Design Of The Hydrogen Production System From City Natural Gas For PEMFC

The proton exchange membrane fuel cell (PEMFC) is the most promising fuel cell recently, and it has a strict requirement on the purity of hydrogen. The advantages of the hydrogen production from city natural gas for PEMFC are both expanding the application field of city natural gas and satisfying the total demands of energy conservation and protecting the environment. In this dissertation, the syngas production from natural gas indirectly both here and abroad, the synthetic ammonia industry and the removal technology of CO from fuel gas for PEMFC have been considered comprehensively. The experiment process of the hydrogen production for PEMFC is designed, including the choose and preparation of catalysts and the evaluation of the whole hydrogen production system. The catalysts is used in hydrogen production via methane partial oxidation and CO removal via CO partial oxidation. 1) In the experiment of syngas production from methane, the catalyst is Ni/Al₂O₃, which is prepared by impregnating Ni into Al₂O₃ support . The catalytic activity is evaluated in the continuous fixed bed reactor, choosing the five indexes as follows: the CO selectivity, the H2 selectivity, the CH4 percent conversion, the syngas formation rate and O₂ percent conversion. 2) In the experiment of CO selective oxidation, the catalyst is CuO/CeO₂, which is prepared by impregnating CuO into CeO₂ support. The catalytic activity is evaluated in the continuous fixed bed reactor too, choosing the CO percent conversion and the CO₂ selectivity as evaluation indexes. The content of CO below 10 ppm after reaction must be achieved or else the excessive CO will poison the membrane. 3) The optimization of the hydrogen production system from natural gas for PEMFC is a process of adjusting again and again. The goal is to make the transition between the POM reaction and CO partial oxidation reaction smoothly, that is there isn't fluctuation in the velocity and temperature of the gas flow. And the part of the desulfurization reaction and the WGSR is required or not according to result of the experiment. In order to operate feasible and economically, the system of hydrogen production from natural gas for PEMFC is designed with the most favorable conversion methods and catalysts in the dissertation. And the system designed in the dissertation has laid the scientific basis for the optimization of experiment of the hydrogen from natural gas.