Methods and compositions for the removal of metal sulfides from spent catalysts in reactor vessels and associated equipment are described herein. Using the methods described herein, metal sulfides of a spent catalysts are converted to metal oxides and gaseous and liquid by-products when reacted with a formulation having one or more oxidizing agents. Also, using the methods described herein, metal sulfides and sulfides in the process equipment are oxidized, eliminating the potential formation of polythionic and thionic acids protecting materials from polythionic stress corrosion cracking. Also, using the methods described herein, halides (including chloride) and halide containing compounds and salts in the process equipment are removed, eliminating the potential formation of halide acids and further neutralized via pH buffering, and protecting materials from halide stress corrosion cracking.

New/fresh catalyst is added to a dehydrogenation unit and aged catalyst is removed from the dehydrogenation unit on a continuous or semi-continuous basis while the dehydrogenation unit is in operation. The conversion achieved by the higher activity catalyst results in the production rate of olefin product being maintained at near start-of-run production for longer, with a slower rate of decline. The higher activity catalyst extends run time, reduces feed consumption for each unit of olefin product, and minimizes fresh catalyst expenses.

A reactor for producing a synthesis gas from a fuel, with a housing (2) with a combustion part accommodating a first fluidized bed in operation, a riser (3) extending along a longitudinal direction of the reactor (1) and accommodating a second fluidized bed in operation, a down-comer (4) positioned parallel to the riser and extending into the first fluidized bed, and one or more feed channels (33) for providing the fuel to the reactor (1). The reactor (1) further has a riser air chamber section (B) connected to a lower part of the riser (3), the riser air chamber section (B) comprising a cylindrical wall (28) with a plurality of circumferentially located holes (24, 25).

A reactor for producing a synthesis gas from a fuel, with a housing (2) with a combustion part accommodating a first fluidized bed in operation, a riser (3) extending along a longitudinal direction of the reactor (1) and accommodating a second fluidized bed in operation, a down-comer (4) positioned parallel to the riser and extending into the first fluidized bed, and one or more feed channels (33) for providing the fuel to the reactor (1). The reactor (1) further has a riser air chamber section (B) connected to a lower part of the riser (3), the riser air chamber section (B) comprising a cylindrical wall (28) with a plurality of circumferentially located holes (24, 25).

A coke control reactor, and a device and method for preparing low-carbon olefins from an oxygen-containing compound are provided. The coke control reactor includes a coke control reactor shell, a reaction zone I, and a coke controlled catalyst settling zone; a cross-sectional area at any position of the reaction zone I is less than that of the coke controlled catalyst settling zone; n baffles are arranged in a vertical direction in the reaction zone I; the n baffles divide the reaction zone I into m reaction zone I subzones; and a catalyst circulation hole is formed in each of the baffles, such that a catalyst flows in the reaction zone I in a preset manner. A catalyst charge in the present coke control reactor can be automatically adjusted, and an average residence time of a catalyst in the coke control reactor can be controlled by changing process operating conditions.

Methods of reducing heat exchanger fouling rate or of producing polyolefins may include providing a first gas stream comprising a gas and entrained fine polyolefin particles to a gas outlet line; removing a portion of the entrained fine polyolefin particles from the gas outlet line to form a bypass stream; and providing the bypass stream to a bypass line comprising a bypass line inlet and a bypass line outlet. The bypass line inlet and outlet are located upstream and downstream of a first heat exchanger. The methods may further include providing at least a portion of the first gas stream to the first heat exchanger; and combining the bypass stream and a second gas stream at the bypass line outlet to form a combined gas stream comprising one or more olefins or paraffins. A temperature of the combined gas stream is below the dew point of the combined gas stream.

The invention relates to a method for cleaning a phosgene-conducting apparatus by pressurization with ammonia gas to constant pressure. In this way, phosgene residues in the apparatus to be cleaned are decomposed effectively.

Systems and methods of reducing heat exchanger fouling rate and of producing polyolefins are provide herein. In some aspects, the methods include providing a first gas stream comprising a gas and entrained fine polyolefin particles to a gas outlet line; preferentially removing a portion of the entrained fine polyolefin particles from the gas outlet line to form a bypass stream comprising a higher concentration of the entrained fine polyolefin particles than is present in the first gas stream; providing the bypass stream to a bypass line comprising a bypass line inlet and a bypass line outlet, wherein the bypass line inlet is located upstream of a first heat exchanger, and wherein the bypass line outlet is located downstream of the first heat exchanger; providing at least a portion of the first gas stream to the first heat exchanger, which produces a first cooled gas stream; and combining the bypass stream and a second gas stream at the bypass line outlet to form a combined gas stream comprising one or more olefins or paraffins, wherein a temperature of the combined gas stream is below the dew point of the combined gas stream.

Systems and methods of reducing heat exchanger fouling rate and of producing polyolefins are provide herein. In some aspects, the methods include providing a first gas stream comprising a gas and entrained fine polyolefin particles to a gas outlet line; preferentially removing a portion of the entrained fine polyolefin particles from the gas outlet line to form a bypass stream comprising a higher concentration of the entrained fine polyolefin particles than is present in the first gas stream; providing the bypass stream to a bypass line comprising a bypass line inlet and a bypass line outlet, wherein the bypass line inlet is located upstream of a first heat exchanger, and wherein the bypass line outlet is located downstream of the first heat exchanger; providing at least a portion of the first gas stream to the first heat exchanger, which produces a first cooled gas stream; and combining the bypass stream and a second gas stream at the bypass line outlet to form a combined gas stream comprising one or more olefins or paraffins, wherein a temperature of the combined gas stream is below the dew point of the combined gas stream.

A direct decomposition device for hydrocarbons for directly decomposing hydrocarbons into carbon and hydrogen includes a rector containing a catalyst including a plurality of metal particles with an iron purity of 86% or more. The reactor is configured to be supplied with a raw material gas containing hydrocarbons.