Steam reforming process with low carbon dioxide emission

Abstract

A steam reforming process for producing synthesis gas from hydrocarbons, comprising: a first steam reforming step in which a gas stream of a hydrocarbon feedstock is supplied to a first reforming section (51) comprising at least a first gas-heated reformer in which a steam reforming reaction takes place, forming a partially reformed effluent; a second steam reforming effluent, in which the partially reformed effluent exiting the first reforming section (51) is supplied to a second steam reforming section (52) comprising at least one second reformer, in which air combustion takes place in the radiant chamber outside the tube; the second reformer is a gas heated reformer.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS [0002] This patent application claims the priority of Italian Patent Application No. 102019000008280, filed on June 6, 2019. Its entire disclosure is incorporated herein by reference. technical field [0003] The present invention relates to a steam reforming process, especially for the production of synthesis gas, which ensures that the carbon dioxide emission is greatly reduced, and the reduction rate is higher than 90%. Background technique [0004] As we all know, syngas is a gas mixture mainly composed of hydrogen (H 2 ) and carbon monoxide (CO), with a small amount of methane (CH 4 ), carbon dioxide (CO 2 ), nitrogen and other inert gases. [0005] Syngas is typically produced by steam reforming of hydrocarbons (eg, methane) in a reforming reactor (reformer). [0006] Typically, the steam reforming process is carried out in a tubular reactor consisting of one or more rows of tubes arranged inside a combustor that co...

AI Technical Summary

Problems solved by technology

[0007] Known steam reforming processes are not satisfactory and have some disadvantages

[0008] First, the CO2 emissions associated with the process are very large: for every ton of hydrogen produced by this method, 9 tons of CO2 are also produced

[0009] Furthermore, if with CO 2 Combined with the capture step, the energy efficiency of the process is unsatisfactory in reducing emissions if it were carried out in the gas conversion section

In practice, due to the introduction of combustible gases in the combustion section, the maximum capture percentage is limited to the CO produced 2 About 65% of the total

For alternative flue gas capture systems, this limitation is overcome and up to 90-95% capture can be achieved, resulting in a huge loss of overall efficiency in generating the energy required for purification, while increasing the installation cost, which is practical results in a doubling of the total cost of the plant

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