A Possible New Grass Tablet CSE Strategy
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jock...@gmail.com
Jul 1, 2008, 8:19:16 PM7/1/08
to Grass Energy
I have recently received from BHS Energy in PA some samples of 1.5
inch diameter by 3/4 inch switchgrass "tablets" made with a prototype
mini-plugger they have in development. [Pls see the picture I uploaded
in the files section.]
They look very promising indeed. I am looking forward seeing them work
in a wood chip combustion system for domestic use. Soonest. As they
say, the proof is in the pudding. So far, the elements of the pudding
that I have had in my hand are very interesting indeed.
In the Community Supported Energy model I am sketching out here, the
biomass tablet production facility would serve a radius of about 5
miles and draw its fiber from about 238 acres of local grass lands.
I am assuming a base rate of 650 pounds of tablets produced per hour =
2.6 tons per day or 13 tons per week - on a one shift per week
schedule. No drying required, just hammer milling through a 3/4 inch
screen. Raw material can have a moisture range of 8% - 14%.
At an average of 650 tons per year per machine [50 weeks X 13 tons per
week], over 7 years, the amortized equipment cost per ton is just
$10.99 [assumes $50K all in cost of production facility].
Labor, 1.5 FTEs at $15 per hour, would be $46.15 per ton + $75 per ton
for energy hay + fuel cost to manufacture etc. and we are looking at
something like a $202.24 per ton delivered price to a CSE member
living within 5 miles of the production center. These energy
tablets have an energy value of about 15.58 MM BTUs per ton or 113
gallons of oil energy equivalent. Thus $202.24 per ton is equal to
heating oil at $1.79 per gallon. Note: The energy used to produce
the tablets is about 3% of their gross energy content.
Obviously these numbers are very rough, back of the envelope,
estimates. If production per hour goes up and the cost of feed stock
goes down, free paper waste from the transfer station?, the picture
gets even better. If other costs increase, the opposite is true.
Now here is a key point. A conventional industrial pellet plant will
cost on the order of $14 million dollars. It will operate three
shifts per day and produce on the order of 100K tons of pellet fuel
per year. Or we could use the $14 million to set up about 280 Mini
Slugger tablet production units @ an estimated $50K each.
280 distributed tablet production centers could produce, in aggregate,
on the order of 182,000 tons of tablets per year! This would be
enough to heat about 20.5 thousand conventional VT homes, each
burning 9 tons of grass tablets per year. Of course, it would be
better to heat Near Zero Net Energy homes requiring just one ton of
tablets per year. This would allow us to heat 9X more homes for the
same effort and stress on our limited fiber shed.
Importantly, the distributed solution will create the BTU equivalent
of 172,900 tons of wood pellets, a 73% increase in yield over the 1
mega pellet plant. This distributed scenario is thus a more robust,
more resilient and more secure energy strategy. It also substantially
reduces the fossil fuel used in transportation of both raw and
finished materials. This strategy thus appears to be more
thermodynamically efficient as well as to deliver greater economic
benefits to a greater number of communities.
Of course, the missing link at the moment is heating systems, stoves
and boilers, that can safely burn grass in the tablet form for
domestic heating. My hope is that a firm in MA has this under
control. Eventually, other researchers will develop other solutions
as well.
All of this suggests we need to be flexible enough to consider all of:
green wood chips, pellets and tablets when we consider biomass heating
fuels. There is a role for all three fuel types -- three sources of
silver buck shot. Taken together, net value should be greater than the
sum of the pieces.
I hope we can pull everything together for a first demo on September
20th of this year
inch diameter by 3/4 inch switchgrass "tablets" made with a prototype
mini-plugger they have in development. [Pls see the picture I uploaded
in the files section.]
They look very promising indeed. I am looking forward seeing them work
in a wood chip combustion system for domestic use. Soonest. As they
say, the proof is in the pudding. So far, the elements of the pudding
that I have had in my hand are very interesting indeed.
In the Community Supported Energy model I am sketching out here, the
biomass tablet production facility would serve a radius of about 5
miles and draw its fiber from about 238 acres of local grass lands.
I am assuming a base rate of 650 pounds of tablets produced per hour =
2.6 tons per day or 13 tons per week - on a one shift per week
schedule. No drying required, just hammer milling through a 3/4 inch
screen. Raw material can have a moisture range of 8% - 14%.
At an average of 650 tons per year per machine [50 weeks X 13 tons per
week], over 7 years, the amortized equipment cost per ton is just
$10.99 [assumes $50K all in cost of production facility].
Labor, 1.5 FTEs at $15 per hour, would be $46.15 per ton + $75 per ton
for energy hay + fuel cost to manufacture etc. and we are looking at
something like a $202.24 per ton delivered price to a CSE member
living within 5 miles of the production center. These energy
tablets have an energy value of about 15.58 MM BTUs per ton or 113
gallons of oil energy equivalent. Thus $202.24 per ton is equal to
heating oil at $1.79 per gallon. Note: The energy used to produce
the tablets is about 3% of their gross energy content.
Obviously these numbers are very rough, back of the envelope,
estimates. If production per hour goes up and the cost of feed stock
goes down, free paper waste from the transfer station?, the picture
gets even better. If other costs increase, the opposite is true.
Now here is a key point. A conventional industrial pellet plant will
cost on the order of $14 million dollars. It will operate three
shifts per day and produce on the order of 100K tons of pellet fuel
per year. Or we could use the $14 million to set up about 280 Mini
Slugger tablet production units @ an estimated $50K each.
280 distributed tablet production centers could produce, in aggregate,
on the order of 182,000 tons of tablets per year! This would be
enough to heat about 20.5 thousand conventional VT homes, each
burning 9 tons of grass tablets per year. Of course, it would be
better to heat Near Zero Net Energy homes requiring just one ton of
tablets per year. This would allow us to heat 9X more homes for the
same effort and stress on our limited fiber shed.
Importantly, the distributed solution will create the BTU equivalent
of 172,900 tons of wood pellets, a 73% increase in yield over the 1
mega pellet plant. This distributed scenario is thus a more robust,
more resilient and more secure energy strategy. It also substantially
reduces the fossil fuel used in transportation of both raw and
finished materials. This strategy thus appears to be more
thermodynamically efficient as well as to deliver greater economic
benefits to a greater number of communities.
Of course, the missing link at the moment is heating systems, stoves
and boilers, that can safely burn grass in the tablet form for
domestic heating. My hope is that a firm in MA has this under
control. Eventually, other researchers will develop other solutions
as well.
All of this suggests we need to be flexible enough to consider all of:
green wood chips, pellets and tablets when we consider biomass heating
fuels. There is a role for all three fuel types -- three sources of
silver buck shot. Taken together, net value should be greater than the
sum of the pieces.
I hope we can pull everything together for a first demo on September
20th of this year
Steve John
Jul 1, 2008, 9:06:30 PM7/1/08
to Grass-...@googlegroups.com
Jock,
This does look very promising. I will look forward to updates.
Do you have a write-up, Powerpoint, or other stuff you can share that
describes your "Community Supported Energy model"?
I am in Illinois talking up the concept of of a Local Bioenergy Movement
patterned after the Local Food Movement. Clearly, your CSE -- as a
companion to CSAgriculture -- fits right in to our thinking.
FYI, I will be speaking about "Creating a Local Bioenergy Movement" at
the Illinois Renewable Energy Fair in early August. I would like to
include your ideas, with full credit provided.
Steve John
Agricultural Watershed Institute
Decatur, Illinois
(217) 877-5640
Cell: (217) 620-0300
Steve Burnett
Jul 2, 2008, 9:21:00 AM7/2/08
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