Abstract: The present invention relates to a process for purifying a crude nitrogen-containing, sulfur-containing, halogen-containing pyrolysis oil originating from the pyrolysis of plastic waste, comprising (i) subjecting the crude pyrolysis oil to a treatment with a trapping agent selected from (a) an elemental metal of group 1, 2, 6, 7, 8, 9, 10, 11, 12, 13 of the IUPAC periodic table, a mixture or an alloy thereof; (b) an oxide of metals of group 1, 2, 6, 7, 8, 9, 10, 11, 12, 13 of the IUPAC periodic table or a mixture thereof; (c) an alkoxide of metals of group 1, 2 of the IUPAC periodic table or a mixture thereof; (d) a solid sorption agent as defined in the claims; or a combination of at least two trapping agents (a), (b), (c) or (d); (ii) separating the product obtained into a purified pyrolysis oil fraction having a reduced nitrogen, sulfur and halogen content in relation to the crude pyrolysis oil and a fraction comprising the trapping agent which has bound at least a part of the sulfur, nitrogen, halogen pre