[Gasification] R: Clean Air Regulation requirements imposed

[Doug]

On Mon, 30 Jun 2014 08:55:45 +0200
"Artem Filimonov - TVT" <artem at termoventiltecnica.com> wrote:

Hello Mr Filimonova,

Answers in the text of your letter:

> Dear Mr. Dong,
> 
> Thank you very much for your comments. To keep the flop at high temperature
> is keep keeping tars at gaseous state.

I am surprised that you consider these types of filters to be a practical solution in any process that has tars or pyrolysis oils present in their gas stream. While they can function without blockage after all the process components are up to their operating temperature, what do you do with the gases that are made during the cold start-up phase, and after the system stops during the cooling phase. In each case, if the filters are filled with gas containing these uncracked hydrocarbons, they will condense on the filter cake and seal it off.

Having personally been involved with the issues of using these types of filter systems, and put in place the necessary by-pass systems, the ability of on site in remote areas with huge variations of climatic conditions, has to be seen as a reliability risk for reliable service free operation.

 Regarding you ref. Cerafume, I can
> say we are not using that type. I do believe they have the same properties.
> We use this type:
> http://www.bwf-envirotec.us/en-us/bwf-envirotec/products/pyrotex_ke.html, as
> we are partners since long time.

The technologies would appear to be much the same as far as how they might be manufactured. I personally see them as a very good solution for filtering tar free producer gas, but their down side is for them to need pressurised back pulsing supplied from a compressor. This limits them to larger rather than smaller gasification systems.

 
> This is our typical solution:
 
> In washing step it could a chemical reagents or biodiesel to capture and
> separate tars.

All these things may be possible, but are they practical for installations not able to purchase biodiesel or chemicals? Biodiesel is only quoted as a tar or pyrolysis oil scrubbing medium, in order to satisfy the green option of disposal for the dirty oil as a boiler fuel fuel. Boilers are not universally used in many places, and it's disposal becomes the same as other toxic black liquors. Contamination of ground water by these toxic black liquors are well documented around pyrolysis/char/coke making facilities, and are extremely difficult to monitor.

 
> Looking forward for your comments,

While the subject and my comments are slightly off the original Clean Air Regulations, any discussion about Dioxin needs to be opened up to include liquid wastes from either gasification or pyrolysis oil/char making plants. I am quite sure you will notice that when questions are submitted to this Forum, the specific type of process is often not stated, so possibly correct answers are offered, but for the incorrect type of process. 
 
> I’m at your disposal,

Thank you for your kind offer, but I am trying to be retired, but am always interested in watching the technical progress of gasification and bio-char applications.

Regards,
Doug Williams,
Fluidyne Gasification.