Energy retrofit study of an ammonia plant

Detailed energy integration study of the front-end of an existing ammonia plant has been performed, using recent advances in Pinch technology. Utility loads demanded by the existing process were found to be very close to the calculated minimum targets. This indicated that the selected ammonia plant is well integrated, and not much saving is expected through process-to-process energy integration. Alternatively, the retrofit study concentrated on better placement of available utilities. Two promising options have been investigated. The first one studied the flue gas temperature in the convection section of the primary reformer, and proposed new arrangements of the heating coils. Boiler feed water heating for high-pressure steam generation has been also considered as a possible source for reduction in energy consumption. Total benefit claimed amounted to 17.6% reduction in combustion fuel consumption. The overall results of this case study are promising, However, economical evaluation of the proposed modifications is essential. Additional possible reduction in energy consumption is also possible in energy and power integration of the back-end section. (C) 2000 Elsevier Science Ltd, All rights reserved.