Hydrogen (Hydrogen) is the lightest gas known in the world. Its density is very small, only 1/14 that of air, that is, at standard atmospheric pressure and 0°C, the density of hydrogen is 0.0899g/L. Hydrogen (H2) was first synthesized artificially in the early 16th century, when the method used at that time was to place the metal in a strong acid. Nowadays, the industry generally produces hydrogen from natural gas or water gas instead of the high-energy-consuming electrolysis of water. The hydrogen produced is used in cracking reactions and ammonia production in the petrochemical industry. Today, Niu Ruide Special Gas Editor introduces a new method for synthesizing hydrogen—the study of hydrogen permeation and yield in a catalytic membrane reactor for producing pure hydrogen.

The goal of this research is to build a catalytic membrane reactor with two palladium membrane tubes, using the commercial MDC-3 catalyst to recombine methanol vapor to produce pure hydrogen, and to study the hydrogen permeation and recovery rate in the reactor. The results show that every time a new catalyst is loaded and activated in the reactor, the amount of hydrogen permeation is reduced because the metal catalyst (copper, zinc, chromium) may be deposited on the surface of the palladium membrane. After 288 hours of reaction, water vapor treatment was introduced, and the hydrogen permeation increased by 30%, because water vapor can remove the coke on the palladium membrane. The hydrogen permeation data was fitted into a mathematical model of pressure n-th power (n=0.69~0.92) through nonlinear regression, and it was found that the experimental data is very consistent with the mathematical model.

The experimental results of methanol vapor recombination in a catalytic membrane reactor show that as WHSV decreases, the conversion rate of methanol vapor recombination and the hydrogen recovery rate increase accordingly. In the studied WHSV range, the reverse water vapor transfer reaction has a maximum value. Among the four temperature-pressure research conditions, when the temperature is 618K and the pressure is 11.8bar, there is the best hydrogen recovery rate. At this time, WHSV is 1.05h-1, L/S is 35.7mol/h/m2, and hydrogen The recovery rate is 0.74, which is enough for methanol vapor to recombine in the catalytic membrane reactor to achieve heat self-equilibration. After four hours of activation at 653K, the catalytic activity of MDC-3 was stable in the 76-hour methanol vapor recombination experiment. It is suggested that the catalyst activation should be carried out outside the catalytic membrane reactor to prevent the palladium membrane from being deposited by the metal catalyst and reduce the hydrogen permeation.