Could biochar roof tiles be coming soon to a roof near you?

roof tile overview

As the college year comes to a close the RIT senior design team focusing on biochar based roof tiles that I have been working with is showing some exciting results.  The team was tasked with coming up with a tile design as well as a biochar-concrete recipe which could be tested on homes being built by the 4 Walls Project in El Sauce, Nicaragua.  Each house is typically built by volunteers, family members of those receiving the house plus one skilled home builder and measures 6 x 6 meters. Currently the zinc roof is one of the more costly parts of the house ($400) and is one of the few parts that cannot be sourced locally. Zinc roofs are also loud when the heavy rains come and they conduct heat way too efficiently making the homes uncomfortably warm on hot days.

The challenge for the team was to design a roof that was cheaper, quieter and more insulating than the current roof.  Preferably they would design one that could be made locally thereby creating local jobs and spurring economic development, something which is sorely needed throughout the region.  While some testing still remains to be done, the design of the tiles has been finalized and the first several prototype tiles have been cast (see picture above).  The results are far more impressive than I think any of us were expecting!

The recipe chosen for the current batch includes roughly 30% biochar by volume (10% by weight).  Cement, sand and water make up most of the rest but the students sprinkle in some magic pixie dust – in the form of shredded plastic from soda bottles – to lend the tiles more strength.  The team even designed a handy little device to turn bottles into string – yet another possible job for locals in Nicaragua! Each tile contains roughly ½ of a 2 liter bottle’s worth of plastic.

A plastic mold was created for the tiles with a wood-like finish on the sunny side of the roof.  Current cost estimates put the entire roof at less than half the price of the zinc roof.  Although a realistic price on biochar has yet to be assessed, the amount of char needed could likely be made in one day using 1 or 2 Kon-Tiki soil kilns so in a place like Nicaragua where the cost of labor can be as low as $5/day, the cost of biochar would be negligible.  Plastic bottles are a nuisance, so putting a nominal fee on collecting them could go a long ways towards keeping them from cluttering up the landscape while also providing a steady stream of raw material for tile makers.

Not only could these biochar cement roofs be cheaper (see comparison of different roofing materials and their costs, weights and other properties here), but all indications are that they will be quieter and will help reduce heat gain as well.  That’s a sustainability trifecta as far as I can tell: People get more sleep due to less heat and noise; on the profit side homes will cost less and local jobs can be created; and the planet benefits from reduced mining for zinc, less waste from plastic bottles and up to ½ ton of CO2 gets sequestered in a single roof!

The students will be debuting their roof tiles May 7th at Imagine RIT! – the heat recovery team will also be showing off the tricked out Kon-Tiki as well!

Displacing desiccants with biochar


I hate to desecrate those supposedly ‘harmless’ desiccant packs that are found in an increasing number of packages, but there is a much more benign alternative!  Allow me to explain…

Desiccants are materials used to prevent spoilage, mold, mildew, odors, corrosion and other damage caused by moisture, including something called ‘pop-corning’ which can afflict semiconductors if they come into contact with a bit to much humidity.  The main quality of interest in desiccants is that they are ‘hygroscopic’ meaning that they attract and retain water either through adsorption or absorption.  High surface area and pore volume are generally what allows for good hygroscopic properties, but ionic compounds come into play as well.

Various materials are used as desiccants but the most popular is silica gel, the (mostly) colorless, odorless micro-beads that come in little (and big) packets that are stuffed into everything from food to shoes to electronics. Silica gel is made from sodium silicate which is made from quartz sand which goes through an awful lot of processing i.e. washing, desliming (who knew that was a word!), scrubbing, flotation, acid leaching not to mention transportation. Translation: silica gel comes with a high carbon footprint not to mention a high likelihood of lots of other negative environmental impacts to make this so-called ‘harmless’  desiccant which is normally only used once then tossed in the trash. Note: Silica gel is also used in cat litter, pillows and a growing number of other products.

Here, of course, is where I must bring up biochar as a much more eco-friendly, not to mention cheaper alternative!  While biochar doesn’t normally have as high a surface area as silica gel does (800 m2/g1), biochars made using high temperatures (e.g. 700C+) can have relatively high surface area (interesting comparative table here).  Non-activated high temperature chars can have surface areas in the 450+ m2/g1 range, but my research buddy Charchemides has produced biochar with surface areas >860m2/g1 using various highly secret post-treatments!

Moving on to the money angle, biochar can provide advantages at least when it comes to using them in larger quantities such as when they are used in cargo containers.  Some of the large silica gel or clay filled cargo bags or pillows can be rather pricey (case in point here; note that the product is only good for 50 days). Material that is only good for 50 days renders it effectively a one time use product meaning that  whoever receives the container with the silica gel bags must pay to get rid of then.  It also means the original shipper must keep purchasing new bags for every new shipment. This linear economy really only benefits silica gel manufacturers doesn’t it?

Now imagine a food producer getting ready to ship a container of nicely packaged food, say coffee or cacao.  Most food producers such as these have large stockpiles of underutilized organic waste which they can easily carbonize into biochar.  In lieu of having to purchase countless single use bags of high carbon footprint desiccants for every shipment, they could generate their very own bio-upgradable desiccants in the form of biochar. This not only reduces their costs but it reduces their organic waste stockpiles and very likely improves their own environmental impact on the local environment!  When the biochar arrives at the purchaser of these goods, they can either use or sell the biochar.  Worst case scenario is that if it ends up in a landfill, it will continue to do good things as I’ve already blogged about previously here.  Doesn’t this type of closed-loop scenario make a lot more sense all around?

Yes more research is needed to understand which biochars would perform best in this capacity, but with a few humidity indicator strips/cards, you can do this sort of research at home! Use biochar in your basement, garage, closets, tool box, storage container or anywhere else where humidity might do some damage.

The Quest for the Killer “Biochar” App

Discovery of something doesn’t always lead to quick, practical applications of said discovery.  For some game-changing discoveries such as aluminum, practical applications had to wait a few decades for future discoveries (e.g. airplanes) before the real value could be realized.  Electricity suffered the same fate.  Its transformative power, so to speak, wasn’t readily apparent when the ‘aha’ moment of discovery arrived. Yet in less than a century, electricity moved from an exotic notion to a luxury commodity enjoyed by the few to a desirable one wanted by the masses to something that is often seen as a ubiquitous necessity nowadays.

I suspect biochar is similar to electricity in terms of the lag time between the discovery of the material and its practical application.  It is also likely to be as versatile as electricity in terms of practical applications. For various reasons, the adoption sequence of biochar may, however, be the opposite of the adoption sequence for electricity; i.e. rural before urban and developing world before developed world.

As our understanding of the various and variable properties of biochar become better understood, new and unanticipated uses for biochar are likely to emerge.  As we learn how to pyrolyze, pre-treat, and post-treat organic matter and see how each of these creates specific physical, chemical and biological properties, new notions for what biochar is capable of will emerge.

The original focus on its use in soils may or may not end up being the most scalable or the most cost effective application for biochar.  Mapping the many variables of agriculture (e.g. soils, crops, climate, etc.) to the many variables of biochar (i.e. caused by differences in production, feedstock, etc.), makes accurate generalizations about cost benefit difficult and well, just plain variable!

Killer appI understand that there is a more purist school of thought that would like to limit the use of the term biochar to this particular end use.  But what does constraining ourselves to just thinking about this one application, especially if this turns out to be difficult to scale in the short term, really achieve?

For me the critical benefit or end use is its ability to safely, economically and effectively disrupt the carbon cycle. As long as we can prevent absorbed CO2 in plants from returning to the atmosphere, I consider carbonized biomass to be biochar. In much the same way turning downed trees into furniture or homes sequesters carbon at least for decades, turning charred biomass into building materials, mixing it into tires or asphalt, blending it into paper or plastics, all prevents the CO2 from floating upwards where it will help trap more heat down below.

If rapid adoption is the goal, then we may want to take a lesson from the downfall of “King Coal’ to help figure out the best applications for biochar.  Coal is being displaced less as a result of beating the environmental drum and more because the financial rug was pulled out from under the industry.  Once a cheaper alternative became viable both investors and consumers (i.e. coal plants) started jumping off the coal bandwagon in droves and beating a path to (unfortunately) fracked gas and (fortunately) renewables.

Similarly carbonized biomass whose price point will start to fall as output rises, could very likely displace all sorts of expensive, non-renewable, toxic or high carbon footprint products (e.g. activated carbon, carbon black, vermiculite, etc.).Those on the hunt for biochar killer apps, IMHO, should caste as wide a net as possible and not limit themselves to just what biochar can do beneath our feet.  Filtration, remediation, battery storage, building materials, and many, many more applications – all of these and more are fair game for biosequestration opportunities using charred organics.

Tapping into the wisdom of the (char) crowd


As I mentioned in the previous post, the amount of biochar research happening around the world these days is growing exponentially.  It is no longer feasible, if in fact it ever was, for one person or even a single organization, to stay abreast of all of the research.  Given that, how can all this ever-increasing amount of valuable information from labs and field trials be harnessed in a manner that will enable the use of biochar to realize its maximum potential quickly?

In Peter Miller’s book ‘Smart Swarm’ the author describes a model currently being used by the US Intelligence agency that could work for the biochar community.  ‘Intellipedia’ was created to keep the intelligence community up-to-date in real time on thousands of different topics.  It combines different Web 2.0 functions such as Wikis, blogs, instant messaging, shared drives, photo galleries, tag-connect functionality (e.g. Digg), and subscribe functions.  All of this information is collected, curated and to some extent corroborated (or vetted) by volunteers within the intelligence community. Very soon after its creation, the system became an invaluable collaboration and crime-solving resource.

The creation of a shared platform similar to Intellipedia but customized for the needs of the biochar community could enable improved knowledge sharing and speed up discovery of how best to make, modify and use biochar. “Charpedia” could include Wikis with individual ‘stubs’ or pages that focus on different end uses (e.g. soils, filtration, GHG mitigation, etc.), feedstocks or crops.  The tag-connect or bookmarking function is a role that could be expanded to include the addition of keywords on published literature that maps to an agreed Charpedia stub taxonomy.  This would facilitate more accurate linking to appropriate stubs.  A database with information on different biochars already exits thanks to the efforts of the University of California Davis, but could be expanded.  A subscribe functionality would keep interested parties informed of new developments.  And finally a shared literature database would allow deeper understanding and knowledge sharing. 

Many of the key challenges to biochar knowledge sharing are no doubt common to many other research topics.  An increasing percentage of publications are written in language that are not easily accessible outside of the country they are published in.  This is especially true of Chinese research where biochar research is booming.

The other hurdle is that many if not most of these peer reviewed articles are written in a manner that most non-scientists or non-specialists struggle to understand (I often include myself in that category!) Synthesizing and simplifying publications is an urgent priority if we are to train farmers on the best ways to make and use biochar in different geographies, on different crops and in different soils.

Tapping into volunteer subject matter experts or perhaps different universities that could act as curators to manage specific biochar research stubs (e.g. biochar made from bamboo, biochar used in rice cultivation) could be one way to agglomerate or consolidate research.  Volunteer curators are the backbone of Wikipedia a platform which has transformed the way knowledge is pulled together and published for all to peruse.  Perhaps it’s time to replicate this success to enable biochar to flourish!

Support the International Biochar Initiative

IBI logo

You know that feeling of excited anticipation you get when something arrives after you have been waiting for days or weeks?  I get that feeling every time the International Biochar Initiative (IBI) newsletter arrives in my email box. Why?  Because I love to see the list of newly published biochar research which takes up an ever growing section of the newsletter. 

Yesterday the newsletter arrived in my email box and I was oh-so-tempted to put everything else on hold so I could glance through it immediately. The problem is that glancing isn’t really possible anymore because the list of papers gets longer and longer with every newsletter.  This latest newsletter cited more than 200 new publications! 

Publications include everything from peer reviewed journal articles to books, to graduate student theses to materials from meetings or conferences.  Newly published research comes from more than a dozen different countries from around the world including, to name a few: Australia, Bangladesh, Brazil, Canada, China, Ethiopia, Finland, Germany, Ghana, India, Italy, Korea, Malaysia, Nigeria, the UK and the USA.  They cover an ever increasing variety of biochar related topics such as: climate change mitigation, soil impact, yield impacts, remediation, filtration, waste management, renewable energy, and various different biochar production technologies and how they impact the characteristics of biochar.  The feedstocks used for biochar production ranges ever more widely and just this past month included: rice, bamboo, sewage sludge, water hyacinth, straw, tobacco stalks, and a few I’d never even heard of such as sea mango and arecanut!  The crop trials are nearly as diverse as the feedstocks covering cotton, rice, maize, wheat, peppers and many, many more!

As an IBI Board Member, as a biochar researcher and as a citizen fully engaged in finding financially viable, environmentally safe and scalable solutions to climate change, I believe this is one of several hugely valuable services that IBI has been providing over the past several years.  Right now they could use some financial support to keep on providing it.  Please join me in making a tax deductible donation here to IBI. 

The on-going curation of this biochar research bibliography is an excellent service, but the biochar community, the agricultural community and many other related communities could see much more rapid progress if we were able to expand this function even further.  In a future post I’ll address how tapping into the power of indirect communication similar to how a smart swarm works, might be a great way to discuss, edit, share, and organize the ever increasing amount of knowledge and research coming out of biochar labs, fields and production facilities!

The ‘4 pour 1000’ Initiative & Biochar


2015 was dubbed the ‘Year of Soils’ by the UN, but sadly the biochar world let the opportunity of celebrating what biochar could do for soils pass relatively unpromoted. The French are offering up another great opportunity for soils to be in the spotlight with their newly announced ‘4 pour 1000’ initiative, and though they don’t (yet) mention biochar as one of the possible solutions, it is, in fact, one of the best ones available (IMHO).

Basically the 4 parts per 1,000 initiative is highlighting many of the same things the UN hoped to spotlight last year: the massive soil degradation and erosion which the skin of the planet has suffered due to deforestation, industrial agriculture, and just plain old human abuse over the past 100+ years has led to food insecurity, climate change (etc.)  and we need to do something about it. The idea is that various different sustainable agricultural practices can lead to increasing soil carbon which not only improves soil fertility and food security, but also rebalances carbon levels by pulling more out of the air and putting it into the soil thereby breaking or slowing down the carbon cycle. They mention agroecology, agroforestry, conservation, landscape management as possible solutions but leave out the nitty gritty on measurements and specific tools.

Allow me to muse for a few moments about what ‘4 pour 1,000’ might look like from a biochar perspective. How much biochar might you need to add to boost soil carbon by 4 parts per 1000 (as in .4% of 1,000)? One could interpret that to mean that for every 1,000 lbs of soil the carbon content should increase by .4% per year or 4 lbs of carbon (if your biochar has 80% carbon content then you’d need 5 lbs of it). However doing things by weight gets very tricky due to this little thing called moisture content, so working with volume might be a bit easier. One cubic yard of soil covers roughly a 10’ x 10’ garden to a depth of 3” and contains just under 202 gallons of soil (and for those of you that just have to think in terms of weight, ideal soils might weigh between 1,700 – 2,200 lbs per cubic yard). Four percent of that would be roughly 1 cubic foot of high carbon biochar (or somewhere in the vicinity of 8 – 10 gallons) but a mere .4% would be about 1 gallon per cubic yard of soil!

Perhaps the biochar community should join the ‘4 pour 1,000’ initiative by way of creating various ‘4 pour 1000’ demo gardens around the globe where soil carbon level is monitored before biochar, then after biochar and then annually. Gardens with annual biochar additions (let’s say at the ,4% level for 10 years) versus a single addition of biochar ‘(let’s say at the 4% level) could be compared to gardens where compost or livestock manures are added each year. (Given the low carbon levels [20 – 40%] in manures, you would definitely have to add a lot more of that odiferous stuff!) My guess is that the biochar gardens will not only hit the .4% targets more easily than other soil amendments, but that the yields on these gardens will be very impressive!

What do you say fellow charistas?

A Biochar Salute to COP21

COP21As the Climate Talks begin in Paris today, I thought it might be worthwhile to provide a biochar ‘greatest hits’ to highlight just how helpful biochar can be in terms of climate change. There is a fast growing body of biochar research these days (check out IBI’s bibliography here), so much so that it is increasingly difficult to stay abreast of it all. However I have previously covered many of the disparate biochar research areas in my blog, so I thought I would select the 21 most relevant posts on climate change mitigation and adaptation. Here there are in no particular order:

  1. The Precautionary Principal & Biochar & Climate: given the dire predictions for the climate, waiting for all possible research questions related to biochar to be answered, might not be the best option.
  2. Decarbonization Roadmap: the various ways biochar can lower the carbon footprint in different industries.
  3. Dr. James Hanson & Biochar: former NASA scientist cautiously talks about his biochar experiments with his granddaughter.
  4. Methane Rising – Can Biochar Help? The various ways biochar can mitigate CH4 from rice fields, landfills and manure piles.
  5. Biochar & Landfills: research shows biochar used as daily cover can help reduce CH4 emissions.
  6. Disaster Debris & Char: converting downed biomass from natural disaster into biochar provides multiple benefits.
  7. Disaster Recovery & Char Part II: biochar production with a Kon Tiki can help purify water, provide heat for cooking, upcycle human waste, create building materials, etc.
  8. Markets for Biochar: long lasting products made with biochar go far beyond soil amendments.
  9. CHAB Markets: closed loop market opportunities for combined heat and biochar (CHAB) production technologies.
  10. Biochar Products are BioUpgradable: Biodegradable is so last century. We need bioUPgradable products!
  11. Microbeads & Biochar: Replacing microbeads with biochar will help keep our dwindling supply of drinking water free of polluting plastics.
  12. Harvesting Heat from a Kon-Tiki kiln: RIT engineering students testing ways to purify water and dry crops while making biochar
  13. E-coli & Biochar: biochar can reduce leaching of E-coli into groundwater as well as plant uptake.
  14. Acid Rain & Biochar: instead of flying in lime to rebalance pH, perhaps biochar could be made from forest debris and used in remote lakes damaged by acid rain.
  15. Storm Water Management & Biochar: slowing down and filtering storm water with biochar is a win win.
  16. Charvest the Invaders: burning off invasive species is a common but wasteful and polluting practice. Converting it into biochar would be beneficial on many fronts.
  17. Algae Blooms, Invasive Species & Drinking Water: biochar helps reduce fertilizer leaching into waterways.
  18. Aging Infrastructure = Carbon Sequestration Opportunity: adding biochar to cement offers new sequestration opportunities.
  19. Ruminations on Ruminants ruminating on biochar: how adding biochar to livestock feed can lower CH4 emissions, improve weight gain and health in cows.
  20. Bovine Bedding & biochar: adding char to cow bedding reduces odors, CH4 emissions and leaching.
  21. Could the next biochar frontier by “Sea-questration”?: could biochar cement help rebuild coral reefs?

E. coli & Biochar

E coliE. coli has been in the news again of late thanks to the Chipotle outbreak in the Pacific North West. Not only are such outbreaks expensive to business but they can sometimes prove deadly to consumers. E. coli, the pathogenic variety that is, can result from a number of sources along the farm to fork continuum.

A large source of the problem lies in the tummies of infected warm blooded animals (e.g. cows, sheep, deer, etc.). Infected animals mean infected manure and when this infected manure is not properly aged or composted before being applied to soils, well then we get infected soils, which leads to infected plants which leads to more infected warm blooded mammals of the human variety. Not exactly the virtuous circle we’d like to promote.

There are preventive practices that can reduce this risk which include timing guidelines for manure application in line with harvest dates (e.g. do not apply 90 – 120 days before harvest), composting manure, animal barriers to fields, etc. I am happy to report that biochar is showing promise as being another means of mitigating the risk of spreading E. coli.

Research out of McGill University has shown that biochar amended soils can reduce leaching of fecal coliforms (translation: nasty stuff you do not want in your food or water supply) into ground water or surrounding local water bodies. Additional research out of the USDA’s Food Safety and Intervention Technologies Research Unit has shown that various different types of biochars can inactivate (meaning that plants won’t take up the bacteria) E. coli in certain types of soils amended with 10% biochar by weight. Prevention of uptake and leaching are both critical to keeping E. Coli out of the food chain.

Considering that that USDA’s Economic Research Service estimated the annual cost of E coli at nearly $480M, (73,480 infections including 61 deaths at an average cost per case of $6,510), perhaps it’s time to promote the biochar ‘soil-ution’ to farmers that apply manure to their fields. Not only can it help reduce pathogens and the related financial risk associated with finding E coli in your crops, but mixing in biochar with the manure will also help reduce odors and retains nutrients in soils longer.

Harvesting Heat from the Kon-Tiki

Heat Capture

This academic year I am very excited to be working with two different engineering teams from the Rochester Institute of Technology (RIT). One team is looking at how to optimize heat capture while carbonizing biomass. The other is prototyping the creation of roofing tiles made of biochar and concrete to be used, if all goes well, on the homes built by the 4 Walls Project in Nicaragua (more on that project later!).

Last Saturday the heat capture team came over for a few hours of hands-on biochar making using the Kon-Tiki. Every time I teach people how to make biochar, I learn something new. What was great about this group is that they came loaded with gadgets! Just listening to them problem-solving was quite an experience as they are all mechanical engineers – a far cry from my business background! What temperature could the probes handle (one did start to melt!)? What timing intervals would be best? Where should temperatures be taken and why? All good questions, and I would have to leave it to them to provide in depth answers! Fortunately lots of this data can be found on the project team’s website.

The team is now designing various possible prototypes for sterilizing water, pasteurizing liquids and drying crops. This kind of low cost, low tech heat capture can be enormously helpful in the developing world, in post-disaster scenarios, in refugee camps, etc. In addition to working locally with me on this, the team has tapped into some excellent international help from experts in Switzerland, Australia and Serbia that have already been experimenting with heat capture using Kon Tiki.

The best design will be built, tested and should debut at next year’s RIT Imagine event in May, along with the roofing tiles. Mark your calendars to come check it out!

A special note of thanks goes out to Sarah Brownell, the RIT lecturer (holding her daughter in the picture above) that is coordinating this and dozens of other senior engineering projects that have the potential to materially improve lives of those in the developing world.

Toxic Mining Waste & Biochar

Mining Waste

One would think that the sight of a river of gold would fill one with awe. But the recent golden rivers that flowed in Colorado carried toxic ghostly remains from abandoned gold mines inspired horror, not awe. Of course people will blame the EPA for causing this horrendous problem, but this problem has been lurking beneath the surface, quite literally, for a long time. More than 3,500 abandoned mines can be found all over the world and it is not uncommon for one or more of them to spillover and cause similar damage to the surrounding eco-system. Heavy rains have often been the culprit for this kind of toxic overflow and as we know heavy rains are increasingly in the forecast what with all that increased CO2 looming in the air.

Naturally the biochar question popped into my head. Could char somehow be capable of mitigating such extreme toxic damage? Once again Master Google quickly rescued me from the completely ignorant side of the knowledge scale and led me to understand that abandoned mines are often filled with gravel and then capped off with concrete. In many cases even with these precautions, old mines get filled with water from rain. The good news is that this water can help reduce methane emissions which are released from certain types of mines (e.g. coal mines). The bad news is that all that water could at some point start leaching out via cracks in the concrete or via other routes (see my spiel on the whole biochar & sinkhole topic here)

Biochar might be a much better substance to fill an old mine as compared to the decidedly non-porous gravel! Not only would it fill up more nooks and crannies within old mines, but some chars have the ability to absorb 5 times its weight in water, so when heavy rains hit, it is less likely to cause a liquid disaster.

Filling old mines with biochar cold also potentially reduce methane emissions which are responsible for up to 10% of total CH4 emissions related to coal mining.

Of course there is the question of how to source and pay for the massive quantities of biochar that would be required to fill the mines. Perhaps pyrolizing local municipal waste could fill the void, as it were. Or perhaps fast growing, phyto-remediating plants could be planted after mines are closed (admittedly this is a challenge in and of itself given toxic soils around some old mines) and then be pyrolized with the resulting biochar used to fill the barren bowels beneath the earth.

I can’t claim to have all the answers here, but it seems to me a scenario worth investigating!