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Mild
Hydrocracking（MHC）
MHC
was developed in FRIPP, SINOPEC in 1980’s for enlarging
resources of steam cracker feeds. Typical commercial data
are listed bellowing.
Typical
commercial data of MHC
|
Feed |
Shengli
VGO |
|
End
point/℃ |
520-560 |
|
Operating
conditions |
|
|
H2
partial pressure/MPa |
7.6(6--8) |
|
LHSV/h-1 |
1.00/1.57 |
|
Product
qualities |
|
|
Naphtha,
yield/m% |
14.5 |
|
Diesel,
yield/m% |
20.6 |
|
Cetane
number |
42 |
|
Solidification
point/℃ |
<-20 |
|
S/N/μg/g |
<30/<10 |
|
Tail
oil, yield/m% |
20.6 |
|
BMCI |
16.7 |
Results
of steam crackers with different feeds
|
Feeds
of steam crackers |
MHC
tail oil |
SR
naphtha |
SR
diesel |
|
Cracker
outlet temperature/℃ |
800 |
840 |
800 |
|
Yields
of main products/m% |
|
|
Ethylene |
26.7 |
23.6 |
23.7 |
|
Propylene |
16.6 |
12.5 |
16.1 |
|
Butadiene |
5.3 |
4.5 |
5.2 |
|
Sub-total |
48.6 |
40.7 |
45.0 |
|
BTX |
7.4 |
18.4 |
9.7 |
|
Fuel
oil |
6.9 |
2.8 |
8.1 |
When
controlling the conversion of 350℃＋
products
at 30m%~ 50m%, the yield of good quality light diesel is
20m%~ 30m%, sulfur content is less 30mg/g,
cetane number is above 40; yield of naphtha is 7m%~ 12m%,
aromatics potential is above 52%, it is good quality feed
of reformer; 350℃＋（or
370℃＋）
tail oil is good
quality feed for FCCU or steam cracker. Steam cracker
results show that per pass ethylene yield at 820℃
can reach 28m%, which is better than that of SR naphtha
and SR diesel.
Though
MHC can not produce clean diesel directly, but to refiners
who have ethylene production units, MHC can enlarge the
resources of ethylene feed and substitute the low sulfur
clean light diesel in which increase the refiners’
profits.
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