A collapsible stroller includes a mobile base and a juvenile seat coupled to the mobile base. The process comprises filtering a bio-oil containing residual solids from a conversion reaction in the presence of the biomass filter aid to produce a filtered bio-oil. The invention has the following advantages. With the method according to the invention there is no risk of producing conductive chips resulting from the working of metallic elements, the tuning of the antenna becomes accurate, and structural faults in the medium will be automatically compensated for.