that ZSM-5 zeolite rare earth - the optimal solution of phosphorus modified as follows: using impregnation method, first to introduce cerium in ZSM-5, and then at pH = 6.0 under the conditions of the introduction of phosphorus. Ce-Modified, phosphorus and cerium phosphate modified zeolite structure modification on almost no effect. Ce-modified ZSM-5 surface of fine particles resulting cerium modified ZSM-5 crystallinity decreased, the smallest increase in the amount of acid; phosphorus modified ZSM-5 crystals have a small reunion, the largest increase in the amount of acid, phosphorus can also inhibit zeolite hydrothermal aging process in the crystalline phase transition; cerium - phosphorus modified ZSM-5 surface of the joint no significant change in the amount of increase in acid medium. And compared to the unmodified ZSM-5, modified ZSM-5 crystallinity with aging time prolonged decline slowed. Common laboratory and industrial test results to prove: the cerium phosphate modified ZSM-5 catalyst for the preparation of the active component, not only with a substantial increase in hydrothermal stability and catalytic cracking activity has also been enhanced.
　　Natural vermiculite modified with a larger surface area, pore volume and pore size appropriate, a small amount of acid modified vermiculite B acid, modified pillared vermiculite of a large number of B acid and a small amount of L acid. Layer of vermiculite water column thermal stability, acid modified vermiculite slightly stronger than the thermal stability of the water, add a small amount of acid in the catalyst modified vermiculite Shiyou Li on improving heavy oil conversion capacity. However, if the added amount of acid modified vermiculite is too high, dissolution of magnesium which will be played with the zeolite acid sites and the role, leading to lower yield of propylene and LPG, it is not appropriate as a catalyst for propylene catalytic cracking activity of the carrier.
　　Spinel materials, the best preparation conditions: use of hydrochloric acid to be boehmite gel preparation of aluminum, magnesium http://www.everbeenmagnet.com/en/products/110-sintered-neodymium-magnets aluminum atomic ratio of raw materials in the stoichiometric MgAl2O4, after drying the slurry mixture 800oC roasting. Prepared by impregnation of the modified spinel materials only weak L acid. Prepared by hydrothermal synthesis of modified spinel material with strong acid and a small amount of B L in the strong acid, and the aging of heavy oil still has a good ability to transform, can be partially replaced by kaolin, to improve heavy oil catalytic cracking catalyst performance.
　　Degree Year: 2010...