NREL is creating biorefinery systems for converting biomass into a range of precious fuels, chemical substances, materials, and products—very like oil refineries and petrochemical plants do.→ نَقِيٌّ čistý ren rein αγνός puro puhdas pur čist puro 純粋な 순수한 puur ren czysty puro чистый ren บริสุทธิ