Removal of catalyst fines from a reaction system
AssigneeExxonMobil Chemical Patents Inc.
InventorsJames H. Beech, Jr., Yun-feng Chang, Michael P. Nicoletti
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Abstract
This invention provides a process for limiting the loss of catalyst particles through olefin product streams and regenerator flue gas streams exiting the reaction system. In particular, this invention provides for removing catalyst particles from the reactor using a water stream and from the regenerator using a two step separation process. The two step process involves the use of a catalyst fine separation unit.
Claims34
A process for removing silicoaluminophosphate molecular sieve catalyst particles containing [AlO4] and [SiO4] tetrahedral units from an oxygenate to olefin reaction system having a reactor and regenerator, comprising:
- a) exposing the molecular sieve catalyst particles to regeneration conditions to remove carbon;
- b)separating the molecular sieve catalyst particles from a flue gas stream in the regenerator so that the flue gas stream exits the regenerator at an average catalyst loading of greater than or equal to 10 mg/NM3;
- and
- c) flowing the flue gas stream exiting the regenerator through a catalyst fine separation unit to form a final flue gas stream having an average catalyst loading of less than that of the stream exiting the regenerator;
- wherein the catalyst fine separation unit is an electrostatic precipitator operated at a catalyst resistivity of not greater than 1012 ohm-cm and a temperature of at least 250° C.
A process for removing silicoaluminophosphate molecular sieve catalyst particles containing [AlO4] and [SiO4] tetrahedral units from an oxygenate to olefin reaction system having a reactor and regenerator, comprising:
- a) exposing the molecular sieve catalyst particles to regeneration conditions to remove carbon;
- b separating at least a portion of the catalyst particles from a flue gas stream in the regenerator so that the flue gas stream exits the regenerator at an average catalyst loading of from 10 mg/NM3 to 200 mg/NM3;
- c) flowing the flue gas stream exiting the regenerator through an electrostatic precipitator operated at a catalyst resistivity of not greater than 1012 ohm-cm;
- and
- d) recovering a final flue gas stream from the electrostatic precipitator having an average catalyst loading less than that of the flue gas stream from the regenerator;
- wherein the molecular sieve catalyst comprises an electrostatic charging modifier that provides a catalyst resistivity of not greater than 1012 ohm-cm and a temperature of at least 250° C.
A process for removing silicoaluminophosphate molecular sieve catalyst particles containing [AlO4] and [SiO4] tetrahedral units from an oxygenate to olefin reaction system having a reactor and regenerator, comprising:
- a) contacting the catalyst particles with an oxygenate stream in the reactor to form an olefin product;
- b) contacting the olefin product with a water stream in a quench column to remove catalyst particles entrained in the olefin product;
- c) exposing the molecular sieve catalyst particles to regeneration conditions to remove carbon;
- d) separating at least a portion of the catalyst particles from a flue gas stream in the regenerator so that the flue gas stream exits the regenerator at an average catalyst loading of from 10 mg/NM3 to 200 mg/NM3;
- e) flowing the flue gas stream exiting the regenerator through a catalyst fine separation unit;
- and
- f) recovering a final flue gas stream from the catalyst fine separation unit at an average catalyst loading less than that of the flue gas stream from the regenerator;
- wherein electrostatic precipitator is operated at a catalyst resistivity of not greater than 1012 ohm-cm and a temperature of at least 250° C.
Dependencies are inferred from the claim text.