Ammonia single train plants

Application To produce ammonia from natural gas, LNG, LPG or naphtha. Other hydrocarbons—coal, oil, residues or methanol purge gas— are possible feedstocks with an adapted front-end. The process uses conventional steam reforming synthesis gas generation (front-end) and a medium-pressure (MP) ammonia synthesis loop. It is optimized with respect to low energy consumption and maximum reliability. The largest single-train plant built by Uhde with a conventional synthesis has a nameplate capacity of 2,000 metric tons per day (mtpd). For higher capacities refer to Uhde Dual Pressure Process. 

Fig. 1.4-1. Flow chart of a single-train plant for the synthesis of ammonia using the Steam-...

In single-train plants it is necessary to store a certain amount of ammonia to cover production breakdowns. The ammonia is either stored at atmospheric pressure and low temperatures (-33°C), or under moderate pressures at -f5 to -5°C. Ammonia is also transported under these different conditions. 

J.G. Sawyer and G.R. Williams, Ammonia... Turndown efficiency of single train plants, Chem. Engin. Prog. 70(2), 62, Feb. 1974. 

Since 1963, there has been a revolution in ammonia-manufacturing technology. The advent of large single-train plants has resulted in a large increase in production capacity, the... 

Steam-Reforming Natural Gas. Natural gas is the single most common raw material for the manufacture of ammonia. A typical flow sheet for a high capacity single-train ammonia plant is iadicated ia Figure 12. The important process steps are feedstock purification, primary and secondary reforming, shift conversion, carbon dioxide removal, synthesis gas purification, ammonia synthesis, and recovery. 

W. Turner, "Ten Years of Single Train Ammonia Plants," NMPO 74, ICI Operating Symposium, BiUingham, UK, 1974. 

KBR has designed a 4,000 tonne/day plant in which all the equipment is single-train except for the primary reformer and the ammonia converter, each of which consists of two identical, parallel units. The design uses the KAAPplus technology, which includes the KBR Reforming Exchanger system (KRES) and the KBR Purifier. These technologies are discussed earlier in this chapter and in Chapter 5215. 

Figure 4. Flow sheet for high-capacity, single-train ammonia plant...

Commercial plants Over 200 large-scale, single-train ammonia plants of KBR design are onstream or have been contracted worldwide. The KAAP plus advanced ammonia technology provides a low-cost, low-en-... 

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