Catalytic Cracking of Heavy Olefins into Propylene, Ethylene and Other Light Olefins

Abstract

Hybrid catalysts developed for the thermocatalytic cracking of liquid hydrocarbons were found to be capable of cracking C 4 ? olefins into light olefins with very high combined yields of product ethylene and propylene (more than 60 wt%) and C 2 -C 4 olefins (more than 80 wt%) at 610-640°C, and also with a propylene/ethylene weight ratio being much higher than 2.4. The olefins tested were heavier than butenes such as 1-hexene, C 10 ? linear alphaolefins (LAO) or a mixture of LAO. The hydrogen spillover effect promoted by the Ni bearing co-catalyst, contributed to significantly enhancing the product yield of light olefins and the on-stream stability of the hybrid catalyst.Keywords TCC-type hybrid catalysts Á Cracking of heavy olefins Á Effect of hydrogen spillover on product yields and coke deposition

Mixed Naphtha/Methanol Feed Used in the Thermal Catalytic/Steam Cracking (TCSC) Process for the Production of Propylene and Ethylene

“…In our previous papers [3,[6][7][8]15], the use of a co-catalyst having some hydrogen-spillover capacity induced some coke cleaning effect on the zeolite acid surface, resulting thus in a better catalyst on-stream stability.…”

“…The Thermal Catalytic/Steam Cracking (TCSC) process [3], formerly called SDCC or selective deep catalytic cracking [4,5], and then TCC or thermo-catalytic cracking [6][7][8], has been developed with the objective to selectively produce light olefins from various liquid hydrocarbon feedstocks. The TCSC process, which combines the (mild) thermal cracking with the acid cracking promoted by a zeolite-based catalyst, can provide very high yields of light olefins while operating at temperatures much lower than those used in the steam cracking technology.…”

“…Therefore, the rigid and ''ideally sparse particles configuration'' of the hybrid catalyst ensures an easy two-way diffusion (of reaction intermediates) within the catalyst network; this is the so-called ''pore continuum'' effect, which has been observed on many occasions, such as in adsorption/desorption [11], and in different catalytic reactions such as aromatization and cracking [9,10,12,13]. It has been seen that the co-catalyst can exert some ''cleaning action'' on the coke precursors so that coking of the main catalyst surface can be significantly reduced [3,[6][7][8]. This beneficial effect has been attributed to the action of hydrogen spillover species [3 and refs therein, particularly ref.…”

Nine-Lump Kinetic Study of Catalytic Pyrolysis of Gas Oils Derived from Canadian Synthetic Crude Oil

“…Having higher light olefin yields, lower energy consumption, and wider feed scope are a number of advantages of this process over conventional steam cracking. The catalytic pyrolysis feeds include butane [1,2] or heavier alkanes [3,4], butene [5,6] or heavier olefins [7][8][9], 5 raffinate [10], natural gasoline [11], naphtha [12,13], fluid catalytic cracking naphtha [14,15], coker naphtha [15], gas oil [16,17], heavy oil [18,19], waste tire [20], plastic mixture [21], and bio-oil or biomass [22,23].…”

The Thermo-Catalytic Cracking of Hydrocarbons: Effect of Polymethylbenzenes Added to the n-Hexane Feed on the Reactivity of ZSM-5 Zeolite Containing Hybrid Catalyst

“…The thermo-catalytic cracking process (TCC) has been recently developed to crack heavy hydrocarbon feedstocks (naphthas, gas oils) [1,2] or heavy olefins [3] into propylene, ethylene and other light olefins. The most recent TCC catalysts have a hybrid configuration, comprising a main (acidic) component and a co-catalyst [1][2][3].…”