Membrane to condense water and recover heat from flue gas
NETL has partnered with Gas Technology Institute (GTI) and Media & Process
Technology Inc. (MPT) who have developed a nanoporous ceramic membrane device
that condenses water and recovers heat from flue gas. The innovation is called
the Transport Membrane Condenser (TMC). The TMC has been tested in various
boilers and configurations and has been shown to be effective at heat and water
recovery. The technology can be particularly beneficial for coal-fired power
plants that use high-moisture coals and/or a wet flue gas desulfurization (FGD)
for flue gas cleanup.
In the TMC,
water vapor from flue gas at the feed side condenses inside the nanopores of the
membrane and passes through by direct contact with low-temperature water from
the permeate side. In this way, the transported water is recovered along with
virtually all of its latent heat. The conditioned flue gas leaves the TMC at a
reduced temperature and with a relative humidity below saturation.
Flue Gas Water and Heat Recovery with a two-stage TMC is shown here. Preliminary
Aspen study shows, if the TMC/stage 1 is integrated into the steam cycle, it can
increase the cycle efficiency by 0.72% from a baseline 36.3%, save 2% makeup
water, which is 500 kg/min for a 550MW unit. TMC/stage2 can recover about 3,506
kg/min water for cooling water makeup.
Media and Process Technology Inc. (MPT)
specializes in the development of advanced ceramic membranes and their
applications in separations, purifications and environmental processes. M&P’s
core expertise is in the synthesis and modifications of membranes and the use of
materials for the removal of contaminants from gas, aqueous and hydrocarbon
streams.
Since Alcoa divested its separations business in
1991, MPT, as a spin-off organization, has been continually active in these
areas. Under the leadership of Dr. Paul K.T. Liu, formerly Manager
of Research and Development of Alcoa Separations, MPT has placed its business
focus on the development of a low cost, high performance ceramic membrane as an
alternative to traditional multichannel ceramic membranes.