LAC™ (the Linde Ammonia Concept) makes possible the production of ammonia from natural gas or light hydrocarbons. High-pressure gasification makes use of refinery residue, heavy oils and coal with oxygen for the production of ammonia.
LAC™ Process
The Linde Ammonia Concept is a leading-edge process for the production of ammonia from natural gas or light hydrocarbons. It is based on a combination of proven process steps. An LAC plant primarily comprises a modern hydrogen plant, a standard nitrogen plant and high-efficiency ammonia synthesis.
In the hydrogen plant, the synthesis gas is purified by pressure swing adsorption in a single process step The pure nitrogen delivered from the nitrogen plant is first mixed in with the synthesis gas upstream of the synthesis gas compressor. With the exception of a third-party license for the NH3 synthesis of Ammonia Casale, all the other process steps are based on Linde's own technology.
The LAC process means a simplification vis-à-vis the classic process route and leads to savings in investment and operating costs, as well as simplified plant start-up and operation.
Additional savings in investment costs can also be brought about when the nitrogen is supplied by over-the-fence delivery. The specific operating costs can be further lowered by selling valuable by-products. Hydrogen and nitrogen are immediately available, e.g. as intermediate products of an LAC plant. Other by-products such as oxygen, argon and carbon dioxide can be produced if the plant is properly aligned.
Thus far, four plants based on the relatively new Linde Ammonia Concept have been constructed with capacities of between 230 to 1,350 mtd of NH3. The applied process steps have already frequently proven their reliability in large-scale operation and can also be partially installed in modularized form for cost savings. Linde has, for instance, built more than 2,700 air separators, 50 hydrogen plants and 300 PSA plants, while Ammonia Casale has more than 100 references for ammonia synthesis.
The first LAC plant was built for GSFC in Baroda, Gujarat, India and went into operation in 1998 with a capacity of 1,350 mtd. Urea is an final product of this plant. Further LAC plants have been constructed in Australia and China, and ammonium phosphate, ammonium nitrate and methylamine are among the final products produced in subsequent plants.
