Re: Research Topics

[FMurrl@aol.com]

In a message dated 4/21/02 6:31:33 PM Eastern Daylight Time, Andries.Weststeijn@essent.nl writes:


> Natural gas can in fact be fired quite easy in an utility style coal plant, provided of course that gas burners have been installed.
> The funny thing is that it is easier to fire full power on gas, than to cofire gas with coal on a -say-  50/50 basis.


Andries:

I should have been more clear on my comment, and I acknowledge that your comment that gas can be successfully used in a coal fired plant is often correct. However, not always. 

At the utility I worked at, we studied conversion of two of our four coal fired units to gas. We determined that it was a bad idea. 

First, the cost of getting gas to those units was huge, since there was no infrastructure. 

Second, we modeled a de-rate in those units. It has been too long for me to remember exactly what parameters worked against us, but I recall something about the difference in heat transfer of the flame characteristics. I badly assumed that this problem that I observed held true for all coal plants -- a careless act on my part. 

Third, the efficiency -- compared to combined cycle gas -- was just not there.

Fred Murrell
Biomass Development
Bradenton Florida USA