【Information on Haichuan Chemical Project】Jinmei Huahua’s 550,000-ton ammonia-alcohol production project utilizes 5 Sideng coal crushing pressurized gasification furnaces
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The total investment in Huahua Chemical’s 550,000-ton ammonia and methanol technology upgrade project is 2,994,657,200 yuan. The project is located in the Dangyang Economic and Technological Development Zone in Hubei Province, and it will be constructed in two phases: Phase 1 involves the upgrade of production capacity for synthetic ammonia to 400,000 tons per year, while Phase 2 focuses on upgrading the capacity for methanol production to 150,000 tons per year. Based on the production requirements specified for the facility and the quality of the raw coal, 5 Saiding coal crushing and pressurized gasification furnaces with a diameter of φ3842mm and a pressure of 4.0 MPa have been installed for ammonia synthesis, operating in a configuration of 4 units in use and 1 unit as backup during normal production. One coal-crushing pressurized slag gasification furnace is equipped with methanol. In actual production, the load of the Saiding coal pulverization pressurized gasification units is adjusted based on the operating conditions of the coal pulverization pressurized slag gasification unit; the maximum operating scenario is one in which the coal pulverization pressurized slag gasification unit is not in use, with all 5 Saiding coal pulverization pressurized gasification units running at full capacity to meet the annual production requirement of 550,000 tons of ammonia alcohol ； Similarly, when the crushed coal pressurized slag gasification furnace reaches full load, the operating load of the crushed coal gasification furnace is adjusted accordingly.
Full-process description: The raw coal sourced from outside the plant area is delivered to the gasifier via a coal preparation belt. In the coal gasification furnace, raw coal and oxygen from the air separation unit are used to produce crude gas through gasification. This crude gas is sent to conversion and cooling units (where conversion takes place separately for ammonia synthesis and methanol production). A sulfur-resistant, wide-temperature conversion process is employed to convert CO in the crude gas into H2. The conversion gases obtained for ammonia synthesis and methanol production are respectively sent to low-temperature methanol washing units to remove acidic gases such as CO2 and H2S from them. The cooling capacity required for these acid gas removal units comes from ammonia compression refrigeration in the refrigeration system. The purified ammonia gas from the acidic gas removal unit is sent to the ammonia synthesis plant after being washed with liquid nitrogen, while the purified methanol gas is sent to the methanol synthesis plant via deep cryogenic separation. The LNG obtained through liquid nitrogen washing and cryogenic separation is sold as a product. Sulfuric acid is produced from the acidic gases generated as a by-product of low-temperature methanol washing.
The process for producing ammonia in the first stage involves using crushed coal under pressure for solid slag discharge gasification to generate crude gas; through shift cooling, low-temperature methanol washing, and liquid nitrogen washing, a suitable feed gas for ammonia synthesis is obtained, which is then used to produce liquid ammonia. Sulfuric acid is produced from the acidic gases generated as a by-product of low-temperature methanol washing. The LNG separated by liquid nitrogen washing is sold as a product. In the second-stage methanol process, crushed coal is pressurized and used for slag gasification to produce raw gas; through shift cooling, low-temperature methanol washing, and deep cryogenic separation, a suitable feed gas for methanol synthesis is obtained to produce methanol. The LNG separated by cryogenic methods is sold as a product. Sulfuric acid is produced from the acidic gases generated as a by-product of low-temperature methanol washing.
In phases one and two, a total of 400,000 tons of liquid ammonia were produced, along with 150,000 tons of methanol. The by-products included 87,800 tons of LNG, 48,000 tons of sulfuric acid, and 49,700 tons of ammonia water. Among them, the coal crushing and pressurized slag gasification furnace for methanol in Phase 2, as well as the methanol washing and sulfur recovery units, are shared with Phase 1 and constructed in Phase 1. The remaining facilities (transformation cooling, cryogenic separation, methanol synthesis) will be constructed in Phase 2.
Equipment configuration: Saiding coal pulverization pressurized gasification – 5 pressurized gasification units (4 in operation and 1 as backup), with a gasification pressure of 4.11 MPa and a daily coal input of 1,900 tons. The inner diameter of the gasifier is φ3842 mm, its height is 14500 mm, and its volume is 121.3 m3. The total effective gas output (CO+H2) is 115,000 m3/h. Pressurized slag gasification using crushed coal; gasifier specifications: φ3.6m/4.2m, 6.5MPa, water-cooled wall structure. 550 tons of coal are supplied per day.
Air separation: air compression cycle + internal compression process. Supply oxygen with a pressure of 4.8 MPa, a flow rate of 44,472 m3/h, and a purity of 99.6% to the gasification unit ； It supplies medium-pressure nitrogen at a flow rate of 43,340 m3/h and a pressure of 3.8 MPa for nitrogen supply in ammonia synthesis units, as well as low-pressure nitrogen required for gasification, low-temperature methanol washing stripping, purging and displacement during the startup of various process units, and catalyst heating and reduction.
Transformative cooling employs adiabatic transformation and a wide-temperature sulfur-tolerant cobalt-molybdenum catalyst. One unit with an effective gas capacity of 115,000 m3/h (CO+H2), and one unit with an effective gas capacity of 45,000 m3/h (CO+H2). Acid gas removal is carried out using low-temperature methanol washing. The regeneration section of low-temperature methanol washing is shared by ammonia synthesis and methanol. Separate absorption towers are provided for synthetic ammonia and methanol. Phase 1 includes one unit with an effective gas flow rate of 115,000 m3/h (CO+H2), while Phase 2 includes one unit with an effective gas flow rate of 45,000 m3/h (CO+H2).
Gas purification: The raw gas for ammonia synthesis is purified by liquid nitrogen washing, while the raw gas for methanol production uses cryogenic separation techniques to remove trace impurities. Liquid nitrogen washing and cryogenic separation are used to recover the by-product LNG, at a rate of 87,800 tons per year. Ammonia synthesis: low-pressure synthesis technology, with a designed capacity of 400,000 tons per year per unit. It is a radial internal component for two heat exchangers in a three-catalyst bed, with external dimensions of φ2500×27500, and is vertical in design.
Methanol synthesis φ3800mm shell and tube reactor. The designed capacity is one set of 150,000 tons per year. Distilling methanol using a three-column process. Ammonia refrigeration: Ammonia compression refrigeration technology. Sulfur recovery: The ECOSA wet acid production technology is used to treat acidic gases, producing 98% concentrated sulfuric acid. The designed capacity is one set of 48,000 tons per year, to be shared by Phase I and Phase II.
Huahua Chemical is located in Baling Industrial Park in Dangyang City. It currently has a production capacity of 450,000 tons of liquid ammonia per year, 150,000 tons of methanol (for a total of 600,000 tons of ammonia and methanol products), 700,000 tons of urea, 300,000 tons of compound fertilizers, 100,000 tons of dimethyl ether, 60,000 tons of sodium nitrate and sodium nitrite, 60,000 tons of hydrogen peroxide, 50,000 tons of melamine, and 800,000 tons of nitrato-sulfate compound fertilizers.
Huahua Chemical Group is a large chemical enterprise group that was established at the end of 2002 through the restructuring of former state-owned enterprises. In 2009, a strategic joint venture was established with Shanxi Jincheng Coal Industry Group, one of China’s top 500 enterprises. It currently has fixed assets worth 4 billion yuan and over 5,000 employees, with 8 subsidiaries under the group. The products cover more than 10 varieties in five major fields, including fertilizers, chemicals, thermal power, plastic products, and new building materials.