Method for starting up a fluidized catalytic reaction apparatus used for producing lower olefins

Patent metadata

Field	Value
Publication number	US-10259757-B2
Application number	US-201815936754-A
Country	US
Kind code	B2
Filing date	Mar 27, 2018
Priority date	Aug 23, 2006
Publication date	Apr 16, 2019
Grant date	Apr 16, 2019

Abstract

Disclosed is a method for starting up fluidized reaction apparatus that is used for producing lower olefins from methanol or/and dimethyl ether. Said method includes after heating the catalyst bed of circulating fluidized catalytic reaction apparatus to above 200° C. or 300° C. by using a starting-up auxiliary heat source, feeding methanol or dimethyl ether raw materials to a reactor, whereby heat released by the reaction makes the temperature of the reaction system apparatus increase quickly to a designed temperature, consequently making the system reach normal operation state rapidly. Said method is suitable for starting up an exothermic fluidized catalytic reaction apparatus and can simplify the apparatus and operation, accordingly lowering the cost.

First claim

We claim:

1. A method for starting up a fluidized catalytic reaction apparatus for producing lower olefins,
wherein said fluidized catalytic reaction apparatus is a circulating fluidized catalytic reaction apparatus comprising a reactor and a regenerator;
wherein the reactor is a dense phase fluidized bed reactor in which is provided with a reactor heat extractor and cyclones, and the regenerator is a dense phase fluidized bed regenerator in which is provided with a regenerator heat extractor and cyclones;
wherein the dense phase fluidized bed reactor is operated under a gauge reaction pressure of 0.05 to 0.3 MPa, a reaction temperature of 420 to 550° C., a dense phase apparent linear speed of 0.3 to 1.5 m/s and a bed layer density of 150 to 600 Kg/m 3 ;
the dense phase fluidized bed regenerator is operated under a gauge reaction pressure of 0.05 to 0.3 MPa, a reaction temperature of 600 to 750° C., a dense phase apparent linear speed of 0.3 to 1.5 m/s and a bed layer density of 150 to 600 Kg/m 3 ;
in the reactor heat extractor, cooling water is used as cooling medium, wherein the cooling water is evaporated into steam by absorbing reaction heat, and the reactor heat extractor is a coil heat extractor or a fingertip heat extractor;
in the regenerator heat extractor, cooling water is used as cooling medium, wherein the cooling water is evaporated into steam by absorbing reaction heat, and the regenerator heat extractor is a coil heat extractor or a fingertip heat extractor; and
methanol or a mixture of methanol and dimethyl ether is taken as raw material,
the method including the steps of:
1) supplying air which has been heated by using a first external auxiliary heat source into the regenerator and introducing nitrogen gas which has been heated by using a second external auxiliary heat source into the reactor, so as to realize the heating of the circulating fluidized apparatus;
2) adding an active catalyst into the reactor become a catalyst bed of the reactor and into the regenerator to become a catalyst bed of the regenerator when the temperatures in the middle parts of the regenerator and the reactor are increased to 200° C. or above, wherein with the addition of the active catalyst, the temperature in the middle part of the reactor is reduced to be 120-180° C. and the temperature in the middle part of the regenerator is reduced to be 120-180° C.,
3) adjusting the supply of the heated air into the regenerator and the supply of the heated nitrogen gas into the reactor, while operating the cyclones of the reactor and the regenerator so as to avoid the loss of the active catalyst;
4) heating the catalyst bed of the reactor to a temperature of 200° C. or above by using the heated nitrogen gas, and heating the catalyst bed of the regenerator to a temperature of 300° C. or above by using the heated air;
5) circulating the catalyst between the reactor and regenerator with a circulation rate as low as possible, wherein the catalyst circulation rate is higher than zero and lower than half of the normal catalyst circulation rate, wherein the normal catalyst circulation rate=catalyst loading amount in terms of kilogram in the catalyst bed of the reactor divided by the normal catalyst residence time in the reactor, wherein the normal catalyst residence time is 45 minutes;
6) feeding the raw material to the catalyst bed of the reactor in the fluidized catalytic reaction apparatus, while stopping the introduction of nitrogen gas, whereby the catalyst bed of the reactor is further heated to 350° C. or above, by the heat released by the reaction of the raw material, and, as a consequence of the reaction of the raw material, the coke deposition on the catalyst reaches 0.5% or above; and
7) circulating the catalyst in the reactor with the coke deposition on the catalyst of 0.5% or above to the regeneration bed of the regenerator with a normal catalyst circulation rate, wherein the coke is burn in the regenerator in the presence of air, and thus the temperature of the catalyst bed of the regenerator is increased to 540° C. or above by the heat transported by the circulating catalyst from the reactor, and/or the heat released by the coke being burn in the regenerator; and
8) further increasing the temperature of the catalyst bed of the reactor to 400° C. or above, by the heat released by the reaction of the raw material, and then starting to supply cooling water into the reactor heat extractor and adjusting the supply of the cooling water so as to control the temperature of the catalyst bed layer in the reactor to be stabilized in the range of 420-550° C.; and
9) further increasing the temperature of the catalyst bed of the regenerator to 600° C. or above by the heat released by the coke being burn in the regenerator, and then starting to supply cooling water into the regenerator heat extractor and adjusting the supply of the cooling water so as to control the temperature of the catalyst bed layer in the regenerator to be stabilized in the range of 600-750° C., consequently making the fluidized catalytic reaction apparatus reach normal operation state.

2. A method for starting up a fluidized catalytic reaction apparatus for producing lower olefins,
wherein said fluidized catalytic reaction apparatus is a circulating fluidized catalytic reaction apparatus comprising a reactor and a regenerator;
wherein the reactor is a dense phase fluidized bed reactor in which is provided with a reactor heat extractor and cyclones, and the regenerator is a dense phase fluidized bed regenerator in which is provided with a regenerator heat extractor and cyclones;
wherein the dense phase fluidized bed reactor is operated under a gauge reaction pressure of 0.05 to 0.3 MPa, a reaction temperature of 420 to 550° C., a dense phase apparent linear speed of 0.3 to 1.5 m/s and a bed layer density of 150 to 600 Kg/m 3 ;
the dense phase fluidized bed regenerator is operated under a gauge reaction pressure of 0.05 to 0.3 MPa, a reaction temperature of 600 to 750° C., a dense phase apparent linear speed of 0.3 to 1.5 m/s and a bed layer density of 150 to 600 Kg/m 3 ;
in the reactor heat extractor, cooling water is used as cooling medium, wherein the cooling water is evaporated into steam by absorbing reaction heat, and the reactor heat extractor is a coil heat extractor or a fingertip heat extractor;
in the regenerator heat extractor, cooling water is used as cooling medium, wherein the cooling water is evaporated into steam by absorbing reaction heat, and the regenerator heat extractor is a coil heat extractor or a fingertip heat extractor; and
dimethyl ether is taken as raw material,
the method including the steps of:
1) supplying air which has been heated by using a first external auxiliary heat source into the regenerator and introducing nitrogen gas which has been heated by using a second external auxiliary heat source into the reactor, so as to realize the heating of the circulating fluidized apparatus;
2) adding an active catalyst into the reactor become a catalyst bed of the reactor and into the regenerator to become a catalyst bed of the regenerator when the temperatures in the middle parts of the regenerator and the reactor are increased to 200° C. or above, wherein with the addition of the active catalyst, the temperature in the middle part of the reactor is reduced to be 120-180° C. and the temperature in the middle part of the regenerator is reduced to be 120-180° C.,
3) adjusting the supply of the heated air into the regenerator and the supply of the heated nitrogen gas into the reactor, while operating the cyclones of the reactor and the regenerator so as to avoid the loss of the active catalyst;
4) heating the catalyst bed of the reactor to a temperature of 300° C. or above by using the heated nitrogen gas, and heating the catalyst bed of the regenerator to a temperature of 300° C. or above

Assignees

• Dalian Inst Chem & Physics Cas

Inventors

• Liu Zhongmin
• Lv Zhihui
• He Changqing
• Liu Yu
• Qi Yue
• Min Xiaojian
• Wang Gongwei
• Wang Xiangao
• Zhang Jinling
• Ye Mao

Classifications

• C07C1/24 Primary

  by elimination of water · CPC title

• B01J8/26

  with two or more fluidised beds, e.g. reactor and regeneration installations · CPC title

• B01J2229/126

  in order to reduce the pore-mouth size · CPC title

• Y02P20/52

  using catalysts, e.g. selective catalysts · CPC title

• C07C11/04

  Ethene · CPC title