The present invention provides a system and method for producing high-purity vanadium tetraoxide powder. Industrial grade vanadium pentoxide is converted to vanadium oxytrichloride by low temperature fluidizing chlorination, wherein chlorinating gas is preheated via heat exchange between fluidizing gas and chlorination flue gas, and an appropriate amount of air is added to enable a part of carbon powder to combust so as to achieve a balanced heat supply during the chlorination, thereby increasing the efficiency of chlorination and ensuring good selectivity in low temperature chlorination. The vanadium oxytrichloride is purified by rectification, and then subjected to fluidized gas phase hydrolyzation, thereby producing a high-purity vanadium pentoxide product and a by-product solution of hydrochloric acid, and further obtaining a high-purity vanadium tetraoxide powder product through fluidized hydrogen reduction. The system and method have advantages of favorable adaptability to raw material, no discharge of contaminated wastewater, low energy consumption, etc.

A multi-zoned fluidized bed reactor system may include a multi-zoned fluidized bed reactor and at least one catalyst regeneration loop. The multi-zoned fluidized bed reactor comprising a housing, a fluid bed distributor plate positioned at the bottom of the housing, a fluidized catalyst bed disposed vertically above the fluid bed distributor plate and a condensation zone disposed vertically above the fluidized catalyst bed. The at least one catalyst regeneration loop may be fluidly coupled to the stripping zone and a reaction zone. The at least one catalyst regeneration loop may be operable to withdraw a portion of spent catalyst from the stripping zone, regenerate the portion of spent catalyst to produce regenerated catalyst, and return the regenerated catalyst to the reaction zone. A method of regenerating catalyst in a multi-zoned fluidized bed reactor may include passing a portion of spent catalyst from a stripping zone to a catalyst regeneration loop.

A multi-zoned fluidized bed reactor system may include a multi-zoned fluidized bed reactor and at least one catalyst regeneration loop. The multi-zoned fluidized bed reactor comprising a housing, a fluid bed distributor plate positioned at the bottom of the housing, a fluidized catalyst bed disposed vertically above the fluid bed distributor plate and a condensation zone disposed vertically above the fluidized catalyst bed. The at least one catalyst regeneration loop may be fluidly coupled to the stripping zone and a reaction zone. The at least one catalyst regeneration loop may be operable to withdraw a portion of spent catalyst from the stripping zone, regenerate the portion of spent catalyst to produce regenerated catalyst, and return the regenerated catalyst to the reaction zone. A method of regenerating catalyst in a multi-zoned fluidized bed reactor may include passing a portion of spent catalyst from a stripping zone to a catalyst regeneration loop.

Apparatus for carrying out a catalytic gas-phase olefin polymerization having a first polymerization zone for growing polymer particles to flow upward under fast fluidization or transport conditions, a second polymerization zone for the growing polymer particles to flow downward, and a gas/solid separation zone; wherein the second polymerization zone has an upper part being connected to the separation zone and a lower part being connected to the upper part; wherein the ratio of the height H01 of the separation zone to the diameter D01 of the separation zone is 2.5 to 4.5.

Apparatus for carrying out a catalytic gas-phase olefin polymerization having a first polymerization zone for growing polymer particles to flow upward under fast fluidization or transport conditions, a second polymerization zone for the growing polymer particles to flow downward, and a gas/solid separation zone; wherein the second polymerization zone has an upper part being connected to the separation zone and a lower part being connected to the upper part; wherein the ratio of the height H01 of the separation zone to the diameter D01 of the separation zone is 2.5 to 4.5.

PROBLEM TO BE SOLVED:

In an apparatus for synthesizing methane from carbon dioxide and hydrogen, a device which is capable to remove the reaction heat and lower the reaction temperature as the reaction progresses in order to increase the conversion ratio to methane has been desired.

SOLUTION:

In the present invention, powders of magnesium hydroxide and magnesium carbonate, which are chemical heat storage agents, are used as part of the fluidizing medium of the multi-stage fluidized bed in the temperature range where the methanation reaction proceeds. The heat generated during the methanation reaction can be absorbed and stored in the powder. At this time, carbon dioxide generated from magnesium carbonate can be used as a raw material gas for the methanation reaction. Furthermore, after discharging the magnesium oxide generated by endotherm, the powder can be regenerated with an external regenerating facility and then the storage heat can be released and recovered. The regenerated powder can be fed to the uppermost stage of the multi-stage fluidized bed at a temperature lower than the internal temperature of the reactor to lower inside temperature. This made it possible to lower the reaction temperature of ascending reaction gas in the reactor along with the reaction progress, and to increase the conversion ratio to the produced methane by this lowered temperature.

PROBLEM TO BE SOLVED:

In an apparatus for synthesizing methane from carbon dioxide and hydrogen, a device which is capable to remove the reaction heat and lower the reaction temperature as the reaction progresses in order to increase the conversion ratio to methane has been desired.

SOLUTION:

In the present invention, powders of magnesium hydroxide and magnesium carbonate, which are chemical heat storage agents, are used as part of the fluidizing medium of the multi-stage fluidized bed in the temperature range where the methanation reaction proceeds. The heat generated during the methanation reaction can be absorbed and stored in the powder. At this time, carbon dioxide generated from magnesium carbonate can be used as a raw material gas for the methanation reaction. Furthermore, after discharging the magnesium oxide generated by endotherm, the powder can be regenerated with an external regenerating facility and then the storage heat can be released and recovered. The regenerated powder can be fed to the uppermost stage of the multi-stage fluidized bed at a temperature lower than the internal temperature of the reactor to lower inside temperature. This made it possible to lower the reaction temperature of ascending reaction gas in the reactor along with the reaction progress, and to increase the conversion ratio to the produced methane by this lowered temperature.

A fluidized bed reactor, a device, and a method for producing low-carbon olefins from oxygen-containing compound are provided. The fluidized bed reactor includes a reactor shell, a reaction zone, a coke control zone and a delivery pipe, where there are n baffles arranged in the coke control zone, and the n baffles divide the coke control zone into n sub-coke control zones which include a first sub-coke control zone, a second sub-coke control zone, and an nth sub-coke control zone; at least one catalyst circulation hole is provided on each of the n-1 baffles, so that the catalyst flows in an annular shape in the coke control zone, where n is an integer. The device and method can be adapted to a new generation of DMTO catalyst, and the unit consumption of production ranges from 2.50 to 2.58 tons of methanol/ton of low-carbon olefins.

A fluidized bed reactor includes a main shell and a coke control zone shell; the main shell includes an upper shell and a lower shell; the upper shell encloses a gas-solid separation zone, and the lower shell encloses a reaction zone; the reaction zone axially communicates with the gas-solid separation zone; the coke control zone shell is circumferentially arranged on an outer wall of the main shell; the coke control zone shell and the main shell enclose an annular cavity, and the annular cavity is a coke control zone; n baffles are radially arranged in the coke control zone, and the n baffles divide the coke control zone into n coke control zone subzones, where n is an integer; the coke control zone subzones are provided with a coke control raw material inlet; and a catalyst circulation hole is formed in each of n-1 of the baffles.

A fluidized bed reactor includes a main shell and a coke control zone shell; the main shell includes an upper shell and a lower shell; the upper shell encloses a gas-solid separation zone, and the lower shell encloses a reaction zone; the reaction zone axially communicates with the gas-solid separation zone; the coke control zone shell is circumferentially arranged on an outer wall of the main shell; the coke control zone shell and the main shell enclose an annular cavity, and the annular cavity is a coke control zone; n baffles are radially arranged in the coke control zone, and the n baffles divide the coke control zone into n coke control zone subzones, where n is an integer; the coke control zone subzones are provided with a coke control raw material inlet; and a catalyst circulation hole is formed in each of n-1 of the baffles.