Approximately 75% of all urea plants worldwide still produce prills. This discussion reports on the experiences of different plants and the solutions available to increase the strength of urea prills to reduce dust problems during handling.
In all urea plants, high pressure pumps are used to pump the feedstock ammonia and carbon dioxide to the high pressure synthesis section and in most urea plants carbamate liquid is recycled from the recirculation section to the synthesis. Reciprocating pumps are used for these services and sometimes vibration problems occur in the discharge pipeline. This discussion considers the possible causes and solutions to problem.
A discussion on what measures can be taken to unblock pipelines and heat exchangers after a urea plant shutdown.
In every urea plant, high-pressure pumps are used to pump the feedstock ammonia and carbon dioxide to the high-pressure synthesis section and in most urea plants carbamate liquid is recycled from the recirculation section to the synthesis section. This discussion compares the advantages and disadvantages of reciprocating and centrifugal pumps based on operating experiences in the industry.
Austenitic stainless steel can be protected against carbamate corrosion in urea plants by adding oxygen in the urea process. This discussion explores the experiences with different amounts of oxygen in the HP stripper in various urea processes.
A discussion about the differences between loose liners and overlay welding for protection of high pressure equipment in urea plants.
Sometimes a serious problem occurs in a urea plant, which forces the plant to reduce capacity or even forces a shutdown. It is then vital to find the root cause of the problem as soon as possible, especially if the problem repeats. Such a situation happened at Khorasan Petrochemical Company in Iran which experienced a problem with the high pressure scrubber.
Pressure safety valves are critical equipment items in any chemical process plant. This article discusses experiences and challenges of pressure safety valves in urea plants.
Operating at the wrong synthesis operating pressure is always a tricky situation for any urea plant operator, knowing that operating at too high a pressure will lead to the pressure safety valves blowing off. The key is to measure the synthesis pressure in a reliable way.
In several urea plants, 3-way valves in urea melt lines have experienced leakage problems but successful innovations are available that provide a reliable solution.