Published December 2007
While the overall process lay-out of some well-proven ammonia processes remain identical for the last decade, their performance have improved due to improvements in areas such as the recovery of the hydrogen and ammonia from the synthesis purge gas, the energy efficiency of carbon dioxide removal systems, the ammonia synthesis catalysts, synthesis loop equipment designs and the switch from electrically driven compression to the use of waste heat generated steam- driven centrifugal compressors. In addition, new plants tend to be larger, with improved economies of scale.
This review evaluates a SRIC design based on KBR Advanced Ammonia Process (KAAP) technology incorporating features reflecting above-mentioned improvements. The front-end synthesis gas generation is through natural gas reforming. Our analysis indicates that at a base case capacity of 1,448 million lb/yr (2,000 metric tons per day), the total fixed capital is $597.5 million. The overall natural gas energy consumption (for feed and fuel) is 13,230 Btu/lb NH3 on LHV basis and CO2 emission is 1.52 lb/lb NH3. The base case product value (net production cost plus 25%/yr return on investment) is 28.4¢/lb when natural gas is priced at 674¢/MMBTU.
