Transportation and Storage of Ammonia

T. P. Hignett, Transportation and Storage of Ammonia, Fertilizer Industry Round Table, Washington 1979. 

Due to the safety concerns associated with ammonia transportation and storage of ammonia near populated areas, the use of urea instead of ammonia has been investigated. Noroozi (1993) concludes that based on economics, anhydrous ammonia is the SCR reactant of choice. Should safety hazards or regulations dictate a ban on anhydrous ammonia, aqueous ammonia can be used. If even more restrictive safety considerations are present, the use of urea is theoretically possible, although it has not yet been used at an operating plant. 

On a small scale, cracking ammonia can produce hydrogen for reduction. Transport and storage of hydrogen as ammonia is compact, and the cracking procedure involves only a hot pipe packed with catalyst and... 

Ammonia causes not only problems of slip but also of transportation and storage. A solution to these problems is the transportation and storage of aqueous ammonia. 

Major environmental trends that we see for land, air, water, and transportation of environmentally hazardous materials are shown in Box 9. These trends require that we get ahead of these issues and lead the chemical industry in the reduction of toxic metal (e.g., Sb, Sn, As) compounds, greenhouse gases, mercury emissions, and sulfur from gasoline and diesel, and find ways to control and sequester C02. Reduction of arsenic, as well as nitrates and ammonia, in drinking water is necessary. It is also imperative in these days of terrorism that we reduce transportation and storage of hazardous materials and continue our drive to develop inherently safer processes. 

The ammonia is also a work medium for effective conversion, transportation and storage of solar energy (Fig. 10.23). 

Pig. 10.23 Schematic diagram of conversion, transportation and storage of soiar energy by using ammonia as medium... 

This section deals with certain physical and chemical data, which have particular reference to the safety in storage, transportation and use of ammonia. 

Various road vehicles are used to transport ammonia. The U.S. Department of Transportation has limited the use of certain high stress steels only for ammonia which has a minimum content of water of 0.2 wt %, or a purity at least 99.995% [33]. A more recent reference [17] mentions that when ammonia is shipped in containers constructed of quenched and tempered steel it must contain a minimum of 0.2 wt % water. Various countries specify maximum percentage filling of tanks to provide a cushion. The European Council of Chemical Manufacturer s Federation (CEFIC) Zurich has issued a safety card for road transportation of anhydrous ammonia, containing certain information and recommendations which have been used in some European countries in connection with local recommendations and lists of laws and rules relevant to transportation and storage of anhydrous ammonia [34]. 

The mature Haber-Bosch technology is unlikely to change substantiaHy in the foreseeable future. The centers for commercial ammonia production may, however, relocate to sites where large quantities of natural gas are flared from cmde oil production, eg, Saudi Arabia or Venezuela. Relocation would not offset the problems for agriculture of high transportation and storage costs for ammonia production and distribution. Whereas the development of improved lower temperature and pressure catalysts is feasible, none is on the horizon as of this writing. 

During the composting process much moisture is evaporated and a slight smell of ammonia is perceptible. After a successful spontaneous heating process has taken place, manure is obtained with a dry-matter content of at least 55%. This manure is suitable for transport and storage in the open air and can be easily applied by means of conventional manure spreaders. The minimum manure-storage requirement is not less than a 6 weeks capacity, a hardened floor and a roof. 

In like manner, for the United States one may mention safety manuals and standards for the storage, transport, and handling of anhydrous ammonia compiled... 

Ammonia has been identified in at least 135 of the 1,613 hazardous waste sites that have been proposed for inclusion on the EPA National Priorities List (NPL) (HazDat 2002). However, the number of sites evaluated for ammonia is not known. The frequency of these sites can be seen in Figure 6-1. Of these sites, 132 have been identified that are located within the United States and 2 sites have been identified that are located in the Commonwealth of Puerto Rico (not shown). Significant amounts are also released during the manufacture, formulation, transport, storage, and disposal of ammonia (see Section 6.2). 

Storage and transport of ammonia at the retail level will be described in Chapter 6. The present chapter is concerned mainty with large-scale transport and storage. 

Natural rubber-based adhesives constitute many nsefnl types of adhesives. They have been made from the latex that is collected from the sap of rubber trees grown in Malaysia and other countries of Sonth East Asia. Rnbber of this type was first collected from the Hevea brasiliensis tree - seeds from the tree were first taken from the Amazon forests in Brazil, propagated in Kew in London, and then supplied, over a century ago, to Malaya and adjacent counuies, where there are now many millions of rubber trees, yielding cis-polyisoprene-based natnral rnbber. This has similar properties to the principal SBR synthetic rubber, derived from styrene and butadiene, both of which are obtained by the cracking process from crnde oil, with subsequent chemical reactions. Natural rubber is obtained from the uee by tapping the bark, when the latex flows out spontaneously as the tree is wounded. This latex is about 33% solids - most natural rubber latex is concentrated to 60% and preserved with ammonia for transport and storage. 

Aluminium is very widely used in equipment for the transportation and the storage of ammonia water, and in production plants for nitric acid. As in gaseous ammonia, the presence of carbon dioxide CO2, sulphur dioxide SO2, hydrogen sulphide H2S, ammonium carbonate NH4CO3 and ammonium sulphide S(NH4)2 in ammonia does not alter the corrosion resistance of aluminium. On the other hand, the presence of chlorides (and of salts of certain heavy metals such as copper) has a noxious effect. 

The facility stores ammonia to supply nearby fertilizer manufacturers. It is transported to the plant by ship, transferred and stored in the tank for transfer as needed. The facility mainly consists of a storage tank, a refrigeration system, a control system, and a pipe connecting the tank with the plants. Ammonia is transported and stored as a refrigerated liquid (-33 C) at atmospheric pressure. 

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