Increasing yield of diesel fuel from Fischer-Tropsch process - by hydrocracking and oligomerising prim. fractions

摘要

Mfr. of diesel fuel from coal (i) gasifies it with O2 and H2O; (ii) converts synthesis gas from (i) by the Fischer-Tropsch process; (iii) treats the primary prod. of (ii) separately by (iiia) and (iiib) to increase the yield of diesel fraction; (iiia) hydrocracks the fraction of b.pt. above 320 deg. C, pref. at 100-150 atmos. over a catalyst of noble metal supported on a Li or Ba zeolite, and pref. having first satd. the olefins in this fraction by H2 over a Ni-contg. catalyst at 100-150 atmos.; and (iiib) oligomerises the olefins of b.pt. below 140 deg. C, pref. treating the C3's and C4's separately, and hydrogenates the oligomerisate over a Ni-contg. catalyst. The yield of diesel fuel is increased to 61% of the Fischer- Tropsch prim. prods., and it is of good quality (cetane number 59). In contrast to coal hydrogenation methods, coals of high ash content may be used.