(414ab) Continuous Olefin/Paraffin Separation with Imtex Facilitated Transport Membranes

As worldwide demand for light olefins increases, there is an enormous
incentive to explore reliable alternatives to distillation for the separation of olefins
from paraffins with lower energy consumption, reduced capital cost and less
environmental impact. In pursuing increases in production capacity, many
facilities are faced with the challenges of expense and complexity of additional
distillation equipment. Attempts have been made to develop alternative
separation technologies, including significant work on facilitated transport
membranes. The main unresolved challenge was membrane performance
instability over time. Imtex Membranes Corp. has developed a membrane
separation process that has shown performance stability over extended periods
of operation during trials using spiral wound membrane elements. Imtex
continued to optimize the hydrogel-based membrane process, demonstrating
continuous, uninterrupted operation in olefin/paraffin gas separation. This in
contrast to dry solid polymeric and immobilized liquid membrane technologies for
which stability, permeation rate and selectivity challenges have been well
documented. Results were very encouraging for C2, C3 and C4 splitting
applications as greater than 99.5% olefin purity was achieved in all cases with
steady permeation at commercially viable rates. With these characteristics and
its modular nature, Imtex membrane technology is presented as a practical
alternative to the costly distillation approach. In addition to ethylene production,
this technology can be applied in other commercial applications such as
upgrading refinery grade propylene to polymer grade or in propane
dehydrogenation and other on-purpose propylene processes that are becoming
more prevalent due to the trend towards lighter feeds to ethylene plants. There
is also promising potential for butene/butane separations where traditional
distillation separations require large numbers of trays and extremely high reflux
ratios. Monomer recovery from polyolefins production is another potential
application. Extended tests were performed at Imtex to verify the stability and
continuity of operations relevant to these applications. The promising findings
are presented.