Integrated process and unit operation for conditioning a soot-containing syngas

Patent metadata

Field	Value
Publication number	US-10793797-B2
Application number	US-201715678564-A
Country	US
Kind code	B2
Filing date	Aug 16, 2017
Priority date	Aug 16, 2017
Publication date	Oct 6, 2020
Grant date	Oct 6, 2020

Abstract

The present invention relates to a method for conditioning a soot-containing syngas stream in a single integrated apparatus containing a scrubbing vessel wherein particulate matter is decoupled from the waste water stream.

First claim

What is claimed is:

1. An integrated process for conditioning a soot-containing synthesis gas stream, comprising:
(a) introducing a raw soot-containing synthesis gas having particulate matter and gaseous contaminants therein at a temperature of less than about 900° F. into a quenching device to reduce the temperature of said synthesis gas to a range of about 250-400° F., thereby forming a two-phase stream;
(b) routing the two-phase stream through a first scrubber device to substantially transfer majority of particulate matter from the gas phase to the liquid phase;
(c) directing said two-phase stream to a second scrubbing device wherein the two-phase stream is separated into a liquid-phase fluid contaminated with particulate matter and a gas-phase fluid having water-soluble contaminants at a lower section of the scrubbing device;
(d) cleaning and cooling the gas-phase fluid having water-soluble contaminants in an upper section of the second scrubbing device where the gas-phase fluid comes in direct contact with process water cooled to a temperature below 150° F. dispensed through a spray nozzle device thereby reducing the temperature of the gas phase fluid below the dew point temperature and removing water soluble impurities and remaining particulate matter therefrom;
(e) further routing the cooled and cleaned gas phase fluid of step (d) through a mist eliminating device disposed in the upper section of the second scrubbing device to remove substantially all of the remaining entrained water droplets, thereby producing a cooled and substantially soot-free synthesis gas stream.

2. The integrated process of claim 1 , further comprising: recycling at least a portion of said liquid-phase fluid contaminated with particulate matter from said second scrubbing device to said quenching device.

3. The integrated process of claim 1 , further comprising removing at least a portion of the liquid-phase fluid with particulate matter from said second scrubbing device, pumping it through a filtration device, removing the particulate matter and recycling at least a portion of a clean process water stream to the spray nozzle device disposed in the second scrubbing device.

4. The integrated process of claim 3 , wherein the portion of said clean process water stream routed to the spray nozzle is routed through a heat exchanger and cooled to about 150° F.

5. The integrated process of claim 4 , further providing another portion of said clean process water to a second set of spray nozzles in communication with said mist eliminating device.

6. The integrated process of claim 1 , wherein the raw soot-containing synthesis gas has a composition by volume on a dry basis by volume: 50 to 75% H 2 , 20 to 45% CO, 1 to 10% CO 2 , 0.1 to 5% CH 4 , 0-1% N 2 , 0-1% Ar, 0-1% of small hydrocarbons.

7. The integrated process of claim 1 , wherein the raw soot-containing synthesis gas includes 0 to 500 mg/Nm 3 of particulate matter consisting primarily of soot derived from the hydrocarbon feedstock and refractory dust from upstream process equipment.

8. The integrated process of claim 1 , wherein the raw soot-containing synthesis gas is at a pressure ranging from about 1 to 600 psig.

9. The integrated process of claim 1 , wherein the substantially soot-free synthesis gas stream has a temperature in the range of about ambient temperatures to 150° F., a pressure in the range of about 1 to 600 psig and a particulate contaminant of about 0 to 10 mg/Nm 3 .

10. The integrated process of claim 1 , wherein substantially all of the NH 3 is removed from the substantially soot free synthesis gas stream and the remaining water-soluble impurities including HCN, CHOOH, HCl, H 2 S, COS are partially removed from the syngas stream in the second scrubbing device.

11. The integrated process of claim 2 , further comprising routing a portion of the liquid-phase fluid contaiminated with particulate matter to said first scrubbing device.

Assignees

• Praxair Technology Inc

Inventors

• Coleman Luke
• Shah Minish Mahendra
• Schwartz Joseph
• Jankowiak Jerome

Classifications

• B01D2247/107

  using an unstructured demister, e.g. a wire mesh demister · CPC title

• C10L3/08 Primary

  Production of synthetic natural gas · CPC title

• C10K1/101

  with water only · CPC title

• B01D47/06 Primary

  Spray cleaning · CPC title

• C10G1/06

  by destructive hydrogenation · CPC title