Electrolysis ammonia plants based

About one-half of the world s ammonia capacity based on coke-oven gas is located in the Peoples Republic of China. In most cases, the plants using coal, off-gases and water electrolysis are at locations where special circumstances dictate the economic or political viability of the project. They also tend to serve local rather than international markets. 

In addition the investment cost for conventional water electrolysis is rather high, about 1 000 DM/kWe] in 1989. This would give a total investment for a world-size plant capacity 1 200 t/d of ammonia, which is about 2.5 times the value of a natural-gas-based steam reforming ammonia plant [590],... 

As part of the Manhattan District Project during World War II, a small plant to produce heavy water 6 Mg/a) was built by Standard Oil Development Co. at Trail, B.C. and was operated by Cominco from 1944 to 1956 (14). It was based on steam-hydrogen catalytic exchange plus steam-water equilibration coupled to water electrolysis. However, byproduct heavy water from this process is economic only if the electrolysis cost is borne by the hydrogen product, which at Trail was used for ammonia production. In any case, the small scale of operation imposed by electrolytic capacity and the large exchange tower volume have made this production method economically unattractive. 

Industrial scale electrolyzers were developed early in the 20th century for the manufacture of chlorine and caustic soda from brine, and for the commercial production of hydrogen used in ammonia synthesis. Large water-electrolysis plants were constructed in Norway and Canada in the 1930 s, based on cheap hydroelectric power, and the hydrogen so produced was used in fertilizer manufacture. With the advent of natural gas and low cost petroleum, hydrogen production moved toward catalytic steam-reforming of hydrocarbons, and water electrolysis became less significant. 

---