RE: FW: GAS-L: Drying

[Weststeijn A <A.Weststeijn@epz.nl>]

Hi Peter,

> Peter Singfield[SMTP:snkm@btl.net]
> 15 februari 2001 16:47
> 
> I propose a simple economizer (vertical fire tube boiler style) in the
> "stack" through which refrigerant (prefer butane) is circulated. Then
> energy is extracted by rankine cycle after. The flu gas exhausting in this
> method of operation would be brought down to well below 160 F.
> 
> The response was that "clients" are only interested in proven technology.
> And I know that is a fact of life. so there you go. 
> 
> We are only allowed to fine tune what we have at present -- even putting
> an
> economizer in the stack is considered to "radical".
> 
Considered too radical by whom?
It is being done in Germany as I mentioned in my posting of 15 februari 2001
1:09
quote
At the moment in Germany a new 900 MWe lignite plant is being build with
flue gas recuperation htex built from engineering plastic materials. 
unquote

> But yes -- it certainly would appear the solution to "wet" fuel burning
> would lay in this direction of endeavor.
> 
Or accept that wet fuel is not suited.

Just to mention some other "radical" idea in the same hot-but-wet flue gas
area:
we are preparing a test to produce distilled water from the stack of a PC
plant by way of membrane technology. This is after desulpherisation. Reason
is that this particular plant has only sea water close by and no fresh
water. Fresh water for boiler make up needs to be piped in over 60 miles at
an considerable expense. Next to a lake, river or canal it wouldn't pay of
course.

This would not be the ultimate solution to cofiring wet biomass, though,
because the practical bottleneck (apart from efficiency motives) is in the
upstream area (before the water is taken out) of regenerative
fluegas-to-combustion air heat exchange and in the ESP. Lots of fly ash and
lots of water and high temperature makes for.....yes, a mess, and hard to
clean out.

Andries