When it comes to renewable energy, solar, wind, and hydro keep coming up as number 1, but what about number 2? Literally. I\u2019m talking about … well, poop. There\u2019s a rich, carbon-neutral resource that we could tap into: Turning crap into energy instead of flushing it down the toilet. It could be used as a coal alternative, to sequester carbon, strengthen concrete and more. There\u2019s an old technology that\u2019s starting to make a splash and might change the way you think about number 2. Let\u2019s see if we can come to a decision on turning waste into energy and if it\u2019s worth it.<\/p>\n
We\u2019re always looking for clean energy in any source we can: solar, wind, crops, even the currents at the bottom of the sea. Trying to get more and more creative to find something that really stands out. A couple of months ago a fan of the channel put me into contact with a company that\u2019s doing just that \u2026 and in a way I wasn\u2019t expecting. What if we could turn good old number 2 into a resource for generating energy or producing products we use everyday, all while cleaning up the environment? Sounds like an idea that doesn\u2019t stink. This was a topic right up my alley.<\/p>\n
Usually we\u2019re talking about new technologies, but this tech has been around since 1913! So what gives? Why are we still literally flushing away renewable energy, instead of taking \u201crecycling\u201d to a whole new level?<\/p>\n
I\u2019d argue that there are 3 unavoidable things in the world: death, taxes, and bathroom breaks. Doesn\u2019t matter how much you hate creating waste: even the most hardcore recycler has to go sometime. Everybody poops.<\/p>\n
I\u2019m going to go out on a limb and guess that the vast majority of you haven\u2019t given much thought to what happens to your waste after you flush. I know I hadn\u2019t. The trip to the porcelain throne is just the beginning. After our waste travels through the sewage system, to the wastewater treatment plant, they separate the solids from water. In rural areas, it travels to a septic tank where the water leeches out and the sludge is removed to be treated elsewhere. The water is treated through an intensive process (flocculation, chlorination, etc) before being discharged into local bodies of water.1<\/a><\/sup> The leftover solids generally get taken care of in three different ways:<\/p>\n You can incinerate it, which is pretty much what it sounds like: you burn it. All of those materials\u2014and its energy\u2014literally go up in smoke (and into our atmosphere).<\/p>\n The second way is to landfill it. In the landfill those biosolids break down into methane and CO2, depending on whether oxygen is present. If there is no oxygen, anaerobic digestion takes place, generating CO2 and methane. If there is oxygen present, aerobic digestion occurs, generating CO2.2<\/a><\/sup><\/p>\n The third way, and the most common, is to apply those biosolids to agricultural fields. About 50% of biosolids produced in the US are used for agriculture to grow products for animal feed.3<\/a><\/sup> So human waste is used to grow products to feed farm animals like dairy cows.<\/p>\n The problem with sewage management is that it never stops. Everybody poops about a pound per day, give or take4<\/a><\/sup>. Multiply that by several billion people, 365 days a year, and you can start to get a sense of the magnitude of the problem. In the US alone, we produce an estimated 5-135<\/a><\/sup>6<\/a><\/sup> dry tons of sewage sludge (human waste, generally 25% solid). Add the water content, and that\u2019s billions of gallons of waste to treat every year, and it\u2019s never going to stop.7<\/a><\/sup><\/p>\n Even after treatment, the final biosolids can still have contaminant issues. To put this politely \u2026 sometimes things come out in the same state they went in. This doesn\u2019t just mean corn: it also includes things like detergents, microplastics, pharmaceuticals, and \u201cforever\u201d chemicals like PFAS.8<\/a><\/sup> This becomes an even bigger problem when these solids are reused for fertilizer, because those contaminants are put right back into the crops, and the cycle continues. Multiple dairy farms in Maine have already had to close production because their milk had high levels of PFAS, leading to loss of income and public trust9<\/a><\/sup>.<\/p>\n As you can imagine, this type of waste isn\u2019t always great for the environment either. The water content is usually treated and discharged to water bodies, but if the water isn\u2019t treated properly, the solids, metals, and other contaminants can choke out wildlife habitats and fisheries.10<\/a><\/sup> The waste is nutrient rich. If it\u2019s dumped in a lake without treatment, it can lead to overgrowth of certain bacteria and algae, which also disrupt the natural habitat of aquatic life.<\/p>\n Then there\u2019s the energy consumption part of this to consider. Wastewater treatment plants are estimated to consume more than 30TWh per year of electricity\u2013that\u2019s about $2 billion in annual electric costs, and likely not from very clean sources. Electricity usually takes up 25% to 40% of a wastewater treatment plant\u2019s annual budget, and those needs are likely to rise with population growth and tightening water quality requirements.11<\/a><\/sup><\/p>\n Biosolids also have a greenhouse gas problem. As I mentioned before, they break down in the landfill to methane and CO2. The problem there is that methane is 25X times potent than CO2 as a greenhouse gas (although it does have a shorter lifespan)12<\/a><\/sup>. Municipal solid waste landfills are the third-largest source of human-related methane emissions in the U.S.13<\/a><\/sup>14<\/a><\/sup><\/p>\n Throughout history, humans have simply moved bowel movements out of sight and out of smell-range. Some of these sewage disposal methods have been in practice for nearly one hundred years, mostly because nobody has come up with a better way to deal with poop. There\u2019s got to be a better way.<\/p>\n That\u2019s where this old, 1913 technology comes in.<\/p>\n Hydrothermal carbonization (HTC), also known as subcritical water or hot compressed water carbonization, was first identified in 1913 by the German Nobel prize chemist, Dr. Bergius.15<\/a><\/sup> Right after this find, however, the 20th century had other plans for Germany, including a World War, the rise of Nazism, another World War, the breakup, a wall, and reunification of East and West Germany. With all this turmoil, it wasn\u2019t until 2006 that it got its foothold at the Max Planck Institute for Colloidal Science in Potsdam Germany. This waste-management alternative has been seeing a surge in popularity in recent years. I had a chance to talk to Dan Spracklin from SoMax where they are commercializing the technology.<\/p>\n \u201cWhat hydrothermal carbonization, or HTC, is, essentially most simple way of thinking about it is, an industrial size pressure cooker. But it runs continuously, so it’s not like you would have at home where you have maybe cooking some chicken in a pressure cooker or a crock pot where you do it in a batch. We do it consistently. What happens is, we apply heat and pressure to the material. Applying pressure puts water into a subcritical state.\u201d -Dan Spracklin <\/p><\/blockquote>\n When you put water into a subcritical state that means it starts to boil, but the pressure won\u2019t let it turn into steam. This all happens with 10-50 bars of pressure at about 180-250C. This is the perfect temperature to have that water act as a reagent \u2026 meaning it sets off a whole chain of chemical reactions, which separate the larger molecules in the mix16<\/a><\/sup>.<\/p>\n \u201cWhat we’re doing essentially is taking large molecules, first, we chop them up and then we pull off some oxygen atoms and some hydrogen atoms to make a more stable compound and smaller molecules. Then the last step is we recombine those molecules to make useful products and those products are essentially coal. We’re mimicking the way that mother nature formed coal. Typically earth does it over the period of hundreds of millions of years, so coal is typically about 250 to 360 million years in formation. We’re able to do this with sewage sludge in less than an hour.\u201d -Dan Spracklin <\/p><\/blockquote>\n The resulting product doesn\u2019t just look like coal: it can be used as a coal alternative.17<\/a><\/sup> The fuel value is similar to that of lignite coal18<\/a><\/sup>, and treatment plants have used these solids to co-fire in coal-handling infrastructure.19<\/a><\/sup> And, in spite of its origins, the high temperature has killed all bacteria and other biological threats, making the new fuel sanitary.<\/p>\n As part of this process, the solid-phase of HTC produces a liquor-rich process water as a byproduct that is chock full of VOCs, formic acid, acetic acid, phenols and other derivatives (yum)18<\/a><\/sup>.<\/p>\n So what do we do with the HTC process liquid? This is where it gets exciting. That process liquid can be used alongside anaerobic digestion to produce biogas. That\u2019s right: this liquor \u201cbyproduct\u201d can be used as fuel in itself!21<\/a><\/sup>21<\/a><\/sup> This is why HTC has been suggested as an intermediate step for producing biodiesel. Certain governments, including Germany and Italy, heavily subsidize the practice of generating biogas from wastewater plants. Europe\u2019s biogas production from industrial and urban sewage sludge increased by 40 percent between 2013 and 2017.20<\/a><\/sup><\/p>\n So how much energy can you actually get from this, and does it balance out with the energy needed to make it happen? As with everything: it depends. When it comes to sewage in particular, HTC shows some strong energy potential. The energy requirement of sewage sludge\u2019s drying process is reduced up to 62% from normal drying techniques21<\/a><\/sup>.22<\/a><\/sup><\/p>\n Traditionally, wastewater treatment plants consume a tremendous amount of energy and that\u2019s a huge chunk of their operating costs.23<\/a><\/sup> Those savings can add up quickly. Some studies even say that the economic benefit from the hydrochar production for energy recovery has exceed the profits from biogas production per tonne of sewage sludge24<\/a><\/sup>. Translated: the plant can produce more biogas (possibly up to 5%) while saving on energy costs.24<\/a><\/sup><\/p>\n The best part? That source of energy is ALWAYS plentiful. You don\u2019t have to wait for the sun to shine or the wind to blow to collect that energy. You can treat waste 24\/7, 365 days a year, and the material never stops flowing in.<\/p>\n You can also make some pretty cool things from the HTC process besides coal and biogas: there are diamonds to find in the roughage here.<\/p>\n One promising application is to replace the sand in concrete with the solid products of HTC. The construction industry is already infamous for their negative environmental impacts: they contribute a whopping 40% of the world\u2019s energy-related CO2 emissions. Part of that is because they require a ton of virgin materials to produce things like brick and concrete25<\/a><\/sup>. By using the solid products of HTC, they no longer need to mine these materials.<\/p>\n In 2019, engineers from Australia\u2019s Royal Melbourne Institute of Technology tested bricks made up of up to 25 percent biosolids and found that these hybrids cut down energy use by nearly half during the firing process.25<\/a><\/sup> Companies like SoMax are working with sewage sludge to replace sand in the concrete mix. At just 10% replacement, you could offset all the emissions from cement production.26<\/a><\/sup><\/p>\n We\u2019re not just \u201crecycling\u201d here either: incorporating biosolids into construction materials is also a powerful carbon sequestration tool. These companies can use biosolids to offset sand consumption while also sequestering the carbon from the biosolids for thousands of years in the concrete. You can break it, reuse it, toss it: no matter what, that CO2 isn\u2019t going to magically come out.<\/p>\n Also, remember that biosolid fertilizer problem earlier? With HTC in the mix, you can create a carbon-neutral fertilizer from the hydrochar, only this time, you can get rid of that pesky PFAS. This is no small feat. PFAS is called the \u201cforever chemical\u201d for a reason: they\u2019re made up of carbon-fluorine bonds, which are one of the strongest bonds around. That makes it great for weather-resistant clothing and Teflon, but not so much for the environment. But for HTC? It doesn\u2019t give a crap. You\u2019re breaking those molecules apart and getting rid of those potentially harmful pollutants at the same time (with some energy generation to boot)27<\/a><\/sup>28<\/a><\/sup><\/p>\n That pollutant-destroying aspect of HTC also makes it a good candidate for making another important resource: drinking water. (Ok, hear me out here.) HTC is just creating a carbon product, so you can activate it chemically or thermally, which opens the pores to filtration. That\u2019s right \u2013 activated carbon, a crucial product to filtering drinking water29<\/a><\/sup> 30<\/a><\/sup>.<\/p>\n Remember, HTC is literally tearing these molecules apart and sticking them back together. On a chemical level, the end product is different from what you started with. It\u2019s essentially a giant autoclave.<\/p>\n \u201cThat’s what we’re essentially doing is acting as a large autoclave. I would never do this and grab sewage sludge or biosolids, but I have no problem going and grabbing hydrochar, smelling it. I don’t recommend eating it. It won’t kill you, but I’m sure it doesn’t taste well. But yeah, it’s completely safe material.\u201d -Dan Spracklin <\/p><\/blockquote>\n Depending on what you use as feedstock, HTC can pretty much make everything from supercapacitor materials, to anode materials for fuel cells31<\/a><\/sup>, to energy, to syngas, to steel, to concrete and cement. The general process is the same: toss it in, cook it, and bam: at the end, you have carbon. (It\u2019s like the world\u2019s largest, and grossest, Easy Bake Oven.)<\/p>\n An economic study in Switzerland found that HTC-treatment per dry ton digested sewage sludge with industrial-size plant costs around $600-700 (compared to current sewage sludge treatment costs of $660-1000).32<\/a><\/sup> Similar studies in Germany reported that HTC reduced the costs involved in sludge treatment and disposal.33<\/a><\/sup> 34<\/a><\/sup> Treating biosolids with HTC can not only reduce energy costs, but at the end of it, you literally have less crap that you need to get rid of, which really puts a dent in those operational costs.35<\/a><\/sup><\/p>\n SoMax has seen these energy savings first hand.<\/p>\n \u201cIn the case of our project in Phoenixville Pennsylvania, we’re able to meet 153% of the energy demand of that treatment plan. It goes from being the largest consumer of energy in that municipality to a net energy producer, and we’re going to produce 153% of the energy demand. That extra energy is going back out onto the grid to run things like City Hall, street lights, stop lights. It’ll run the police station, and the fire station, and provide them with electricity 24\/7.\u201d -Dan Spracklin <\/p><\/blockquote>\n So if this is such a great system, why haven\u2019t we been hearing more about it? Besides the fact we\u2019re talking about poop. Google the studies on HTC, and you\u2019ll soon see just how much it\u2019s exploded across academia in the past few years. (You\u2019ll even find a few that aren\u2019t behind a paywall!) However, the lab-scale applications are still catching up to real-life applications (and with it, the real-life funding).<\/p>\n \u201cIt has not attracted the investment that say oil and gas gets, or other, solar. You’re not seeing hundreds of billions of dollars invested in this because A, the investors don’t know. B, even the so-called sustainability or carbon experts aren’t aware of this process, because it hasn’t really made its way out of academia into the real world. By building this plant in Pennsylvania, the first one in North America, we’re bringing it out into the world to make people aware of it. This was, to us, it’s really a coming out party. We’ve been operating in stealth mode until October of last year when there was a public announcement that our technology was selected by the US Department of Energy as the technology that should be implemented at small and medium wastewater treatment plants across the country.\u201d -Dan Spracklin <\/p><\/blockquote>\n While HTC has a lot of technical aspects to consider, the biggest challenge right now may actually be regulatory. Remember, this isn\u2019t just a plumbing issue: it\u2019s a public health issue. HTC requires biomass, and biomass comes with quite a bit of red tape. This red tape is due to the fact that poop is a biohazard and can harbor disease, but the legal paperwork can take years to process.<\/p>\n \u201cSo even we’ve got the stamp approval from the US Department of Energy to implement this process at wastewater treatment plants across the United States. In Pennsylvania it’s taken us three year to get the permit to even try this process out at a wastewater treatment plant.\u201d -Dan Spracklin <\/p><\/blockquote>\n If you tell people about the environmental value, back it up with the economic benefits, and have leaders lead by example, that\u2019s when the magic happens. It may not be polite conversation, but talking about the literal power of crap is the first step.<\/p>\n Still surprised that biosolids can do so much? You\u2019re not alone\u2013just ask Dan!<\/p>\n “One of the final questions I do want to ask you is, “What is one of the most surprising things about this type of work in your experience?” What is the thing that’s caught you kind of off guard that you weren’t expecting? Is there anything? -Matt Ferrell <\/p>\n \u201cThe most surprising thing is that everything works. We have a little game we play in our lab here, on Wednesday we have a will it carbonize Wednesday. So, we just take off the wall things and say, “Will it carbonize?” So I’ve brought in some t-shirts that they had holes and them stuff, so we cut up the t-shirts and we put it through this process. Guess what? They carbonized. So it’s everything from macadamia nuts, to sunflower seeds, to flowers themselves. We’ve actually processed flowers whole, and even carcasses. The unique thing about that is the whole thing will carbonize. The bones will remain the shape but once you touch the bone it just goes into powder. Huge surprises for me were about the raw sludge converted into hydrachar. Actually, how well it acted as an activated carbon to filter out pollutants. That was surprising to me. I thought, “That will never work.” But yeah, it did.\u201d -Dan Spracklin: <\/p><\/blockquote>\n For me the decision seems pretty clear. HTC is a great, two birds-one stone solution. We have to deal with our shit \u2026 literally. Why not get some extra use out of it? Academia and industry leaders like Dan Spracklin agree: this tech has the potential to make a difference now. The question seems to be how to get over that gulf between the theoretical and full-scale application. Simply put, it may be time to carbonize, or get off the pot.<\/p>\n When it comes to renewable energy, solar, wind, and hydro keep coming up as number 1, but what about number 2? Literally. I\u2019m talking about … well, poop. There\u2019s a rich, carbon-neutral resource that we could tap into: Turning crap into energy instead of flushing it down the toilet. It could be used as a coal alternative, to sequester carbon, strengthen concrete and more. There\u2019s an old technology that\u2019s starting to make a splash and might change the way you think about number 2. Let\u2019s see if we can come to a decision on turning waste into energy and if […]<\/p>\n","protected":false},"author":2,"featured_media":6995,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"video","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[260],"tags":[24],"ppma_author":[303],"aioseo_notices":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/undecidedmf.com\/wp-content\/uploads\/2022\/07\/Featured-5.jpg","authors":[{"term_id":303,"user_id":2,"is_guest":0,"slug":"matt","display_name":"Matt Ferrell","avatar_url":"https:\/\/undecidedmf.com\/wp-content\/uploads\/2021\/03\/portrait-small.png","last_name":"Ferrell","user_url":"https:\/\/wordpressmu-787287-2686879.cloudwaysapps.com","first_name":"Matt","description":"Matt Ferrell lives in the Boston area and is a UI\/UX designer by trade, but has always been obsessed by technology and how it works. In 2018 he started his YouTube channel, Undecided with Matt Ferrell, where he explores sustainable and smart technologies like EVs, solar panels, and smart homes."}],"_links":{"self":[{"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/posts\/6994"}],"collection":[{"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/comments?post=6994"}],"version-history":[{"count":0,"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/posts\/6994\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/media\/6995"}],"wp:attachment":[{"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/media?parent=6994"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/categories?post=6994"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/tags?post=6994"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/undecidedmf.com\/wp-json\/wp\/v2\/ppma_author?post=6994"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}The Current Problems<\/h3>\n
HTC Explained<\/h3>\n
\n\n