What is the water content in the exhaust gas from a Texaco gasifier?
Thread Content
Texaco uses coal slurry gasification, but the available information generally only specifies the concentrations of gases such as H2, CO, and CO2; no data on H2O is provided. Surely there must be some water present, right?
The saturated vapor pressure of water at the corresponding temperature and pressure can be used to estimate the water content in the process gas
There must be moisture! The gasifier has two outlets – is it the furnace outlet or the quench chamber outlet? There is no water at the furnace outlet; it’s steam. Water is carried out at the quench chamber outlet, in an amount of around 20 tons, though this isn’t exact.
Before entering the quench chamber at the outlet of the GE gasifier furnace, the water content in the syngas is approximately 20%. At the outlet of the gasifier’s quench chamber (before any condensate is injected), the water content in the syngas is around 64% – a high level due to the water carried in the gas, far above the corresponding saturated water level. The water content in the syngas at the outlet of the scrubber tower (after leaving the gasification zone) is roughly 58%, slightly higher than the equilibrium water vapor content; the gas-to-gas ratio is about 1.4, which meets the requirements of cobalt-molybdenum catalysts used in shift reactions under wide temperature conditions.
The crude syngas outlet definitely contains water, but there is no fixed value for this amount; the level of water present depends on the furnace temperature, pressure, and the liquid level in the quench chamber. In normal operation, a significant amount of water is present, which is used to supply water to the carbon scrubber in order to maintain a certain balance within the water system. There is a **operating method**: when it is not possible to supply water to the carbon scrubber due to issues with the high-pressure gray water system, the black water with a high flash point from the quench chamber and the carbon scrubber can be disconnected, thereby reducing the production load. By allowing water to be present in the crude syngas, it is possible to maintain a continuous supply of quench water and ensure short-term operation.
What will the instrument readings show when syngas contains water? High or low? Fluctuations – what are the reasons for them?
The gas composition given in the general information is dry gas. The moisture content should be able to be estimated using the saturated vapor pressure at that (P, T) condition.