Can ceramic filters be used in gasification with a quenching process?

Used for dust removal in raw gas? I’m afraid that won’t work; it’s more likely to get clogged.

It’s not necessary, nor is it possible to use one. After quenching, just carry out a wet washing process, just as in the gasification process during quenching – no ceramic filter is required. Moreover, with such low temperatures and a high water content in the syngas, the filter would get clogged very quickly; besides, the cost of installing a ceramic filter is too high.

Reply to 3# shanxg: Indeed, the syngas after quenching is essentially saturated with water vapor, making it easy for steam condensation to cause blockages.

Could the original poster explain the specific technical approach, and the purpose of using a quenching process followed by a ceramic filter?

I didn’t think much about it; I just wanted to remove the fine dust as cleanly as possible

I’ve always had an idea, though I’m not sure if it’s feasible: Ceramic filters are criticized mainly because (1) they are expensive, (2) their operation is unstable and they can break down, leading to the shutdown of the equipment, and (3) the procedures for dealing with fly ash are complicated. Therefore, under the current conditions, I think the ash removal process can be adjusted and simplified. For example, two stages of cyclones are used in series; with an efficiency of 70% for each stage, the overall efficiency is 91%, and then a venturi and a scrubber are employed. Omit the quench tank. Of course, the efficiency of the first cyclone stage can be higher; the second cyclone stage may not reach 70%, but overall, the total efficiency should be around 90%, so there shouldn’t be any problem. The ash falling from the cyclone can be collected using a water seal. Similar approaches are actually used in normal-pressure dry powder gasification for these ideas; in high-pressure systems, certain measures need to be taken for the water seal, and ash removal is not as simple as in normal-pressure systems. There is a small amount of dissolved gas in the water (this has not been calculated, and it’s unclear whether it can be discharged directly). In this way, the cyclone has no stability issues aside from wear problems, and the system is also much simplified. Of course, in my opinion, precise dust removal using ceramics is an inevitable trend; however, high costs and stability are the biggest issues. I’ve put forward these ideas under the current circumstances, and those who are interested are welcome to discuss them.

Cyclone separators have a history of use in the coal chemical industry; KBR and Shell seem to have employed them. However, at high temperatures, heat-resistant linings must be used inside the separators, which I believe reduces the efficiency of ash removal to some extent. How to address this issue is something that professional manufacturers need to consider. Additionally, I think that in dry ash removal, it is possible to carry out some water washing for ash removal, as steam will be added later in the conversion process to meet the requirements of that process; therefore, it’s better to resolve this issue through water washing.

Reply to 1# wildhalf: If it is carried out in the washing section, filtration equipment can be used to filter the sprayed liquid and recycle it. I’m not sure what the temperature is where you are; I can ask my friends in the engineering field to see if there are any suitable devices. Lfcn100@163.com

Reply to 7# ahtao: A total efficiency of 90% for two-stage cyclones is far from sufficient, as some processes involve very high levels of dust suspension. For the second-stage cyclone, since it is designed to handle very fine dust, it is difficult to achieve a collection efficiency of over 90%. Because it is under high pressure and high temperature conditions. A total efficiency of over 98 is considered good.

Cyclone separators are indeed very good, but their cost is quite high.