We have successfully completed our production and delivery of 300Nm3 /h delivery ceremony of Sinopec distributed rich methane gas hydrogen production plant.Here I would like to give a brief introduction to the process of hydrogen production from natural gas. With the intensification of energy consumption, finding new energy has become an important task. As the most potential energy, hydrogen has a wide range of sources, almost no pollution, high conversion efficiency and wide application prospects. Hydrogen production from natural gas can alleviate China's energy crisis to a certain extent and further promote the transformation of China energy utilization structure. This paper will focus on the principle of hydrogen production from natural gas, the process and technology of hydrogen production from natural gas, the classification of hydrogen production technology from natural gas and the cost accounting of hydrogen production from natural gas. 1 Principle and process of hydrogen production from natural gas 1.1Principle of hydrogen production from natural gas The principle of natural gas hydrogen production process is to pretreat natural gas first, then convert methane and steam into carbon monoxide and hydrogen in the reformer, and convert carbon monoxide into carbon dioxide and hydrogen in the shift tower after waste heat recovery. The basis of this process technology is realized on the basis of natural gas steam conversion technology. In the shift tower, the reaction temperature is controlled in the presence of catalyst, and the carbon monoxide in the conversion gas reacts with water to produce hydrogen and carbon dioxide. Under appropriate pressure and temperature, alkanes in natural gas will undergo a series of chemical reactions to generate conversion gas. After the conversion gas passes through PAS device equipped with various adsorbents under automatic control, carbon monoxide, carbon dioxide and other impurities will be adsorbed by the adsorption tower, and hydrogen will be sent to the gas consuming unit to adsorb the adsorbent of impurities, After desorption, the analytical gas can be sent to the shift furnace as fuel, and the adsorbent can also be regenerated. The main reaction formula is as follows: Natural gas and water react at 800 ~ 900 ℃ and nickel oxide catalyst to produce carbon monoxide and hydrogen. The reaction formula is: CH4 + H2O → CO + H2-Q Carbon monoxide and water react at 300-400 ℃ with ferric oxide catalyst to produce carbon dioxide and hydrogen. The reaction formula is: CO + H2O → CO2 + H2 + Q In addition, the relevant technical index requirements in the preparation process are as follows: The pressure is generally 1.5 ~ 2.5 MPa, and the unit consumption of natural gas is 0.4 ~ 0.5 m3 / m3 hydrogen;Operation time: > 8000h;Industrial scale: 1000 m3 / H ~ 100000 m3 / h. 1.2 Natural gas hydrogen production process The hydrogen production process of natural gas mainly includes four processes: feed gas pretreatment, natural gas steam conversion, carbon monoxide conversion and hydrogen purification. The first step is the raw material pretreatment step. The pretreatment here mainly refers to the desulfurization of the raw gas. In the actual process operation, the natural gas cobalt molybdenum hydrogenation series zinc oxide is generally used as the desulfurizer to convert the organic sulfur in the natural gas into inorganic sulfur and then remove it. The flow of raw natural gas treated here is large, so the natural gas source with high pressure can be used or a large margin can be considered when selecting the natural gas compressor. The second step is the steam conversion of natural gas. Nickel catalyst is used in the reformer to convert alkanes in natural gas into feed gas with main components of carbon monoxide and hydrogen. Then, carbon monoxide is converted to react with water vapor in the presence of catalyst to generate hydrogen and carbon dioxide to obtain the conversion gas whose main components are hydrogen and carbon dioxide. According to the different conversion temperature, the conversion process of carbon monoxide can be divided into two types: medium temperature conversion and high temperature conversion. The high temperature conversion temperature is about 360 ℃, and the medium temperature conversion process is about 320 ℃.With the development of technical countermeasures, the two-stage process setting of carbon monoxide high-temperature conversion and low-temperature conversion has been adopted in recent years, which can further save the consumption of resources. However, for the case that the carbon monoxide content in the conversion gas is not high, only medium temperature conversion can be adopted. The last step is to purify hydrogen. Now the most commonly used hydrogen purification system is PAS system, also known as PSA purification and separation system. This system has low energy consumption, simple process and high purity of hydrogen production. At the highest, the purity of hydrogen can reach 99.99%.