Common issues with Texaco gasification units
Thread Content
From the first Texaco gasification unit introduced in the country to those currently in operation, there is a common problem of ash and water in the gas phase; the degree of ash and water presence varies depending on the type of coal and the pressure conditions. Regarding newly installed units, GE has recognized this issue and has begun making design improvements by increasing the diameter and height of the quench chamber, so that the gas, liquid, and solid phases can exchange heat and separate properly within the quench chamber, thereby avoiding problems associated with the presence of ash and water.
I largely agree with the original poster’s view, but I think it is also very important to determine whether the washing and separation performance of the carbon scrubber meets the required standards, in addition to the quenching chamber of the gasification furnace. The design of the quenching section determines the amount of slag and ash carried from the gasifier to the venturi and the carbon scrubbing tower; however, the ultimate amount of ash and mist that reach the downstream conversion units is primarily determined by the carbon scrubbing tower. The trays at the upper part of the carbon scrubber are crucial for washing and separating fly ash from syngas; if the design of these trays or their separation efficiency does not meet the required standards, it is inevitable that the syngas will contain ash. It is crucial for whether water will end up in the downstream systems that the demister at the top of the tower can effectively separate the mist carried by the syngas; moreover, the design of this demister is quite important, as otherwise blockages are likely to occur. Additionally, poor insulation of the syngas pipeline after the carbon scrubber can also lead to a drop in syngas temperature and vapor condensation, which has nothing to do with the separation efficiency. Furthermore, gas-liquid separation is quite sensitive to the gas flow rate; when the load on the vaporization unit exceeds its designed capacity, separation becomes more difficult, and entrainment tends to occur.
There are many problems, such as burner life issues and uneven water distribution in the quenching ring
The graywater system is a major problem; I’ve seen this happen before. All other equipment is fine, but due to the high level of sediment in the graywater, the graywater pumps stop working, forcing the plant to shut down.
In my opinion, these problems can only be mitigated, but not avoided, as such devices operate under conditions of high temperature and pressure and present significant challenges; moreover, the operational issues arising from high flow rates in both gas and liquid phases are inevitable. These problems cannot be completely resolved – they can only be alleviated through optimized design of the devices, equipment, and processes
Three major problems with GE furnaces: burners, refractory bricks, and quench chambers~~
The problems of ash and water in the gas phase during the quenching process are difficult to resolve fundamentally or to reach a level comparable to dry ash removal. Improvements in design, on the other hand, lead to a decrease in energy utilization levels.
1. Process burner 2. Refractory bricks 3. Quenching ring and downcomer 4. Sections of black water/gray water pipes 5. Some valves