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EBMUD staff is also asking for a
large subsidy for this project ($1M the last I heard) from our local
disfunctional recycling agency. While I can't blame them for going after
the pot of money (since it will only get spent on something that doesn't
actually need a subsidy), one wonders about the economics of this even with high
energy prices since the material in question can be taken straight to
a composting facility as it is (and there's a brand-new one with spare
tonnage very close by). The claimed VOC reduction seems like a thin
argument.
-- Steve
Bloom
Doug
- Yeah, I’m not a waste water treatment guy. Ann asked for the view from
recyclers, and I’m connecting her to folks at EBMUD. Good questions,
though. I’m sure there’s a world of literature on the first one.
Regarding
the second, my understanding is that greater energy value can be yielded from
source-separated food scraps because they can tailor the digestion process for
food scraps for greater efficiency & higher energy production. This
has to be considered together with the other benefits I’ve mentioned - solids
from a food scrap –dedicated digester can go to compost facilities that don’t’
accept bio solids, their energy value degrades less when separated and not piped
in, and those solids represent lower VOCs/ton of feed stock. The
latter is a considerable factor in California where our compost facilities are
facing mounting and critical regulatory obstacles related to VOC
emissions. These are complementary, cascading benefits. Add the
stranded capacity in proximity to available feed stock, and EBMUD’s effort comes
into greater focus, I hope.
Peter
From: Doug Koplow
[mailto:Koplow@no.address]
Sent: Tuesday, June 10, 2008 11:03
AM
To: GreenYes; Slote, Peter
Subject: [GreenYes] Re:
Anaerobic Digestion of Food Waste Final Report
Available
Is there any data on
the fugitive emissions from food wastes delivered "by pipe"? Would the fugitive
emissions from food wastes be higher than what must also be occurring with
standard sewage?
Also, I was curious
about your point that much of the value of food waste is being lost if it isn't
source separated. Don't most of the larger POTWs capture and reuse methane
from all organic matter that is delivered "by pipe"? If so, this would
seem to capture the energy value of the food waste, regardless of which way it
reached the plant. Are you mostly worried about the degradation of the
biosolids due to commingling with more contaminated
wastes?
_______________________________
Doug
Koplow
Earth Track, Inc.
2067 Massachusetts Avenue - 4th
Floor
Cambridge, MA 02140
www.earthtrack.net
Tel:
617/661-4700
Fax:
617/354-0463
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>>> <pslote@no.address>
6/10/2008 12:35 PM >>>
Ann - The City of Oakland Recycling staff
has been consulting with
EBMUD on their commercial food scraps program.
Some issues:
1) Fully capitalized, existing digesters that aren't
currently used
represent "stranded capacity" which EBMUD is planning to
utilize with
source-separated, trucked-in food scraps from restaurants
and
institutions, a high-value feedstock for energy production. This is
a
major part of the value proposition. Interestingly, these
digesters
have gone unused due to the flight of the food processing sector
from
the EBMUD service area to the Central Valley. Well, a lot of
that
food is consumed here, and it's finding it's way back to
these
digesters.
2) Another critical part of the value proposition is
that the solids
produced from digestion of source-separated food scraps can
go to
existing composting facilities, ones that don't take
bio-solids.
Furthermore, the solids from food scraps have been stabilized
and
contain lower VOCs. This is a great fit in the current environment
of
tightening emissions requirements for composting facilities: it
means
more tons can be composted at a fixed emissions threshold.
3)
I've been told that these same food scraps sent "by the pipe" (via
sink
disposals) degrade every step of the way creating
fugitive
emissions.
4) And of course, material sent by the pipe aren't
source separated,
so a lot of potential value is lost. Source-separation is a
hallmark
of highest-best use recycling. Same thing applies,
with
qualifications, to digestion of commercial food scraps.
This
isn't a universal answer to management of all organic discards or
even all
food scraps. It is a great addition to the portfolio of
options for
clean, source-separated food scraps, where treatment
capacity, and the other
conditions supporting this effort in Oakland,
exist.
Peter
Slote
City of Oakland Public Works Agency
Solid Waste and Recycling
Programs
Visit www.zerowasteoakland.com now!
On Jun 8, 6:58 pm,
Ann Schneider <schneider...@no.address> wrote:
> Hi ZWForum, CNRCC
Energy & Climate Comm & GRRN:
>
> Just curious but what is
the general feeling in the greater recycling
> community about sending
food waste to sewage treatment plants (POTWs
> publically operated
treatment works) so energy can be recovered and the
> end product I assume
used as a soil amendment. In the study just
> released below the
food waste is kept separate from other materials
> entering the POTW so
should be no cross contaimation with sewage sludge.
>
> If this is a
good idea, we may want to add this to suggestions we are
> sending to Cool
Cities as a good way for gargage and energy to work
> together aka achieve
both composting and energy goals and sustainability
> goals (handling
things close to the source) by getting each communities
> POTW to add this
type of process to their operations.
>
> Ann Schneider
>
Chair, National Zero Waste Committee
> Sierra Club
>
Ann.Schnei...@no.address
>
>
>
> --------- Forwarded
message ----------
> From: Peck.C...@no.address
> Date: Tue, 22
Apr 2008 12:37:01 -0700
> Subject: Anaerobic Digestion of Food Waste Final
Report Available
>
> Greetings,
>
> The US EPA, Region 9
Office of Pollution Prevention and Solid Waste is
> pleased to announce
the final report "Anaerobic Digestion of Food
> Waste."
>
> In
2006 EPA Region 9 awarded a $50,000 grant to East Bay Municipal
> District
(EBMUD), a wastewater treatment facility in Oakland, California
> to
investigate anaerobically digesting food wastes from restaurants,
>
grocery stores and other food-handling facilities at a wastewater
>
treatment facility. EBMUD bench-scale digesters were fed only food
>
wastes, but were operated under a variety of conditions, varying
>
digester loading rates, temperature, and other parameters. The
project
> recovered significant quantities of energy from food waste as
well as
> high volatile solids reduction, showing the potential of
diverting large
> quantities of valuable food waste from
landfills.
>
> The final report and a fact sheet summarizing the
results can be found
> on our website
athttp://www.epa.gov/region09/waste/organics/ad/index.html
>
>
Please feel free to contact me if you have any questions.
>
> Thank
You,
> Cara Peck
> U.S. EPA Region 9
> Office of Pollution
Prevention and Solid Waste
> (415)972-3382
>
Peck.C...@no.address
>
> Recycling: It is not just about landfill
diversion, it is about
> replacing virgin material production which will
significantly reduce
> energy consumption and greenhouse gas
emissions.
>
____________________________________________________________
> Visa,
MasterCard, AMEX & Discover. Compare Offers & Apply Online. Click
here!http://thirdpartyoffers.juno.com/TGL2141/fc/Ioyw6i3m2HW02otB3faR0mTff...-
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