Fluidized bed reactor and method for preparing polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde

Patent metadata

Field	Value
Publication number	US-9346916-B2
Application number	US-201514589651-A
Country	US
Kind code	B2
Filing date	Jan 5, 2015
Priority date	Apr 1, 2014
Publication date	May 24, 2016
Grant date	May 24, 2016

Abstract

The invention belongs to energy chemical technical field, especially relates to a fluidized bed reactor and a method for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde. The fluidized bed reactor comprises a gas inlet, a gas distributor, a catalyst inlet, a gas outlet, a fluid inlet, a catalyst outlet, a bottom component and an interstage component, a bottom component related gas upward channel, an interstage component related gas upward channel, a fluid outlet, a bottom downcomer and an interstage downcomer. A process for preparation of polyoxymethylene dimethyl ethers comprises the steps of: fluidizing gas is introduced into a bottom bed from the gas inlet via the bottom component related gas upward channel through the gas distributor; the fluidizing gas goes upwards and flows out of the reactor via the gas outlet; paraformaldehyde and dimethoxymethane are introduced into a bed through the fluid inlet; the fluid goes downwards and leaves the reactor via the fluid outlet. Compared with a conventional cannula reactor, the fluidized bed reactor improves the dispersion uniformity of catalyst and conversion of formaldehyde.

First claim

What is claimed is:

1. A fluidized bed reactor for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde,
wherein the reactor is single-stage or multi-stage, and equipped with a bottom component ( 107 , 207 , 307 ); when the reactor is a multi-stage fluidized bed reactor, one or more interstage components ( 211 , 311 - 1 , 311 - 2 ) are installed inside the reactor above the bottom component ( 107 , 207 , 307 ), thus dividing the space between the bottom component ( 107 , 207 , 307 ) and the top of the reactor into two or more stages;
in each stage of the fluidized bed reactor, a catalyst inlet ( 103 , 203 - 1 , 203 - 2 , 303 - 1 , 303 - 2 , 303 - 3 ) is disposed at upper region of the reactor wall, a catalyst outlet ( 108 , 208 - 1 , 208 - 2 , 308 - 1 , 308 - 2 , 308 - 3 ) is disposed at lower region of the reactor wall; and a gas distributor ( 102 , 202 - 1 , 202 - 2 , 302 - 1 , 302 - 2 , 302 - 3 ) is installed near bottom of the stage;
the gas distributor ( 102 , 202 - 1 , 302 - 1 ) in the lowest stage is connected with a gas inlet ( 101 , 201 , 301 ) disposed at bottom of the reactor wall through a bottom component related gas upward channel ( 109 , 209 , 309 ); the bottom component related gas upward channel ( 109 , 209 , 309 ) is disposed through the bottom component ( 107 , 207 , 307 ); the gas distributors ( 202 - 2 , 302 - 2 , 302 - 3 ) in stages above the lowest stage are connected with an adjacent lower stage through an interstage component related gas upward channel ( 212 , 312 - 1 , 312 - 2 ); the interstage component related gas upward channel ( 212 , 312 - 1 , 312 - 2 ) is passed through the interstage component ( 211 , 311 - 1 , 311 - 2 );
an inlet channel of fluid ( 104 , 204 , 304 ) is disposed on the top stage of the reactor, and inserted through the top of the fluidized bed reactor, with one end outside the top stage and the other end inside the top stage; a bottom downcomer ( 106 , 206 - 1 , 306 - 1 ) is disposed in the lowest stage and is disposed through the bottom component ( 107 , 207 , 307 ), both ends of the bottom downcomer are located inside the fluidized bed reactor, with one end above the bottom component and the other end below the bottom component; an interstage downcomer ( 206 - 2 , 306 - 2 , 306 - 3 ) is installed across two adjacent stages and is disposed through corresponding interstage component ( 211 , 311 - 1 , 311 - 2 );
a fluid outlet ( 110 , 210 , 310 ) is disposed at the bottom of the fluidized bed reactor, a gas outlet ( 105 , 205 , 305 ) is disposed at the top wall of the top stage of the fluidized bed reactor.

2. The fluidized bed reactor for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 1 , wherein a strain is installed at an inlet of the bottom downcomer ( 106 , 206 - 1 , 306 - 1 ) and/or an inlet of the interstage downcomer ( 206 - 2 , 306 - 2 , 306 - 3 ), to prevent solid catalyst or solid paraformaldehyde from entering into space below the bottom component ( 107 , 207 , 307 ) or into an adjacent lower stage of the fluidized reactor.

3. The fluidized bed reactor for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 1 , wherein the gas distributor ( 102 , 202 - 1 , 202 - 2 , 302 - 1 , 302 - 2 , 302 - 3 ) is a plate-type distributor, and multiple pores or multiple nozzles are provided on the plate-type distributor.

4. The fluidized bed reactor for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 1 , wherein the gas distributor ( 102 , 202 - 1 , 202 - 2 , 302 - 1 , 302 - 2 , 302 - 3 ) is a tubular distributor.

5. The fluidized bed reactor for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 4 , wherein the tubular distributor is of ring type, with 1˜5 rings and multiple pores or multiple nozzles are set on each ring.

6. The fluidized bed reactor for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 1 , wherein cross section area of the bottom component related gas upward channel ( 109 , 209 , 309 ) is 0.1%˜20% of cross section area of the bottom component.

7. The fluidized bed reactor for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 1 , wherein the cross section area of the interstage component related gas upward channel ( 212 , 312 - 1 , 312 - 2 ) is 0.1%˜20% of the cross section area of the interstage component.

8. A method for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde by use of the fluidized bed reactor according to claim 1 , comprising steps of:
a. when the fluidized bed reactor is a single-stage fluidized bed reactor, the fluidizing gas flows into the reactor through the gas inlet ( 101 ), then enters bed through the bottom component related gas upward channel ( 109 ) via the gas distributor ( 102 ); the fluidizing gas goes upward and flows out of the reactor via the gas outlet ( 105 ); paraformaldehyde and dimethoxymethane flow into the reactor through the fluid inlet ( 104 ), and the fluid goes downwards through the downcomer ( 106 ) after the fluid level reaches the inlet of the downcomer ( 106 ), and finally leaves the fluidized bed reactor via the fluid outlet ( 110 ) at bottom of the reactor,
b. when the fluidized bed reactor is a multi-stage fluidized bed reactor, the fluidizing gas flows into the reactor through the gas inlet ( 201 , 301 ), then enters the bottom stage fluidized bed through the bottom component related gas upward channel ( 209 , 309 ) via the corresponding gas distributor ( 202 - 1 , 302 - 1 ); the fluidizing gas flows upward into a higher and next stage fluidized bed via the interstage component related gas upward channel ( 212 , 312 - 1 , 312 - 2 ) successively, and at last leaves the top stage fluidized bed via the gas outlet ( 205 , 305 ); paraformaldehyde and dimethoxymethane, flow into the top stage fluidized bed through the fluid inlet ( 204 , 304 ); the fluid flows downwards into a lower and next stage fluidized bed through the corresponding downcomer ( 206 - 1 , 306 - 1 ; 206 - 2 , 306 - 2 , 306 - 3 ) successively, and at last leaves the reactor via the fluid outlet ( 210 , 310 ).

9. The method for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 8 , wherein a jacketed means for temperature control is installed at outside of the fluidized bed reactor wall.

10. The method for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 9 , wherein heat transferring medium adopted by the jacketed means for temperature control is one or more of hot water, steam, thermal oil and cooling water.

11. The method for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 8 , wherein the material of the fluidized bed reactor is carbon steel or stainless steel.

12. The method for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 8 , wherein the temperature of each stage fluidized bed is in the range of 40° C.˜120° C.

13. The method for preparation of polyoxymethylene dimethyl ethers from dimethoxymethane and paraformaldehyde according to claim 8 , wherein the operation pressure of each stage fluidized bed is in the range of 0˜0.5 MPa.

Assignees

• Shandong Yuhuang Chemical Co Ltd
• Univ Tsinghua

Inventors

• Wang Jinfu
• Tang Qiang
• Wang Shengwei
• Wang Tiefeng
• Chen Shuangxi
• Wang Yuqiang

Classifications

• B01J2208/00902

  Nozzle-type feeding elements · CPC title

• B01J2208/00212

  Plates; Jackets; Cylinders · CPC title

• B01J2208/0092

  Perforated plates · CPC title

• B01J8/1818

  Feeding of the fluidising gas (B01J8/44 takes precedence) · CPC title

• B01J8/28

  the one above the other · CPC title