Oxygen is an indispensable gasification agent for solid fuel gasification. Fixed-layer intermittent coal gasification technology generally uses air as the gasification agent. The process is simple and requires low investment, but it has low gas production and high raw material consumption. The oxygen-enhanced gasification technology is a new energy-saving and consumption-reducing technology that uses oxygen-enhanced air that is 3% to 10% higher than the oxygen content in the air as the gasification agent for intermittent gas production on the production equipment of the original fixed-layer intermittent coal gasification process to improve the furnace blowing efficiency and reduce The blowing time increases the gas production time, reduces the loss of sensible heat and latent heat, improves the carbon utilization rate in the raw material, reduces the emission of blowing gas and its heat loss, thereby achieving the purpose of increasing the production capacity of a single furnace, reducing raw material consumption and reducing the cost of synthetic ammonia production. The oxygen-adding method is to add oxygen to the air main pipe, that is, to add oxygen during the blowing, blowing, recycling and nitrogen adding stages of the gas furnace to increase the oxygen concentration of the air entering the furnace.

The oxygenation and gas production process of the gas furnace is adjusted according to the balance of the amount of oxygen entering the furnace. According to the changes in oxygen concentration in the air entering the furnace, the number of blowing air in a single furnace is adjusted to balance the heat load of a single furnace. After adding oxygen to the gas furnace, the combustion reaction speed of the char increases, and the upper and lower temperatures of the furnace increase slightly. The upper gas temperature increases by an average of 9°C, and the downward gas temperature increases by an average of 17°C. However, there are certain differences between the upper and lower temperature changes and the types of coke used. After adding oxygen, the CO2 content in the semi-water gas increased by 0.6%, the CO content increased by 2.6%, and the H2 content decreased by 2.8%. This was mainly reflected in the increase in the CO content. When the effective gas CO+H2 was kept unchanged, the H2 content decreased, and the nitrogen addition amount or nitrogen addition time was correspondingly increased, which is very beneficial to the increase in gas production of the generator.

 

Since the argon content in the air entering the furnace increases after oxygenation and gas production, the hydrogen-to-nitrogen ratio index needs to be re-verified to keep the synthesis system in the best reaction state. Secondly, when the generator uses air blowing to increase oxygen and at the same time uses upward blowing to increase oxygen, the CO2 and argon content in the gas will increase. Generally, for every 1% increase in the oxygen volume fraction in the air entering the furnace, the argon volume fraction in the semi-water gas will increase by 0.04%, and the increase in the inert gas content is not conducive to the production of the synthesis system. Therefore, the choice of oxygenation method needs to consider the production of the post-system. The implementation of intermittent oxygenation and gas production in the generator is a technical transformation project with low investment, quick results, increased production and efficiency. http://www.cngrjx.com