Mainstream hydrogen production technology for industry-hydrogen production from coal/hydrogen production from natural gas/hydrogen production from methanol

1. Hydrogen production from coal gasification

In 2019, the production of hydrogen from coal gasification was about 8.03 million tons, accounting for about 35% of the total hydrogen production.

Hydrogen production from coal gasification refers to the gasification of raw coal or coal char to obtain crude gas mainly composed of H2 and CO, and then through purification, CO conversion, separation and purification and other treatment processes to obtain hydrogen with a certain purity.

Coal gasification hydrogen production technology is mature and low cost. The hydrogen produced is usually used for the production of feed gas for ammonia synthesis and methanol. The disadvantage is that the investment cost of the device is high, the carbon emission is large, and the amount of carbon dioxide produced per kilogram of hydrogen is about 30.2kg. Coal gasification hydrogen production technology combined with CCS/CCUS technology is one of the future development directions.

2. Hydrogen production from natural gas reforming

In 2019, the production of hydrogen from natural gas reforming was about 3.7 million tons, accounting for about 16% of the total hydrogen production.

Natural gas reforming hydrogen production technology refers to the chemical reaction between alkanes and water vapor under the action of a certain temperature, pressure and catalyst, and the resulting conversion gas is heat exchanged and enters the converter to make CO react with water vapor to produce CO2 and H2. After heat exchange, condensation, steam separation and other processes, the product hydrogen is purified and extracted by pressure swing adsorption device.

The technology of hydrogen production from natural gas reforming is mature, the cost of hydrogen production is relatively low, and the hydrogen conversion rate is high. The amount of carbon dioxide produced per kilogram of hydrogen produced is about 8-10kg. However, due to the lack of natural gas resources in China, the development of hydrogen production from natural gas reforming is limited in China.

3. Hydrogen production from methanol steam reforming

Methanol hydrogen production technology also includes methanol steam reforming hydrogen production, methanol cracking hydrogen production and methanol partial oxidation hydrogen production.

Methanol steam reforming hydrogen production refers to the conversion of methanol and water into about 75% H2, 24% CO2 and a small amount of CO and CH4 under the action of a certain temperature, pressure and catalyst. After hydrogen purification and other processes to achieve hydrogen production. The process is mature relative to methanol cracking hydrogen production and methanol partial oxidation hydrogen production process, and is suitable for industrial production. The reaction conditions of methanol steam reforming for hydrogen production are relatively mild (220-280 ℃), and the product components are few and easy to separate.

The methanol feedstock is rich in resources and easy to store and transport. However, the process is suitable for small-scale hydrogen production, and the Cu/Zn/Al catalyst used is easy to be deactivated. The process produces about 20.6kg of carbon dioxide per kg of hydrogen produced. At present, the domestic methanol steam reforming hydrogen production plant (60,000 Nm3/h) has been put into production by Shandong Shouguang Luqing Petrochemical Co., Ltd. in July 2018.