System and method used for producing high purity hydrogen via concentrated-solar-energy-driven high-temperature bubbling-type methane direct pyrolysis

Abstract

The invention discloses a system and a method used for producing high purity hydrogen via concentrated-solar-energy-driven high-temperature bubbling-type methane direct pyrolysis. According to the method, collecting lens is used for concentrating of sunlight onto a heat absorber so as to generate a high temperature heat source, a heat carrying fluid is introduced into the heat absorber, and is used for delivering high temperature heat energy into a specially-made bubbling-type reactor; in the specially-made bubbling-type reactor, production of solid state carbon nanoparticles and hydrogen gasis realized via methane direct pyrolysis, the carbon nanoparticles are left in the specially-made bubbling-type reactor and are collected, a mixed gas of hydrogen gas and unreacted methane is delivered into a hydrogen gas separator to obtain high purity hydrogen gas; the heat carrying fluid discharged from the specially-made bubbling-type reactor is relatively high in temperature, so that the heatcarrying fluid is used for generation of high temperature high pressure superheated steam via heating, and driving turbines to produce electricity; generated electricity is used for driving a heat carrying fluid circulation pump and a front booster pump, and the excess electricity is output into a electricity grid. The method is capable of producing high quality carbon nanoparticles, high purityhydrogen, and electricity, and realizing zero carbon discharge, large scale production can be realized; the method is friendly to the environment; and economic benefit is relatively high.

Description

technical field [0001] The invention belongs to the technical field of hydrogen production from methane and utilization of concentrated solar energy, and relates to a system and method for producing high-purity hydrogen by direct cracking of high-temperature bubbling methane driven by concentrated solar energy. Background technique [0002] Energy is an important supporting factor for the survival and development of human beings, and ensuring the source of energy is one of the major basic strategies of all countries in the world. At the same time, the adverse impact on the environment caused by the use of conventional energy sources (such as oil and coal) cannot be ignored. Therefore, sustainable, clean and low-carbon energy is an inevitable development trend in the future. [0003] Hydrogen energy is a very promising and important environmentally friendly energy source, which has the characteristics of high energy density and low impact on the environment (because its comb...

AI Technical Summary

Problems solved by technology

[0004] However, the biggest operational problem of the methane cracking hydrogen production system is that carbon particles will accumulate on the surface of the catalyst and the tube wall, resulting in catalyst deactivation and reactor channel blockage

[0005] Hydrogen production using bubbling methane reactor still needs to face two main technical problems: (1) Hydrogen production by methane cracking requires a large amount of high-temperature heat energy

At present, the source of heat energy can be provided by methane combustion, but the chemical formula of methane combustion is CH 4 (g)+O 2 (g)→CO 2 (g)+H 2 O(g), there is a large amount of carbon dioxide emissions in the process, which greatly reduces the advantages of zero carbon emissions from methane cracking reaction for hydrogen production; (2) The reaction purity of direct methane cracking reaction for hydrogen production is not high, and methane and hydrogen need to be further separated

The results of the current experiment show that the methane conversion rate of the bubble reactor is 30% to 50%, so the separation of hydrogen needs to consume a lot of mechanical energy or electrical energy

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