Does it require any EU/Member State Authority permit to install/operate a pyrolysis plant?

YES, in Europe there is mandatory requirement to get permit from the MS Authorities according to EU regulations to install/operate a pyrolysis plant for commercial production of all and any types of biochar and usually ten advising Authorities involved in this mandatory permit process. The REACH regulation is also defining mandatory certificate for import, placing on the market and manufacturing of commercial biochar above 1 t/y capacity.