The choking of the pathways (pipelines, tubes) caused by carbamate and urea fluids with high crystallization points, mainly due to a pressure drop in the steam system and lack of proper tracing of pipelines and equipment of urea and carbamate pathways, is one of the problems during the commissioning of urea units.

This case study investigates the effects of a steam pressure drop, which causes widespread problems in recommissioning of the urea unit, on the performance of the scrubber section in one of the urea units. The case study also examines the causes of these problems and the solutions that can be deduced and concluded. We hope this case study increase the skills and technical knowledge of the control of urea units by colleagues.