The present invention relates to the field of high polymer material manufacturing, and discloses an air-isolated continuous feeding system for synthesizing polylactic acid from lactide and a feeding method thereof. The continuous feeding system comprises a raw material bag/box and a raw material collector for collecting and outputting lactide, the raw material bag/box is connected with a shielding gas input pipeline, a discharge pipe is movably inserted into the raw material bag/box, a cyclone separator is connected downstream of the discharge pipe, and a solid substance outlet of the cyclone separator is connected with the raw material collector. According to the invention, deterioration of the lactide raw material incurred by moisture absorption and oxidation is avoided, and the reaction conversion ratio and final product purity are improved. The continuous feeding system is easy to operate, can save manpower and material resources, and is applicable to industrial application.

A method for processing a chemical stream includes contacting a feed stream with a catalyst in an upstream reactor section of a reactor having the upstream reactor section and a downstream reactor section, passing an intermediate product stream to the downstream reactor section, and introducing a riser quench fluid into the downstream reactor section, upstream reactor section, or transition section and into contact with the intermediate product stream and the catalyst to slow or stop the reaction. The method includes separating at least a portion of the catalyst from the product stream, passing the product stream to a product processing section, cooling the product stream, and separating a portion of the riser quench fluid from the product stream. The riser quench fluid separated from the product stream may be recycled back to the downstream reactor section, upstream reactor section, or transition section as the riser quench fluid.

The present disclosure relates to fluid bed processes that utilize silica particles as a fluidization aid. The process comprises reacting one or more reactants in a reactor comprising a fluid bed to form a product. The fluid bed comprises a catalyst composition comprising a catalyst and an inert additive composition comprising silica particles from 0.5 wt % to 30 wt %, based on the total weight of the catalyst composition. The silica particles are discrete, inert particles that are mixed with the catalyst in the fluid bed.

A device for cooling a fine-grained solid includes a fluidized bed cooler/heater in which the solid is fluidized with a fluidizing gas and thereby releases energy in the form of heat within the cooler/heater at least two cyclones which are connected in parallel. The cyclones are arranged such that after the fluidization of the solid the fluidizing gas passes through the cyclones so contained particles are removed.

Apparatus and processes herein provide for converting hydrocarbon feeds to light olefins and other hydrocarbons. The processes and apparatus include, in some embodiments, feeding a hydrocarbon, a first catalyst and a second catalyst to a reactor, wherein the first catalyst has a smaller average particle size and is less dense than the second catalyst. A first portion of the second catalyst may be recovered as a bottoms product from the reactor, and a cracked hydrocarbon effluent, a second portion of the second catalyst, and the first catalyst may be recovered as an overhead product from the reactor. The second portion of the second catalyst may be separated from the overhead product, providing a first stream comprising the first catalyst and the hydrocarbon effluent and a second stream comprising the separated second catalyst, allowing return of the separated second catalyst in the second stream to the reactor.

A particle disengagements device comprising a baffle plate, wherein the baffle plate comprises one or more guide baffles and one or more separation baffles, wherein the one or more guide baffles and the one or more separation baffles define one or more air flow paths and one or more solid flow paths and associated systems and methods.

Apparatus and processes herein provide for converting hydrocarbon feeds to light olefins and other hydrocarbons. The processes and apparatus include, in some embodiments, feeding a hydrocarbon, a first catalyst and a second catalyst to a reactor, wherein the first catalyst has a smaller average particle size and is less dense than the second catalyst. A first portion of the second catalyst may be recovered as a bottoms product from the reactor, and a cracked hydrocarbon effluent, a second portion of the second catalyst, and the first catalyst may be recovered as an overhead product from the reactor. The second portion of the second catalyst may be separated from the overhead product, providing a first stream comprising the first catalyst and the hydrocarbon effluent and a second stream comprising the separated second catalyst, allowing return of the separated second catalyst in the second stream to the reactor.

The invention provides an improved system for separation technology intended to reduce unwanted catalyst/thermal reactions by minimizing contact of the hydrocarbons and the catalyst within the reactor.

A fast fluidized bed reactor, device and method for preparing para-xylene and co-producing light olefins from methanol and/or dimethyl ether and benzene, resolving or improving the competition problem between an MTO reaction and an alkylation reaction during the process of producing para-xylene and co-producing light olefins from methanol and/or dimethyl ether and benzene, and achieving a synergistic effect between the MTO reaction and the alkylation reaction. By controlling the mass transfer and reaction, competition between the MTO reaction and the alkylation reaction is coordinated and optimized to facilitate a synergistic effect of the two reactions, so that the conversion rate of benzene, the yield of para-xylene, and the selectivity of light olefins are increased.

A process for the catalytic cracking of hydrocarbon oils includes the step of contacting a hydrocarbon oil feedstock with a catalytic cracking catalyst in a reactor having one or more fast fluidized reaction zones for reaction. At least one of the fast fluidized reaction zones of the reactor is a full dense-phase reaction zone, and the axial solid fraction ε of the catalyst is controlled within a range of about 0.1 to about 0.2 throughout the full dense-phase reaction zone. When used for catalytic cracking of hydrocarbon oils, particularly heavy feedstock oils, the process, reactor and system show a high contact efficiency between oil and catalyst, a selectivity of the catalytic reaction, an effectively reduced yield of dry gas and coke, and an improved yield of high value-added products such as ethylene and propylene.