Azura’s David Ellis and Trisha Aldovino joined Louis Savard from the Ontario Association of Certified Engineering Technicians and Technologists (OACETT) to talk about all things AD! In this episode of the Tech Takes Podcast, they discussed why biodigesters are important for a lower carbon future, the science of how they work, and how the public can help raise awareness to reach Canada’s biogas potential. Click the link below to listen and scroll down for the full transcript.
Louis Savard: Hello. I’m Louis Savard, host of Tech Takes Podcast, and today, we’re exploring waste beyond our landfills and the exciting things the engineering field is doing to put waste to good use. I’m talking about anaerobic digestion technology, a possible game-changer in minimizing waste volumes and transforming waste into something we need more of, green energy.
Since the 20th century, the management and disposal of waste has increasingly become a major global problem. One of the ways Ontario is responding to this challenge is through anaerobic digestion. This once-niche technology has become a cornerstone in the renewable energy sector as a powerful waste management solution.
The roots of anaerobic digestion are ancient, but its evolution into a practical technology for waste management and energy production has blossomed over the last two centuries. In the 21st century, advances in engineering and microbiology have improved the efficiency of anaerobic digestion systems, making them more viable for municipal, agricultural, and industrial applications. These improvements have also led to reduced greenhouse gas emissions worldwide, generated more renewable energy, and supported global economy initiatives.
Today I have with me Dave Ellis and Trisha Aldovino from Azura Associates, experts in anaerobic digestion technology.
David Ellis is the Principal Engineer & Director of Azura Associates. He is a professional engineer with over 30 years of experience managing anaerobic digestion and wastewater issues for clients like waste-to-energy plants and food processing facilities. Known for their expertise, David and his team at Azura have been called upon for, now listeners take out two hands, 8-figure legal cases when digester projects go astray. Azura takes pride in being the first call for solving complex AD system problems.
Trisha Aldovino is a chemical engineer and process analyst at Azura Associates. She focuses on process design & optimization for all Azura projects, while leading the company’s technical training programs. Trisha also creates online educational content to raise anaerobic digestion awareness and provide valuable industry resources.
Trisha, Dave, welcome to Tech Takes.
David Ellis: Thanks for having us!
Louis Savard: Now, anaerobic digestion is a mouthful, certainly a topic that our listeners may have little or no knowledge about but the hope is by the end of this discussion we’ll have much more knowledge, much more confident topic about it, and maybe we can start the conversation with, “hey, let’s talk about bacteria.” Dave, hotseat for you right away, anaerobic digestion, what is it?
David Ellis: Anaerobic Digestion, or AD because like you said that’s a mouthful, is this a naturally occurring process that’s been occurring in nature every single day for millions of years! It happens at the bottom of rivers, in swamps in the mud down there, and inside the stomachs of cows. In the anaerobic digestion process, little microbes process organic material into biogas. These microbes the biodegrade things like dead fish at the bottom of a river, or grass in a cows’ stomach, and part of their natural life processes, one of the things they give off, they “exhale” biogas. So, the same way that we give off CO2, they give off biogas. Biogas is a mixture, about 50/50 methane and carbon dioxide. Methane is the same as natural gas that we use to heat our homes. Except in this case it comes from an organic source instead of drilling or fracking or something like that. One of the things about anaerobic digestion that we really like is making biogas from waste is the only established carbon-negative fuel in the world. I’ll say that again, it’s the only one!
Louis Savard: You want to say it one more time, just in case the listeners didn’t hear that?
David Ellis: The only one.
Louis Savard: The only one. I think it’s very important to drive that point across, right? Since we have to be so careful about where we get the information from, it’s important to highlight the important items we are talking about, so Trisha, AD, we’ll keep it that way, what’s its purpose really?
Trisha Aldovino: I’ll try to answer this question with a story, the story of how we as humans industrialized AD. 150 years ago, when human civilization was much smaller, and we used to use our farming waste (like manure) to fertilize our crops. So that waste we would put on our lands and it kind of just degrades in nature, and sometimes it would end up in our rivers and waterways, but it wasn’t that big of a problem because there wasn’t that much waste and our rivers could dilute it. Over time we get to the industrial revolution, civilization grows, and because there are so many more people, we were like “oh, we need to feed more people too,” we invented commercial food production to feed everyone. The consequence of that is more people = more food = more waste. And at this time, we were still doing what we had been doing for hundreds of years which was put our waste into the ground, in holes, or in a pile in a landfill, but then we realized that nature couldn’t handle that waste management anymore. And so, the like the way we focused on commercial food production; to feed everybody, we focused on processing more waste. In farming, we intensified this natural thing, which is food growth, with AD we are intensifying a natural biodegradation process, to handle that increased organic waste. So in total the main purpose of anaerobic digestion is to make the waste safe and in that process it also creates useful products like biogas, like Dave said, and natural organic fertilizer.
Louis Savard: Now that’s an interesting story. You mentioned something that is sparking something in my mind, “make the waste safe.” Now you might have a lot of people that say waste is waste, you know waste is just not safe period, but I’ll look to you Dave really quickly, speaking about waste, why is it so dangerous in the landfills specifically?
David Ellis: Excellent question. Let me ask you a question Louis, in terms of the landfills say here in Ontario, as these are a big hole in the ground conceptually, or piles, how long do think it would take us to fill up our landfills just here in Ontario? 5 years, 15, 20, 50, any guess?
Louis Savard: Oh wow, putting me on the spot! That’s a role reversal I wasn’t expecting. Knowing what we are dealing with here in the municipality and it’s probably shorter than I think so I’m going to go with 10 years.
David Ellis: That’s an excellent answer. It’s actually a little bit less than 10 years to fill up. And right now at that 10 year level, we’re still trucking about 1/3 of waste in Ontario to the US. 40% of what Ontario sends to landfill is organic material. Now it naturally biodegrades and breaks down in the landfill anyway, and releases methane. The problem is, over a 20-year time frame, methane is 84x worse than CO2 as a greenhouse gas. From that landfill, if we were to capture that methane from the landfill, just burn it, sometimes you’ll see these flares, if you just capture that methane, it’s still 80 times better than letting that methane out into the air. From a landfill, if we let that methane just seep out through the dirt, it becomes a tremendous greenhouse gas issue for people.
Louis Savard: So, there’s the connection. It’s not the waste per se, it’s the by-product and the impact, snowball effect, it has on greenhouse gasses, being that much more potent than most of the other ones, right?
David Ellis: Exactly.
Louis Savard: Great. Anaerobic Digestion, sounds complex, sounds complicated, Trisha, is it? How does it work.
Trisha Aldovino: I’ll try to explain it in a simple way with an example that I think most people would be familiar with. Here in Waterloo, Ontario, we have a green bin program and I’m pretty sure Toronto has one too. For people who are not in these areas, that’s the bin we put our organic waste into, like kitchen scraps and that plate of leftovers from last week in the back of the fridge that you swore you were going to eat, sometimes that ends up in the green bin instead. The city will collect these green bins and transfers them to an AD facility. Sometimes they’re also called Waste-to-Energy facilities. And the truckers will dump that green bin organic waste into a receiving pit or tank, so it just collects there. No one is perfect at using the green bin, so sometimes there’s packaging or plastic bags. One of the first steps would be to separate that organic waste from the non-biodegradable waste. The waste from the pit goes through equipment that removes non-biodegradable material to free up the juicy organic waste. Now that we just have that organic waste stream, it goes through a series of mechanical equipment like shredders, choppers, and mills, until it makes like a smoothie, something more pumpable that your banana peel. That smoothie is pumped to the digester tank, where the bugs live, they will eat that waste smoothie and transform it into biogas through a series of biochemical reactions. The biogas can be used as is for electricity and heat, or it can be refined into Renewable Natural Gas with an upgrader, and you can put that into the natural gas pipeline, if there’s one in the area. Unfortunately, the bugs can’t turn everything to gas, they can’t eat everything, so what’s leftover is a liquid product called digestate and that digestate can be used as an organic fertilizer. So, this example was more with a waste stream that could possibly have packaging, like the paper bags, or sometimes people don’t use the right bags for the green bin. If the organic waste doesn’t come with packaging, like if it came straight from a food processing factory before it even gets to people, then there’s no need for the separation equipment, it can just go through the smoothie steps and straight into their digester. That’s a pretty simplified summary of it, I hope that’s good for listeners.
Louis Savard: Yeah, you told us a story before now we can kind of cartoon action of the bugs needing to eat and the packaging being flung out the window. You mentioned digestate being an organic fertilizer, as a by-product. What’s the ratio? What’s the ratio of energy or biogas production verses digestate production on a per ton basis or any percentage in your experience?
David Ellis: Sure, I can answer that. For each of the different waste materials are biodegradable to a different extent. So, if we are putting in for example, leftover soda or something like that, we’re going to degrade pretty near 100% of that, and most of that is going to turn into biogas. If it’s something that’s less degradable, there’s some fibrous material in it, that would be your banana peels and things like that, we’re going have about half of that material is going to break down and degrade, so the solid portion, typically around half is going to break down and be converted into biogas. So one of the good things about the digestate with that half that is left in the digestate, is that still has all of the nutritional pieces from that banana peel, whatever phosphorus or nitrogen any of those kind of fertilizer components that are in the banana peel, those are still there in the digestate, they don’t go off in the biogas stream itself, they stay in the soupy digestate stream, so that’s ready for land application.
Louis Savard: Any financial benefits to digestate? We’re talking digester processes, I see dollar signs, right, in terms of recovery, is that digestate a marketable product?
David Ellis: Well, it depends on who you talk to; certainly, the farmers who take clean waste, pre-commercial waste, they are able to use that on their own land, so for them it’s fertilizer that they don’t pay for, in fact they get paid a tip fee to take, if there’s residual from your local apple pie factory, you go to the grocery store and see those boxes of frozen apple pies, they came from an apple pie factory so that waste goes to a farm and that farmer is essentially getting free phosphorus and free nitrogen with that waste, but after they extract the energy from it in their digester, they can apply that for free under their own field. So that’s very attractive for them from that perspective. Additionally, on say like private digestive facilities, I’ll say the farmers who take the material and the digester operators, they’re all good capitalists, so they’re always going back and forth on, who’s paying for trucking, and how far is it going, and so there’s usually a commercial relationship works out there. I think in terms of where we are now, definitely there’s a lot more interest from the farming community to take digestate and we have had conversations with a number of the owners that we work with where they’re starting to get a small fee for some of their digestate.
Louis Savard: We incentivize things like that, right. Done right, really gets the buy of sometimes segments of the population you never thought would buy in. It’s nice to see there’s something that could be done.
David Ellis: Absolutely.
Louis Savard: Dave, two questions. I mean, one question, but it might turn out into two questions. Trisha mentioned the green bin program in Waterloo and Toronto, I know here in Cornwall it’s launching in January. That’s residential, some commercial, maybe some industrial here within the municipality. But are there any other areas where waste is collected for AD? And the follow up to that is we talked about digester very briefly, is it one size fits all? Are there different digesters for different waste streams? Can we just chat about that a little bit?
David Ellis: Sure thing. The example that Trisha gave is for a municipality with a curbside green bin program for banana peels from, you making lunches. So that waste is collected by the municipality, so the city may have digesters for that or maybe contract network commercial digester. These are typically very large commercial operations that would process 100,000 or 150,000 tons per year of material. So these are very large operations, because of the economies of scale needed to take in the waste put it through any sort of de-packaging equipment, removing plastics or grit from the front end cleaning the biogas and injecting it into the gas distribution grid, the economics of it all require those to be operated at a large scale. So, in addition to that, there are, many private digester facilities. Some digesters are located on farms, where the farmer may use it for their own agricultural waste for their own manure from their farm, and at the same time they would have an additional revenue stream by taking in food waste from local food factories. And some of them can even take in waste from SSO that’s been cleaned and processed and made suitable for them to go to these facilities. Additionally, there are certainly major food processing facilities have been using digesters for 30, 40 years in some cases, treating the residual sugary material that they would have from their food processing operations.
Some are standalone digesters where companies pay to take waste and some of them would be located at a farm operation or a food factory. And also in sewage treatment plants. Many of them will also have anaerobic digesters to process the waste, the waste biosolids, the waste sludge that’s produced at the sewage plant also.
Louis Savard: Right, right. Super interesting. Now I happen to dabble, well, more than dabble, it’s been over a decade now, but I brew my own beer? And essentially my fermenter at home, which is nothing more than a plastic bucket with a spigot, ends up being an anaerobic digester because I don’t want any oxygen in there at all.
Now, the byproduct, it may be a little bit more interesting than, you know, than digestate and biogas, but it’s still a digester, nonetheless. Now, when you’re talking these big industrial facilities and the municipal facilities, I picture just a larger plastic bucket. Am I looking at this right? Or, are there actually different types of digesters out there? What are the different parts of them? Is that, or am I just wrong, or am I right and it really just a bigger bucket?
David Ellis: I would say you’re 90% exactly dead on, right. So, an anaerobic digester at its heart is exactly the same as your bucket at home. It’s a tank, with a mixer, and a heater. It’s not a rocket ship. So, there’s really no reason for these things to go wrong because they are typically a fairly simple operation; now, there are specific nuances and specific hybrid types of reactors where the scientists and engineers that really have gotten ahead of themselves in terms of specialized reactors and specialized configurations working on specialized biology. But for most of the digesters that we’ve been talking about, these are wet digesters, operating tanks, very much exactly like a five-gallon pail brewing beer.
Louis Savard: Ah, interesting. So, it’s not rocket science, it is science, it’s just not rocket science.
David Ellis: It’s nutritional science, not rocket science. Nutritional science. So, so much like, your brewing beer, if we can keep the nutrition correct so the right phosphorus, the nitrogen, the carbon ratios, make sure the bugs are all well cared toward and they have lots of nutrition, then it, you know, pretty much works; it’s hard to screw it up in that regard, if it’s kept in balance.
I tell folks it’s not more complicated than taking care of a goldfish, but it’s also not more simple than taking care of a goldfish. You still need to tend to it.
Louis Savard: Hey, you still need to feed the goldfish, right?
David Ellis: That’s right. You still, you know, and if you put in a whole tin of food on Monday because you’re going go on vacation for two weeks and come back two weeks later, it’s not going be a good situation.
Louis Savard: Yeah, it’s not, definitely not. Now, while we are on the subject of nutritional science, Trisha, we spoke about the banana peel and the lunch that you had all the intent of eating tomorrow, but two weeks later it’s still in the back of your fridge. What are the different types of organics that can be consumed and used into anaerobic digestion?
Trisha Aldovino: Yeah, so I had mentioned the whole banana peels and this green bin waste stuff, that’s something we call source separated organics, so that’s post-consumer waste food that went to someone, and then someone tried to remove the packaging themselves, and separated the organic part. That’s why its source separated organic.
So that’s one. We also mentioned at farms, that’s agricultural waste, it’s also largely manure. So farmers will have livestock and they collect all of the manure and the manure has, especially if it’s from a ruminant, like a cow will have the right bugs to do anaerobic digestion.
As well, there’s biosolids, which is a more scientific way to say the stuff we put down the toilet and in the sinks.
So aside from those ones, there’s the industrial food waste, like residuals from the apple pie factory or potato peels from wherever McDonald’s gets their fries.
There’s retail food waste. So, if you go to the grocery store, not all of that gets sold before it gets before it goes bad. So those can also end up in an anaerobic digester. It’s not just grocery stores, though, it could be from restaurants or other food services. The trouble with that is that you know, things at the grocery store, sometimes they have packaging stuff at the restaurant, sometimes people will mix in the cutlery, or the plate that the food was on, which is not always great.
So aside from those ones that resemble food or was food for us, there’s other organic waste from industrial facilities, that’s not what we consider food. So like from medicine for example, there’s like medicine that went bad or specific ingredients in medicine or chemicals production that’s gone bad, that could degrade organically, or sorry, that can biodegrade.
And then lastly, I’ll call this the final boss. This is the organic fraction of municipal solid waste, OFMSW the final boss. Why? Because this is just your general mixed waste, like the black bag waste that has everything in it. It has pencil shavings, it has your can of coke that was half drank, but you didn’t want to drain some of it in the sink and you just put the whole thing in. It’s just the garbage mixed with everything. So, the city will collect that garbage and it will try to sort it into recycling, organics, and landfill, but sorting isn’t perfect, like there’s no perfect robot that can separate all the organic stuff from there. So as you can imagine, trying to use OFMSW as a feedstock for anerobic digestion has its complexity.
But I would say those are the main categories.
Louis Savard: All right. So more than your banana peel. Wait. Now, full disclosure, there may or may not be a nice shiny silver fork in some organic collection somewhere. And now we have 11 forks on home, not 12, but I can’t confirm or deny that’s where it went.
David Ellis: It happens.
Louis Savard: It does happen. What about grease? Right? You mentioned restaurant, you mentioned industrial, the producers. I know, you know, we are brought up, you know, in terms of the composting side of things and sometimes even just the organics collection is we don’t want greasy stuff, it messes up the, you know, the bacterial composition, oils will just kill them – is there truth behind that? Is it really just scraping my whole plate into the green bag?
David Ellis: Scrape your whole plate into the green bag. So certainly the grease is the highest caloric value, it’s got the most calories in it. And so we get the most gas ever from grease for sure. So definitely a number of municipalities, so, city of London, since they have a terrific program to collect they distribute like paper cups for you to collect your household grease and the bacon fat you have on Saturday morning, that there, and then that does go to digesters and it’s converted into renewable natural gas. So definitely the grease is an excellent fuel value that way. And that’s part of the whole push-pull of keeping grease out of the sewers for a few years back, a lot of folks were hearing about grease-bergs and things blocking up the sewers and having flooding during rainfall events because the sewers had so much grease and blockages in them. And so just as the municipalities are educating people, not to put your grease down the sink please, they have also given them a please put it over here instead, as opposed to just the one side or the other. So definitely the grease is an excellent piece to add into the green bin program.
Louis Savard: Good to hear. I love bacon, so that’s really good to hear. Trisha, I know we mentioned earlier in a previous discussion about where digesters are being used generally at commercial industrial on farms, maybe municipalities, maybe small-scale privates, where do you really see them used mostly right now?
Trisha Aldovino: To give you some numbers, some idea for North America, there’s about a thousand digesters in wastewater treatment plants. So that’s the whole biosolids stuff. And there’s about 500 on farms. So that’s their agricultural waste and the manure, and only about a hundred food waste digesters, so that’s like the stuff from the food processing plant.
Then these numbers aren’t really including the number of digesters that are inside food processing plants, like that they own, these numbers are more for standalone digesters. The key takeaway here is that it’s not like, whatever, five, or you can count with more than two hands where this technology is being used.
And it’s an established technology, it just could be adapted from a different kinds of waste.
David Ellis: Yeah, absolutely. The like many of those farm digesters will codigest, so mixing their on-farm manure with a grease that they take from grease trap, clean out truck operations or other things from local food factories as well.
Louis Savard: I actually, the numbers sound large, but when you precede them with, in North America. It actually makes them sound quite small. So, it’s certainly a technology that’s worth exploring and worth employing and I really hope that if you ever have a follow up podcast, that you tell me it’s 10,000 and not a thousand, right.
David Ellis: So, well, certainly in Europe, for instance there’s more than 5,000 digesters in Europe in comparison of the size of Europe to the size of North America. So certainly it’s a business opportunity for good capitalists in North America to be involved with new digestive facilities. Yeah, it’s an excellent untapped opportunity for sure.
Louis Savard: Okay. We’re going go a little bit out in the left field here because you mentioned Europe, you can plead the fifth if you’d like, and we’ll move on. But why is that? And it’s not that, and I’m just, full disclosure, this is not the first podcast where you know, someone says, but Europe has been there before us and they’re already well and on their way, and we’re like, yeah, we’re still fighting the red tape over here. Is there a reason for that?
David Ellis: Sure. I think that the reason is policy and government action. So my old boss, who’s retired a long time now, he was involved in some of the first farm digesters in Ontario in the, I think 81, 82 timeframe, fully 40 years ago. And those early digesters did not do that well, you know, after a handful, 5, 6, 7 years, we learned a lot about corrosion. Oil did not go to $200 a barrel at the time. So there’s a lot of reasons why those early digestive were shut down. But we certainly had a lot of that digester technology here in Canada.
I think that the big shift came about when in Europe the policies were set such that, say for a grid connection, so here across Canada, a natural gas injection point, you know, we’re probably looking at a million dollars to get started. So for a modest farm operation that by itself is prohibitive, that’s a deal breaker. Whereas by policy, in parts of Europe, if you built a green energy facility, the grid, was required, the grid operator was required to connect you at no cost. And so that incentive or that policy mandate, and that those systems could flourish while we had a really prohibitive connection costs here in Canada. And so Europe was far ahead of us because now that they have the greater track record and experience with those farm systems, we started bringing that technology back to North America I would say. Now one thing where North America, I think is ahead of Europe is, in the more complex feeds. So, on the farm sides, these thousands of digesters in Europe, a lot of them are farm based and mostly manure; so relatively simple in terms of the feedstocks they take. Whereas the green bin program the banana peels, the grease and those things, I think we’re, on par for sure, if not a little bit ahead of some of the practices in Europe. The City of Toronto, for instance, their green bin program they solicit things like pet waste, like diapers, things that are prohibited in Europe. So, the Europeans don’t, I think, have that same experience that the City of Toronto would have in processing those kind of more complicated materials.
Louis Savard: Thank you for that. Sometimes it’s hard to, you know, to always go back and say, we’re second again, or we’re way behind the eight ball. And really it’s not, we’re behind the eight ball, it’s because it just, policies just has to catch up with where we are. And it’d be nice if it was a global policy, hey, to our listeners out there, someone wants to take that challenge on, make it a global policy, let’s do it. But at the end of the day, that’s not the reality. So, thank you for clarifying that.
Trisha, one thing that you said earlier, actually Dave also pipe-in for that, was when I asked about the ratio of digestate, the biogas you know, and it’s about 50% of the solids that, that get turned over. But there’s an energy requirement in terms of heat to be maintained, AD – do you have the supplemented with other types of fuel to keep it going, or is it once it going it’s self-sustainable?
Trisha Aldovino: Okay, so I know when people hear, wow, I can use my leftovers to heat my home, no way, that’s really exciting. It really is. But before you go to your backyard and then start building a digester, the amount of gas a household would generate could probably power a gas stove, realistically speaking, and not really the whole home. And this is only the case if you live in a warm enough climate that doesn’t require a heater for the digester. So, like you said, supplemental heating. So this kind of thing has been happening for like hundreds of years in South Asia, like India and other warm climates because you don’t have to heat the digester, it’s hot enough there. But in Canada, for example, our winters are really cold, so you might need to supplement that heat.
But industrially speaking, it depends on how much waste you’re processing. So, it’s true that we can make energy from our garbage, and a food manufacturing facility might have enough feedstock or waste to put in the digester to produce enough energy to cover the digester’s heating costs or even more than that to cover some of that electricity, it just depends how much you’re putting in. And for standalone digesters, so these are the ones that get paid to take in other people’s garbage, they typically get a lot of waste and produce a lot of gas. And so they’re able to upgrade it to natural gas and inject it to the natural gas grid. And so, depending on the business case, we’ve seen that for some clients, it’s actually more economic for them to send it to the grid and then buy back their own gas instead of using their own gas; so it depends how much you’re putting in. But if there is a threshold where if you put enough in, you’re able to cover your heat and electricity cost for the digester plus more.
David Ellis: Yeah, that’s right. Certainly, that is a big question that’s answered usually in that early feasibility stage, assessing the business case. We looked at digesters up in the Arctic, up in Nunavut for instance, or sorry, looked at the business case of those. And so for those digesters, you need a lot of fat waste, so very high energy input, as you said, to make the energy balance, make sense. If you were somewhere where you know, it was cold, like some parts of Canada -40 is a real thing, so understanding the heat balance and how much gas you get versus how much gas you use in the wintertime and what’s going make sense over all the seasons. But generally speaking, almost everyone that gets built is energy positive, that’s the business case that makes it work.
Trisha Aldovino: Yeah, and another interesting one is we’ve heard of people who will feed or digester during the warm months and then just kind of let it idle in the cold months because they don’t want to, or they might not have the business case to heat it up.
Louis Savard: Okay. I mean, pros, cons, are we doing that?
David Ellis: We like biology, so I think there’s a lot of cons to doing that. It takes a reasonable amount of heat to take, say, a digester that’s idling at say, 10 degrees Celsius and warm that up to 40 degrees Celsius. And if you’re trying to do that in April it’s going to, you know, often take you like six weeks or so, so you’re into like May and June, then you’re making good gas, you know, throughout the summer months and then into the fall. And then eventually if you pull the plug and stop feeding it, you’ll continue to make gas for another couple weeks or so. But then eventually the bacteria would go dormant and start to cool off, and where you still then need to put some heat in over the winter, make sure everything is weather hardened, you not going get issues with lines freezing. It’s, you know, it’s a system that likes to stay active and kinda like a car, if your car is sitting idling for six months when you go to get in there, the brakes are rusted and the fuel lines are starting to seize up with water and there’s lots of issues. I prefer, I like to see them keep going all the time.
Trisha Aldovino: Yeah, for sure. I mean, technically you can still drive a car that you didn’t drive for six months, but it doesn’t mean it’s going to be great.
Louis Savarad: Yeah, that’s a good analogy actually, because, you know, what comes to mind is, you know, it’s like closing your pool, right? I mean, I could run my pool and my heater all winter and not have to incur the cost of lowering the lines up, lowering the water, more water in the spring. But there’s the cost of heating the water, -40-degree weather. I’m assuming with the digester, kind of a similar thing where, you know, anything that is not under the heat of the bacteria, let’s say, you still have to make sure those lines don’t freeze up or pipe bursts. You have to maintain a certain amount of heat to keep your bacteria alive, even if dormant. So there’s still a cost to not using it, right? It’s just, I’m assuming it’s the big mass balance of, is the cost in this particular case anyway, is it costing me more to keep it running or will it cost me less to just winterize it and then kick it back up in March or April?
David Ellis: Exactly, just all how the business case pencils out.
Louis Savard: Right? Right. It’s always a business case. Now Dave, We’d like to think we’re a smart species. We’d like to think that we always learned from the past learn our mistakes. The fact of the matter, we’re in the 21st century, you know, we are now reeling with the industrial revolution. We’re dealing with that waste. Where do you see AD playing a role in combating the waste that’s been generated there, and in the future to help Ontario specifically, reach its green energy goals?
David Ellis: Currently Ontario only diverts about a quarter of our waste from landfill. And so that quarter waste diversion that we’re doing, that’s both organic and recycling combined. Now, you may recall the goal is supposed to be 30% diversion by 2020. So we haven’t hit that yet. But definitely diverting food waste, organic waste can really help bump up that diversion rate. By 2030, Ontario is planning 90% of the electricity to be generated from renewable and non-emitting sources. And so this is an area for sure where waste-to-energy can definitely help us hit that goal.
Louis Savard: Okay, so yeah. So it’s more than just getting rid of the organic waste, right? It plays a role in the grand scheme of that waste-to-energy life cycle?
David Ellis: Absolutely it does. There’s some policy statements were released even just in the last 10 days where the IESO is calling for input on opportunities, looking at renewable and non-emitting sources for electricity. And so we’re optimistic that we’re going see some positive signs on the policy front, where the existing digesters that do take their biogas make burn in a cogen engine and make electricity that those programs will be renewed. And then there’ll be, you know, more opportunities to get this green electricity onto the grid.
Louis Savard: Alright, fantastic. Now let’s stay on the topic of energy and we’re gonna go out and left field again. Now, last time we went maybe just a little bit behind shortstop. I’m going to the fence with this one. In a previous life we did some proof of concept projects with anaerobic digestion. And the premise was that hydrogen was a renewable energy source, that was really coming up. It was really being talked about in Japan and Australia, some parts of Europe, but here in North America it was rather quiet. So the idea was in a wastewater treatment facility, we could take the biosolids into an anaerobic digester, the resulting digestate and remaining solids would become field fertilizer, but then the biogas would then be subjected to an electrification process by which a hydrogen would be removed from the methane and produce green hydrogen.
David Ellis: Yes.
Louis Savard: Thoughts on that? Have you heard about that experience with it?
David Ellis: So yes, we’ve heard of that. The notion of taking some electricity to crack the methane molecule and to utilize the hydrogen that is produced from that. So chemically that’s entirely possible. I think from my thinking, I don’t think it there’s any chance of it making sense, thermodynamically, for at least a hundred years. The reason I say that is, the methane that we use or that the make is already useful, we can put it in the natural gas grid, we have enough storage in Ontario that we could run all of Ontario’s natural gas needs all winter long, just from the storage we have. So we already have tremendous amount of infrastructure for natural gas. So that biomethane or the biogas from the sewage plant, we can use that as is, we don’t necessarily need to have the additional cost to crack off the hydrogen, the cost of then trying to store a hydrogen molecule somehow put into some hydrogen infrastructure that could use that. So there’s a lot of investment required to, to use that. I would say, and perhaps maybe some of my personal biases show when if we’ve got electricity, we’re much better off to try to use that, I think it’s wasteful to use that electricity to try to make hydrogen and then try to use that hydrogen to do something; whereas if we can just use direct electrification, so if we just use that electricity, we got to charge batteries and to run cars, run our computer systems, to electrify our society as much as we can. I think it makes much more sense to try to do that first, so using the methane as is, and using the electricity as is, before we add in those additional steps of converting into hydrogen. Because remember, ultimately hydrogen’s not an energy source, right? Hydrogen is just a battery. It’s a chemical battery, but it’s just a battery. So the question is hydrogen a good battery or a bad battery? What are the efficiency losses as we convert something to hydrogen and convert hydrogen to something useful? There’s those kind of questions as well. But at the end of the day, I consider hydrogen to be a battery, and the question is: is that the best battery for us?
Trisha Aldovino: Also, just to add on to that, sometimes people put biogas or biomethane against electrification, then hydrogen, but they’re all just solutions for climate change and renewable energy, so we don’t actually have to fight.
David Ellis: That’s right. And we consider biomethane to be renewable because as long as we’re going to eat bananas, we’re going to have banana peels. And so, we’re going to have that organic waste, it’s not going away anytime soon. So that’s the renewable part, is the ongoing food waste. As long as we keep eating food.
Louis Savard: Yeah, I mean, you’re, again, I’m not going to try to, not to show my bias to you too much here, but you know, it’s a, that’s a perfect circle, right? We’re taking waste to create energy that, that waste would create the same, I’m going to use this, the word loosely type of energy, but to waste and then, you know, impact our environment even more. Whereas if we can take it away from that, we reuse it and not have to rely on other energy. So, you hit it bang on, I think when we ran the pilot the biggest hurdle was how do you then clean the hydrogen? Right? It’s not clean. Right. It’s probably 98.7%, I think is the number somewhere around there. But they needed 99.999, is what was needed to use. Right. So it’s one of those things, I may be wrong in numbers, but I know it was a high, and that was the killer right there, right. The investment to do that was just, and you know, the amount of energy, the amount of methane you had to generate to make it worthwhile was also in the question.
David Ellis: Exactly. In the renewable natural gas upgrade, so from a biomethane to a renewable natural gas, it doesn’t have to be perfect, there are small, there are specifications that the Enbridge and gas utilities use, a small amount of carbon dioxide is allowed, a small amount of oxygen is allowed, a small amount of ammonia or other trace gases are allowed. It doesn’t have to be, 3, 4, 5 nines of a quality. So, it is quite economical to upgrade into that grid or gas grid quality for sure.
Louis Savard: Right, right, right. Now, you know, we’ve been talking about everything kind of rosy, even though it’s, we’re talking about waste, but it’s all positive. I mean, I’m not seeing many negatives in what we’ve been talking about, but I’m assuming someone out there saying, hold my banana peel, here comes the challenges. Trisha, challenges with anaerobic digestion?
Trisha Aldovino: Sure. So some of the operational challenges, we’ve touched on it a little bit, and that’s with contamination with more complex waste streams. So, like I said, mixed garbage bag waste that just has everything in it; trying to get just the food part is quite difficult. Things like needles, things like cutlery, all the batteries could end up in the organic fraction because we don’t have the good enough separation processes for it, or it’s not perfect at least. So that’s one.
And what comes in also has to come out. So if we’re not good at removing it, sometimes it might end up in the digestate, or sometimes for example, things like shampoos and soaps and stuff, they can degrade and then release some VOCs, some compounds in the gas that reduce the quality of the biogas, and that could be a challenge as well to remove. So that’s one.
The other one is that sometimes the digester just kind of fills up with nonsense, like I said stuff like plastic bags and stuff; but like, let’s say from a farm that doesn’t have any packaging, you might get rocks and sand, maybe broken glass or scrapes of metal, just from working around the fields and over the years, it might accumulate at the bottom of the tank and just fill up with useless stuff and reduce the efficiency of the tank. So that’s a pretty common problem.
Outside of operational problems, there’s a bigger systemic issue with finding enough people to operate these plants. There’s no degree or certification or school, you don’t get a cool ring, and so there’s a little bit of lack of awareness, and specific skill building for operating these digesters. And operating digesters is both like an art and a science. So a lot of operators, they’ll blend their technical knowledge, whether that’s in the mechanical sense with pumps and valves and so on, and or if they have, they also have a background in some wastewater labs. So some of the testings are kind of similar. So they blend their technical knowledge with their intuition because with biological systems, nothing’s ever that predictable, and so you have to be able to think on the fly. And so because there’s no official schools, no official programs, people don’t even know that you can have a career in AD. In fact, I didn’t know I could have a career here, not until like a year ago now. And that’s why at Azura we want to provide that quality education, even if it’s not coming from the coolest university or something, we still want to provide that kind of material so that we can grow the industry and get more adoption.
David Ellis: Absolutely. So we have some of our fleet clients say in the United States, for instance. You know, they’re building three plants now. They’re talking about building 30 plants in five years. Like, it’s those kinds of numbers where when the Azura folks, we go to conferences and they say, wow James might you, you’ve been in this three years you’re a veteran of the game. But for the folks who get in, you know, soon there’s an opportunity for a really rapid advancement as more facilities come on stream. You know, in two years someone can be, you know, relatively senior in the game just because they have a lot of experience that other people have, and just not a lot in time, but just a lot of different experiences in that short time.
Louis Savard: Very interesting. Now hypothetically, if a technical association which show interest in developing a certification that may or may not also include a cool ring, would there, do you see, do you think there would be an opportunity to market that designation?
David Ellis: I think so, yes. You know, we’re aware of like all of the courses in, we know most of the trainers, so across Canada, US, Europe, UK and there is not a national program in Canada at all right now, at this point. And so I think, yeah, there’s a gap there for sure. We know that sewage treatment, plant operators, they have a licensing program, they have hierarchies, they have skill levels, and they know that, with increasing skill levels like there’s better pay, there’s more clarity about what jobs and what jobs are transferrable between different facilities, whether you’re in a, whatever, a class two plant, a class three plant, and what processes are there. So there is, you know, there is a good history with industries that are similar but a little bit different, that we can certainly draw to understand how to model a workforce development program that gives people, really good rewarding careers.
Trisha Aldovino: Yeah, and also when I’ve talked to some of the operators, something that they note about operating a digester is that your everyday work actually has impact on how the process will go. Whether for example, how fast you feed, or how much you feed, it’s going to have like a real impact on how much energy is getting made, and that’s through the work of the operators day to day.
David Ellis: It’s a combination of skills, so it’s not as much like car repair, it’s more like farming. So part of it is, you know, jack of all trades, like somebody, the operator, he or she has to be able to repair the tractor, repair the pump, understand the programming, the PLCs and the control systems, but they also have to be able to, like farming, be able to gauge what feedstock is coming in this week and what’s going to come in next week, and maybe something is different than the weather, and so that’s the art piece as well, which is a lot of experience goes into that in addition to the technical bits of how to keep the equipment running properly.
Louis Savard: Hey, that’s super, super interesting. You know, as an emerging technology, I mean, it’s been around, but as an emerging technology that it is today you know, I may know of an association with an emerging technologies committee that may be looking to diversified designations. I might send a few emails after to this podcast. Yeah, stay tuned.
David Ellis: Always happy to talk.
Louis Savard: Yeah. There we go. We’ll make some connections. Emerging technologies, Dave, future investment, what does it look like?
David Ellis: I see there’s three bits to that. The first is the early waves were, you know, the easiest feedstock material, so that is the straight manure or sewage sludge. Those are pretty well-established technologies. The second wave was in, adding in food waste to those, co-digestion or just food waste systems. I think the future will be the OFMSW, so that would be black bag waste, where the consumer puts whatever they have at the curb, and then that goes to some type of centralized sorting facility. Because as Trisha was saying, current green bin sorting programs, we see little button batteries, we see cigarette butts, syringes, there’s lots of contamination there. And so because of that, the idea of having more a centralized waste sorting and cleaning facility recover the recyclables and the metal, and that same time, being able to generate a more pure plastic free organic material to go to the digester. I think that would be where I see the future going.
Louis Savard: Fantastic. So I, again I’m not going to confirm more than deny that my Silver fork may or may not have been in one of those, but it certainly is. Trisha, you know, the three of us here are talking, I’m sure most of our listeners are probably nodding in agreement with everything we’re saying, but ultimately, something that has this potential of an impact really goes nowhere if the public’s not behind it. How do we get them there?
Trisha Aldovino: Okay. I got a couple of things. Listeners, if your area has an organic waste program, like the green bin program we’re talking about, try your best to separate the organics. Well, I am bad at it too sometimes because I think the Waterloo and the Toronto guidelines are a little bit different and so I’m like, I moved from Toronto, so I’m like, oh, I can put this in, but somebody told me it’s not. Anyways, it really helps the operators when the green bid is well sorted. I mean, like one time one of our clients pulled out car parts from the receiving pit, I don’t know how the car part ended up in the green bin! On a more serious note try to keep an open mind, especially if there’s a digester that’s opening up in your area. Remember all of the waste and energy benefits that we just talked about in this podcast. Lots of the concerns locals might have, the internet loves hate, like truly, so you will find a lot of hateful things, or not even just hateful, but a lot of the failures of digesters get good coverage compared to successful ones sometimes on social media and on news outlets. But because we’ve been at this technology for years, a lot of the concerns that locals may have can be addressed by engineering, or engineers while they’re designing the facility. Of course, it’s important to if you have concerns to voice them, but keep an open mind, know that a lot of the problems can be solved now, technologically speaking. And finally, if you’re looking for a job where what you do for work has an impact on everyday things maybe look into AD,
Louis Savard: There we go. So that’s a full cycle, right? Believe in AD for your waste reduction, renewable energies, and why not get paid while you’re working at the same time, right? This is this fantastic. Well there you have it. It’s just amazing after these discussions that, that we realize what we can do with this waste-to-energy applications, how it’s also addressing some of our renewable energy needs. Now, in the future, and for decades and decades to come.
I truly think the future looks promising with this technology. I’ve seen it in action. I’ve never operated it, but I have played with it. It’s truly a fantastic, amazing technology. Dave Trisha, thank you so much for being with me tonight.
David Ellis: Oh, thanks for having us.
Trisha Aldovino: Thank you.
Louis Savard: Before I close out any final words, I always want to give my guests the final word.
David Ellis: Trisha, any closing comments?
Trisha Aldovino: Okay, totally follow us on YouTube, that’s where we post free educational videos, blogs, interesting things about the industry. So that’s YouTube search, Azura Associates. You can also follow us on LinkedIn, same thing, Azura Associates. LinkedIn’s the best for just getting the most recent updates about what we do and the kinds of projects we’re doing. Actually, a lot of our projects are confidential, so most of the time the posts we’re just like, “Ooh, we’re going somewhere cool.”
David Ellis: We take a lot of pictures in the Tim Horton’s parking lot of our various travels, yes, it happens.
Trisha Aldovino: So yeah, fun Tim Horton’s pictures and when we’re going to hold our next webinar or next guest appearance, like this one.
David Ellis: Yeah. It’s been terrific. So really thank you and thank the association for having us. I really think that, you know, this is an overnight success that’s been 40 years in the making. Waste-to-energy is the only carbon negative fuel that we have, it’s, it is something we need to take seriously and lean into it where we can.
Trisha Aldovino: If you have any questions, we are happy to answer on YouTube, on LinkedIn, in my emails, in the info@AzuraAssociates.com, anywhere.
David Ellis: Yeah. We’re real humans, we actually do respond to things.
Louis Savard: Perfect. And I can confirm this was not AI generated. I can confirm it. They are real. Thank you. Thank you very much. As always, I want to thank our listeners for joining us. Remember, if you are interested in learning more about today’s topic or if you had a topic, you would like us to feature in a future podcast, please email us at techtakes@oacett.org.
‘Til next time, bye for now.