Energy and Global Warming News for September 30: How biochar production could help climate change fight; 80% of global water supplies at risk

How biochar production could help climate change fight

Win-win solutions can be hard to come by. But if Cornell University soil scientist Johannes Lehmann is right, there may be a way to lower our emission of heat-trapping greenhouse gases, save millions of people’s lives, and significantly boost the productivity of the world’s farms””all at the same time. And, most remarkably, his strategy is based on a deceptively simple technology invented 8,000 years ago.

Lehmann’s idea starts with organic leftovers that people normally burn or leave to rot””forest brush, corn husks, nutshells, and even chicken manure. When this stuff decays or goes up in smoke, it releases vast amounts of heat-trapping carbon into the atmosphere. Lehmann’s plan is to short-circuit this carbon cycle by creating a material called biochar. Making biochar involves heating this organic matter without oxygen in a process called pyrolysis. It can be carried out in a small household stove, or it can be an industrial operation. Either way, the pyrolysis doesn’t produce carbon dioxide as ordinary, oxygen-fueled fire does. Instead, the carbon gets locked up in black chunks of charcoal-like matter.

Take that biochar and bury it in farm fields, and it acts like a giant carbon sponge holding in moisture and nutrients that boost crop yields. In 2003, Lehmann and his colleagues treated farm fields in Colombia with biochar and found they yielded up to 140 percent more corn per acre compared to biochar-free fields.

What’s more, the buried biochar turns out to be remarkably stable, locking up carbon for hundreds or even thousands of years. Lehmann’s calculations suggest that transforming the crop waste from 120 million hectares of U.S. farmland alone could sequester ten percent of the nation’s annual carbon emissions. Play that out on a global scale, and you can make a serious dent in climate change….

To provide a sense of scale potential, Lehmann has made some preliminary calculations using U.S. land figures. Pyrolysis of forest residues from 200 hectares of timberland, pyrolysis of crop residues from 120 million hectares of farmland, and pyrolysis of fast-growing vegetation from another 30 million hectares of idle cropland could each sequester about ten percent of U.S. annual fossil-fuel emissions.

But Lehmann believes that biochar production can also work on much smaller scales in the developing world to save lives and reduce carbon emissions. In many parts of the world, people are wiping out forests to make charcoal for fuel. When they cook with charcoal, they often use poorly designed indoor stoves that fill their houses with a deadly cloud of pollutants. (Indoor air pollution kills 1.6 million people every year.) Moreover, when wood burns in an ordinary stove, it releases soot and carbon dioxide, both of which can trap heat in the atmosphere.

Biochar stoves could potentially knock out both threats with one proverbial stone. Several inventors are designing cheap, efficient models that allow people to cook without generating a lot of smoke. Instead of heating wood, these stoves use other plant material””even run-of-the-mill farm refuse. “Rather than women having to trudge into the forest and bring out a big log, they can use brush or corn husks,” says Lehmann. They simply load the stove with fresh organic matter and light a conventional fire just long enough to get the material hot enough to release gases, which the stove can then burn to release even more heat.

80 Percent of Global Water Supplies at Risk

River biodiversity and our water security are in serious trouble, according to a comprehensive survey of waterways released yesterday. At risk are the water supplies of nearly 80 percent of humanity, and two-thirds of the world’s river habitats.

Hotspots of concern include nearly the whole of Europe, the Indian subcontinent, eastern China, southern Mexico, and the United States east of the Rockies.

But experts say there may be hope for restoring rivers and securing future water needs for cities, farms, energy production, industry””and for ecosystems””by “working with nature.”

“We, as a global society, are taking very poor care of water resources,” said survey co-leader Peter McIntyre, a zoologist at the University of Wisconsin-Madison. (See the UW website about the report.)

Rivers, wetlands, lakes, and the life that relies on them, are at risk around the world because of a variety of stresses, including overuse of water, pollution, introduction of exotic species, and overfishing, according to the new study, published today in the journal Nature.

Climate Change Is “A Serious Public Health Issue”

Calling climate change a “public health issue” over a 100 leading health advocates went to Washington to ask for the regulation of greenhouse gas emissions, the Hill reported.

Eighteen national public health organizations including the American College of Preventive Medicine, the American Academy of Pediatrics, the American Lung Association and the American Medical Association, 66 state-based groups and several individual medical professionals asked policymakers to support measures that will reduce the health risks due to climate change.

“In order to prepare for changes already under way, it is essential to strengthen our public health system so it is able to protect our communities from the health effects of heat waves, wildfires, floods, droughts, infectious diseases, and other events,” the advocates wrote Tuesday to House, Senate and White House policymakers. “But we must also address the root of the problem, which means reducing the emissions that contribute to climate change.”

The group asked Washington lawmakers to allow the EPA to regulate emissions in an attempt to fight West Virginia Senator Jay Rockefeller’s (D.) bill which aims to delay emissions standards for power plants, refineries and other industrial facilities for two years.

A High-Risk Fossil Fuel Boom Sweeps Across North America

Energy companies are rushing to develop unconventional sources of oil and gas trapped in carbon-rich shales and sands throughout the western United States and Canada. So far, government officials have shown little concern for the environmental consequences of this new fossil fuel development boom.

The most direct path to America’s newest big oil and gas fields is U.S. Highway 12, two lanes of blacktop that unfold from Grays Harbor in Washington State and head east across the top of the country to Detroit.

The 2,500-mile route has quickly become an essential supply line for the energy industry. With astonishing speed, U.S. oil companies, Canadian pipeline builders, and investors from all over the globe are spending huge sums in an economically promising and ecologically risky race to open the next era of hydrocarbon development. As domestic U.S. pools of conventional oil and gas dwindle, energy companies are increasingly turning to “unconventional” fossil fuel reserves contained in the carbon rich-sands and deep shales of Canada, the Great Plains, and the Rocky Mountain West.

Colorado, Utah, and Wyoming hold oil shale reserves estimated to contain 1.2 trillion to 1.8 trillion barrels of oil, according to the U.S. Department of Energy, half of which the department says is recoverable. Eastern Utah alone holds tar sands oil reserves estimated at 12 billion to 19 billion barrels. The star sands region of northern Alberta, Canada contains recoverable oil reserves conservatively estimated at 175 billion barrels, and with new technology could reach 400 billion barrels. Deep gas-bearing shales of the Great Plains, Rocky Mountain West, Great Lakes, Northeast, and Gulf Coast contain countless trillions of feet of natural gas. If current projections turn out to be accurate, there would be enough oil and gas to power the United States for at least another century.

First forestry credits issued under Voluntary Carbon Standard

An “historic milestone” in the forestry carbon market was reached this week as the first carbon credits from a land-use project were verified and issued under the Voluntary Carbon Standard (VCS).

Credits from the Uchindile-Mapanda reforestation project in Tanzania were issued on the VCS registry system hosted by APX in a move that experts predict will further stimulate growing investor interest in forestry protection projects.

Jonathan Shopley, managing director of The CarbonNeutral Company, which is currently the only carbon offset firm to make the credits available, said the new VCS-approved credits would bolster the credibility of forestry-related carbon credits.

Businesses that are committing to significant carbon reductions can now achieve this by purchasing and retiring high-quality, verified VCS Agriculture, Forestry and Other Land Use (AFOLU) carbon credits,” he said. “This credible, permanent offsetting development is a historic milestone for us, for our clients, for the carbon marketplace and for forestry.”

The Uchindile-Mapanda project takes degraded grassland and converts it into sustainably harvested forests that sequester carbon emissions from the atmosphere and generate carbon credits. Some 40 per cent of the credits have been set aside – a world first – to mitigate against the risk of ” non-permanence”, such as the forest burning down.

China leading the world in clean energy investment

As weary visitors wait to enter the Shanghai Corporate Pavilion at Expo 2010, a sprinkler system using recycled rainwater and powered through a solar thermal system cools them off with periodic misting. Once they enter the exhibit at the world’s largest fair, tourists learn about high-speed trains and other energy-efficient inventions that have begun to proliferate in China.

“Shanghai has developed so fast, its natural resources have disappeared,” reads one placard at the expo. Several yards away, a film presentation plays in which the narrator asks, “What’s the future of Shanghai?”

It is a question that is far from decided. But China’s emphasis on developing clean energy sources has rattled some of its economic competitors and could transform the global energy marketplace.

In 2009, according to the Pew Charitable Trusts, China surpassed the United States and other members of the G-20 for the first time as the leader in clean energy investment. Last year clean energy investment in China totaled $34.6 billion, compared with $18.6 billion in the United States. Last month, Chinese officials announced they will spend $75 billion a year on clean energy.

Growing Nanowires Horizontally Yields New Benefit: ‘Nano-LEDs’

While refining their novel method for making nanoscale wires, chemists at the National Institute of Standards and Technology (NIST) discovered an unexpected bonus — a new way to create nanowires that produce light similar to that from light-emitting diodes (LEDs). These “nano-LEDs” may one day have their light-emission abilities put to work serving miniature devices such as nanogenerators or lab-on-a-chip systems.

Nanowires typically are “grown” by the controlled deposition of molecules — zinc oxide, for example — from a gas onto a base material, a process called chemical vapor deposition (CVD). Most CVD techniques form nanowires that rise vertically from the surface like brush bristles. Because the wire only contacts the substrate at one end, it tends not to share characteristics with the substrate material — a less-than-preferred trait because the exact composition of the nanowire will then be hard to define. Vertical growth also produces a dense forest of nanowires, making it difficult to find and re-position individual wires of superior quality. To remedy these shortcomings, NIST chemists Babak Nikoobakht and Andrew Herzing developed a “surface-directed” method for growing nanowires horizontally across the substrate.

27 Responses to Energy and Global Warming News for September 30: How biochar production could help climate change fight; 80% of global water supplies at risk

  1. Alec Johnson says:

    George Monbiot rather savaged claims about biochar over a year ago in this article:

    I’d like to know a good deal more about it before joining the cheerleading squad.

  2. James Newberry says:

    Yes, I would say setting forests and mined fossilized carbon materials on fire leading to climate change is a serious public health issue. This is what Physicians for Social Responsibility and climate scientists worldwide have been saying for decades now.

    Maybe when the USA is twenty percent underwater we can discuss this further, under the blistering energy of the sun.

  3. Harold Pierce Jr says:

    Pyrolysis of organic plant matter is an energy intensive process. Biochar is essentially charcoal. Dried plant matter is not dense and energy would be required to collect and compact it for shipment by truck to the processing plant. The biochar would then have to be trucked back to field. Heavy equipment would then be required to dispense and mix the biochar into soil.

    Although nat gas is a suitable fuel and affordable, capital and transportation costs would probably render the plan uneconomical.

  4. I was a biochar enthusiast until I dug deeper for an article I wrote for Green Right Now
    The issue boils down, like so many, to what is the driver of policy: environmental sustainability or profits. If the latter, biochar will be a biomess. If the former, it will not take down natural forests, it will use stock like agricultural waste. It will be on a smaller scale, but safer.

  5. David B. Benson says:

    Alec Johnson — Biochar is a heck of a good idea most places. There are many sites with more information. Here is one.

  6. Michael Tucker says:

    Water is our most precious resource. We in the developed world see articles about the coming water crisis and believe that our leaders will take care of it but that is just not the case. Just because we have never experienced outages does not mean they will not happen. In the US we have no central authority that sets water policy. The EPA manages water quality and the solution it has for polluted ground water supplies is to shut down the well and the solution to river and lake pollution is to fine the offender. As long as the penalty is paid we are all good. The other life forms that depend on the water simply have to adapt or die. If the threatened species is lucky enough to get a group to sponsor it, and have it listed as endangered, then the people who depend on the water will compete in the courts and the voting booth for access to the water. No national government agency manages water in the US. It is managed regionally or locally. For example, the fight for the Colorado will heat up soon if the 11 year drought continues and the emergency low water plan goes into effect. Under the existing plan California gets first consideration ensuring that it will get virtually all it needs from the river. The other states line up next with Nevada, think Las Vegas, coming in last for consideration. I wonder how vicious the legal and political battle will be when they SERIOUSLY begin to shut down Las Vegas’ access to the Colorado River? Will this fight over the Colorado help the other species that depend on the water? Will it address the problems of silt and sedimentation? No!

    The other hotspots of concern include India and China. India can’t even provide regular reliable freshwater delivery to the residents of New Delhi and many aquifers are running dry. India is up there with several African countries that cannot provide fresh drinkable water to a very large portion of its rural population as well. I don’t see how India will be able to set aside water resources to help other species. It is interesting that no African country makes the list of hotspots. China is another country in peril and they have an enormous plan to move water across the entire length of the country to provide water for the thirsty north. It will require a construction effort estimated to dwarf the Three Gorges project. The water will consume monstrous amounts of energy to transport and will require purification, consuming even more energy, before it can be delivered. This is one reason China desperately needs to develop a tremendous amount of cheap (coal?) electricity.

    I sure hope Europe is better prepared to handle these water issues when they become critical problems in the coming decade. A look into the effluent of the Danube indicates that species other than humans are expendable and a lot of clean-up and policy changes are necessary. What do the experts say the future of the Jordan River is likely to be? How many countries compete for that water? If we do finally achieve peace in that region will it last when the water runs low?

    I also hope those who think Canada will have enough water in the future are right. However it is easy to find articles that have a different prognosis. Recently Statistics Canada reported: “From 1971 to 2004, water yield in Southern Canada, the area in which 98% of the population lives, fell by an average of 3.5 cubic kilometers a year.”

    A water crisis is upon us now and it will only get worse. In the US we have no central planning authority to prepare for shortages and droughts and mandate efficiency. We know that floods are more likely in our Hell and High Water future and we also know that our infrastructure is crumbling, including our levees, as was recently demonstrated by the flooding in Wisconsin.

    If we continue to do nothing I think the future will not be bright for any country.

  7. Dan B says:

    I’ve used a carbon product in ecological restoration work. The results are quite noticeable. Foliage on depleted subsoils to which biochar and/or fixed carbon is applied develops a vivid sheen. This sheen develops even without the addition of any fertilizers or micronutrients.

    We also managed to turn mudstone and soft sandstone into rich loam. Depending upon the rate of application the benefits seem to last for years.

    I agree that burning anything we can get our hands on is a terrible prospect. There is, however, a huge amount of carbon rich waste that’s being trucked to landfills or subject to “cut, slash, and burn”.

    Typical home composting releases the carbon as CO2 and methane and chemical fertilization releases NO2, all greenhouse gases. Reducing the amount of these pollutants would be a good thing. I’m not convinced that biochar will address as large a percent of emissions as is believed. It’s worth further deployment to determine best uses.

  8. Including today’s 959 MW, California has approved 6 large solar energy projects in California desert totaling 2,829 MW:

  9. Leland Palmer says:

    That’s good news about the biochar, Joe.

    The same technology, pyrolysis of biomass and organic waste, could also of course provide a carbon neutral substitute for coal. Because pyrolysis charcoal is much cleaner than coal, it should be substitutable for coal in coal fired power plants, up to 100% of the coal.

    If carbon capture and sequestration technology was then applied to these power plants, what would result of course are carbon negative power plants, whose aggregate effect is to transfer carbon from the atmosphere back underground.

    Wikipedia – BECCS (BioEnergy with Carbon Capture and Storage)

    Universal adaptation of this technology worldwide could transfer something on the order of 8 billion tons of carbon per year back underground. We could improve on this number, if natural gas power plants are also converted to BECCS.

    Biomass tends to be roughly as cheap as coal, or sometimes slightly cheaper. Pyrolysis charcoal of biomass would not be too much more expensive, and might even be less expensive because combustible gases containing hydrogen are produced during the pyrolysis, and these could be burned by small local plants, and the resulting electricity sold to help offset the cost of charcoal production.

    Transport costs and logistics are often mentioned as being impractical for biomass, but charcoal is both less massive to transport and easier to store than biomass. Coal fired power plants are often located on rivers and lakes for cooling water. Sometimes, as with the Mississippi river system, these are navigable waterways, filled with thousand ton barges of river traffic. Sometimes, these coal fired power plants actually have unloading docks along these rivers, used in the past for coal. Biomass or charcoal produced anywhere upstream of converted BECCS power plants on these waterways could be transported to these power plants in thousand ton lots by river barges. Smaller barges could go further up the waterways, and could result in a mostly gravity powered transport system for millions of tons of biomass or charcoal. River transport, by the way, is generally considered the cheapest form of transport for many bulk commodities.

    It’s all doable, and even perhaps economical. One strategy for making this retrofit idea practical would be to add a topping cycle to the converted coal fired power plants, using a gas turbine run on heated air to form a combined cycle power plant. This extra thermal efficiency from the topping cycle could increase overall efficiency from roughly 30% to roughly 50%. This idea was extensively investigated by the Clinton era Combustion 2000 program and other related programs known by the ancronyms HIPPS and IFCC. The extra efficiency could then be used to pay for the retrofit.

    During the Clinton administration, several materials were investigated for the high temperature heat exchangers needed for the HIPPS power plants, including oxide dispersion strengthened alloys, ceramics like silicon carbide, and especially ceramic matrix composites like silicon carbide whisker reinforced alumina. The alloy MA954 was especially promising.

    With political will, willingness to be reasonable and compromise, and logical thinking, technological solutions to the problems of putting carbon back underground can be found, I am convinced.

    It’s good people are investigating biochar. This is very helpful, very hopeful.

    Biochar to enhance soil fertility could be combined with export of charcoal to converted coal fired power plants from dedicated biomass plantations, too.

  10. David B. Benson says:

    Harold Pierce Jr — Your completely misunderstand about biochar production. Joe Romm was good enough to fix the link to the Terra Preta site; its up a few comments. Read first, opinionate later, hmmm?

  11. Michael T says:

    NASA posted two fascinating discussions on the global temperature anomalies during winter 2010 and summer 2010:

    How Warm Was Summer 2010?

    2010 — How Warm Was This Summer?

  12. Michael Tucker says:

    Threats to Food Security

    “90 percent of the world’s wheat supplies, which produce one-third of the calories that humans consume, is at risk.”

    The threat comes from a fungus known as Ug99 and it could now destroy what is left of Afghanistan’s wheat crop that was not eliminated by the flood. Pakistan and India could be next.

  13. Prokaryotes says:

    Hooray! In worst case we ship some breeding pairs!!!

    Researchers Find First Planet That Could Support Life,2817,2370008,00.asp

  14. jcwinnie says:

    Obviously, After Gutenberg is not mandatory reading for interns, or there would have been a tinge of Syngas Spin skepticism even when it comes from the Ivy League.

    Biochar looks good, but doesn’t scale. The technology promoted is Fischer-Tropsch of tar sands renown and what Death Train Boyce was going on about.

  15. Ryan T says:

    I still think biochar has a significant role. But it either has to be cost-competitive with coal on a per-BTU basis (in which case it becomes carbon-neutral, not carbon negative, given the questionable commercial viability of CCS), or it must be semi-permanently sequestered at a sustained rate of a few billion tons annually to offset half of today’s fossil fuel emissions. Other recent research seemed to suggest that 12% of global emissions could be achieved, but it would be quite a challenge in the absence of carbon pricing.

  16. Lewis C says:

    jcwinnie at 14 –

    “Biochar looks good, but doesn’t scale. The technology promoted is Fischer-Tropsch of tar sands renown and what Death Train Boyce was going on about.”

    Your parameters for judging a technology’s utility seem a bit arbitrary. When you claim that biochar “doesn’t scale” I guess you may be referring to the high transport costs of freighting biomass to a massive centralized facility. While this may well discourage large corporations’ involvement, it is irrelevant to those living in or near the forest or farmland producing the biomass. For them the technology scales beautifully – potentially to a catchment area with a radius equaling a day’s haulage with oxen.

    In an era of food shortages, peak oil, and desperate rural unemployment, being able to provide jobs, liquid fuels and biochar may look rather attractive.

    And if the village wood refinery gets a few percent less efficient output than would the billion-dollar titanic-scale corporate facility, so what ?

    With regard to processing the hydrocarbon gasses output from wood pyrolysis, given that the basic Fischer Trop process is long out of patent, and that laboratories in many countries are working on its development, the past assumptions of its necessary operating scales will not define them in future. For instance, research commissioned by the EU recently converted wood to methanol (via syngas) over a novel nickel-based catalyst, achieving a laudable conversion rate of about 63% by weight, in a small scale plant.



  17. riverat says:

    Since biochar is essentially charcoal why not just use it to power the biochar production process? What would be the net biochar produced?

    Same thing for tar sands. They should use their own product for the energy they need to power the production. What would be the net petroleum produced?

  18. Leland Palmer says:

    With regard to biomass conversion to biochar being an energy intensive process (post #3) no, not really. The biomass itself contains sufficient hydrogen to make this an exothermic process. In fact, excess energy can be produced and even exported in the form of combustible gases including hydrogen and carbon monoxide, during the pyrolysis of biomass to charcoal or biochar. Drying the biomass can be a problem, though, and solar assisted drying or utilization of waste heat to help dry the biomass could boost the efficiency of the process, I think.

    With regard to transport costs of biomass, (post #3) one thing that is often not considered is that sources of biomass are often at higher elevations than are current coal fired power plants. Coal fired power plants tend to be located along rivers and lakes, for cooling water, and are generally fairly close to population centers. So, biomass or biochar produced at higher elevations than the converted BECCS power plants could be transported by gravity assisted transport, especially by river barges. In the language of physics, the biomass contains gravitational potential energy which can be utilized to help transport the biomass or charcoal. Log flumes, which used to transport huge quantities of logs fairly long distances to sawmills, are one older application of this principle. The millions of tons of materials barged along the Mississippi river system are another example of this gravity assisted transport.

    Modern technology, combining regenerative braking with an electric railway, for example, could improve a great deal on the older examples of gravity assisted transport, allowing transport uphill and down, so long as the net change in elevation was negative. Full railway cars going downhill could be harvested for gravitational potential energy by regenerative braking systems, in order to power lighter empty railway cars going back uphill.

    With regard to biochar integration into the soil being an energy intensive process, I don’t think this is necessarily the case, either. Once again, the biomass or biochar contains energy, and some of this energy can be utilized to power the tractors to do the soil cultivation. Farm soils have to be cultivated at least once every couple of years, anyway, and there is no reason that the biochar couldn’t just be dumped onto the fields, and then mixed into the soil when the cultivation is done. Options to power harvesting, transportation, and cultivation machinery include external combustion/Stirling cycle, external combustion/steam engine, internal combustion engines run off of “wood gas” as was done during WWII, and possibly even vehicles powered by compressed hydrogen drawn directly from the pyrolysis process.

    The difficulties of CCS have been exaggerated, IMO. Sites around the world have been doing carbon storage routinely for many years, on small and medium scales.

    The scalability and carbon negativity of BECCS and biochar depend on how we do them. Straightforward cost projections involving non-creative use of technologies borrowed from fossil fuel industries very likely underestimate the efficiencies possible from creative use of new and existing technologies.

  19. Prokaryotes says:

    Emanuel’s Replacement Might Calm the Climate Debate

    [JR: A truly nonsensical analysis. It ain’t the WH that has been roiling the climate debate — it is the disinformers.]

  20. Jeffrey Davis says:

    Charcoal sounds like it would make a very good peripheral technology. Maybe we should pursue it as a measure to replace the petroleum produced fertilizers we’ve become so dependent upon.

  21. Leif says:

    Perhaps we can make bio char with concentrated solar energy for the main heat source. I would think that that would improve efficiency as well as help with the particulate output of the process. I do not believe I have seen that attempted. Can anyone enlighten me?

  22. catman306 says:

    Farmers have always put wood ashes from their wood stoves or fire pits into the garden or compost. Stove ashes can contain quite a bit of charcoal. Old technologies worked for thousands of years. We need to periodically reexamine these old techniques to see what worked and why, and whether those techniques can still be used in our modern, changed world.

    When everyone can agree that biochar and charcoal are the sustainable fuels for the future, that charcoal powered fuel cells will power our electric vehicles, and that solar, wind, wave and geothermal are power sources for all our electric production, we will begin to be able to bring back our old climate.

  23. Chris Winter says:

    Indeed, Leif, using some form of solar oven would seem to be the best way to cook the plant matter into biochar. The equipment could be inexpensive and it would fit into the local-use paradigm.

    Thus, two of Harold Pierce’s objections to the process would be overcome.

    I don’t know if solar heat is being used this way, but it seems… logical.

  24. Ryan T says:

    Leland, although some of the challenges might be similar, it seems that the difficulties with CCS are usually discussed within the context of the huge volumes from coal. But I’d be interested in the details of any medium-scale commercial operation that runs in the absence a regional market for the CO2. Or some specific indication that the process of separating and transporting the stuff isn’t at it’s most efficient in the fossil fuel industry, where there can actually be a monetary benefit. Otherwise, cost (in a scenario where CO2 supply greatly exceeds industrial demand) seems to be the big issue. That is, assuming there would be enough uncontentious storage sites for a massively scaled up operation.

  25. Lewis C says:

    Leif at 21 –

    There are essentially four levels of sophistication in making charcoal:

    – the feedstock is fired in a pit or an earth mound :- giving ~ 10% conversion to charcoal by weight;
    – or is fired within a steel kiln :- giving ~ 22% conversion;
    – or is heated in a retort by the woodgas output:- giving ~ 30% conversion;
    – or is microwaved within a retort:- giving ~ 42% conversion.

    In the first two methods the control of air inlets halts the start-up combustion once the flaming kindling has lit a substantial fire and driven off the feedstock’s water vapour, after which oxygen scarcity causes the wood to be kilned to charcoal and the volatiles to be burnt or driven off as faintly blue smoke. The process is highly exothermic – the one-tonne kiln here on the farm gets so hot you couldn’t stand within six feet of it. Its also very laborious as the kiln-firing must be monitored for about 36 hours.

    I aspire to building a 33%-yield six-chamber retort-kiln, where part of the woodgas output from one active (oil-drum) chamber is burnt to initiate the next one, while a third is being loaded, a fourth is ready to empty, the fifth is cooling, and the sixth is completing its firing. Surplus woodgas can be piped away for cleaning & processing to syngas (CO + H2) for diverse applications, and surplus heat can be extracted as steam for power or heat. In theory the syngas could be processed to methanol, but I’m not a chemical engineer so it’ll need both external skills and funding to set it up. The retort itself I can manage, but sadly it’s not tomorrow’s job.

    The microwave kiln I know little about other that it being an Australian prototype that gets an exceptionally high charcoal yield, (wood is around 50% carbon, so 42% is very good) at the expense of outlay on a much higher tech plant and some electricity input. What it yields in the way of woodgas I’ve yet to learn. This would seem the logical option for powering with solar energy, and I’d be interested to read anything you may find out about it.



  26. Leland Palmer says:

    Yes, as Lewis C says, biomass conversion to charcoal is an exothermic process, and the biomass itself contains more than enough hydrogen to fuel its conversion into charcoal.

    One interesting technology for large scale, fairly efficient conversion is the University of Hawaii’s flash carbonization process, which uses the increased oxygen content of compressed air to ignite a flash fire within the biomass, speeding up its conversion into charcoal. Yields of roughly 25-30% are possible with this process.

    University of Hawaii Flash Carbonization of Biomass Process

    Another way to speed up the process without the use of a heavy pressure vessel might be to enrich the combustion air with oxygen. Swing bed desorption is one way to produce reasonably large amounts of oxygen enriched air with little energy input.

  27. Leland Palmer says:

    Hi Ryan T. at 24-

    Massive quantities of CO2 would be produced by BECCS, or any significant CCS effort, this is true.

    On the other hand, pipelines can move huge quantities of liquids or gases economically, and deep saline aquifers under the U.S. have an ultimate capacity of roughly half a trillion to a trillion tons of CO2. We already have a fairly substantial network of supercritical CO2 pipelines, used for transporting CO2 from natural reservoirs to oil fields, so this is a mature technology.

    Compression costs for the CO2 would be significant, as would energy costs of generating oxygen for oxyfuel combustion- one of the proposed technologies for CCS.

    On the other hand, existing coal fired power plants are very inefficient, adding a topping cycle to existing existing plants could almost double the electricity produced from the same amount of fuel, and the increased temperatures and better heat transfer of oxyfuel combustion could raise the Carnot efficiency of the combustion process.

    In an ideal scenario, an alloy or reinforced ceramic composite capable of withstanding the corrosive coal environment would be found, and high temperature heat exchangers made from it, operating at at least 1000 degrees C. Those high temperature heat exchangers would be used to add an air/gas turbine topping cycle to existing coal fired power plants.

    The increased efficiency from the topping cycle would be enough to more than compensate for the parasitic losses from oxygen generation and CO2 compression for deep injection. So, the end result would be more complex but more efficient coal fired power plants, which are capable of CCS.

    In parallel with the development of oxyfuel/combined cycle retrofits of existing coal fired power plants, increasing amounts of pyrolysis charcoal and biomass would be transported to the CCS power plants, progressively making them into carbon negative BECCS power plants. A lot of the biomass would come from dedicated biomass plantations, planted on the watershed of the converted BECCS power plants, and transported to them by river barge when possible, or by rail or pipeline when necessary. Some charcoal could come from further away, from small satellite plants which produce it from local biomass, via river, rail, or slurry pipeline.

    Ideally, the President would use his emergency powers to seize the coal fired power plants and convert them to BECCS by fiat. The same with CCS and deep injection of CO2- the government would take reasonable precautions to protect drinking water from acidification and choose secure sites for the CO2, and simply drill the injection wells by fiat.

    One potential site which could store at least 300 billion tons of CO2 is the Juan de Fuca plate off the California/Oregon/Washington coast. This site offers the potential of being an in situ mineral carbonation site, with the CO2 being injected into fractured basalt strata and forming calcium and magnesium carbonates, for permanent sequestration as a carbonate. This site offers multiple attractive features, including multiple barriers to trap CO2, and highly fractured basalt layers for in situ mineral carbonation. One additional attractive feature of the Juan de Fuca plate is the presence of large methane hydrate deposits. Methane from plumes rising from these deposits could be harvested, burned by oxyfuel/CCS, electricity produced for export back to shore, and the resulting CO2 injected deep under the sea floor. This would help prevent ocean acidification from the methane, while being carbon neutral and generating electricity. The same injection wells could be used for CO2 transported by pipeline from onshore.

    There are existing CO2 injection sites, operating at small and medium scales. Some of them are listed in this Scientific American article:

    Can We Bury Global Warming?