Systems for two-stage biomass pyrolysis

Patent metadata

Field	Value
Publication number	US-9908092-B2
Application number	US-201715436029-A
Country	US
Kind code	B2
Filing date	Feb 17, 2017
Priority date	Feb 23, 2016
Publication date	Mar 6, 2018
Grant date	Mar 6, 2018

Abstract

The present disclosure relates generally to two-stage biomass pyrolysis systems configured to maximize pyrolysis vapor yield from a lignocellulosic biomass while being conducive to commercial-scale throughput of lignocellulosic biomass. The system includes a reactor first stage comprising at least one auger pyrolyzes a lignocellulosic feedstock at a temperature and residence time that produces pyrolysis vapors derived predominantly from cellulose and hemi-cellulose fractions of the feedstock. A reactor second stage is configured to partially-pyrolyzed feedstock from the reactor first stage at a higher temperature for an additional residence time to produce additional pyrolysis vapors that are predominantly derived from of lignin. Certain embodiments arrange multiple reactor first stages around a single reactor second stage.

First claim

We claim:

1. A system for the pyrolysis and upgrading of lignocellulosic biomass, comprising:
a pyrolysis reactor comprising,
a reactor first stage, comprising:
a first end portion,
a second end portion,
at least one auger configured to transport the lignocellulosic biomass through the reactor first stage toward the second end portion,
wherein the reactor first stage is configured to pyrolyze a lignocellulosic biomass feedstock at a temperature between 315° C. and 400° C. for a residence time sufficient to produce a first product comprising a first condensable pyrolysis vapors and a first solids comprising partially-pyrolyzed feedstock and char,
wherein the reactor first stage comprises at least one inlet configured to receive a lignocellulosic biomass, at least one inlet configured to receive a solid particulate heat carrier, and at least one inlet configured to receive a sweep gas,
wherein the reactor first stage comprises an interface proximal to the second end portion that is directly connected to a reactor second stage;

a reactor second stage, comprising:
a receptacle that delineates a bed comprising solids, the reactor second stage configured to receive the first solids from the reactor first stage and pyrolyze the partially-pyrolyzed feedstock at a temperature that is higher than the temperature maintained the reactor first stage to produce a second condensable pyrolysis vapors and a second solids comprising char,
a disengagement zone configured to allow the terminal falling velocity of entrained solids to become greater than the upward local velocity of the first condensable vapors, thereby facilitating retention of at least 99.5 wt. % of the solid particulate heat carrier and char in the reactor second stage, the cross-sectional area of the disengagement zone further configured to separate the first condensable pyrolysis vapors and second condensable pyrolysis vapors from the first solids and second solids and transport the first and second condensable pyrolysis vapors out of the pyrolysis reactor within five seconds after each is produced,
a solids outlet located proximate the bottom of the reactor second stage that is configured to allow removal of the second solids from the reactor second stage.

2. The system of claim 1 , wherein the reactor second stage further comprises at least one inlet for a second sweep gas that moves upward through the bed and facilitates transport of the second condensable pyrolysis vapors to the disengagement zone and out of the pyrolysis reactor.

3. The system of claim 1 , wherein the at least one auger in the reactor first stage is configured to provide a lignocellulosic feedstock residence time ranging from 5 to 20 seconds.

4. The system of claim 1 , wherein the reactor second stage is configured to provide a residence time for the first solids in the range from 30 seconds to 120 seconds.

5. The system of claim 1 , wherein the reactor first stage is configured to pyrolyze a lignocellulosic biomass feedstock at a temperature in the range from 325° C. to 400° C.

6. The system of claim 1 , wherein the reactor second stage is configured to pyrolyze the partially-pyrolyzed feedstock at a temperature that is in the range from 401° C. to 700° C.

7. The system of claim 1 , wherein the reactor second stage is configured to pyrolyze the partially-pyrolyzed feedstock at a temperature that is in the range from 450° C. to 700° C.

8. The system of claim 1 , wherein the reactor second stage is configured to pyrolyze the partially-pyrolyzed feedstock at a temperature that is in the range from 500° C. to 700° C.

9. The system of claim 1 , wherein the reactor second stage is configured to pyrolyze the partially-pyrolyzed feedstock at a temperature that is at least 50° C. higher than the temperature maintained in the reactor first stage.

10. The system of claim 1 , wherein the reactor second stage is configured to pyrolyze the partially-pyrolyzed feedstock at a temperature that is at least 100° C. higher than the temperature maintained in the reactor first stage.

11. The system of claim 1 , wherein a cross-sectional area of the disengagement zone is configured to allow the terminal falling velocity of particles in the first and second solids to become greater than the upward local velocity of the first and second condensable pyrolysis vapors in the disengagement zone, thereby causing at least 99.5 wt. % of the combined solids to be retained in the reactor second stage.

12. The system of claim 1 , wherein the bed within the reactor second stage further comprises at least one catalyst configured to facilitate pyrolysis of the un-pyrolyzed biomass, upgrade the second condensable pyrolysis vapors to a transportation fuel or fuel intermediate, or combinations thereof.

13. The system of claim 1 , wherein the reactor first stage is configured to maintain a temperature and feedstock residence time that produce first condensable pyrolysis vapors derived predominantly from the pyrolysis of one or more of cellulose and hemicellulose, wherein the reactor second stage is configured to maintain a temperature and first solids residence time that produce second condensable pyrolysis vapors derived predominantly from the pyrolysis of lignin.

14. The system of claim 1 , wherein the reactor second stage comprises at least one inlet configured to add at least one catalyst to the bed, wherein the at least one catalyst is configured to facilitate pyrolysis of the un-pyrolyzed biomass, facilitate upgrading of the second condensable pyrolysis vapors to a transportation fuel or fuel intermediate, or combinations thereof.

15. The system of claim 1 , wherein the system is configured to remove first condensable pyrolysis vapors from the pyrolysis reactor within 5 sec after being produced in the reactor first stage, wherein the system is configured to remove the second condensable pyrolysis vapors from the pyrolysis reactor within 5 sec after being produced in the reactor second stage.

16. The system of claim 1 , wherein the system is configured to remove first condensable pyrolysis vapors from the pyrolysis reactor within 3 sec after being produced in the reactor first stage, wherein the system is configured to remove the second condensable pyrolysis vapors from the pyrolysis reactor within 3 sec after being produced in the reactor second stage.

17. The system of claim 1 , wherein the system is configured to remove first condensable pyrolysis vapors from the pyrolysis reactor within 1 sec after being produced in the reactor first stage, wherein the system is configured to remove the second condensable pyrolysis vapors from the pyrolysis reactor within 1 sec after being produced in the reactor second stage.

18. The system of claim 1 , wherein the pyrolysis reactor is configured to comprise more than one reactor first stage, with each reactor first stage directly interfacing with the reactor second stage, and each reactor first stage is configured to pass the first product directly into the reactor second stage.

Assignees

• Phillips 66 Co

Inventors

• Dalluge Dustin L
• Lusk Steven E
• Jones Samuel T
• Gorke Johnathan T

Classifications

• B01J8/0045 Primary

  by means of a rotary device in the flow channel · CPC title

• C10B49/16

  with moving solid heat-carriers in divided form · CPC title

• B01J8/082

  Controlling processes · CPC title

• B01J8/005

  Separating solid material from the gas/liquid stream (separation processes per se B01D) · CPC title

• C10B53/02

  of cellulose-containing material (production of pyroligneous acid C10C5/00) · CPC title