Biochar stability vs Carbon stability

biochar-movement

Next up on my reading list from the biochar bible, is Chapter 11 “Movement of Biochar in the Environment”.  Rather unsurprisingly something light and fluffy such as biochar is fairly mobile.  It can move both vertically down into the soil profile and horizontally across the landscape and into water bodies.  Lots of different forces cause this movement as can be seen from my one page overview above.

It is possible, in some scenarios, say for example freshly top-dressed, hydrophobic char applied on steep slopes with no soil cover, that quite a lot of char could be eroded away during the next big rain (similar to how freshly applied Nitrogen gets leached away). The final resting place of that biochar varies largely depending on topography, but there is a good chance that it could still sequester carbon whether it is in the soil or in a body of water. If char simply moves across land, it may fractionate and some tiny particles may volatilize, but much of the char will simply be moved from one spot to another – much to a farmers chagrin.  If it lands up in water, the carbon may still remain as carbon, but as with so many things related to biochar ‘it depends’! From what I can tell after reading this chapter, a lot more research is needed to really assess carbon stability in real-world vertical and lateral transportation scenarios of biochar.

If you want to reduce mobility, here are a few things to keep in mind:

  • Particle Size –larger particle may fractionate into smaller ones when hit by raindrops; but smaller particles will tend to leach and erode more quickly;
  • Hydrophobicity – fresh char, especially made at low temps (<500) is likely to move more
  • Soil texture matters as always! Sandy soils will experience more leaching & erosion.

What they didn’t say: A lot of chatter about biochar tends to tout ‘once & done’ benefits of biochar but in fact according to this chapter biochar can be quite mobile so ‘once & done’ could end up as ‘once & gone’ under the right (or really wrong) circumstances.  Ancient soils such as Terra Preta in the Amazon or the Plagganthrepts soils in Europe (see picture in lower left hand corner above) are not the result of single applications.  These soils were continually amended with char and other organic wastes for decades or centuries and created a deep dark soil profile that has persisted for millennia.  It is highly unlikely that adding a single instance of biochar, even at high application rates, would create similar profiles.  Thus adding lower rates more frequently may be preferable in the long run for both long-term carbon storage and soil fertility.

Biochar & Heavy Metals

biochar-remediation-mechanisms-v2

I recently took the plunge and purchased the updated ‘Biochar for Environmental Management’ (Lehmann & Joseph 2015), which I often refer to as the ‘biochar bible’.  Any book with more than 900 pages would be daunting, but this one is filled with scientific jargon that would keep your average non-scientist (e.g. me) googling for hours just to get through one chapter! Still if one is to succeed in the world of biochar, it is important to try to really understand where the current biochar research is leading, how to optimize biochar characteristics and how biochar impacts soils, carbon & economics.  This is one of the few books that endeavors to do that.  As I wade through various chapters I thought I would share some of the more interesting nuggets using infographics (an updated variation of ‘Cliff Notes’ if you will) which I designed to help  depict and distill the sometimes dense dissertations.

Having just returned from a visit to China where biochar research is heavily slanted towards remediation of toxic soils, I dove into chapter 20 which is titled “Biochar & Heavy Metals” (Beesley et al).  The above infographic covers the first part of the chapter which talks about how soils are contaminated, how toxicity can be mitigated and most importantly how biochar can remediate toxic soils.  The mechanisms by which biochar can help immobilize toxins deserves an infographic on its own (working on it!), but this first one gives an overall view of the problem and how biochar can help. Hope you find it useful!

How not to pound sand

disappearing-sand

Sand. How in the world can we be running out of sand? The world seems full of it, right? River-beds, oceans and deserts are full of sand.  Yet according to a number of recent articles, certain types of sand are being depleted so rapidly that some countries are putting bans on exporting it.  Such bans have given rise to sand mafias in some parts of the world.  Such sand mafias, which could have been called  Sandinistas if the name hadn’t already been taken, clandestinely mine river-beds and vacuum ocean floors to sell this finite resource to voracious buyers both far and near, leaving behind devastated eco-systems and sandless beaches.

To what end you ask? Our insatiable appetite for concrete is largely to blame; more specifically for the construction of housing, offices, factories, in fact brand new cities that spring up practically overnight in some parts of the world.  One kilometer of road requires 30,000 tons of sand and a single house can quickly use up to 200 tons (more details here). Concrete accounts for 80% of mined sand usage. Depending on the specific end use for concrete, up to 3 times the amount of sand will be required for every part of cement. Its role is to fill in the spaces of larger aggregates (e.g. stone). Both fine and course sand are used in cement with varying impacts on comprehensive strength, flex strength, permeability, durability, shrinkage, cracking, etc. Desert sand, due to its smoother and rounder geometry, doesn’t work as well as river and ocean sand so it is largely ignored.

Given that I blog about all things biochar, where does biochar come in to play on this most recent tragedy of the commons (i.e. disappearing sand)?  It is no secret that biochar is being tested and used in concrete recipes (see here, here, and here).  To date, however, the motivation for including biochar in concrete has focused on carbon sequestration or to lighten up the weight of concrete.  Perhaps displacing the use of sand with biochar in concrete should focus more on the ecological benefit of saving our rivers, oceans and related flora & fauna from utter devastation.

But since eco-system services is often a tough sell, especially without regulations to control those that feel no shame in ruining the environment, economic impact must be addressed.  Sand is still shockingly cheap (roughly $6/ton) given that it is the most in demand natural resource after water.  At that rate, biochar is unlikely to compete purely on price for a very long time.  However this recent paper suggests the biochar added to cement can help reduce cracking and improve flexural strength as compared to using just sand for the fine aggregate. This same research claims that biochars ‘jagged and irregular shape provides a snug fit to cement paste’.  Earlier research out of Korea showed that certain types of biochar ‘reduces water evaporation from concrete which reduces both the plastic shrinkage and drying shrinkage’.  Thus improving concrete through the use of biochar could potentially reduce liabilities related to concrete failure, or reduce curing time which means faster building, or could provide better insulation which will reduce building operating costs.  If we start to approach the use of biochar in buildings through this lens, it just might attract more interest than focusing on its carbon sequestration potential.  Future research would be well served to use a Triple Bottom Line approach to using biochar in building materials.

How the sea can help rebalance C

sargassum

This week I happened upon some fascinating biochar research focusing on charring seagrass wrack as a more sustainable means of disposal.  Not only is this environmentally preferable as compared to landfilling it, which causes all sorts of GHG emissions from the decomposition stage, but in all likelihood it could be economically better too.

Let’s discuss climate change mitigation potential first.  The reports states that in a mere 9.5km of Kenyan coastline, 6.8M kg of seagrass (dryweight) carpets the coast on an annual basis.  In their research they achieved biochar production yields of 48 – 57% which is actually pretty astounding and definitely not the norm with most current biochar production technologies.  (They did pulverize the seaweed prior to pyrolyzing so that likely provided increased yield.)  Still for conservative calculations, let’s assume 25%  biochar yield which is far more common.  Using the low end of the carbon content range they found for seagrass of 34.6%, this one small stretch of beach, which is less than 1% of Kenya’s coastline, could sequester more than 2M kgs of CO2e per year – not including calculations for reducing methane emissions from rotting wrack! 

Now on to economics.  Imagine how places like Kenya could benefit from creating sustainable jobs, cleaning up coastlines and possibly even becoming a carbon negative country by carbonizing excess seagrass! On the cost reduction front, the article states that one coastal town in Australia spent more than $28M for wrack ridding in just one year.  While there is a cost to collecting, handling, possibly drying and pyrolyzing seagrass, if mobile units could be taken to affected beaches, costs would most likely be lower, especially if carbon offsets were available. 

Seagrass is not the only excessive bounty from the sea that could be carbonized. Seaweed, an algae that grows 30 – 60 times faster than most land-based plants, is becoming ever more abundant due to fertilizer abuse (amongst other reasons).  Countries around the world that depend on beach tourism are increasingly beleaguered by odiferous mountains of Sargassum seaweed and kelp.  This too often gets carted off to landfills or buried in ditches at great expense, largely born by hotel chains or governments. Carbonizing fast growing seaweed could be a very efficient and relatively low-tech way to rebalance carbon levels and meet CO2 reduction targets while solving other problems that can depress tourism income.

A challenge with this particular type of biochar is likely to be the (relatively) high salt content.  For that reason it may not be ideal for use in certain soils.  However, it could be used in other ways that might help island or coastal communities to adapt to climate change.  Bagging it and piling it up to create artificial dunes could help when storm come and waters rise.  Using it as a construction material for sea walls might be interesting.  Perhaps it could be briquetted and used as green charcoal to reduce deforestation.  Incorporating seachar into salt licks for livestock might even be worth testing.  The point is, uses can be found!

I can’t even begin to calculate what the overall carbon mitigation potential is for all of this excess sea-based flora, but it is, as one of least palatable presidential candidate’s in US history would say, HUGE!

2016 USBI Biochar Conference Recap

USBI2016

The 2016 USBI Biochar Conference flew by in a flash this week.  It was great to see old friends, meet so many folks that I’ve corresponded with but never met in the flesh and to see so many new people that are joining the biochar fray. Academics mingled with industry, government representatives (USDA NCRS and Forestry mainly) chatted with NGOs and Venture Capitalists; Idealists focused on reversing climate change spoke to pragmatists focused on building the next big industry; Newbies met with the biochar literati and technology promoters exchanged ideas with agronomists.  Beyond those from within the US border were attendees from Canada, Mexico, Guam, Norway and South Africa (and probably other countries as well but those are the ones that I met).  It truly lived up to the ‘Synergy of Science and Industry’ theme.

Conferences like this tend to be like a smorgasbord – where there is more than a little something for everyone.  Hors d’oeuvres in the form of table displays showcasing various pre-production & pyrolysis technologies (I was particularly impressed with Forest Concepts “Crumbles” technology) as well as some other non-traditional technologies where biochar is part of an overall system (check out this amazing Algae Aqua Culture Technology).  Biochar producers brought samples and new products which I always love to see (and take!).

Also on the menu was an abundance of biochar presentations – nearly 90 in all.   Presentations were categorized into 4 subject areas: Agriculture/Horticulture, Forestry, Policy, and Stormwater & Remediation. Many of the presentation slides will be added to the USBI2016 website in the near future, so if you are interested in exploring a particular topic a bit further, check that out next month sometime.  I was particularly impressed with the sessions I attended in the Stormwater & Remediation track.  There is so much positive news coming out of that arena in terms of regenerating mine lands as well as using biochar to filter different waste streams.  Several folks are working on the sewage/biosolids and biochar front – both academic but also in terms of production technologies that can deal with high moisture content feedstocks such as biosolids.  Since I just recently wrote about this topic in the Biochar Journal, it was great to find and chat with others focusing on this endlessly renewable waste stream. 

Though there has been a burn ban on in Oregon due to the drought, a few folks did bring some small scale production technologies to display at the conference including a very nice version of the Kon-Tiki kiln, a funky pyramid kiln with the ability to flare off syngas (a new one for me), a rather fancy TLUD, and a little biochar bar-b-que (forgot to take pictures!)

Against the gorgeous backdrop of Corvallis and OSU’s campus, the ambiance, the knowledge sharing and the vibe was really great at this Conference.  Sincere thanks to all of the organizers!

 

Towards a Biochar Ethos

rhetorical triangle

Jonathan Shapiro’s book “Lawyers, Liars, and the Art of Storytelling: Using Stories to Advocate, Influence and Persuade” has a great perspective on ethos as it relates to Aristotle’s rhetorical triangle.  The biochar world would be well served to understand his thinking.  Ethos is often used to describe beliefs or ideals that define a community. In the context of Aristotle’s rhetorical triangle (i.e. ethos, logos, pathos), ethos refers to credibility.

Credibility can be boosted in many ways.  Clothes credentialize cops, cadets and candy stripers.  Certifications credentialize professions and products.  Testimonials, if provided by respected authorities, can also boost credibility.  Shapiro calls this ‘ethos by extension’.  Oddly enough he then adds “The field of expertise almost doesn’t matter.” This conflating of relevant expertise is something I see in the biochar world fairly often, yet I can’t quite bring myself to agree with Shapiro.  While it might work in a courtroom, I can’t say that is works in corn fields!

The biochar world has all manner of “experts”: agronomists, engineers, business people, climate scientists, farmers, environmental activists and more.  Each brings their own perspective, their own priorities and their own passions to the table.  Yet the question of who is most credible is critical.  It will determine who lives or dies, not only at the company level but for the industry as well.  [I could go on to say quite possibly for the planet as well, but that would likely lower my credibility in the eyes of many!] The question for the biochar community and more importantly for future buyers of biochar, is who to trust when they are talking about biochar? Whom do you trust before you incorporate massive amounts of the stuff permanently into your fields; fields which provide sustenance for you family, your community, and food security for us all. 

This is not a trivial or rhetorical question, nor is there a simple answer.  Scientists are often pushed to publish only positive requests if they want tenure.  Businessmen may take advantage of a lack of scientific understanding by the buying public and make extraordinary claims, perhaps unproven, about performance or may claim that only their product is safe.  Neither of these scenarios helps to build ethos for the individual nor for the industry.

For the biochar industry to succeed, we must take the other path outlined by Shapiro.  Instead of taking advantage of the confusion caused by a new and complex product, we should aim to enlighten and educate.  We should not attempt to sell biochar to everyone everywhere, but to sell the right kind of biochar and/or production technology to the farmer (i.e. ‘the audience’ in Aristotle’s parlance) whose specific constraints it can alleviate.  There are many ways to position biochar, but understanding what is most important to your audience is key to any selling effort. That is a much taller order, a much longer sell, and requires much more than just slick marketing of products with broad generalizations of the potential benefits of biochar.  But in the end, this additional effort will enable biochar to succeed and will facilitate word of mouth selling amongst satisfied customers which at the end of the day is what an industry needs to be truly sustainable. 

Time to update the Food Waste Recovery Hierarchy!

food hierarchy

The US EPA created the Food Waste Recovery Hierarchy (FWRH) in an effort to divert various organics towards the highest and best end uses. Sadly an inordinate amount of food waste, roughly 65% of the total waste stream, still ends up getting incinerated or landfilled.  Both of these disposal options waste valuable nutrients and landfilling organics generates CH4 which contributes to climate change. Newer technologies are evolving that can harvest nutrients and prevent emissions and even sequester carbon.

The New York State Pollution Prevention Institute just rolled out an updated Organics Resource Locator, a great resource to identify what and where various organics are produced. The database is meant to facilitate connections between producers of various underutilized organics (e.g. Food Processors, Restaurants, Institutions, etc.) with those that might want to use them (e.g. Compost facilities, Anaerobic Digestion operators, Food Banks, CAFOs, etc).

Wherever possible food waste can and should be diverted to feed humans and livestock. However this is often difficult to manage if proximity to end users with a consistent need for a particular kind of food waste is lacking. Sorting and transportation are often costly and time consuming as well.

Anaerobic digesters (AD) can take certain kinds of organics and convert it into energy but ADs can be finicky and require a balance of various inputs in order to work efficiently.  There is also a significant amount of high moisture digestate that remains at the end of the AD process.  Composting is a good option but operators often don’t want dairy, meat, fish or oils or any foreign objects mixed it.  It can also be constrained by seasons and by the need to balance carbon and nitrogen levels.

Carbonization via pyrolysis or gasification could be a very viable option for certain types of organic waste streams.  High moisture content (i.e. >25%) and heterogeneous waste streams have traditionally not been a primary target for feedstock for biochar. Carbonizing this kind of waste can be very difficult and often results in char which is low in carbon, with low surface area and potentially high salinity – not the greatest kind of char for soil amendments if you are looking for yield increases.  However a recent study from Singapore showed that gasifying blended food waste & woody biomass could produce high quality biochars that can be used effectively in nutrient poor, acidic soils.

Other waste streams which are more uniform and less seasonal could make for  more attractive carbonization targets.  Take the recent surge in craft and micro-breweries as an example.  Each brewery has to find an outlet for their spent brewer’s grain (SBG), a high moisture and high protein residual from the brewing process. Breweries in rural areas happily provide this to cattle or pig farmers that are willing to pick it up, but that is less feasible for urban brewers.  I am currently involved in a project focusing on pyrolyzing SBG which has recently been trialed rather successfully (see pictures below) once it was mixed with dryer feedstock to reduce MC.  Overall the char came out looking very nice though we are currently putting it through its paces to understand optimal end uses for high temperature SBG char.  Updates on this front will be presented at the Biochar 2016 Conference in August so I hope to see you there!!

SBG Char

Biochar for Mercury Detox?

charcoal smoothies

This weekend I tabled at a local event to keep spreading the word on biochar.  A woman came up and was simply gushing about biochar so I asked her why she was so enthusiastic. Most people that have ever heard about it in my neck of the woods are either gardeners or farmers, but that was not the case here.  She told me that she’d been suffering from mercury poisoning for a long time, had tried many different treatments to no avail.  Finally a holistic medical practitioner asked if she’d be willing to try biochar as a detox option.  Having been told there were few possible side effects she was more than willing to give it a go.  The prescription was to take small doses for 3 days, then wait 3 weeks and take another round for 3 days.  Blood work was conducted before and after and the biochar proved to work amazingly well.  She was happy and finally healthy.

Feeling a bit incredulous that a local medical practitioner in the Finger Lakes would know about biochar, I asked if she meant activated carbon or actually biochar.  She said, yes, it was definitely biochar.   Knowing that biochar is still uncommon in the Finger Lakes, I asked her where she bought it.  She told me the name of a local woman that I had sold a small amount of biochar to last year who wanted to test it on a few dairy cows that were not fairing too well.  Although I was hesitant to sell her char for this purpose as I’d not tested my chars on cows, eventually I provided her with a char that I felt would be safe and have relevant properties for that type of use. I’m pretty sure that is the char that ended up cleaning up the mercury for the woman that told me the story.  Never in my wildest dreams would I have thought of selling it to someone for human consumption without further testing – to date its mostly been tested for filtration purposes and has done quite well.  Turns out however, it was highly successful at sorbing mercury and a pretty cheap cure at that – at least in this scenario.  I am still smiling after hearing this story.  More investigation is surely necessary, but in a pinch I’d have to say I would definitely take this particular kind of biochar (made from grape seed extract which is a bit hard to come by unless you happen to know someone making grape seed oil!) to detox. 

Biochar: “Tiz bit dear”

Tiz bit dearThe question of how to price biochar has come up many, many times in conversations over the past several years.  While there is no perfect answer, I would argue that the current price is still too expensive for biochar to become widely used.  Apparently SouthDevonGardener would agree!

Focusing on biochar’s use as a soil amendment there are a few major questions that need to be answered to come up with a price that will spur the market: 1) who are you selling to and 2) what other products are you competing with and what do those cost?  The question of target markets for soil amendments is pretty straight forward.  There are three basic categories: gardeners, the “green industry” and farmers. 

The gardening market is often biochar producer’s favorite category as gardeners are not generally focused on making a profit off their small plots so their price tolerance is generally much higher than other potential buyers.  The downside is that it is a much smaller market overall and volumes purchased per transaction are very small.  This $7.6B market is large and growing, but there is a lot of competition for soil amendments and a lot of big name players dominate.  While some small biochar producers may do quite well selling biochar locally, at a national level this is a tough market to penetrate for small producers.

The price for other soil amendments that biochar could displace within the gardening market should play a role in setting an attractive price for biochar.  To some extent it does – at least when sold in smaller packages (e.g. quarts or gallons) when compared to peat moss, perlite or vermiculite though not so much when compared to potting mixes which make similar claims to boosting plant growth that biochar producers tout.

Pricing biochar

Here is a quick look at biochar prices on Amazon as compared to a few other soil amendments (I’m not a big fan of buying any kind of soil amendment on Amazon – but it provides for easy comparisons!):

Price comparison

Within the larger ‘green industry’ (~$130B) is the $20B greenhouse, nursery floriculture industry which could be a good recurring buyer for biochar.  However selling to this industry is a tad more challenging as they are much more savvy about soils and specific plant needs than many in the gardening crowd.  They are also much more focused on improving their bottom line which means increasing yields, decreasing costs and preferably both.  They buy in larger quantities (i.e. cubic feet, yards or by the ton) and are looking for much lower unit prices than gardeners.  While the costs for larger quantities is harder to pin down, it is still not close to the cost of other soil amendments.

In a recent plant trial that I was associated with, we used a commercial biochar which produced solid yield increases but when the cost of the biochar used in the potting mix was factored into the overall profit that would result from the two crops (i.e. lettuce and basil), the net financial result was negative for the farmer as compared to the net profit associated with the control in all but one scenario.    

While this is obviously only one trial, it is critical to consider the economics of yield increase versus cost increase.  Greenhouse growers generally do not reuse potting soil to reduce the spread of disease or because the potting soil is sold with the product.  To compete effectively in this market then, the price of biochar needs to come down to something that more closely mirrors the bulk cost of other potting soils used by greenhouse growers.

 

 

The CharCone: a great little kiln that will cook your food and help uncook the planet!

I am always flattered and excited when asked to do product reviews related to biochar.  Recently Bruce F. designed the CharCone, a mini Kon-Tiki geared towards the cooking crowd and asked if I’d be interested in taking it out for a test drive.

Bruce comes to the biochar world from a unique perspective.  A former chef and now a small business owner of SpitJack, he definitely knows his way around fire.  He also managed the sumptuous banquet at the US Biochar conference in Amherst which included some very unique biochar elements.  Bruce is very collaborative which isn’t overly common in the commercial world of biochar, so of course I agreed to test his kiln!

CharCone burn

The first burn I did was on a day which was too windy so I aborted before getting too close to the edge of the kiln.  Even so, about 5 gallons of char came out very nicely with only a few larger pieces that didn’t char through thoroughly (those just go in the next burn).  One trick with a small kiln is using easily bendable feedstock (e.g. dried reeds) to get a bed of coals going. This kind of fast burning feedstock is also good to use for the last 10 minutes or so of a burn as it keeps the fire going but doesn’t need a lot of time to fully char.

The second burn was on a perfect day wind-wise but a bit on the hot side!  Here are a few thoughts on using different feedstocks with the CharCone:

CharCone feedstock

  • Honeysuckle – this invasive shrub is a bit unwieldy but charring it is the best way to minimize its spread.  It is best to let it dry out for at least a few weeks, but even then it can take some care to safely use it.  It bends easily enough and burns great, but it unbends in the fire and often hangs over the side of the kiln, so it’s best to keep an eye on it at all times.
  • Old fence wood – burned fast.  If you use this sort of thing, make sure it is untreated wood so no nasty stuff gets airborne or into your soil.
  • Sawdust – a great starter feedstock as it makes an ember bed quickly; also good to use at the end to finish off the burn.  Make sure you don’t smother the flame though.  You may want to use a poker to move the sawdust around if it is clumpy as the sawdust might not fully burn otherwise.
  • Densified ethanol waste – Not something most people will have access too, but a local company asked me to make some char from this awhile back and I had some leftover.  This is a somewhat sticky, chunky feedstock which burns hot and for a relatively long time.  Seems to have completely charred through probably because I put it in about mid-burn.
  • Bones are a great source of renewable phosphorous or phosphates and calcium.  They take a while to burn so add them in early and make sure they don’t get covered over too quickly so they can char thoroughly.  If you are making char for soil use, add as many bones as you can find!
  • Lobster shells – thanks to a lavish Christmas dinner I have 2 buckets full of smelly lobster shells (even 5 months later they still smell!).  Lobster shells are also a good source of renewable calcium and a little something called chitin – a nitrogen rich polymer which has found use in everything from biomedicines to agriculture to golf balls.  [Fun fact: the world generates 6 – 8 M tons of crab, shell and lobster waste every year with most of it going to waste!] A biochar researcher friend of mine recently purchased chitin, which can be fairly expensive, to mix with his char.  Charring your own lobster shells is completely free and you get to enjoy a delicious lobster meal beforehand too! (Other research on pyrolyzing chitin shows it has promise as an electro catalyst with similar properties as platinum.)  These shells burn pretty quickly so they can be tossed on to the fire at almost any point.

A full burn took 1:45 and generates more than 10 gallons of what looks to be very good biochar.  Quenching the burn takes less than 5 gallons of water which is very handy.  The timing of feeding the fire is entirely dependent on what feedstock you are using.  If you are planning to cook, it would be better to use larger sticks so you don’t need to feed the fire so often.

What I really like about this kiln is its transportability.  With a few tools the legs can easily be taken off at which point the kiln fits nicely into the back of a car.  This makes it ideal for taking the CharCone to educational events or over to a friend’s house to help them char through yard debris while cooking a few hot dogs. With this kind of kiln you could also create a local Uber or CharB&Q for Kilns, which I believe Bruce has set up in Easthampton, MA. For more information on purchasing or renting kilns, check out the CharCone website.

Overall I highly recommend the CharCone!