Issues related to the utilization of waste gases from coal chemical industries
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This post was last edited by lflsedin on 2015-4-5 at 20:32. After gasification, some residual gas is inevitably left over after the useful gases have been utilized; how can this residual gas be put to use? From what I know at present, only Yankuang Guotai Chemical uses gas turbines to generate electricity from its exhaust gases; Yankuang Yulin’s coal-to-oil facility also employs gas turbines for power generation. Shanxi Lu’an Group’s exhaust gases may be used to drive gas turbines for electricity production, or they might be used for other purposes. The question is why other manufacturers don’t utilize exhaust gases? Is it still expelled through very tall chimneys? And why didn’t the 600,000-ton methanol project at Yankuang Yulin use gas turbines for power generation either? Or are there any other better ways to use this exhaust gas? For example, returning to the process flow to be absorbed and reused again? I hope everyone will share their thoughts: Thank you!
The off-gases from methanol or synthetic ammonia production are typically processed using pressure swing adsorption or membrane technology to recover hydrogen, which is then returned to the system. The gas resulting from this process is generally used as fuel; in our plant, part of it is sent to fixed-bed gas generation units as blowing air for recovery, while another portion is supplied to the residential area for domestic use； The CO2 from the methanol purification unit is sent to the liquid carbon dioxide plant and then exported.
The gas turbine requires tens of thousands of cubic meters of gas at a minimum; otherwise, it becomes unfeasible to generate electricity economically. Such a large volume of gas cannot be considered exhaust gas. The several projects you mentioned actually do not generate power from exhaust gases; rather, they involve gasification for combined heat and power production, with some of the syngas being used to manufacture chemical products and some being used as fuel for power generation and steam production. The amount of exhaust gas continuously emitted by the gasification unit itself is very small, and its calorific value is low; it has little practical use, so it is ultimately sent to a flare or released on-site. The exhaust gas resulting from the recovery of the off-gases from the synthesis unit does possess a certain calorific value, and can be used as fuel gas within the unit for serving as a backup fuel in water-coal slurry gasifiers or for other purposes.
But the off-gases from the synthesis unit also come from the gases produced in the gasifier. Oh, right – after reacting in the synthesis unit, some other gases are generated, which explains why the Yankuang Yulin coal-to-oil project involves combined oil and electricity production. But what kind of fuel gas is used for power generation by the gas turbines at Yankuang Guotai Chemical? What about the 3 gas turbines of Shenhua Group? The website mentions IGCC, but Yankuang is talking about co-producing methanol through power generation – it certainly can’t be IGC
Yankuang’s so-called IGCC is actually used to apply for **funding. Are there any gas turbines whose impact on the overall operation and production capacity of a plant is minimal? By adding two small gas turbines, an IGCC combined heat and power system can be created; in this regard, **there is policy support and financial funding available, and it is also easier to obtain approval for such projects**. A true IGCC is designed primarily for power generation, rather than focusing on coal chemical production like Yankuang does
Yeah, Shenhua’s project seems to not be called IGCC either; from what I remember it’s also a coal chemical processing project. It’s strange that it suddenly changed to IGCC
I wonder what Bone’s background is; it seems like he knows everything – he has a thorough understanding of all aspects related to gasification, including various techniques and metrics. The fact that he can analyze exhaust gases in such detail is truly impressive
I think it’s the most cost-effective to provide it free of charge for use in daily cooking by the residents of the family area after processing! Reduce the burden on businesses and invisibly increase employees’ incomes!