Process for the production of synthesis gas

Patent metadata

Field	Value
Publication number	US-9828246-B2
Application number	US-201515120341-A
Country	US
Kind code	B2
Filing date	Feb 26, 2015
Priority date	Feb 28, 2014
Publication date	Nov 28, 2017
Grant date	Nov 28, 2017

Abstract

The invention relates to a process for the production of liquid hydrocarbons by Fischer-Tropsch synthesis in which the reforming section of the plant comprises a process line comprising autothermal reforming (ATR) ( 5 ) or catalytic partial oxidation (CPO), and a separate process line comprising steam methane reforming (SMR) ( 8 ).

First claim

The invention claimed is:

1. A process for the production of synthesis gas comprising:
(a) passing a first hydrocarbon feedstock, a tail gas from a Fischer-Tropsch (FT) synthesis stage, and an oxidant gas to an autothermal reforming (ATR) stage or catalytic partial oxidation (CPO) stage to form a raw synthesis gas;
(b) passing a second hydrocarbon feedstock through a primary reforming stage in the form of steam methane reforming (SMR), to form a primary reformed gas;
(c) combining part or all of the primary reformed gas of step (b) with the raw synthesis gas of step (a) to form a synthesis gas according to a R SMR ratio between 1 and 20%, where R SMR is defined as the volumetric flow rate of carbon monoxide and hydrogen in the primary reformed gas to the volumetric flow rate of the hydrogen and carbon monoxide in the synthesis gas.

2. The process according to claim 1 in which said first hydrocarbon feedstock and said second hydrocarbon feedstock are split from a single hydrocarbon feedstock and wherein prior to split the single hydrocarbon feedstock is subjected to pre-reforming.

3. The process according to claim 1 wherein naphtha formed or synthesised in the FT-synthesis stage is not added to the first hydrocarbon feedstock or the second hydrocarbon feedstock or to the single hydrocarbon feedstock.

4. The process according to claim 1 wherein each individual stream in the form of first hydrocarbon feedstock, or second hydrocarbon feedstock, or both, are subjected to pre-reforming prior to passing through autothermal reforming stage or primary reforming stage.

5. The process according to claim 1 further comprising subjecting primary reformed gas to the sequential stages of water gas shifting, separating a hydrogen-rich stream in a separation means, and mixing all or a portion of the hydrogen-rich stream with the produced synthesis gas of step (c).

6. The process according to claim 1 wherein the produced synthesis gas of step (c) has a molar ratio of hydrogen to carbon monoxide of 1.7-2.3.

7. The process according to claim 1 wherein in step (a) the autothermal reforming (ATR) stage is combined with heat exchange reforming (HER) arranged in series or in parallel.

8. The process according to claim 1 wherein the process further comprises previous to steps (a) or (b) a step of passing the first or second hydrocarbon feedstock through a desulfurization stage.

9. The process according to claim 1 wherein the process steam-to-carbon molar ratio (S/C) in step (a) is in the range 0.4-1.0, while the process steam-to-carbon molar ratio in step (b) is in the range 1.5-4.0.

10. The process according to claim 1 wherein the process further comprises subjecting primary reformed gas to the sequential stages of water gas shifting, separating a hydrogen-rich stream in a separation means, and mixing all or a portion of the hydrogen-rich stream with the raw synthesis gas of step (a).

11. The process according to claim 1 wherein the process further comprises converting the synthesis gas to liquid hydrocarbons by Fischer-Tropsch synthesis.

Assignees

• Haldor Topsoe As
• Haldor Topsoe As

Inventors

• Dybkjaer Ib
• Aasberg-Petersen Kim

Classifications

• C01B2203/1205

  Composition of the feed · CPC title

• C01B2203/1258

  Pre-treatment of the feed · CPC title

• C01B2203/1235

  Hydrocarbons · CPC title

• C01B2203/148

  involving a recycle stream to the feed of the process for making hydrogen or synthesis gas · CPC title

• C01B3/382 Primary

  Processes with two or more reaction steps, of which at least one is catalytic, e.g. steam reforming and partial oxidation · CPC title