LOHC fuel cell power generation system and method

Abstract

The invention discloses an LOHC fuel cell power generation system and method. The LOHC fuel cell power generation system is composed of a fuel cell subsystem, a high-temperature heat pump subsystem, an LOHC dehydrogenation subsystem and a Rankine cycle subsystem; the fuel cell subsystem is used for converting H2 chemical energy into electric energy; the high-temperature heat pump subsystem is used for converting the low-temperature heat energy of the fuel cell into high-temperature heat energy; the LOHC dehydrogenation subsystem is used for realizing LOHC dehydrogenation by utilizing the high-temperature heat energy; and the Rankine cycle subsystem is used for converting residual heat energy of the system into electric energy. Power generation waste heat of the fuel cell is rapidly absorbed and taken away by a working medium, efficient and stable work of the cell is ensured; one part of the heat is used for driving Rankine cycle power generation, the generated electric energy can be used for internal consumption of the system; one part of the heat is used for LOHC dehydrogenation, and generated H2 is used for the fuel cell. According to the system and the method, the problem of energy waste caused by mismatching of the working temperature of the fuel cell and the LOHC dehydrogenation temperature is solved, the adverse effect of dehydrogenation reaction energy consumption on the power generation efficiency of the fuel cell is reduced, and the overall energy utilization level is improved.

Description

technical field [0001] The invention belongs to the field of hydrogen energy, and in particular relates to a LOHC fuel cell power generation system and method. Background technique [0002] h 2 As a truly clean fuel, it is the key to solving future environmental problems. Its production, storage, transportation and use are different from traditional fuels. The limitation of energy density per unit volume makes it difficult for long-distance transportation to be as convenient and efficient as coal and oil. h 2 The standard boiling point (-253°C) of hydrogen is much lower than that of natural gas (-162°C), the storage and transportation costs of liquid hydrogen are too high, and the problem of hydrogen embrittlement during pipeline transportation is difficult to solve in the short term. Liquid Organic Hydrogen Carrier (LOHC) is a potential H 2 The storage method realizes high-density hydrogen storage through the reversible catalytic hydrogenation and dehydrogenation reacti...

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Problems solved by technology

In addition, due to the generally lower boiling point and thermal decomposition temperature of LOHC, the reaction endothermic heat is higher (~60kJ / mol-H 2 ), in order to ensure a high dehydrogenation rate and conversion rate, the reaction temperature window is generally narrow, and it is difficult to maintain the temperature window

[0004] Some scholars have proposed to use the waste heat of fuel cells to realize LOHC dehydrogenation, but the temperature mismatch between the two makes its implementation difficult.

Some scholars pointed out that using H 2 Low-temperature catalytic combustion provides energy for the LOHC dehydrogenation reaction, but the lower heat transfer coefficient on the flue gas side will greatly increase the size of the equipment

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