A review with 24 refs. covering refinery processes yielding hydrogen for SMEs (illustrated by H refining of liq. fuel fractions prepd. by thermocatalytic decompn. of waste polyolefins), technol. aspects of co-pyrolysis of (1:3 w/w) waste polyolefin-paraffin oil mixts., and upgrading attempts at reducing S content and prepg. more fuel-range fractions in one hydrocracking step.