The European municipalities and their small wastewater treatment plants (WWTPs) with less than 10.000 p.e. (population equivalent) are currently facing the following problems;
Hydro Italia is a company specialised in systems and methods for industrial water purification. It has designed a compact system, called PYROCHAR, to treat and dispose sewage sludge produced in small municipalities and their WWTPs (<10.000 p.e.).
The PYROCHAR system will dry the dewatered sludge and then use a slow pyrolysis technology to thermo-chemically convert the dried sludge into useful solid and gas by-products namely synthetic gas and biochar. Downsteam, a hot gas clean-up unit forllowed by a combined heat and power (CHP) unit will convert the synthetic gas (syngas) in energy (heat and electricity) for the system.
In addition, the by-product of small municipalities' sewage sludge porolysis (biochar) contains a limited amount of heavy metals as compared to sludge from big industries. This makes it pefect for homologations and reuse - for example, in land spreading.
For Hydro-Italia the evidence of success is that the company registered an increase of requests in a sector in which the company was not directly involved before.
More generally, Pyrochar can be considered a succesful practice for potential customers as the system provides a solution able to fuel itself, raising economical and technical benefits.
The expected benefits are:
The project needs to be completed through the construction and installation on site of a pilot plant in order to have concrete data and references in different sectors as well. This could let Hydro Italia be able to provide data to all potential clients that have shown interest for the technology. Lack of financial resources is an obstracle to the realisation of a pilot plant; participation to European projects and creation of international relationship could help removing this obstacle.
Briefly, the lessons learnt from the company are the following: