According to the European Law pyrolysis is a form of burning as long as the resulting biochar is afterwards burned to ashes. So the only conclusion can be that there is no principle obstacle to start with petpyrolysiums.
Directive 2000/76/EC of the European Parliament
Article 3 Definitions
4. “incineration plant” means any stationary or mobile technical unit and equipment dedicated to the thermal treatment of wastes with or without recovery of the combustion heat generated. This includes the incineration by oxidation of waste as well as other thermal treatment processes such as pyrolysis, gasification or plasma processes in so far as the substances resulting from the treatment are subsequently incinerated.
This definition covers the site and the entire incineration plant including all incineration lines, waste reception, storage, on site pretreatment facilities, waste-fuel and air-supply systems, boiler, facilities for the treatment of exhaust gases, on-site facilities for treatment or storage of residues and waste water, stack, devices and systems for controlling incineration operations, recording and monitoring incineration conditions;
Article 2 Scope
1. This Directive covers incineration and co-incineration plants.
2. The following plants shall however be excluded from the scope of this Directive:
(b) Experimental plants used for research, development and testing in order to improve the incineration process and which treat less than 50 tonnes of waste per year.