摘要:
A process and apparatus for indirectly heating reactants in a reaction zone controls the combustion of fuel through the metering of combustion gas from a central channel across perforated plates into outer combustion channels. Controlling the combustion of fuel in channels that supplies heat indirectly to a reaction zone simplifies the operation of the reaction zone and improves reaction zone conversion and/or selectivity. Simplified operation results from the elimination of equipment for the heating of the heat exchange fluid by the controlled combustion of fuel in situ in the reaction zone. Improved conversion and/or selectivity proceeds from reduction in temperature differences between the heating medium and the reactants. Catalyst promotion of fuel combustion may also be varied through other available mechanisms such as variations in residence time, catalyst composition, flow area, and component concentration. Particularly suitable catalysts comprise oxidation promoting catalysts.
摘要:
A method is disclosed for decreasing the emissions of chlorine-containing species from a moving bed process for regenerating spent catalyst particles with a recycle gas stream. A recycle gas stream contacts spent catalyst particles at regeneration conditions, thereby producing a flue gas stream. The flue gas stream which contains chlorine-containing species contacts spent catalyst particles at sorption conditions. The spent catalyst particles sorb the chlorine-containing species from the flue gas stream, thereby producing the recycle gas stream. A portion of the recycle gas stream is vented from the process. This method captures and returns to the process the chlorine-containing species that would be lost from the process and that would need to be replaced by the injection of make-up chlorine-containing species. This method results in a significant savings in capital and operating costs of the process. This method is adaptable to many processes for the catalytic conversion of hydrocarbons in which deactivated catalyst particles are regenerated in a moving bed.
摘要:
A method is disclosed for decreasing the emissions of chlorine-containing species from a process for contacting catalyst particles with a recycle stream containing chlorine-containing species. Prior to contacting the catalyst particles with the recycle gas, an effluent stream that contains chlorine-containing species contacts the catalyst particles at sorption conditions. The catalyst particles sorb the chlorine-containing species from the effluent stream. This method captures and returns to the process the chlorine-containing species that would be lost from the process and that would need to be replaced by the injection of make-up chlorine-containing species. This method results in a significant savings in capital and operating costs of the process. This method is adaptable to many processes for the catalytic conversion of hydrocarbons in which deactivated catalyst particles are regenerated.
摘要:
A catalyst system comprises a physical mixture of a conversion catalyst and a sulfur sorbent to accommodate small quantities of sulfur from a hydrocarbon feedstock. Preferably, the physical mixture comprises a sulfur-sensitive reforming catalyst protected from sulfur deactivation by a manganese-oxide catalyst. The invention shows substantial benefits over prior-art processes in catalyst utilization.
摘要:
A reactor arrangement and process for indirectly contacting a reactant stream with a heat exchange stream uses an arrangement of corrugated heat exchange plates to control temperature conditions by varying the number and/or the arrangement of the corrugations along the plates. The reactor arrangement and process of this invention may be used to operate a reactor under isothermal or other controlled temperature conditions. The variation in corrugation arrangements within a single heat exchange section is highly useful in maintaining a desired temperature profile in an arrangement having a cross-flow of heat exchange medium relative to reactants. The corrugations arrangement eliminates or minimizes the typical step-wise approach to isothermal conditions.
摘要:
A reactor arrangement and process for indirectly contacting a reactant stream with a heat exchange stream uses an arrangement of corrugated heat exchange plates to control temperature conditions by varying the number and/or the arrangement of the corrugations along the plates. The reactor arrangement and process of this invention may be used to operate a reactor under isothermal or other controlled temperature conditions. The variation in corrugation arrangements within a single heat exchange section is highly useful in maintaining a desired temperature profile in an arrangement having a cross-flow of heat exchange medium relative to reactants. The corrugations arrangement eliminates or minimizes the typical step-wise approach to isothermal conditions.
摘要:
Apparatus for regenerating spent hydrocarbon conversion catalyst. Catalyst particles in a vertically-elongated movable tapered bed are contacted with a hot oxygen-containing gas stream in order to remove, by means of combustion, coke which accumulated on the catalyst particles while they were used in a hydrocarbon conversion zone. Catalyst moves downward under the influence of gravity. The catalyst bed is tapered such that the thickness of the bed, in a dimension which is transverse to the direction of catalyst movement, varies from a minimum at the top of the tapered bed to a maximum at the bottom of the tapered bed. Gas passes through the tapered bed in a direction which is substantially transverse to the direction of catalyst movement. Substantially, all of the catalyst in the bed is in contact with the flowing gas. The variation in bed thickness causes a varying gas flow rate through the bed, from a maximum flow rate at the top of the tapered bed to a minimum flow rate at the bottom of the tapered bed and reduces the time that catalyst is exposed to high temperature gases. This flow pattern results in the delivery of oxygen in a manner which more closely matches the oxygen requirement for combustion at each point in the tapered bed. Advantages of the invention include increased coke burning capacity and longer catalyst life. Catalytic reforming is an example of a hydrocarbon conversion process in which the invention may be advantageously employed.
摘要:
A method for regenerating coke-contaminated catalyst particles achieves better utilization of oxygen and minimizes surface area loss of the catalyst by confining particles in the combustion section of a regeneration zone to a tapered bed configuration. In this method, catalyst particles move through the regeneration zone in continuous or semi-continuous flow and are formed into a vertically elongated bed of particles in the regeneration zone. An oxygen-containing gas is passed through the particle bed in a transverse direction and initiates combustion of the coke deposits along a burn front that extends diagonally through the catalyst bed from the inlet surface of the bed to the outlet surface of the bed. The catalyst bed is tapered to reduce the volume of catalyst particles behind the burn wave, with respect to gas flow through the bed, thereby increasing the gas flow through the upper portion of the bed and removing catalyst that would be exposed to high temperature flue gas flowing across the bed from the burn front. The method of this invention can confine catalyst particles to a bed having a continuous taper or the thickness of the bed may be varied by confining the catalyst in discrete bed portions that increase progressively down the length of the bed. This method of regeneration can also include steps for halogenation and drying of the catalyst particles. A particularly useful application of this invention is in reforming processes.
摘要:
Embodiments of processes for producing propylene from paraffins are provided. The process comprises the steps of combining an effluent that comprises propylene and propane from a paraffin dehydrogenation reactor with an offgas stream that comprises propane to form a combined effluent stream. The combined effluent stream is separated into a propylene product stream and a propane-rich recycle stream. The propane-rich recycle stream is introduced to the paraffin dehydrogenation reactor operating at dehydrogenation conditions to convert propane in the propane-rich recycle stream to propylene.
摘要:
Methods for processing a hydrocarbonaceous feedstock flows are provided. In one embodiment, the method includes providing two or more hydroprocessing stages disposed in sequence, each hydroprocessing stage having a hydroprocessing reaction zone with a hydrogen requirement and each stage in fluid communication with the preceding stage. The hydrocarbonaceous feedstock flow may be separated into portions of fresh feed for each hydroprocessing stage, and the first portion of fresh feed to the first hydroprocessing stage is heated. The heated first portion of fresh feed may be supplied with hydrogen from the hydrogen source in an amount satisfying substantially all of the hydrogen requirements of the hydroprocessing stages to a first hydroprocessing zone. The unheated second portion of fresh feed is injected counter current to the process flow as quench at one or more locations in one or more of the reaction zones.