[GreenYes] Re: Landfill methane recovery data

[Alan Muller <amuller@no.address>]

At 04:07 PM 3/1/2007 -0800, you wrote:
>Hi folks ~
>
>This has been a very useful exchange, and yet skirts around a 
>practical question: doesn't it make sense that if the objective is 
>to generate and harvest methane a controlled system, both controlled 
>in its feedstock and controlled in its scale and design, would make 
>more sense than a landfill?
>
>Alan Muller mentioned a study of a digester ("... there are data 
>from in-vessel anaerobic digestion processes that can be used to 
>validate generation calculations.  I found it somewhat convincing 
>and also disturbing in the low percentage recovered.   I don't 
>recall the source or the authors but can probably find it..."). It 
>would be useful for Alan to find and forward this study. It sounds 
>from the findings ("low percentage recovered") that the digester in 
>the study was not designed to control methane? Not sure however why 
>a study of a digester could be used to "validate" landfill capture...

Just that if you do anerobic digestion in a vessel, sealed and under 
control, you can keep track of what comes out, and compare the actual 
gas output with predictions based on chemical calculations.  If you 
do it in a pit or pile that leaks top, bottom, and sideways, you can 
only guestimate ....

>I have felt for some time that we need some information to smoke out 
>the claims of landfill operators that they are preventing climate 
>change by harvesting methane. This is real greenwashing.

My main concern is this:  Yes, it is better to capture as much as 
possible rather than just let it escape.  (Landfill gas is a lot more 
than just methane,  There is all sorts of nasty stuff in it.  Methane 
itself has no particular odor.....).  But if setting up a capture 
system, which in reality only captures a fraction of what is coming 
out, convinces people that landfilling has now become "green" and 
acceptable, "greenwashing" is happening big-time.

The problem gets worse when landfill gas power (we call it "garbage 
fume power," see http://greendel.org/item.xhtml?name=alert_0534 for 
some discussion) is subsidized as "green" or "renewable" energy, 
and/or is used to meet "renewable portfolio standards" 
(quotas)   This creates a political link between electricity vendors 
and dumpers, and encourages continued dumping.

Many people and orgs aren't sure what to make of this issue.....

Alan


>H.
>
>At 03:04 PM 3/1/2007, Wolbert, Brad - DNR wrote:
>>[Here's a reply I attempted to post earlier, only to find out I 
>>couldn't post to the entire group.  I think that's been fixed; we'll see.]
>>
>>Dennis -- on the technical question, I can only point to one 
>>specific study, and it was a conference presentation, not a 
>>refereed published article.  For what it's worth, it's at 
>><BLOCKED::http://www.dnr.state.wi.us/org/aw/wm/solid/gas/finalpaperLFGefficiency2006-Michels.pdf>http://www.dnr.state.wi.us/org/aw/wm/solid/gas/finalpaperLFGefficiency2006-Michels.pdf. 
>>Unfortunately, no one knows what the correct values are for the 
>>model inputs that were used, so I would take the conclusions with a 
>>very large grain of salt.  Still, it may be useful in understanding the issue.
>>
>>My own discussions with researchers in this field lead me to 
>>conclude that there is no firm consensus on system collection 
>>efficiencies of methane from landfills, and it is highly variable 
>>in any case.  There are periods in the life of landfills when there 
>>is no gas collection system installed or operating.  Even when the 
>>gas system is running, in the best of circumstances, there is an 
>>open working face where landfill gas can escape.  I tend to believe 
>>that lifetime capture efficiencies are closer to the higher percent 
>>range you cite below in cases where the landfill is recovering gas 
>>for flaring or utilization.  Probably during the operation of the 
>>gas systems, the capture efficiency is even higher.  Otherwise 
>>these facilities would stink like crazy, all the time.  Well-run 
>>landfills are generally able to control their odor problems most of the time.
>>
>>Two other points are important.  The food scraps very likely have 
>>more value outside the landfill, as compost, than buried in the 
>>landfill, but you'd need a life-cycle analysis to prove it.  Maybe 
>>there's one out there, I don't know.  Also, given the realities of 
>>landfilling (lots of plastic, lots of places where moisture doesn't 
>>reach) some of those landfilled food scraps won't break down for 
>>many years, long after the gas utilization system is gone; that 
>>fraction has no value as fuel at all.
>>
>>Brad Wolbert
>>Hydrogeologist - Wisconsin DNR
>>
>>
>>
>>----------
>>From: GreenYes@no.address [mailto:GreenYes@no.address] 
>>On Behalf Of Alan Muller
>>Sent: Thursday, March 01, 2007 4:44 PM
>>To: Eric Lombardi; Reindl, John; 'Dennis Sauer'; GreenYes@no.address
>>Subject: [GreenYes] Re: Landfill methane recovery data
>>At 03:29 PM 3/1/2007 -0700, Eric Lombardi wrote:
>>>Hi John,
>>>
>>>I am on the Colorado Climate Project, and we are discussing the 
>>>fact that we can't find any studies on "life-cycle methane 
>>>emissions" from landfills.   It seems that everyone keeps citing 
>>>that 75% gas recovery rate for best-available-technology, but my 
>>>understanding is that this number reflects only a point-in-time 
>>>recovery rate when all systems are up and running at peak 
>>>performance.  My understanding is also that that special "point in 
>>>time" begins and ends over a short amount of the time that buried 
>>>organics are actually off-gassing.
>>>
>>>The lack of real data is probably attributable to the fact that no 
>>>one has ever covered a landfill from day one and measured the gas 
>>>generation over time.
>>>
>>>Have y'all in Wisconsin ever done a life-cycle estimate on the 
>>>percent of gas that is actually captured?
>>>
>>>Eric
>>There is a report based on a look at a bunch of California 
>>landfills that estimated a number on the order of 30 percent 
>>recovery.  As I recall it was based on calculations of how much gas 
>>should be generated by the garbage, over what period of time (with 
>>respect to the dumping) vs what was actually recovered.
>>As you say, nobody has apparently ever bagged a landfill and 
>>measured accurately.  But there are data from in-vessel anerobic 
>>digestion processes that can be used to validate generation 
>>calculations.  I found it somewhat convincing and also disturbing 
>>in the low percentage recovered.   I don't recall the source or the 
>>authors but can probably find it.
>>As far as I am concerned it confirmed my sense that landfill gas 
>>burning should NOT be regarded as desirable from a carbon point of 
>>view.  Mostly because if you do that it may lead to support for 
>>continued dumping, which will cause more gas to be leaked than recovered.....
>>am
>>
>>>-----Original Message-----
>>>From: GreenYes@no.address [ 
>>>mailto:GreenYes@no.address] On Behalf Of Reindl, John
>>>Sent: Thursday, March 01, 2007 1:40 PM
>>>To: Dennis Sauer; GreenYes@no.address
>>>Subject: [GreenYes] Re: Landfill methane recovery data
>>>
>>>Hi Dennis ~
>>>
>>>I work for a county that owns a landfill and has very up-to-date 
>>>technology for gas extraction and energy production, with revenues 
>>>of over a million dollars a year.
>>>
>>>When we did our food scraps recovery study, this very question 
>>>came up and our study's conclusion was that the removal of food 
>>>would have negligible impact on gas recovery at the landfill. (We 
>>>used the EPA LandGEM model.)
>>>
>>>On the other hand, removal of food from landfills will cut down on 
>>>odors and the attraction of birds, flies and other vectors. And, 
>>>for waste generators, it means that materials don't need to be set 
>>>out frequently for collection (I set out material only 2-3 times a year).
>>>
>>>Best wishes,
>>>
>>>John Reindl, Recycling Manager
>>>Dane County, WI
>>>-----Original Message-----
>>>From: GreenYes@no.address [ 
>>>mailto:GreenYes@no.address]On Behalf Of Dennis Sauer
>>>Sent: Thursday, March 01, 2007 2:16 PM
>>>To: GreenYes@no.address
>>>Subject: [GreenYes] Landfill methane recovery data
>>>
>>>Does anyone have recent data or studies relating to the capture 
>>>rate of methane from landfills?  As we expand our food scrap 
>>>diversion programs we have received criticism that we are stealing 
>>>fuel from a co-generation facility at our regional landfill. I 
>>>realize that in dry tomb landfills, any reduction of methane from 
>>>removing food scraps is negligible due to the rapid decomposition 
>>>of food scraps.  This has been answered by critics who state that 
>>>the latest landfill and methane recovery technology does capture 
>>>methane from food scraps and all of the methane generated by a 
>>>landfill.   I have read one study that states: despite claims of 
>>>70-75% recovery rates, the actual amount being recovered is more 
>>>like 20%.  Can anyone direct me to additional information to back 
>>>up this data?
>>>
>>>Thanks,
>>>Dennis
>>>
>>>Dennis Sauer
>>>Compost Specialist  compostspecialist@no.address
>>>Central Vermont Solid Waste Management District
>>>137 Barre St, Montpelier, Vermont 05602
>>>802-229-9383 Ext. 303
>>>800-730-9475(Vt only)
>>>802-229-1318 fax
>>><http://www.cvswmd.org>www.cvswmd.org
>>>
>>>
>>>
>>>
>>>
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>
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