A process for preventing hazardous conditions at startup and shutdown of a reactor by sending an inert gas such as nitrogen to strip entrained oxygen from the catalyst when reactor temperatures are below about 240° C. During normal operation the entrained oxygen reacts with hydrocarbons to produce oxides but at the lower temperatures that are present at startup or shutdown these reactions do not occur sufficiently leaving oxygen that can cause hazardous conditions as temperatures increase upon startup. When the temperature is in the safe operating zone above 240° C., the nitrogen gas is stripped by air or other oxygen containing gas.

A fluidized bed regenerator, a device for preparing low-carbon olefins, and a use thereof are provided. The fluidized bed regenerator includes a second activation zone, a first activation zone, and a gas-solid separation zone from bottom to top; the second activation zone axially communicates with the gas-solid separation zone; the first activation zone is arranged on a periphery of a junction between the second activation zone and the gas-solid separation zone; the first activation zone is an annular cavity; n baffles are radially arranged in the first activation zone, and the n baffles divide the first activation zone into n first activation zone subzones; and a catalyst circulation hole is formed in each of n−1 of the baffles such that a catalyst entering the first activation zone flows in an annular direction.

A fluidized bed regenerator, a device for preparing low-carbon olefins, and a use thereof are provided. The fluidized bed regenerator includes a second activation zone, a first activation zone, and a gas-solid separation zone from bottom to top; the second activation zone axially communicates with the gas-solid separation zone; the first activation zone is arranged on a periphery of a junction between the second activation zone and the gas-solid separation zone; the first activation zone is an annular cavity; n baffles are radially arranged in the first activation zone, and the n baffles divide the first activation zone into n first activation zone subzones; and a catalyst circulation hole is formed in each of n−1 of the baffles such that a catalyst entering the first activation zone flows in an annular direction.

A method for improving the light olefin yield in the process of preparation of a light olefin using an oxygen-containing compound, more specifically, in which, a multi-stage dense phase fluidized bed comprising k secondary pre-carbon deposition zones (k≧1) and n secondary reaction zones (n≧1) is used as a reactor, and a multi-stage dense phase fluidized bed regenerator comprising in secondary regeneration zones (m≧2) is used as a main equipment, and by re-refining hydrocarbons with four or more carbons obtained in the separation section, or adding naphtha, gasoline, condensate oil, light diesel oil, hydrogenation tail oil or kerosene in the reaction zone, the method primarily solves the problems in the prior art of the uniformity of carbon deposition amount and the carbon content of the catalyst being difficult to control, and the light olefin yield being low.

A method for preparing a light olefin using an oxygen-containing compound, and a device for use thereof, more specifically, taking methanol and/or dimethyl ether as main starting materials, using a multi-stage (n≧2) dense phase fluidized bed reactor and a multi-stage (m≧2) catalyst regenerator, which solves the problem in the prior art of the uniformity of catalyst carbon deposition and the carbon content being difficult to control and the light olefin selectivity being low.

A regeneration method for catalytic cracking reaction, the method is applied in a catalytic reaction process of petroleum hydrocarbon materials, and the method comprises: feeding the regenerated and semi-regenerated catalyst from a regenerator separately into different positions of a reactor for reaction. A part of the semi-regenerated catalyst is firstly processed in a purification cooler for removing carried nitrogen, oxygen, carbon dioxide and impurity gases before being fed into the reactor. Spent catalyst or the purified and cooled semi-regenerated catalyst is fed into a catalyst mixing section of the reactor for controlling the temperature of the catalyst being contact with the oil material to be gasified, thereby achieving a three stage cycle of the catalyst in the reactor and a three stage control for the reaction outlets of the oil material gasification zone and the cracking reaction zone and the catalyst taking part in the reaction.

A fluidized catalytic reactor system cycles from 0.05-5% of catalyst at a time through a rejuvenation unit to be heated in the presence of oxygen to maintain catalyst activity. The use of the rejuvenation unit that may be 2% of the size of the main catalyst regeneration unit allows for reduction in equipment size and in catalyst inventory. The catalyst that is sent to the rejuvenation unit may be spent catalyst but may be partially or fully regenerated catalyst. The rejuvenation unit may be heated by combusting fuel or by hot flue gas.

A counter-current catalyst regenerator with at least two stages of counter-current contact is proposed. Each stage may comprise a permeable barrier that allows upward passage of oxygen-containing gas and downward passage of coked catalyst into each stage, but inhibits upward movement of catalyst to mitigate back mixing and approximate true counter-current contact and efficient combustion of coke from catalyst.

A counter-current catalyst regenerator with at least two stages of counter-current contact is proposed. Each stage may comprise a permeable barrier that allows upward passage of oxygen-containing gas and downward passage of coked catalyst into each stage, but inhibits upward movement of catalyst to mitigate back mixing and approximate true counter-current contact and efficient combustion of coke from catalyst.

The present disclosure provides an air-soak containing regeneration process reducing its time. The process includes (i) removing surface carbon species from a gallium-based alkane dehydrogenation catalyst in a combustion process in the presence of a fuel gas; (ii) conditioning the gallium-based alkane dehydrogenation catalyst after (i) in air-soak treatment at a temperature of 660 C. to 850 C. with (iii) a flow of oxygen-containing gas having (iv) 0.1 to 100 parts per million by volume (ppmv) of a chlorine source selected from chlorine, a chlorine compound or a combination thereof; and achieving a predetermined alkane conversion percentage for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iv) 10% to 50% sooner in air-soak treatment than that required to achieve the same predetermined alkane conversion percentage for the gallium-based alkane dehydrogenation catalyst undergoing the air-soak containing regeneration process using (i) through (iii), but without (iv).