A regeneration device, a device for preparing low-carbon olefins, and a use thereof are provided. The regeneration device includes a first regenerator and a second regenerator; a first activation zone of the first regenerator is connected to the second regenerator through a pipeline, such that a catalyst in the first activation zone is able to be delivered to the second regenerator; and the second regenerator is connected to a gas-solid separation zone of the first regenerator through a pipeline, such that a catalyst in the second regenerator is able to be delivered to the gas-solid separation zone. The regeneration device can adjust the coke content, coke content distribution, and coke species in a dimethyl ether/methanol to olefins (DMTO) catalyst to control an operation window of the DMTO catalyst, which improves the selectivity for low-carbon olefins and the atomic economy of a methanol-to-olefins (MTO) technology.

Disclosed in the present invention is a tail gas treatment catalyst. The catalyst consists of a carrier, a first catalyst, and a second catalyst. The first catalyst and the second catalyst are provided on both ends of the carrier. The first catalyst can purify pollutants in tail gas. The second catalyst can purify a byproduct, ammonia, obtained by the purification by the first catalyst and pollutants that are not completely purified by the first catalyst. The second catalyst is of a double-layer structure; the lower layer consists of an oxygen storage material, aluminum oxide, and a second active component; the second active component is a composition of Pt and Pd, or a composition of Ce, Fe, Ni and Cu; the upper layer consists of a molecular sieve and a third active component; the third active component is Cu or a composition of Cu and Fe. The tail gas treatment catalyst of the present invention has high purification treatment efficiency, and can significantly reduce the emissions of CH.sub.4, CO, and NO.sub.x in the tail gas, especially reduce the content of the byproduct, NH.sub.3, so that the tail gas can meet China VI emission standards.

Disclosed in the present invention is a tail gas treatment catalyst. The catalyst consists of a carrier, a first catalyst, and a second catalyst. The first catalyst and the second catalyst are provided on both ends of the carrier. The first catalyst can purify pollutants in tail gas. The second catalyst can purify a byproduct, ammonia, obtained by the purification by the first catalyst and pollutants that are not completely purified by the first catalyst. The second catalyst is of a double-layer structure; the lower layer consists of an oxygen storage material, aluminum oxide, and a second active component; the second active component is a composition of Pt and Pd, or a composition of Ce, Fe, Ni and Cu; the upper layer consists of a molecular sieve and a third active component; the third active component is Cu or a composition of Cu and Fe. The tail gas treatment catalyst of the present invention has high purification treatment efficiency, and can significantly reduce the emissions of CH.sub.4, CO, and NO.sub.x in the tail gas, especially reduce the content of the byproduct, NH.sub.3, so that the tail gas can meet China VI emission standards.

A method for fluid catalytic cracking (FCC) of petroleum oil feedstock includes reacting the petroleum oil feedstock with a catalyst mixture in a reaction zone of an FCC unit to obtain a product stream including desulfurized hydrocarbon product, unreacted petroleum oil feedstock, and spent catalyst. During the reacting a process control system develops a process model based on data collected during the reacting, the process model characterizing a relationship among the feed rate of the base cracking catalyst, the feed rate of the FCC additive, the operating conditions, the composition of the product stream, and emissions from the reaction; and one or more of (i) a target feed rate of the base cracking catalyst, (ii) a target feed rate of the FCC additive, and (iii) one or more target operating conditions of the reaction in the reaction zone to reduce the emissions from the FCC unit and to increase a yield of the desulfurized hydrocarbon product in the product stream are determined.

The invention relates to a process of converting methanol in a fluidized bed reactor comprising feeding a methanol-containing feedstock into a fluidized bed reactor, contacting the feedstock with a catalyst, to produce a product comprising ethylene and propylene under effective conditions; the fluidized bed reactor comprises a diluent-phase zone and a dense-phase zone, wherein the diluent-phase temperature difference between any regions of the diluent-phase zone having a methanol concentration of more than 0.1 wt % (preferably more than 0.01 wt %) in the fluidized bed reactor is controlled to be less than 20° C., and the dense-phase temperature difference between any regions in the dense-phase zone having a methanol concentration of more than 0.1 wt % (preferably more than 0.01 wt %) in the fluidized bed reactor is controlled to be less than 10° C.

The invention relates to a process of converting methanol in a fluidized bed reactor comprising feeding a methanol-containing feedstock into a fluidized bed reactor, contacting the feedstock with a catalyst, to produce a product comprising ethylene and propylene under effective conditions; the fluidized bed reactor comprises a diluent-phase zone and a dense-phase zone, wherein the diluent-phase temperature difference between any regions of the diluent-phase zone having a methanol concentration of more than 0.1 wt % (preferably more than 0.01 wt %) in the fluidized bed reactor is controlled to be less than 20° C., and the dense-phase temperature difference between any regions in the dense-phase zone having a methanol concentration of more than 0.1 wt % (preferably more than 0.01 wt %) in the fluidized bed reactor is controlled to be less than 10° C.

A process for producing lower olefins from oxygenates includes the steps of contacting a feedstock comprising oxygenates with molecular sieve catalyst in fluidized bed reaction zone under effective conditions, to produce product including ethylene and/or propylene;

the effective conditions include that in the fluidized bed reaction zone, the weights of catalysts having various carbon deposition amounts are controlled, calculated as the weight of the molecular sieve in the catalysts, to have the following proportions based on the total weight of the catalysts in the fluidized bed reaction zone:

the proportion of the weight of the catalyst having a coke deposition amount of less than 3 wt % is 1-20 wt %;

the catalyst having a coke deposition amount of from 3 wt % to less than 5 wt % represents 10 to 70 wt %;

the catalyst having a coke deposition amount from 5 wt % to 10 wt % represents 10 to 88 wt %.

A process for preparing C.sub.2 to C.sub.4 olefins includes introducing a feed stream of hydrogen gas and a carbon-containing gas into a reaction zone of a reactor and converting the feed stream into a product stream including C.sub.2 to C.sub.4 olefins in the reaction zone in the presence of a hybrid catalyst and in a non-oxidative atmosphere. The hybrid catalyst includes a metal oxide catalyst component comprising gallium oxide and zirconia, and a microporous catalyst component having an 8 membered ring structure. The process also includes periodically introducing an oxidative atmosphere into the reaction zone.

A process for preparing C.sub.2 to C.sub.4 olefins includes introducing a feed stream of hydrogen gas and a carbon-containing gas into a reaction zone of a reactor and converting the feed stream into a product stream including C.sub.2 to C.sub.4 olefins in the reaction zone in the presence of a hybrid catalyst and in a non-oxidative atmosphere. The hybrid catalyst includes a metal oxide catalyst component comprising gallium oxide and zirconia, and a microporous catalyst component having an 8 membered ring structure. The process also includes periodically introducing an oxidative atmosphere into the reaction zone.

A bifunctional catalyst for example for conversion of oxygenates, the bifunctional catalyst comprising zeolite, alumina binder, Zn and P, wherein Zn is present at least partly as ZnAl.sub.2O.sub.4.