Residence time issue in Texaco water-coal slurry pressurized gasifier
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I would like to ask the experts: What is the optimal residence time for Texaco water-coal slurry in pressurized gasification, as well as for oxygen, within the furnace?
Strictly speaking, there is no specified duration for the residence time; it falls within a range of around 3 to 8 seconds. Of course, a longer residence time results in a higher gas production rate. This can be calculated. This post was last edited by Coal Miner on 2009-2-19 12:49.]
The residence time inside the gasifier is a probabilistic value, determined by a combination of factors such as calculations and operational considerations; it is not a value that remains constant in a strict sense!
Official reports all fall within the range of 3 to 10 seconds.
Of course, a longer stay is better. Under the same load, a higher system pressure can increase the residence time of the material in the combustion chamber, thereby increasing the reaction time.
In fact, the quality of the residence time inside the furnace is determined by the activity level of the coal type. The higher the activity of the coal, the shorter the residence time required for complete reaction; this reduces investment costs and increases the load capacity； Of course, if the coal type has low activity, a longer residence time is beneficial for more complete reaction and higher efficiency.
Can this be controlled when the system is running normally?
As mentioned in the above sections, the longer the residence time, the higher the effective gas production and concentration. This can be achieved through modification. For Texaco gasifiers, this can be achieved by reducing the diameter of the slag outlet, and this has already been implemented at Yankuang Luhua. Judging from the results of the renovation, it should still be quite ideal!
The typical retention time is 3 to 5 seconds, as calculated by Yu Zunhong, a former student from East China University of Science and Technology! The residence time in the four-nozzle gasifier at East China University of Science and Technology is 1–3 seconds longer due to the counterflow configuration