What problems did you encounter during the initial commissioning of the hydrogenation unit?
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Since starting work in the chemical industry, three production units have been successfully commissioned. One of them is for the production of styrene at a capacity of 200,000 tons per year, another is for diesel hydrogenation with a capacity of 2.5 million tons per year, and yet another is for hydroprocessing at a capacity of 2 million tons per year. If the first commissioning encounters many problems due to a lack of experience, that’s considered normal (the biggest issue encountered during the first commissioning was oil leakage). In subsequent commissionings, many issues were taken into account, but various problems still arose; it’s really exhausting to go through all this!
Hydrogenation of 17 MPa high-pressure residue can be deadly; oil leaks are rare, but once residue leaks, it catches fire
Generally, once the airtightness is ensured, it indicates that operations can proceed normally. But then, I never expected a whole series of problems such as issues with the furnace load, the amount of raw material used in processing, and the turbine load, which caused a lot of headaches~
Commissioning is a continuous process of identifying and solving problems; even the most perfect commissioning procedure may not be suitable for every set of equipment. Factors such as workers’ skills, execution capability, equipment, installation, scheduling, and support also need to be taken into account
Mainly, there are too many issues with this design, which are hard to anticipate~! The issues you mentioned are all related to the company’s operational capabilities; it depends on one’s leadership skills, training level, and coordination abilities. The problems that arose in terms of design are simply frustrating!
The issue of design is simple in theory; after all, hydrogenation technology has been around for decades, and the overall approach remains largely unchanged. If there are significant differences in the design of a new facility compared to existing ones, those differences are either revolutionary or fatal. This requires caution in the early stages of production.
Hydrogenation technology has been around for decades, but technologies such as hydrocracking and hydrotreating of residue oil are still undergoing further research~! These days, the goal is to maximize efficiency. Many aspects such as the renewal of catalysts, and the proportions of fuel oil and residue used in refining are still under investigation. Of course, the general process remains more or less the same.
The two most memorable incidents that occurred during hydrogenation processes I was involved in are: 1. The liquid level in the separator tank at the inlet for recycled hydrogen reached its maximum, forcing an emergency shutdown at the last moment; it was really scary； 2. Leakage of the gasket at the valve branch line flange in the heat exchanger during the thermal cycling of the distillation system also requires an emergency shutdown. The rest isn’t as exciting
I still think it was lucky that, with the first stimulus, the turbine wasn’t blown apart~!
The coal tar hydrogenation project started producing coking as soon as it began operation; the pipes got blocked in various places, and there was no other choice but to shut down the plant for coking removal. Failure
I haven’t experienced coal tar hydrogenation; it’s always been diesel or catalytic diesel. But it’s easy to see that coke would definitely cause blockages~!