Coke oven gas recycling
Thread Content
Coke oven gas is used in the process of synthesizing ammonia and methanol. How to use gas separation (membrane, PSA) technology to reduce investment and operating costs is currently an issue worth considering. The Second Institute of the Ministry of Chemical Industry and the West China Institute of Chengdu convert coke oven gas into hydrogen and carbon monoxide, which often costs hundreds of millions in equipment investment. Small coking plants cannot afford such a large investment. Are there any industry pioneers who can reduce investment and consumption through separation technology, thus bringing vitality to small coking plants? Please let’s discuss it together! This post was last edited by chc1125 on 2008-11-12 15:04 ]
As far as I know, in addition to hydrogen, methane and a small amount of carbon dioxide and carbon monoxide, the main components of coke oven gas also include a certain amount of benzene, naphthalene, and unsaturated hydrocarbons. If it is not purified, purified, converted, and processed into semi-water gas, it is generally used as fuel. Your idea is creative. I wonder if any colleagues have other research methods. I hope you can get some advice! :lol
Can pressure swing adsorption technology be used to extract more than 50% of the hydrogen in the coke oven gas as the raw material gas for the synthesis of ammonia and methanol, and the remaining desorbed gas can be used as fuel gas? This can save the huge conversion process and also realize the hierarchical utilization of coke oven gas. Everyone is welcome to discuss!
It's a pity that everyone pays more attention to large coke oven gas. So many small coke ovens may be closed. How to save them from the fate of closure is worth thinking about.
If the pressure is high, membrane separation can be used to increase the hydrogen to more than 90%. Methane and other gases are obtained from the tail gas as fuel gas, and the hydrogen on the permeation side is recycled. This technology is now very mature and many membrane manufacturers can do it. If you want to obtain higher purity hydrogen, side membrane separation is a bit difficult, and requires many stages, which is uneconomical. Consider using pressure swing adsorption, or a method that combines membrane separation with pressure swing adsorption.
As far as I know, pressure swing adsorption hydrogen production is in developed* * Here, it is a very mature and widely used technology. A large German company requires a Chinese molecular sieve company to export 5,000 tons of molecular sieves specifically used for pressure swing adsorption to purify hydrogen every year. However, whether pressure swing adsorption technology can be applied to small coke ovens mainly depends on whether it is cost-effective in terms of economic performance.
The utilization of coke oven gas requires a certain amount of investment. If this is not possible, it is best not to use it. The reason is that coke oven gas contains various sulfides and must be desulfurized first, which requires a large investment. If you can achieve this, the gases that come out are usable gases such as H2, CO, CH4, CO2, etc. There is room for discussion. First, it can be used to produce syngas, and then to produce methanol, hydrogen, ammonia, hydrocarbons, etc., that is, the utilization of syngas. It is also possible to consider obtaining H2 and CH4 after methanation and utilizing these two components respectively. The design institute will do all these things, it depends on your needs.