摘要:
The invention concerns methods and systems for minimizing back-mixing of feedstock flow in converting oxygenates to olefins. In one embodiment, back-mixing is reduced by providing a reactor that includes baffles to reduce the hydraulic diameter of at least a portion of the reactor. Some or all of the baffles can also serve as cooling tubes for reducing temperature gradients in the reactor, and thereby maximize light olefin production.
摘要:
The present invention relates to processes for fluidizing a population of catalyst particles that are depleted of catalyst fines. In one embodiment, the process includes providing a plurality of catalyst particles in the reactor, wherein the catalyst particles have a d2 value of greater than about 40 microns. The catalyst- particles are contacted with a fluidizing medium under conditions effective to cause the catalyst particles to behave in a fluidized manner and form a fluidized bed. The particles are contacted with one or more primary obstructing members while in the fluidized bed. By fluidizing the catalyst particles in this manner, the catalyst particles can be maintained at an axial gas Peclet number of from about 10 to about 20.
摘要:
The present invention relates to processes for fluidizing a population of catalyst particles that are depleted of catalyst fines. In one embodiment, the process includes providing a plurality of catalyst particles in the reactor, wherein the catalyst particles have a d2 value of greater than about 40 microns. The catalyst particles are contacted with a fluidizing medium under conditions effective to cause the catalyst particles to behave in a fluidized manner and form a fluidized bed. The particles are contacted with one or more primary obstructing members while in the fluidized bed. By fluidizing the catalyst particles in this manner, the catalyst particles can be maintained at an axial gas Peclet number of from about 10 to about 20.
摘要:
A multi-stage gas-solids separator is configured so that the higher density (solids) output flows of two or more of the separator stages are merged together. The multi-stage separator is preferably composed of cyclone separators, with the diplegs of at least two of the cyclone separator stages merged together.
摘要:
The invention is directed to methods for protecting metalloaluminophosphate molecular sieves, particularly silicoaluminophosphate (SAPO) molecular sieves, from loss of catalytic activity due to contact with a gas containing water. The methods of the invention provide procedures that enable activated sieve to contact water vapor, within a certain range of time, temperature, and water partial pressure conditions, before the sieve becomes substantially deactivated.
摘要:
A gas-solids reaction system with termination devices to connect a riser with one or more separation devices. The termination devices have a radius of curvature that is at least 1.0 times as great as the diameter of the conduit forming the termination device. The termination devices can be openly or closely coupled to the separation devices.
摘要:
Catalyst losses are prevented in riser reactor systems by using a low inlet velocity for the first cyclone separator in each multi-stage cyclone separator in the reactor. Catalyst particles not separated from the product output flow in an oxygenate-to-olefin reactor are also recaptured by cooling the product output flow and passing the flow through an electrostatic precipitator.
摘要:
The present invention is directed to a hydrocarbon conversion apparatus and process. The apparatus comprises the following: a plurality of riser reactors, each having a first end into which a catalyst is fed, a second end through which the catalyst can exit, and optionally a center axis extending therebetween. The apparatus also includes a separation zone having a plurality of inlets, each inlet not being oriented along the center axes of the riser reactors, the separation zone being provided to separate the catalyst from products of a reaction conducted in the hydrocarbon conversion apparatus. A plurality of deviating members are also provided, each deviating member being in fluid communication between the second end of a respective riser reactor and a respective inlet of the separation zone. The apparatus also includes a catalyst retention zone provided to contain catalyst, which is fed to the riser reactors. A catalyst return is in fluid communication between the separation zone and the catalyst retention zone.
摘要:
The present invention provides various processes for fluidizing molecular sieve catalyst compositions in a fluidized bed reaction system. The invention comprises fluidizing a molecular sieve catalyst composition with a reactive fluidizing medium under conditions effective to convert at least a portion of the fluidizing medium to additional product. The invention is ideally suited for implementation into an oxygenate to olefin reaction system, in which the fluidizing medium optionally comprises byproducts of the oxygenate to olefin conversion reaction.
摘要:
The present invention is directed to a hydrocarbon conversion apparatus. The apparatus comprises the following: a plurality of riser reactors, each of the riser reactors having a first end into which a catalyst can be fed and a second end through which the catalyst can exit the riser reactor, a separation zone into which the second ends of the riser reactors extend, the separation zone being provided to separate the catalyst from products of a reaction conducted in the hydrocarbon conversion apparatus; and at least one catalyst return in fluid communication with the separation zone and the first ends of the riser reactors, the catalyst return being provided to transfer the catalyst from the separation zone to the first ends of the riser reactors.