(378h) H2 Membrane Separation and C3H8 Vaporization Synergistic for Energy Saving in Oleflex Dehydrogenation Process
AIChE Annual Meeting
2019
2019 AIChE Annual Meeting
Separations Division
Poster Session: General Topics on Separations
Tuesday, November 12, 2019 - 3:30pm to 5:00pm
H2 membrane separation and C3H8
vaporization synergistic for energy saving in Oleflex dehydrogenation process Xuehua
Ruan, Hongyan Xiao, Gaohong He*, Xiaobin Jiang State Key Laboratory of Fine Chemicals, School of Petroleum
and Chemical Engineering, Dalian University of Technology, Panjin, Liaoning,
P.R. China, 124221 Corresponding Author Email:
hgaohong@dlut.edu.cn In
Oleflex propane dehydrogenation technology, condensation for reaction effluent
is extremely energy-intensive. On the opposite, C3H8
vaporization before the reaction, subject to the mismatch in temperature
(vaporization is at about -25 oC, but condensation is sustaining
from 5 to -100 oC), could not be exploited sufficiently. The
accumulation in permanent gases along with condensation is the underlying
factor. In this respect, H2 membrane separation is embedded in the
condensation system to ameliorate the cryogenic operation and the mismatch in
temperature; meanwhile, H2 can be yielded with the purity meeting
the request for common hydro-treating processes. Our process design and
optimization revealed that it is more suitable to arrange two shallow
condensation units and two membrane units by turns and in series before the
cryogenic condensation, and the suitable operation pressure is about 2.0 MPaG.
For a 600-kt/a Oleflex plant with 221300 Nm3/h reaction effluent,
total membrane area is optimized to be about 42000 m2, and the cold
duty for cryogenic operation (below -25 oC) can be reduced by 90 %,
the minimum temperature for condensation can be raising to -72 oC.
Besides, the recycled H2 and the exported H2 can be
concentrated from 92.3 to 96 and 99 vol%, respectively, with the total recovery
ratio up to 95 %. According to our economic evaluation briefly, taking energy
saving and H2 purification together, the increment in annual gross
profit is about 48.3*106 USD. Overall, membrane separation is highly
promising to save energy and enhance economic returns for Oleflex propane
dehydrogenation process.
Acknowledgement:
The
authors acknowledged the financial supports from the National Natural Science Foundation
of China (Grant No. 21606035 and U1663223), Changjiang Scholars Program
(T2012049), the Fundamental Research Funds for Central Universities
(DUT18JC24), Liaoning Province S&T Department (Grant No.201601037) and
Education Department (LT2015007).
vaporization synergistic for energy saving in Oleflex dehydrogenation process Xuehua
Ruan, Hongyan Xiao, Gaohong He*, Xiaobin Jiang State Key Laboratory of Fine Chemicals, School of Petroleum
and Chemical Engineering, Dalian University of Technology, Panjin, Liaoning,
P.R. China, 124221 Corresponding Author Email:
hgaohong@dlut.edu.cn In
Oleflex propane dehydrogenation technology, condensation for reaction effluent
is extremely energy-intensive. On the opposite, C3H8
vaporization before the reaction, subject to the mismatch in temperature
(vaporization is at about -25 oC, but condensation is sustaining
from 5 to -100 oC), could not be exploited sufficiently. The
accumulation in permanent gases along with condensation is the underlying
factor. In this respect, H2 membrane separation is embedded in the
condensation system to ameliorate the cryogenic operation and the mismatch in
temperature; meanwhile, H2 can be yielded with the purity meeting
the request for common hydro-treating processes. Our process design and
optimization revealed that it is more suitable to arrange two shallow
condensation units and two membrane units by turns and in series before the
cryogenic condensation, and the suitable operation pressure is about 2.0 MPaG.
For a 600-kt/a Oleflex plant with 221300 Nm3/h reaction effluent,
total membrane area is optimized to be about 42000 m2, and the cold
duty for cryogenic operation (below -25 oC) can be reduced by 90 %,
the minimum temperature for condensation can be raising to -72 oC.
Besides, the recycled H2 and the exported H2 can be
concentrated from 92.3 to 96 and 99 vol%, respectively, with the total recovery
ratio up to 95 %. According to our economic evaluation briefly, taking energy
saving and H2 purification together, the increment in annual gross
profit is about 48.3*106 USD. Overall, membrane separation is highly
promising to save energy and enhance economic returns for Oleflex propane
dehydrogenation process.
|
|
|
Figure 1 Retrofitted Oleflex condensation section with 2-step membrane-embedded system. |
authors acknowledged the financial supports from the National Natural Science Foundation
of China (Grant No. 21606035 and U1663223), Changjiang Scholars Program
(T2012049), the Fundamental Research Funds for Central Universities
(DUT18JC24), Liaoning Province S&T Department (Grant No.201601037) and
Education Department (LT2015007).