When used tires are subjected to heat in the absence of air, large quantities of vapours and gases are produced. A large portion of the vapours can be condensed to oils with a yield of 55% by weight. However, the non-condensable gas phase (6% yield) is contaminated with oil droplets, tar, fine particles as well as nitrogen-and sulphur-compounds. The project objective is to develop a gas-cleaning system and design a pumping unit that can maintain the total reactor pressure below 10 kPa and burn the process gas without emission problems. A series of experiments was made in a 25 kg h-' vacuumpyrolysis process-development unit, for which different gas-cleaning units such as a shell and tube heat exchanger, cold traps, cyclones, demisters and filters were tested. A gas burner with a variable orifice was used to burn the pyrolysis gas efficiently. Standard stack sampling was performed to identify the flue gas contaminants. Gas burning in general was successful, but the gas-cleaning system could not remove all the contaminants in the gaseous stream. According to preliminary experimental results, an alternative promising approach is to replace the shell and tube exchanger, cold traps and filters by a liquid-ring vacuum pump.