December 19, 2008

Ms. Susie Caplow
Florida League of Conservation Voters, Floridians Against Incinerators In Disguise,
Panhandle Citizens Coalition, Environmental&Consumer Community Activist and Organizer

Dear Susie:

At your request I reviewed materials related to the “Biomass Gas and Electric, L.L.C.,” project proposed for Tallahassee.  I also had a long and informative conversation with Mr.Al Linero of the Florida DEP Bureau of Air Regulation, who seemed very interested in discussing the project and conveying his point of view.

Bear in mind that these are preliminary impressions and recommendations based on a few hours work.  It’s clear that some very competent people have already been working on this.

First, I address the claim that gasification is something that should be viewed differently from an ordinary burner.

Basically, all combustion is gasification, in the sense that solids and liquids don’t burn.  This can be seen by close observation of a campfire or candle flame or oil burner or whatever.  The essential difference between the type of facility proposed is that the gasification step, to a degree, is physically separated from the combustion step, into different vessels.  That is, simplifying:

Step one:

C & H containing materials such as wood ——> H2 + CO + contaminants and “char” in the “gasifier,”  then

Step two:

H2 + O ——> H2O and CO + O2 ——> CO2 in the combustion turbines and char combustor

There are some engineering advantages to this, such as the ability to burn two-thirds of the material in gas turbines rather than under a boiler, but if we look at a material balance around the overall process, it is really just a burner.  The overall results are the same.

The process is noticeably more complex than a conventional steam power plant of the sort that has evolved over the last several hundred years, and is similar to an IGCC coal plant.  It *may* have lower air emissions but is permitted under the same criteria, so it doesn’t have to.

The draft air permit describes a facility with three main burners:

(1)     A “char combustor” with a rated input of 124 million BTU (British Thermal Units) per hour.  (page 9 of the draft permit).  This is a solid fuel burner.

(2)     Two combustion turbines (“gas turbines”), each with a rating of 147 million BTU per hour (page 15 of the draft permit)  These, obviously, are the “gas” burners.

The emission limits for these are not given in entirely comparable terms, but I can see that the “char combustor” is allowed to emit
10 pounds per hour (each) of particulate matter, NOx, and carbon monoxide. (page 10)

The combustion turbines (both of them together, I think) are allowed to emit 17.2 pounds per hour of carbon monoxide, 17.2 pounds per hour of NOx, and 10 pounds per hour of particulate matter. (page 15-16)

So we can see that this facility is not entirely a gas burner.  Almost one-third of the heat input, and more than one third of the air emissions, come from burning solid materials.

It is also interesting that the carbon monoxide emission limits for the combustion turbines are 17.2 pound per hour on BPG (“biomass product gas”) but 12.1 on natural gas. (page 15)   Similarly, the limits for NOx are 17.2 pounds per hour on BPG and 8.8 pounds per hour on natural gas.  This does not seem to support any claims that the BPG is a fuel comparable in cleanliness to natural gas (!).

Overall emissions

(I am simply taking this information from the “public notice of intent,” which has a cover letter dated October 24, 2008)
(If this wraps and becomes garbled in the email, look at the public notice on line at http://www.dep.state.fl.us/Air/permitting/construction/tallahassee/BGENOTICE.pdf )

Pollutants Estimated Emm. (TPY) Potential Emm (TPY)
Carbon Monoxide (CO)                            204                     231
Nitrogen Oxides (NOX)                           197                     214
Particulate Matter (PM/PM10)        114/114                 156/156
Sulfur Dioxide (SO2)                              83                        83
Volatile Organic Compounds (VOC)     18                        18
Hazardous Air Pollutants (HAP)            <5                        <5
———————-                        —-                    ——
total tons per year                               621                     707
total pounds per year                      1,242,000               1,414,000

Points to note:

The “potential to emit” is what the facility could put out without violating its permit and that is the most important number to use.  Sometimes facilities claim that their “expected” emissions are far less, but that is not the case here:  the “potential is 1.4 million pounds per year and the “estimated,” or “expected” is 1.2 million pounds per year.

To put this in plain terms, the applicants say they expect to belch out over 1.2 million pounds of health-damaging air pollutants every year (3400 pounds per day), and would be allowed to belch out over 1.4 million pounds per year (3900 pounds per day).  This rounds to two tons per day of air pollutants.

There is a lot more to be done to fully understand this permit.  For example, the proposal is to maintain on the site an inventory of 10,000 to 14,000 tons (28 million pounds) of “wet biomass.” (page 6)  This would apparently be kept in covered piles.  There is considerable potential for emissions of hazardous and smelly air pollutants, as well as mold spores and allergens, from such an inventory, especially in the warm and humid climate of Florida.  There is also a possibility of spontaneous combustion which could be hard to extinguish and would be very hazardous and unpleasant to be around.  There is an enlightening report on these issues that came from problems at a New England wood burner.

It’s also worth noting that diesel locomotives tend to be very high emitters.  Judging from the amount of trackage in the area, I’d wonder if the surrounding communities are not already “disproportionately impacted” by rail operations, which would increase if this facility was built.  Up to 5200 carloads per year of fuel shipments are expected and these would be allowed to be spotted for unloading at all hours and days. (page 5-6)  (The overall fuel consumption seems to be estimated at 365,000 wet tons per year.)

There has been no “air emissions risk analysis” performed and I have found no detailed inventory of “hazardous air pollutants” likely to be emitted.

In reviewing the draft permit for a proposed 25 MW wood burner in Minneapolis, Minnesota, I found the following smokestack emissions of human carcinogens:

Arsenic (69 lbs), carbon tetrachloride (147 lbs), benzene (13,220 lbs), beryllium, cadmium (13lbs), chromium (9 lbs), nickel (11 lbs), vinyl chloride (58 lbs) and styrene (5840 lbs).

The proposed technology of the BG&E burner is different, and the emissions might be different, but I suggest taking these numbers as a warning.  “Clean” wood or biomass is often thought to be a “clean” fuel, but this is not the case.  These fuels are very complex chemically and vary a great deal in composition from one species to another, and from different soil and atmospheric uptake in different locales.

It seems unlikely to me that the proposed facility makes economic or environmental sense.  It would likely have a negative impact on public health.  The money to be invested in it would far better be directed to investments in conservation and efficiency programs, and in solar generation or offshore wind capacity.

I hope this brief discussion is of some value to you and will talk to you this afternoon.

Yours very truly,

Alan Muller