Process for capturing carbon-dioxide from a gas stream

Patent metadata

Field	Value
Publication number	US-10376833-B2
Application number	US-201615574965-A
Country	US
Kind code	B2
Filing date	May 18, 2016
Priority date	May 19, 2015
Publication date	Aug 13, 2019
Grant date	Aug 13, 2019

Abstract

The present disclosure relates to a process for capturing carbon-dioxide from a gas stream. In order to capture the carbon-dioxide, a support is provided and potassium carbonate (K 2 CO 3 ) is impregnated thereon to form an adsorbent comprising potassium carbonate (K 2 CO 3 ) impregnated support. The adsorbent is activated to form an activated adsorbent. The gas stream is passed through the adsorber to enable adsorption of the carbon-dioxide on the activated adsorbent to form a carbon-dioxide laden adsorbent. The carbon-dioxide laden adsorbent is transferred to a desorber for at least partially desorbing the carbon-dioxide from the carbon-dioxide laden adsorbent by passing a carbon-dioxide deficient stream through the desorber. The partially regenerated adsorbent is returned to the adsorber for adsorbing the carbon-dioxide from the carbon-dioxide. The process of the present disclosure reduces the overall energy demand by partially regenerating the adsorbent.

First claim

The invention claimed is:

1. A process for capturing carbon-dioxide from a gas stream, said process comprising the following steps:
a) providing a support, wherein said support is one of an alumina support and a silica alumina support;
b) impregnating potassium carbonate (K 2 CO 3 ) on said support to form an adsorbent comprising potassium carbonate (K 2 CO 3 ) impregnated support;
c) activating said adsorbent in an adsorber by passing one of water-vapor and a gas stream comprising water-vapor at a temperature ranging from 40° C. to 80° C., at a pressure ranging from 1 bar to 2 bar, and for a time period ranging from 1 minute to 20 minutes to form an activated adsorbent with active adsorption sites having reduced energies compared to non-hydrated sites on the adsorbent;
d) passing said gas stream through said adsorber containing said activated adsorbent to enable adsorption of the carbon-dioxide from said gas stream on said activated adsorbent at a temperature ranging from 40° C. to 90° C. and at a pressure ranging from 1 bar to 2 bar to form a carbon-dioxide laden adsorbent;
e) transferring said carbon-dioxide laden adsorbent to a desorber; and
f) passing a carbon-dioxide deficient stream through said desorber for at least partially desorbing the carbon-dioxide from said carbon-dioxide laden adsorbent at a temperature ranging from 110° C. to 200° C. and at a pressure ranging from 1 bar to 2 bar to obtain a partially regenerated adsorbent, wherein said carbon-dioxide deficient stream comprises nitrogen, carbon-dioxide, or water-vapor; and
g) returning said partially regenerated adsorbent to said adsorber for adsorbing the carbon-dioxide from said gas stream;
Wherein,
the process of impregnation is carried out in the following steps:
i. treating said support at a temperature in the range of 550° C. to 1100° C. to obtain a treated support;
ii. adding said treated support into a fluid medium comprising K 2 CO 3 in the range of 5 wt % to 60 wt % using an incipient wet impregnation method at a temperature in the range of 20° C. to 50° C.; and
iii. allowing K 2 CO 3 to disperse on said treated support for a time period in the range of 10 min to 20 min to form the adsorbent followed by drying at a temperature in the range of 100° C. to 150° C. for at a time period in the range of 10 hours to 12 hours.

2. The process as claimed in claim 1 , wherein said activated adsorbent is hydrated K 2 CO 3 .

3. The process as claimed in claim 1 , wherein the amount of K 2 CO 3 in said support ranges from 5 wt % to 60 wt %.

4. The process as claimed in claim 1 , wherein the support comprises a surface area in the range of 170 to 550 m 2 /g; pore volume in the range of 0.18 cm 3 /g to 0.95 cm 3 /g; and pore size in the range of 100 Å to 300 Å.

5. The process as claimed in claim 1 , wherein the process step (d) of adsorption is carried out in said adsorber and the process step (f) of desorption is carried out in said desorber in a circulating fluidized bed bubbling flow regime.

6. The process as claimed in claim 1 , wherein the differential temperature between the process step (d) of adsorption and the process step (f) of desorption ranges from 20° C. to 110° C.

7. The process as claimed in claim 1 , wherein the residence time of said:
a) activated adsorbent in said adsorber ranges from 1 minute to 10 minutes; and
b) carbon-dioxide laden adsorbent in said desorber ranges from 1 minute to 5 minutes.

8. The process as claimed in claim 1 , wherein the efficiency of carbon-dioxide removal from said gas stream ranges from 40% to 90%.

Assignees

• Reliance Industries Ltd

Inventors

• Sengupta Surajit
• Amte Vinay
• Das Asit Kumar
• Akuri Satyanarayana Reddy
• Yadav Manoj
• Mandal Sukumar
• Gohel Amit
• Nerivetla Sampath
• Nath Kalyan Chandra

Classifications

• B01J20/3458

  in the gas phase · CPC title

• B01D2251/606

  Carbonates · CPC title

• B01D2253/112

  Metals or metal compounds not provided for in B01D2253/104 or B01D2253/106 · CPC title

• B01J20/3236

  containing metal, other than zeolites, e.g. oxides, hydroxides, sulphides or salts · CPC title

• B01D53/12

  according to the "fluidised technique" · CPC title