摘要 |
Waste oil is treated in a tubular reactor having a length of up to and in excess of 2 km in a plurality of stages each of which involves heating the product to a different temperature and maintaining the product at a different pressure. The released fractions are evacuated from the path for the flow of waste oil and are immediately condensed and distilled to yield a variety of products from oil having a low boiling point to coke. One or more withdrawn fractions can be treated (for example, hydrogenated) in one or more discrete tubular reactors. The heating can involve raising the temperature of waste oil to several times the critical cracking temperature, and the regulation of pressure can involve a reduction of pressure to less than 1 mbar. The last stage of the reactor can be cleaned by abrasive particles, by vibration at high frequencies and/or by acceleration of the conveyed stream to an elevated speed. |