(368d) Economic and Environmental Impact Analyses of Integrated Dehydrogenation and Hydroformylation in Gas-Expanded Liquid Media

Economic
and Environmental Impact Analyses of Integrated Dehydrogenation and Hydroformylation
in Gas-Expanded Liquid Media

Dupeng Liu,^{1, 2} Raghunath
V Chaudhari^{1, 2} and Bala Subramaniam^{1, 2}

¹Department of Chemical & Petroleum Engineering, ²Center
for Environmentally Beneficial Catalysis, University of Kansas

Lawrence, KS 66047

Increased shale gas production in the U. S. has also
enhanced the availability of C₂-C₅ alkanes (the so-called
natural gas liquids) as collateral products, and opportunities for their
utilization in novel ways. For example, propylene production capacity via propane
dehydrogenation (PDH) is slated to grow rapidly over the next several years.¹
However, for a typical PDH process, the per pass conversion is only about 50%.
The separation of propane and propylene mixtures is highly energy and capital
intensive. Previously, we had reported the beneficial effects of propane
expanded liquids (with propylene/propane mixtures as feed) for propylene
hydroformylation with Rhodium-based catalysts. At sufficiently high pressures
(>10 bar), the pressurized propane/propylene mixture forms a gas-expanded
liquid phase that promotes regio-selective hydroformylation of propylene with
homogenous Rh complex. In addition, compared with conventional propylene
hydroformylation process to produce butyraldehyde using polymer grade propylene
as feedstock, the feed in the propane-expanded liquid (PXL) process is 50%
cheaper.³

In this talk, economic and environmental analyses of the integrated
dehydrogenation and hydroformylation in PXL process are presented and
benchmarked against simulated conventional hydroformylation processes for which
data were obtained from the Ruhrchemie/Rh™ne-Poulenc  and Dow processes.^4-5
Preliminary simulation results indicate that capital investment and production
cost associated with the PXL process is lower than the conventional processes
(by up to 40% and 25%, respectively) due to the elimination of the C₃
separation section. Life cycle analysis (LCA) was also performed based on plant
scale simulation of conventional and PXL processes. These analyses have
provided guidance in catalyst design and in choosing materials and operating
conditions that favor process economics while lessening environmental
footprint.

1. Nawaz Z. Light alkane dehydrogenation to light olefin
technologies: a comprehensive review[J]. Reviews in Chemical Engineering, 2015,
31(5): 413-436.

2.Nawaz Z. Dynamic modeling of catofin¨ fixed-bed iso-butane
dehydrogenation reactor for operational optimization[J]. International Journal
of Chemical Reactor Engineering, 2016, 14(1): 491-515.

3. Liu, D., Chaudhari, R.V., Subramaniam, B. Kinetic Modeling of
Propene Hydroformylation in Propane-Expanded Liquid with Rh-Based Complexes, 2016
AIChE annual meeting San Francisco, CA.                 

4. Wattimena F, Heijmen H J. U.S. Patent 4,521,630[P]. 1985-6-4.

5. Devon T J, Phillips G W, Puckette T A, et al. U.S. Patent
5,332,846[P]. 1994-7-26.