Main processes for ammonia and urea production across various regions

Our company’s ammonia synthesis process uses the Kellough process, which was one of the 13 large-scale fertilizer production systems introduced across the country in the 1970s; urea production employs the Stame process. These 13 large-scale fertilizer production units were approved, with the process technology imported from abroad after being signed off by Premier Zhou. What is even more praiseworthy is that the large-scale ammonia synthesis and urea production plants in our factory were the first among the 13 large fertilizer production facilities in the country to undergo technological upgrades. After three major technological upgrades, the current production capacity has increased from 300,000 tons of synthetic ammonia and 500,000 tons of urea per year to 460,000 tons of synthetic ammonia and 720,000 tons of urea per year. After the technical upgrades, the installation was able to produce multiple ‘Canna’ plants. Meanwhile, a world record was set for two such installations operating together for 350 days; this year, those two installations have managed to operate continuously for 350 days, and they are now striving to set a new world record.

Yuntianhua’s urea production process uses Stamicarbon’s CO2 stripping technology, not the Stame process mentioned above:o.

Our company’s ammonia synthesis process uses the Kellog process, while for urea production, the Stame process and a full-circulation aqueous solution process are employed (this process has undergone numerous technical modifications and is gradually moving towards the stripping method; it is no longer a true full-circulation process in the original sense)

Our company’s ammonia synthesis process uses the Kellog process, while the urea production process employs Stamicarbon’s CO2 stripping technology. In the 1970s, China introduced a total of thirteen such systems, including those used by companies such as Yuntianhua, Chitianhua, and Lutianhua. This method uses carbon dioxide gas as the stripping gas; under a constant pressure of 14.0 MPa in the synthesis loop, methylammonium is decomposed and stripped, thereby preventing excessive amounts of methylammonium from entering the low-pressure section. After decomposition, it is absorbed and then sent back to the synthesis loop, which increases energy consumption. Due to isobaric stripping, the amount of ammonium methylate entering the low-pressure section is reduced; as a result, there is no medium-pressure system, and the equipment in the low-pressure section is also fewer. Entering the 21st century, old facilities have been upgraded to improve energy efficiency and increase production through technologies such as dehydrogenation. Companies such as Yuntianhua, Daqing Petrochemical Fertilizer Plant, and Wushihua Fertilizer Plant have revitalized these old factories. At the same time, Stamicarbon has developed an ultra-advanced technology of 2000+ by utilizing dehydration units and pool reactor technologies. By combining this with a new material patented by itself – Safurex, developed in collaboration with Sandvik – it is possible to further reduce oxygen content and enhance the corrosion resistance of the equipment, resulting in lower process costs and energy consumption as well as increased production volumes

China uses 4 types of urea production processes: 1. The modified C process from Japanese Toyō. There is only one set in use nationwide at Sichuan Chemical. 2. Aqueous solution circulation method. Many old factories are still using it; it is a urea process that has been phased out. 3. Italian Snamprogetti ammonia stripping urea process. It was first introduced to China in 1986 and used at Zhongyuan Dahuahua in Puyang, Henan. Subsequently, a series of 3052 projects were carried out, with companies affiliated to Sinopec and CNPC such as Hainan Fudao, Jianfeng, Jinling Petrochemical, and Jiujiang adopting it. Primarily, it is because the company has close cooperation with those two companies in the field of oil pipelines; there are also some smaller nitrogen fertilizer producers such as those in Anyang, Henan. In the past decade, there have only been two such units: Hefei Sifang (400 tons per day) and CNPC’s Tarim project. 4. The CO2 stripping process of Stamicarbon in the Netherlands. It has been used in China since the earliest manufacturing processes, as well as in later improved versions and next-generation improved processes; a large portion of urea produced in China is manufactured using this process. From the 13 sets of large-scale fertilizer plants to the 1,830 units that came into use later on, as well as the recent large-scale fertilizer plants, this process is basically used in all of them.

Jinan South Chemical uses the ACES urea production technology from Japan’s Toyo Company, with an annual capacity of 80,000 tons of ammonia and 100,000 tons of urea (the original design was 60,000 tons per year); this production technology is the same as that used at Shaanxi Weihe Fertilizer Factory.

The synthetic ammonia process for Hulunbuir Jinxin Company (under construction) has not yet been determined; however, an agreement has been reached for urea production: 2000 + Stamicarbon

The process combination selected for the Tarim Fertilizer Project is the TOPSOE process for synthetic ammonia, the SNAMPROGETTI process for molten urea, and the granulation process from TEC Company for large particles. Process Unit Comparison Items Original Process Modified Process Ammonia Synthesis Process Technology KBR cryogenic purification process TOPSOE ammonia synthesis process Source of Technology American company KBR Danish company TOPSOE Scope of Introduction Introduction of basic engineering design Introduction of process packages Melted Urea Process Technology STAMICARBON’s CO2 stripping process SNAMPROGETTI’s NH3 stripping process Source of Technology Dutch company STAMICARBON Italian company SNAMPROGETTI Scope of Introduction Introduction of basic engineering design Introduction of process packages Large-Particle Urea Granulation Process Technology HYDRO jet fluidized bed granulation technology TEC jet fluidized bed process technology Source of Technology Norwegian company HYDRO Japanese company Toyo Engineering Corporation Scope of Introduction Introduction of basic engineering design Introduction of process packages

Our company uses a full-circulation process with aqueous solutions; it seems to be outdated:loveliness:, but it offers excellent efficiency:victory:

The main ammonia synthesis processes in use domestically are: 1. The KBR process developed by the American company Kellogg Brown & Root; 2. The TOPSOE ammonia synthesis process from Denmark; 3. The Cassali ammonia synthesis process. As for urea production processes, the main ones include: 1. Stamicarbon’s CO2 stripping process; 2. Snamprogetti’s ammonia stripping urea process from Italy; 3. Toyobo Corporation’s ACES urea process from Japan