Consumption of small quantities of fertilizer

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Currently, there are nearly 500 small nitrogen fertilizer enterprises across the country, with a total of around 10,000 UGI units. Most of these furnace types are ø2610 and ø2800; in recent years, new types such as special-shaped furnaces and conical jackets have emerged. As production costs rise, many companies that previously used oil and gas as raw materials have switched to coal. At present, gas generation furnaces in China are developing rapidly, with continuous improvements in technical standards. Enterprises with high levels of comprehensive gas generation technology include those in Shouguang, Shandong; Zhangjiagang and Xinyi in Jiangsu; Xinyang in Henan; and Longshan in Zhejiang. These advantages are evident in the following three aspects: 1. Increased ammonia production per furnace and reduced consumption: The mainstream furnace types used in China are Ø2.6M or Ø2.8M, with an average ammonia production of 50–55 tons per day and a coal consumption of around 1.2 tons per day. Enterprises such as Qilu Yihua, Jiangsu Hengsheng, and Jiangsu Huachang can achieve up to 60 tons of ammonia per day. A company in Hubei uses briquetted coal with a carbon content of over 60% and a moisture content of 10%. It consumes 1.5 tons of coal per ton of ammonia, with a production capacity of 45 tons of ammonia per day per furnace. According to the presentation at the meeting, after equipping Qilu Yihua with a conical jacket, its current total coal consumption is around 1.2 tons of coal per ton of ammonia; this figure can rise to 1.1 tons of coal per ton of ammonia when membrane separation is also taken into account. The carbon content in the ash and slag is less than 10%. Those who attended the meeting said that many manufacturers were skeptical and took samples back to conduct their own tests, finding results that were roughly similar. 2. Research on gas production is becoming more detailed: As coal prices continue to rise, companies face increasing pressure to survive. Since energy consumption for gas production accounts for over 60% of the total energy used in ammonia synthesis, this drives companies to invest more in and conduct more research on gas production. Fixed-bed gas generation has been in use in China for over 50 years, and there is little left to consider at the macro level. Currently, most manufacturers are focusing on the details, such as reducing the resistance in the gas generation system, optimizing air and steam flow rates, controlling the operation of automatic valves and their cycling periods, regulating temperatures during the upward and downward processes, controlling and monitoring the composition of the gas, as well as managing and adjusting the volume of circulating water. These aspects are becoming increasingly quantitative, no longer as vague as they used to be. Research on quantifying gas production, combined with the implementation of these practices by many manufacturers in their newly built gas production units, has led to significant improvements in the gas production capabilities of some of these manufacturers. The overall level of gas production in the country has also improved greatly, with energy consumption being reduced. Fixed-bed gasification was discontinued abroad in the past due to its low thermal efficiency, low gasification efficiency per unit area, and low level of automation. These shortcomings are being gradually overcome, and it can be said that there is still room for development in gas production. 3. Various factories are investing heavily in technological upgrades for gas production, and they go to great lengths to improve the working conditions of their staff involved in this process. As many manufacturers are expanding at a rapid pace, in order to enhance efficiency and reduce costs, various new technologies are being applied in gas production, such as cone-shaped jackets and eccentric grates. Currently, many manufacturers are planning or have already begun implementing such upgrades. In terms of its effectiveness and working principle, it is quite good and brings benefits to enterprises. At the same time, due to the increased rate of steam decomposition, some domestic manufacturers have achieved zero discharge of wastewater generated in the gas production process; Qilu First Chemical even needs to add water to the system used for gas production. As for the employees working in gas production, based on the communication with them, it can be seen that most of them earn more than those in other workshops; this is because the level of responsibility shown by these employees has a direct impact on production costs. Additionally, the work involved in gas production is relatively demanding. Based on the on-site visit to Jiangsu Huachang Chemical Co., Ltd., it is indeed worth learning from; the operation room there is clean and well-lit, with clear process parameters. The assessment of individual furnaces and operators is made more detailed and quantitative, focusing on furnace conditions, gas flow rates, and consumption, with all data available for reference. Judging from the ash discharge at the site, the ash mass is generally white and the lumps are mostly porous, which can be considered quite ideal. Blowing gas CO accounts for about 8%. The temperature for both the upstream and downstream sides should not exceed 430°. The coal fed into the furnace has uniform particle size, having undergone three stages of screening. It is said that the gas production rate of the Ø2.4M gas generator at Hua Chang’s old plant has reached 8,300 NM3 per hour, with coal consumption of less than 1,200 kg – which is quite impressive. Huachang established a task force focused on reducing coal consumption in the gas production workshop, and the company offered certain recognition and rewards based on the progress made by this task force; this approach **increased the enthusiasm of the employees involved in gas production to save energy and reduce consumption. Although fixed-bed gas generation is considered a bit outdated nowadays, it still offers economic benefits to a certain extent, though its social benefits are weaker. Improving gas production cannot be achieved simply by setting targets; significant effort is required. The operational skills of workers, their understanding of gas production processes, as well as the technical expertise of engineers and managers, all have a direct impact on the efficiency of gas production. It is recommended to communicate more with technical personnel from related companies, learn from each other’s strengths to compensate for weaknesses, which will definitely lead to improvement. After all, the specific circumstances of each company are different.