SWITCHING FROM HIGH-TEMPERATURE TO STEAM REGENERATION OF OIL IN TRAPPING COKING BYPRODUCTS

摘要

Byproduct-trapping shop 3 employs high-temperature regeneration of the absorbing oil. Some debenzened oil is heated to 300-320 deg C in a tubular furnace and then sent to a regeneration column, to which live steam is supplied. The oil vapor is sent to a benzene column, and polymers collect in the lower part of the regeneration column and are sent to the polymer tank. The benzene department went into operation during a period of unsatisfactory operation of the sulfate department, when the ammonia losses were 0.2-0.8 g/m~3. Such elevated losses considerably hastened the aging of the circulating oil. The oil density was 1.081-1.096 g/cm~3. Before the introduction of high-temperature regeneration, the quality of the circulating oil was maintained by drawing off the spent oil and supplying fresh. The consumption rose to 0.3 ton/ton of raw benzene. High-temperature regeneration proved very effective, and a few days of operation per month were sufficient to renew the circulating oil. However, periodic operation of the regeneration section posed problems for the tubular furnace: the polymer density fluctuated widely, sometimes reaching 1.19 g/m~3. The polymers lost fluidity, leading to clogging of the pipes with coke. Reconstruction of the tubular furnace and improvement of the automatic monitoring did not stabilize the operation of the regeneration section.