Catalytic Partial Oxidation of Natural Gas and Carbon Dioxide Mixture to Syngas

Abstract

The invention relates to a process for preparing synthesis gas through catalytic partial oxidation of natural gas and carbon dioxide mixed gas. The process comprises the following steps: dividing natural gas into two parts, wherein the first part of the natural gas is mixed with medium pressure steam and a first part of CO2 gas and is converted in a one-stage converter after heat exchange, and the second part of the natural gas is mixed with outlet converted gas of the one-stage converter and continues to react in a two-stage converter; outlet converted gas of the two-stage converter is transmitted to downstream side after condensate and CO2 are sequentially separated out of the outlet converted gas; the separated CO2 is compressed and then divided into two parts, wherein the second part of CO2 gas is mixed with medium pressure steam after heat exchange and small particles are filtered, then the second part of the CO2 gas is mixed with pure oxygen; molar concentration of oxygen in a second mixer is controlled at 20-35% (a critical oxygen state, oxygen enriched is less than or equal to 23%, and critical oxygen is less than 23%, which are inconsistent); the CO2 gas participates in heat exchange on a convection section of the one-stage converter and is burned together with converted gas in the two-stage converter, so as to supply heat energy required by reactions in the two-stage converter. The process disclosed by the invention solves the problems that conventional natural gas steam reformed synthesis gas is relatively high in H2 / CO ratio and fails to meet a requirement of carbonyl synthesis gas on a hydrogen-carbon ratio.

Description

technical field [0001] The invention relates to the field of chemical synthesis, in particular to a process for preparing synthesis gas by catalytic partial oxidation of natural gas and carbon dioxide mixed gas. Background technique [0002] Natural gas is a high-quality clean energy with low sulfur content and low pollution. The production of hydrogen, methanol, ethylene glycol, synthetic ammonia, synthetic oil and other products using natural gas as raw material has been widely used in the world. As a chemical raw material, natural gas is characterized by more hydrogen and less carbon. H in the synthesis gas produced by conventional natural gas steam reforming 2 / CO (molar ratio) is generally around 5. In view of this feature, according to different products, H in syngas 2 / CO requirements are different, and various hydrocarbon steam reforming technologies have been derived. [0003] At present, the process technologies for producing hydrogen, methanol and other products...

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Problems solved by technology

[0025] The technical problem to be solved by the present invention is to provide a natural gas pure oxygen with CO 2 and steam in the second stage to produce oxo gas (H 2 +CO) process to solve the H in the synthesis gas produced by conventional natural gas steam reforming 2 The / CO ratio is too high, which does not meet the hydrogen-carbon ratio requirements of oxo synthesis gas; at the same time, in view of the current situation that the current one-stage conversion + two-stage conversion process is mainly used to produce methanol synthesis gas and ammonia synthesis gas, a one-stage conversion + two-stage conversion process is provided. Stage reforming process for producing oxo gas

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