Ammonia flow sheet

A flow sheet of the basic TVA process for granular diammonium phosphate is given in Figure 12. The raw materials are wet-process phosphoric acid and anhydrous ammonia. Feed acid concentration of at least 40% P2 5 required to give a satisfactory water balance. This average concentration usually is provided by two separate feed streams, one of 54% P2 5 concentration and one of about 30% P2 5 arrangement shown, the 54% acid is... 

Peroxide-Ketazine Process. Elf Atochem in France operates a process patented by Produits Chimiques Ugine Kuhhnaim (PCUK). Hydrogen peroxide (qv), rather than chlorine or hypochlorite, is used to oxidize ammonia. The reaction is carried out in the presence of methyl ethyl ketone (MEK) at atmospheric pressure and 50°C. The ratio of H202 MEK NH2 used is 1 2 4. Hydrogen peroxide is activated by acetamide and disodium hydrogen phosphate (117). Eigure 6 is a simplified flow sheet of this process. The overall reaction results in the formation of methyl ethyl ketazine [5921-54-0] (39) and water ... 

Fig. 6. Flow sheet for ammonia production from Lurgi coal gasification.

Fig. 10. Flow sheet for ammonia processiag from steam reforming.

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. 

A variant of the H2/NH2 chemical exchange process uses alkyl amines in place of ammonia. Hydrogen exchange catalyzed by NH2 is generaHy faster using alkyl amines than ammonia, and a dual-temperature flow sheet for a H2/CH2NH2 process has been developed (69). 

Draw up a preliminary flow-sheet for the manufacture of 20,000 t/y nitric acid (basis 100 per cent HNO3) from anhydrous ammonia, concentration of acid required 50 to 60 per cent. 

I. Welded joints would be used on ammonia service and mechanical seals on pumps. Use minimum factor as full equipment details are not known at the flow-sheet stage, factor = 0.1. 

MRR) to recover platinum. The extraction of palladium by the sulfide is slow with 2-3 hr to achieve equilibrium, which inhibits flow sheet design. However, it has been shown that tertiary amines can act as a kinetic accelerator, reducing equilibrium times to minutes, but no information has been published on the effect of these amines on palladium-platinum separation. High loading of the sulfides is possible, and stripping is easy with aqueous ammonia. The overall extraction and stripping equations are as follows ... 

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

Fig. 26.1. Simplified diagrammatic flow sheet for the Solvay ammonia-soda process.

A standard flow sheet for an ammonia synthesis operation currently comprises the following main elements (Fig. 1.19) ... 

Synthesis loops are normally of two types, depending on whether the NHs is recovered before or after compression. The first flow sheet (Fig. 1.19) uses less energy, but both loops scrub the recirculation gases with liquid ammonia, allowing partial dissolution of the impurities and extending catalyst life. 

To illustrate the forgoing discussion of the concept of the single-train steam reforming plant, Figure 105 presents a modern low-energy ammonia plant with flow sheet and process streams (UHDE process). 

A common procedure in decomposition deposition involves mixing ammine solution with a highly dispersed carrier material, and then slowly raising the reaction temperature to the decomposition temperature.During the process, ammonia is released from the complex and the metal hydroxycarbonate species are deposited onto the carrier material. As shown in a typical process flow sheet for this method in Fig. 4,... 

Figure 13.37 is a material flow sheet for a dual-temperature ammonia-hydrogen exchange plant using the same amount of synthesis-gas feed and producing the same amount of enriched ammonia product as the monothermal ammonia-hydrogen exchange plant of Fig. 13.23. Comparison of these figures shows that the hot exchange column of Fig. 13.37 performs both the function of the ammonia dissociation step D of Fig. 13.23 in providing enriched...

Figure 13.37 Material flow sheet for dual-temperature ammonia-hydrogen exchange process. Flow units, kg-mol/h.

Nitschke [N2] has given a partial description of the flow sheet used by Uhde for the dual-temperature ammonia-hydrogen heavy-water plant that company is building at Talcher, India (item 19, Table 13.2). Figure 13.38 is a qualitative material flow sheet for the first-stage exchange columns of that plant. 

Availability of this catalyst has led to interest in its possible use in dual-temperature water-hydrogen exchange processes. With liquid-water feed and recirculated hydrogen gas, this catalyst could be used in a dual-temperature process similar in principal to the GS process, with a schematic flow sheet like Fig. 1325. With ammonia synthesis-gas feed and recirculated water, this catalyst could be used in a dual-temperature process similar to the ammonia-hydrogen process flow scheme of Fig. 13.37, provided that impurities in synthesis-gas feed that would poison the catalyst can be recovered sufficiently completely. 

The dual-temperature, methylamine-hydrogen exchange process described in Sec. 13 could also be used to concentrate deuterium from ammonia synthesis gas produced from natural gas and steam containing the normal abundance of deuterium instead of the enriched steam used in the Sulzer flow sheet. Fig. 13.40. Figure 13.42 is a flow sheet for such a process giving the deuterium content of each stream in the first stage of the plant. 

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