Issues with the gas generation system renovation for the 100,000 tons/year methanol project

Changing from a batch fixed-bed system at atmospheric pressure to a continuous fixed-bed system at the same pressure is not economically viable. Many companies have attempted to make this change in the past, but after using it for a while they seem to have given up on it; for example, various companies under the Jinmei Group such as Jin Kai, Jinmei Jinxiang, and Jinfeng Wenxi all tried this approach, yet none achieved the desired results. Actually, you can think about it. In addition to its serious drawbacks such as high pollution, low capacity, low efficiency, and high power consumption, the key performance indicators of atmospheric-pressure batch fixed-bed reactors, such as specific coal consumption, are very low. The high operating cost of atmospheric-pressure fixed-bed reactors is due to high electricity consumption; the electricity required per ton of ammonia produced ranges from 1,400 to 1,500 kWh per ton, while in cases where performance is better, it’s still around 1,100 to 1,200 kWh per ton. This is roughly twice as much as that of pressurized gasification furnaces, resulting in an increase in the cost per ton of ammonia by 300 to 400 yuan. Most of the electrical energy is used for compressing the gas, and the electricity consumed to raise the gas pressure from atmospheric to 2.0 MPa accounts for over 60% of the total electricity used for gas compression. Therefore, by changing from a batch fixed-bed to a continuous fixed-bed, the power consumption issue remains unchanged. The power consumption remains the same. Additionally, the gasifier for atmospheric-pressure batch fixed-bed operation uses air, which incurs no cost. After switching to continuous gasification with atmospheric pressure pure oxygen, the gasifying agent becomes pure oxygen, which incurs costs. Its specific oxygen consumption is calculated at 240 Nm3, with approximately 530 Nm3 of oxygen required per ton of ammonia. Low-pressure oxygen (with a purity of around 93%) is produced using pressure swing adsorption; the cost of oxygen in such oxygen production systems is approximately 0.25 yuan per Nm3, which results in an increase in the cost per ton of ammonia by 135 yuan per ton. Therefore, compared to atmospheric-pressure batch gasification, atmospheric-pressure continuous gasification seems to have no other ways to reduce costs, aside from an increased gas production capacity and lower scale-effect costs. The additional cost of the gasifying agent seems to be much higher than the cost savings resulting from scaling up. The above are my views; I welcome criticism and suggestions from my colleagues.

Atmospheric pressure batch gas production is an older technology; my friend’s factory uses such furnaces, and it’s necessary to use high-quality coal. Now I use fluidized-bed gasification, which can be done with air, or with oxygen-enriched air or pure oxygen. It is necessary to go to the site to see whether to renovate or build a new fluidized bed. You can contact me at phone number 13864462386 in Zibo, Shandong