A dual-path combined hydrogen production method driven by low-grade thermal energy

Abstract

The invention provides a two-way combined hydrogen production method driven by low-grade heat energy, and belongs to the technical field of new energy. Continuous hydrogen production is realized withthe low-grade heat energy as driving force by the aid of concentration change of a working solution. The method comprises steps as follows: firstly, the low-grade heat energy is converted into chemical potential energy of the working solution with a low-temperature multi-effect distillation method; the chemical potential energy is converted into potential difference between two poles of a cell stack on the basis of the reverse electrodialysis principle; two-way hydrogen production and oxygen production are realized by a reduction reaction or an oxidation reaction simultaneously on corresponding hydrogen production and oxygen production electrodes in two homogenous electrode fluids respectively. The waste working solution is recovered after flowing out of the cell stack, and is regeneratedunder driving of the low-grade heat energy; the two electrode fluids circulate between hydrogen production and oxygen production electrode fluid chambers of the reverse electrodialysis cell stack andcathode and anode half grooves of an external electrolyzer respectively. The low-grade heat energy can be converted and utilized continuously, efficiently and stably; a hydrogen production system is not required to operate under conditions of high temperature and high pressure, few mechanical motion parts are required, and capacity allocation is flexible; two-way hydrogen production and oxygen production are realized, and consumption of the electrode fluids is low.

Description

technical field [0001] The invention belongs to the technical field of new energy, and relates to a method for realizing continuous hydrogen production with low-grade thermal energy as the driving force and by means of concentration changes of working solutions. Background technique [0002] Hydrogen energy is considered to be a new energy source with great development potential due to its advantages such as high energy density, environmentally friendly combustion products, abundant sources (water) and reserves, and a wide range of applications. At present, the common hydrogen production methods mainly include hydrogen production by electrolysis of water, hydrogen production by gasification of coal, catalytic conversion of heavy oil and natural gas water vapor production, etc., but the energy consumed by these methods is greater than the energy produced by them, and some methods are It will increase carbon emissions and exacerbate air pollution. If the method of hydrogen pr...

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Problems solved by technology

[0004] From the perspective of hydrogen production, even if the above-mentioned heat-to-electricity conversion technology based on the power conversion positive cycle system develops mature in the future, there are still some shortcomings in the direct use of the high-grade electric energy generated by it to electrolyze water to produce hydrogen, such as high electrode potential and energy consumption. Large amount, high energy conversion loss, etc., and usually requires the temperature of the driving heat source to be above 150°C

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