| 摘要 |
<p>Cyclic fluidised cracking process for S-contg. oils, using (1) a catalyst of molecular sieve type, in which is incorporated during the cracking process, (2) Mg, Ca, Sr and/or Ba in free or combined form, as fluidisable solid particles or asan oil- or water-soluble cpd. Content of (1) in the catalyst is 10-99.9975 (90-99.9) wt.% and amount of (2) is sufficient to absorb at least 50% of the SO2 formed in the regenerator. In the process, (a) a catalyst mixt. as above is made, (b) the charge is cracked at 454-649 degrees C, (c) the deactivated catalyst is stripped at 454-649 degrees C, using a gas contg. steam in wt.r atio to (1) of 0.0005-0.025, (d) the catalyst is regenerated at 566-788 degrees C, (e) at least 50% of the sulphur oxides is absorbed by the catalyst, (f) the catalyst is recycled to the reactor, (g) a waste gas is drawn off from the regenerator contg. O2 and a low concn. of sulphur oxides, and (h) most of the absorbed SO2 is drawn off from the reactor and/or stripper as S-contg. gas, e.g. H2S. Incorporation of (2) during cracking instead of during prepn. of the catalyst gives a greater reduction in SO2 emission from the regenerator. The cracking process can be controlled by varying the rate or amount at which (2) is added, and it is deposited on the outside or on accessible area of the catalyst.</p> |
