What issues should be considered when operating a DuPont alkylation unit for about three years? Is the leakage problem serious? Thank you

The main hazard faced by alkylation units is acid corrosion, but it is not that serious if properly controlled. The following recommendations are given for normal operation and long-term use: 1. Ensure that there is no acid or ester present in the backstream, in order to reduce corrosion of the backstream fractionation system. 2. The wall thickness of the alkali washing tanks, water washing tanks, acid pipelines, and alkali pipelines must be inspected annually, especially in areas with high flow rates and under harsh operating conditions before and after the mixers ； 3. During long-term operation, it is important to inspect the manholes of the tower during maintenance to check whether the trays inside the isobutane tower are corroded; this provides valuable information that can help in addressing any issues that may arise during routine operations in the future. 4. For heat exchangers in critical areas, such as the isobutane bottom reboiler, if there are no problems normally, it is recommended to disassemble them during major overhauls after 3 years to check the condition of the tube bundles. Large equipment such as acid precipitation tanks and reactors don’t really encounter any problems; they are in an environment of acid passivation, which reduces corrosion to a minimum. Let’s just cover these points; I hope it will be helpful to you.

Let me talk about what I encountered: there was a leak in the pipeline leading to the isobutane removal tower; the pressure was 8 kilograms, and liquefied gas was everywhere. Leak in the light-end tower pipelines, leak in the refrigerant pump, leak in the heat exchanger, failure of the coalescer, leak in the reactor, leak in the reactor seal

Seeing all these leaks scares me; why are there so many areas that are leaking? 1. Are the \"leaks in the pipelines leading to the isobutane purification tower\" and the \"leaks in the pipelines of the light ends separation tower\" leaks at the welds or at the actual pipeline body? 2. “Refrigerant pump leakage” should refer to a leak at the seal, right? 3. Is \"heat exchanger leakage and coalescer failure\" caused by acid corrosion? 4. The frequency of seal leaks in the reactor is high, but there are not many leaks in the reactor itself.

Seeing all these leaks scares me; why are there so many areas that are leaking? 1. Are the \"leaks in the pipelines leading to the isobutane purification tower\" and the \"leaks in the pipelines of the light ends separation tower\" leaks at the welds or at the actual pipeline body? 2. “Refrigerant pump leakage” should refer to a leak at the seal, right? 3. Is \"heat exchanger leakage and coalescer failure\" caused by acid corrosion? 4. The frequency of seal leaks in the reactor is high, but there are not many leaks in the reactor itself.

In the isobutane purification tower, impact on the valve caused the side walls of the valve to thin out, leading to leakage

Well, in areas with harsh operating conditions, erosion is severe; and when the valves develop sanding, the presence of small bubbles makes it easier for leaks to occur. Over time, this is inevitable

Generally, alkylation leads to a good two-year period, after which various forms of corrosion occur; it’s mainly related to the processes that take place afterward. Of course, it also depends on the specific process; pay attention to the wall thickness of various equipment, conduct regular inspections, and carry out enhanced inspections for elbows and tees that are prone to erosion. Replace the heat exchange tubes in the reactor if possible, and it is recommended to use fluorinated linings for acid inlet pipelines. There are so many considerations – so for alkylation processes, it’s better to look for a new factory after two years of operation~~