Sunlit Synergy
This blog is inspired by John
Michael Greer’s Jan. 9th, 2013 post on The Archdruid Report in which Greer remarked that a “reader …
asked what suggestions I might have if I were addressing an audience of
scientists and engineers—that is, people who might be able to come up with new
technologies to help cushion our species’ face-first collision with the brick
wall of planetary limits. What would I want them to explore?”
He adds, “It’s a far more complex question
than it might seem at first glance. To
begin with, there are at least two limits that nearly all attempts to imagine
technologies for the future systematically duck. The first of those limits come
out of the laws of thermodynamics, which dictate that the amount of work you
can get out of any energy source is a function of the difference between the
concentration of energy in that energy source and the background concentration
in the environment…."
And continues, "The second limit comes out of
White’s Law, which is arguably as important in human ecology as the laws of
thermodynamics are in physics. White’s
Law states that the level of economic development possible in any society is
determined by the amount of energy per capita at its disposal.”
Later in his post, Greer proposed a
contest for his readers to offer their own suggestions. He said that, “each
paper should either describe a problem that will confront the deindustrializing
world in the course of the Long Descent, or propose a practical solution to
some problem of this kind, or both.”
What follows is my own suggestion. It is my request to
the scientists and engineers of the world. It is both a re-framing of the energy problem, and a proposed solution that still
needs much research and work. I call the proposed project Sunlit Synergy.
The first thing to say is that
we should perhaps re-phrase the original question in a way that doesn’t
presuppose that our survival requires completely “new” technology. Many
technologies have been littered alongside modern industrial society’s path of
progress toward centralization and control, technologies which could be re-evaluated and could prove
indispensable over time as we move away from the fossil fuel energy sources
which facilitated such centralization and control.
The second thing to say is that
there is no way around the fact that the ultimate energy source is the sun. And
although it falls to the ground in a rather diffuse fashion, there are natural
processes that lead to rather dense concentrations of this solar energy - for example, wood. Although slightly less than half as energy dense as crude oil, and
nowhere near as convenient to transport, wood is a form of solid sunlight.
I’ll phrase that more positively:
wood is almost half as energy dense as crude oil, and has a host of uses besides
energy production, all of which produce a sizable amount of waste wood. This
“waste wood” could be turned into charcoal, which could then be transformed
into biochar, one of the most effective fertilizers in human history. In making
charcoal, ~2/3 of the energy in the wood is released as heat, which could be
used as an energy source in a host of eco-industrial processes. The charcoal,
when buried, is a form of carbon that is highly stable for centuries,
if not millennia. This means that almost 1/3 of the carbon dioxide that would
normally get re-released back to the atmosphere through either combustion or
decomposition of the wood can instead get sequestered in our
farm soils.
There is, of course, an immense
amount to say about the future of forestry and agriculture in this regard. And
I plan on addressing those crucial pieces in the near future. But for right
now, I want to focus on the technological issues surrounding our future’s energy
source. So without further ado:
Sunlit
Synergy
-
Because wood is solid sunlight, alcohol is liquid sunlight, biogas is
gaseous sunlight, biochar is sequestered sunlight, and worms enable the
sunlight to be harvested in the first place.
From a few local inputs:
Non-GMO Corn from local farms; and
Slabs, Wood Chips, and Sawdust from local sawmills,
Sunlit Synergy will produce:
Liquid fuel (alcohol),
Gaseous fuel (biogas),
Livestock feed (wet distiller's grain), and
Fertilizers (biochar and worm compost)
in an overall process that is not only carbon neutral, but because of charcoal's stability within soils, is actually carbon negative.
Non-GMO Corn from local farms; and
Slabs, Wood Chips, and Sawdust from local sawmills,
Sunlit Synergy will produce:
Liquid fuel (alcohol),
Gaseous fuel (biogas),
Livestock feed (wet distiller's grain), and
Fertilizers (biochar and worm compost)
in an overall process that is not only carbon neutral, but because of charcoal's stability within soils, is actually carbon negative.
Sunlit Synergy explores the
potential beneficial synergistic interactions between five technologies that
have been around for quite some time - wood gasification, wood distillation
(pyrolysis), alcohol fuel production, biogas digestion, and vermicomposting -
and investigates how arranging these five technologies in a cascading fashion,
where one utilizes the available waste heat and/or waste materials from the preceding
technology, can allow them to be economically deployed on a smaller, more human
and community-oriented scale than ever thought imaginable.
(Definitions, summaries, and links
for further information for these five technologies can be found below the
following project description.)
The Plan: to build
a small-scale pilot plant to serve as a "proof-of-concept", educational and R&D platform that incorporates the
following:
1) A Wood Gasifier
is fed wood chips from a local wood-waste stream, transforming the wood chips
into wood gas which can either: A) be burned to heat a charcoal
retort, and/or B) fuel an electric generator - either an internal combustion engine or a micro-steam turbine - to produce the electricity necessary for the rest of the
ecological industrial park described below
2) A Charcoal Retort
is filled with slab waste from a local sawmill, and uses the heat from the wood gas to drive Wood Distillation (Pyrolysis)
within the retort, transforming the slabs into charcoal, a process that itself
releases even more combustible gas. This additional gas is directed to a burner
placed under some type of "heat storage battery" to provide heat energy to the
following process:
3) An Fuel Alcohol Still
is filled with "beer" made from fermented local, non-gmo corn. This beer is
distilled to 190 proof fuel alcohol with the heat from the "heat battery". Remaining
heat is used to prepare the next batch of beer for
fermentation. Wet distiller's grain left over from distillation is fed to dairy
cows as a high-protein, high-fat, and high-fiber feed supplement for their
mostly pasture-based diet.
4) A Biogas Digester
is filled with any unused wet distiller's grain from the still, and any other
farm wastes such as cow manure or spoiled hay, and is kept warm in the 90's F from the waste heat from the alcohol still's condenser coils.
5) A Vermicompost (worm compost)
operation mixes the liquid effluent waste from the biogas digester with sawdust
from the local sawmill to feed microbial populations that in turn feed worms.
Some biogas digester effluent is
used to nutrient-load the charcoal. Some worm compost is used to
make compost tea to inoculate the charcoal
with beneficial microbes, thus transforming the charcoal into biochar.
Background Information:
The link above is probably the best website to explain wood gasification, although
All Power Labs unfortunately placed the following words at the very beginning of the page
and then never really define them: wood
gas, syngas, biogas, and producer gas.
So let’s quickly differentiate these terms.
It will help.
Producer
gas is the gas produced by gasification, a process that transforms any
solid organic matter (wood, charcoal, coal, coke, peat) into a combustible gas
- primarily carbon monoxide and hydrogen - which when burned, produces an exhaust of primarily carbon dioxide and water vapor.
Wood
gas is simply a type of producer gas
made specifically with wood as the feedstock.
Syngas
can be made from a gasifier (from any feedstock), and is similar to producer gas, except that it isn’t weakened,by nitrogen, since
straight oxygen is fed into the gasifier instead of air (to eliminate
the 70% nitrogen in air). FYI: 99% of the time in the modern world, syngas is not made from wood.
IMHO, biogas does not belong in the same category as the above gases, but
is made from an entirely different process – the anaerobic biological
decomposition of organic matter. This produces mostly methane and ethane, which
is essentially similar to “natural gas”- a fossil fuel.
Wood Distillation (Pyrolysis) in Retorts for charcoal production for biochar:
A retort is simply a fancy word for a mostly sealed metal or masonry
container – filled with wood, and heated from an exterior source to transform
the wood, through pyrolysis, into charcoal and a combustible gas. Pyrolysis literally means “breaking
apart with heat”.
The combustible gas coming out of a
retort is also called syngas. Whereas a gasifier needs to pull in enough oxygen to fuel
enough combustion to create the heat for pyrolysis to create either producer
gas or syngas, a retort has heat
added from an exterior source for pyrolysis
to create syngas. Pyrolysis can either refer to one part of the process that occurs within a
gasifier, or it can refer to the entire process that occurs within a retort.
So, in summary, wood gasification provides its own heat by combusting a small percentage of its fuel, and transforms its remaining fuel into heat, combustible gases and ash. Whereas wood distillation (pyrolysis) does not provide its own heat, and transforms its fuel into combustible gases and charcoal.
Wood
distillation was the term used in the old industry and literature, while pyrolysis is the term used in the modern
industry and literature.
FYI: For gasifier geeks: wood
gasifiers can be designed and operated to turn their fuel into
charcoal as well, and not just ash. But for the purposes of this project, we’ll
be assuming the gasifier is not producing any charcoal, but only ash. In this
project, it will be the retort that produces the charcoal. This design allows
the use of less-processed wood wastes (slabs vs. wood chips), and also allows
the concentrated capture and combustion of the gas created by the charcoal
production in order to facilitate the alcohol production.
As can be seen by even a quick
glance at Max Klar’s 1920 book The Technology of Wood Distillation, with
Special Reference to the Methods of Obtaining the Intermediate and Finished
Products from the Primary Distillate, one can gain quite an insight into
how sophisticated and evolved the technology was of making charcoal in retorts before the petrochemical age squashed this industry like a bug.
This book is available digitally
at: http://archive.org/details/technologyofwood00klaruoft
And is available, amazingly enough,
in physical book form at: http://www.abebooks.com/servlet/SearchResults?sts=t&tn=The+Technology+of+Wood+Distillation
Unknown in 1920, when Max Klar wrote the above mentioned book, was the incredible
potential for another use of the charcoal -
biochar.
Biochar:
I highly recommend checking out how
the indigenous Amazonians transformed large tracts of some of the world’s worst
soil into some its most fertile, by incorporating biochar into their soils. Those “Terra Preta” soils (literally, “dark
earth”) are often literally mined for
their fertility, and continue to hold on to the great majority of that carbon
originally sequestered so many centuries ago. The indigenous Amazonians were
apparently making charcoal and then burying it in their midden piles to load it
with nutrients and beneficial microorganisms, and then burying the resulting bio-char into their
farm fields.
A quick overview of the discovery of biochar can be
had by watching the hour-long free BBC documentary, “The Secrets of El
Dorado”, available here: http://www.youtube.com/watch?v=0Os-ujelkgw
What’s incredibly important to note
is that charcoal production produces dramatically more heat than it requires.
Now, this isn’t some violation of the Second Law of Thermodynamics. It’s just
that wood is solid sunlight, and pyrolysis releases much of that
stored sunlight in the form of combustible volatile compounds. A 55 gallon barrel
full of wood chips transformed into charcoal releases a net 250,000 BTUs of
heat. Wood, although not nearly as convenient and transportable as petroleum or
natural gas, is a very concentrated form of energy.
My recommendation would be to
utilize an “Adam’s Retort” type design, to be able to utilize less-processed
wood wastes, such as slab and edger waste from small, local sawmill operations
– as opposed to many biochar retort designs that require more processed wood
waste, such as wood chips. Bob Wells of New England Biochar seems
to now offer the most cutting edge types of designs for these here in
North America.
I recommend utilizing the waste
heat from the retort to heat some type of "heat storage battery" to allow the harnessing of a very crude and
basically uncontrollable form of energy – the intense heat that comes from
burning the gases blasting out of the retort – into a form that allows the fine
temperature control necessary to run an alcohol still.
Presently, I propose using a large super-insulated tank of waste fryer oil as the “heat battery”. Although it has ½ the specific heat of water, oil avoids the dangers of having a vessel of pressurized steam, and can be taken to twice the temperature of water. This would only work on a very small scale as proposed in the pilot project. Otherwise, pressurized steam would likely need to be used as the "heat battery".
Presently, I propose using a large super-insulated tank of waste fryer oil as the “heat battery”. Although it has ½ the specific heat of water, oil avoids the dangers of having a vessel of pressurized steam, and can be taken to twice the temperature of water. This would only work on a very small scale as proposed in the pilot project. Otherwise, pressurized steam would likely need to be used as the "heat battery".
To utilize the heat in the
oil, a coil of copper pipe is installed inside the tank of
oil, and has an open end that leaves the tank and enters the body
of the alcohol still. When the still needs more heat, a valve can be opened to run small amounts of water
through the coil, transforming the water into steam - immediately dumping the steam’s
heat into the still without any build-up of pressure.
Small Scale Alcohol Fuel
Production:
Alcohol fuel production often gets
such a bad rap in our culture that I want to take a moment to address its two
biggest criticisms. It is often noted how much energy it takes to make. There’s
more to say about all of this than I have room for here, so I highly recommend
checking out David Blume’s book, Alcohol Can be a Gas, and particularly
its “Appendix A, Ethanol and EROEI: how the debate has been dominated by one
view”. ("EROEI" stands for Energy Returned on Energy Invested)
Suffice it for now to say that I propose to utilize only the waste energy created by transforming waste wood
into biochar as the energy input for the alcohol production. On top of that, this system would require dramatically less energy than is conventionally
required to produce alcohol fuel since 1) we would only make 190
proof alcohol, instead of attempting to make 200 proof alcohol (see David Blume’s book
again for more information on this), and 2) more importantly, we would not be
drying down the waste products from alcohol production (the distiller’s grain),
but would be utilizing it wet by feeding it straight to livestock, or by
feeding it into a methane digester. Both of these design features allow the use
of significantly less energy inputs.
The second big criticism of alcohol
production is that it somehow competes with food production. But in the U.S.,
the biggest alcohol crop is corn. Only a scant percentage of corn gets used
directly for human food, but is mostly fed to animals, and of that, mostly to
cows. But cows could produce more human food if fed the waste products of corn
alcohol production, than if fed straight corn. This is because the sugar and
starch in corn interferes with cow’s natural digestive processes. Alcohol
production removes the harmful sugar and starch from the corn, but leaves and
actually improves the remaining proteins, vitamin complexes, and fats.
Any extra wet distiller’s grain not
eaten by the cows will be sent to a methane digester, along with any other farm
wastes such as cow manure and spoiled hay. At this point, the energy in the
starches and sugars in the crop have been removed by the yeast and have been
transformed into alcohol - liquid sunlight. Now it’s time to remove the energy
left in the proteins, fats, and fibers that remain in the crop and transform
them into gaseous sunlight.
Methane Digestion:
In temperate climates, methane
digesters need to have their temperature maintained in the 90s F, but this
could easily be done with stored waste heat from the alcohol still’s condenser
coils. The methane digester produces biogas - gaseous sunlight - and gets most of the remaining carbon energy out of the crop, so what remains now is liquid nutrient effluent.
Some of the effluent will be used to nutrient-load the charcoal. Charcoal has an incredible amount of tiny pores throughout its structure. The walls of these pores are all chemically adsorptive, and soak up much of the liquid nutrient.
Some of the effluent will be used to nutrient-load the charcoal. Charcoal has an incredible amount of tiny pores throughout its structure. The walls of these pores are all chemically adsorptive, and soak up much of the liquid nutrient.
The rest of the effluent is added
to sawdust from the local sawmill. The effluent is, once again, liquid nutrient. The
sawdust is almost straight carbon. Together they are the perfect workable substrate
for feeding microbial populations that will feed worms for making worm compost.
Some of the worm compost will be used to make compost tea. After soaking the nutrient loaded charcoal in compost tea, we now have biochar. Charcoal is like a deluxe
motel for beneficial microorganisms, and if you haven’t heard of the Soil Food Web, and how critical beneficial soil microbes are for soil fertility, then I
recommend checking that out too. It is unbelievably important. Really. It deserves a whole post of its own.
Summary:
So once again, from a few local inputs – non-gmo corn from local farms; and slabs, wood chips, and sawdust from local sawmills – Sunlit Synergy will produce: a liquid fuel (alcohol), a gaseous fuel (biogas), livestock feed (wet distiller's grain), and fertilizers (biochar and worm compost) in an overall process that is not only carbon neutral, but because of charcoal's stability within soils, is actually carbon negative.
So once again, from a few local inputs – non-gmo corn from local farms; and slabs, wood chips, and sawdust from local sawmills – Sunlit Synergy will produce: a liquid fuel (alcohol), a gaseous fuel (biogas), livestock feed (wet distiller's grain), and fertilizers (biochar and worm compost) in an overall process that is not only carbon neutral, but because of charcoal's stability within soils, is actually carbon negative.
Sunlit Synergy will provide
concentrated energy and fertility for our future – not to replace the immense
quantities of fossil fuels that now support our modern lifestyles, but
that can support a complex, yet sane society connected to the source of its
life in gratitude.
Yes yes.
Thanks for your time and attention.