well, I am not too sure but I think in Germany and Denmark there are only pilots. I would be surprised if there is a full scale plant.

My question arises from the fact that the process of pyrolysis of sewage sludge is described in many books, like state-of-the-art handbook Sludge Engineering by Sanin, Clarkson and Vesilind, but till now it is just present in research articles and few pilot plants. Looking on the web, I have seen that there are some companies offering this technology, like Finaxo Environment (France) or Pyreg (Germany). In Italy there is a plant which operates it (http://www.arapustertal.it/en/home/box/ida-tobl/thermische-schlammverwertungsanlage), but what about the rest of the world? Is it a research topic? Is the incineration process easier to control and preferable with respect to it?

I am looking forward to receiving any information about this topic and I am glad to share my research results.

Well I see a lot of research ongoing on making biochar. - also from sewage sludge. I know only of small pilots no full scale. I have not really looked into details and economy, as I do not really have the feeling this will be competitive against on land use of sludge and incineration. Too expesive against direct use and too little destructive against incineration. - I assume Biochar will focus on waste biomass in the enxt few years.

Looking at the italian plant, I get the feeling it is first drying at relatively high temperatures and then incinerating. ...

Walter, I have collaborated in the past with the UK Biochar Research Centre in Edinburgh. I am sure they will be happy to help you to find the information you are looking for in the UK.

I agree with Kai, most of the work has been oriented towards the production of biochar.

Good luck!

Thanks Dr. Antizar-Ladislao. I agree with the fact that the work is oriented towards the production of biochar; in fact, I got in contact with some societies that told me that their aim is to produce biochar which can be used in agriculture, to reclaim land or as fuel (e.g. Pyrum, Biomacon).

I would be glad to receive any specific information you can give. I will contact UK Biochar Research Centre in Edinburgh.

Thanks a lot.

About 30 years ago the pyrolysis of dried sewage sludge was proposed by the late Prof. Bayer (Tübingen Univ., in Germany), as an easy method to convert dry sewage sludge into Diesel oil!

Somewhat later tests were commissioned by a European Federation at Vrije Universiteit Brussel (VUB) and a small number of tests were run in a lab-scale fluid bed unit and these were easily conducted and very successful in converting the dry sludge into kind of a vaseline. Problem was that such fluid bed treatment did nothing to eliminate the sulphur and nitrogen from the resulting semi-liquid product. The results of a limited number of tests were published at a symposium in Frankfurt sponsored by Hoechst AG. Also Prof. em. Kaminsky (Uni. Hamburg) studied pyrolysis processes in fluid bed units.

Much later we continued these efforts at the micro-scale, using techniques such as pyrolysis gas chromatography. This showed serious differences in results, depending on the raw material, corresponding to distinctions in the waste-water treatment processes at various plants. Nevertheless, the pyrolysis products seemed to be rich in volatile acids. Unfortunately, the work was done by a candidate Ph. D.-student that preferred to look for a job.

So, in the eighties and nineties we monitored what was going on and we were aware of larger-scale ventures in Australia and Canada at that time. Also Waterleau (B) showed some interest.

In another context we looked at chicken droppings, with the aim to convert these into reinforcing black. The tests went well, but the quality of the resulting black was generally more like filler than like reinforcing black.

Should there be enough interest, I could try and retrieve files from those times. Since I am long retired from VUB, yet active at Zhejiang University it would be easy promoting technical support  from my Chinese Institute.

Dear Professor Buekens,

I really thank you for your information and I would be glad to receive more technical details from the past activities you described. 

I know that pyrolysis operated on other products and biomasses is a consolidated technology, widespread all over the world. But the application on sewage sludge is still not widely applied, I think mainly due to the fact that the products have very variable characteristics.

Finally, I will add a little story from Italy: some decades ago, an Italian "inventor" claimed that he could produce oil from waste through thermal cracking; the institutions authorized his plan; the conclusion was that what he produced was a oil that was not marketable because its hich content in chlorine compounds and sulfuric acid; he stored this oil into silos and polluted hectares of land.

Thi Italian government is still paying for the reclamation of land (for the story, see attached link, unfortunately only in Italian).

http://it.wikipedia.org/wiki/Petroldragon

I did a plant 2000 in Yokohama for 200 kg/h.

This was the pilot plant for big Tepko plant 2006 in Tokio for 3x 1350 kg/h.

Both plant are using the hot pyrolysis gas only for combustion.

What is the main intend of your question?

Dear Mr. Gerlach

thanks for your feedback.

My intention is to discover if there are active plants in the world for sewage sludge pyrolysis which are effectively operative. In the discrict of Como (North Italy), a feasibility study was done few years ago in order to implement this kind of treatment, however without any continuation.

In my MSc thesis I studied the situation, finding that an improvement can be achieved with pyrolysis; however, without actual proofs of functioning in Europe and in the world, anyone will take this option into consideration.

Thank you very much for your examples.

Hi Walter,

I am too looking for examples in Europe of pilot scale pyrolysis plants of sewage sludge. In my case, I'm looking into the pyrolysis of digestated sludge, dried at 90% DS. The temperature we are intending to apply is approx. 850oC which will produce mainly H2. The main  concern at the moment is the high concentration of H2, since we want to obtain energy in a CHP. Most of the CHP manufacturers design units for biogas and therefore the feasibility of the project could be compromised since it;s anticipated that the CH4 production will be low.

Any information regarding this would be very grateful.

Gara 

Hi Gara

sorry to reply so late. I contributed in a research project in Italy and found very interesting examples in Italy. Please refer to attached files.

Should you need any further info, please ask.

I am looking forward to hearing about new examples.

Regards

Walter

PYREG GmbH

AQUAGreen and Stiesdal (SkyClean) do the pyrolysis in Denmark

jepps now there is ... several, but not in 2015 when the question was asked ;-)