In this month’s episode of the Oil & Gas Measurement Podcast, host Weldon Wright is joined by Diane Saber of REEthink, Inc., to talk about renewable natural gas and its challenges.

Learn about concerns faced with the introduction of renewable natural gas (RNG) into our transmission and distribution systems.  The discussion takes a historical twist as they discuss many similar challenges faced 60+ years ago, as our industry transitioned from manufactured “Town Gas” to cleaner and more stable Natural Gas.

What is Renewable Natural Gas Show Notes, Links, and Insider Terms:

• Union Oil – Union Oil Company of California (UNOCAL) was founded in 1890. UNOCAL merged with Chevron Corporation in 2005. The UNION 76 gasoline station chain is now owned by Phillips 66.
• Fluor Daniel Consulting, a part of Fluor Corporation, is a global leader in location strategy consulting.
• Gas Technology Institute – GTI Energy develops innovative solutions that transform lives, economies, and the environment
• Bio-Methane or Biomethane is a fuel produced by “upgrading”, or purifying the biogas, into a renewable product that is interchangeable with natural gas.
• BioGas is produced by anaerobic digestion of organic matter, such as dead plant and animal material, manure, sewage, and organic waste in an oxygen-free environment. The natural bacterial decomposition of organic matter releases large amounts of methane, cardon dioxide, other gasses such as hydrogen sulfide. By capturing the escaping gases, greenhouse gas emissions to the atmosphere are reduced. After purification and dehydration biogas is interchangeable with natural gas.
• “Manufactured Gas” / “Town Gas” / “Coal Gas” are used somewhat interchangeably to refer to synthetic fuel gases produced by the gasification of combustible materials, usually coal, but also wood and oil. Manufacture Gas was important for lighting, heating, and cooking purposes throughout most of the 19th century and the first half of the 20th century. The fuel gases generated were mixtures of many chemical substances, including hydrogen, methane, carbon monoxide and ethylene, and could be burnt for heating and lighting purposes. Coal gas, for example, also contains significant quantities of unwanted sulfur and ammonia compounds, as well as heavy hydrocarbons, and so the manufactured fuel gases needed to be purified before they could be used.
• North Dakota has the only remaining commercial-scale coal gasification facility in the United States that manufactures natural gas.
• Renewable Natural Gas (RNG) is natural gas that is produced by capturing and processing the gasses produced from a variety of renewable processes. The RNG must be processed and filtered to achieve pipeline-quality standards, so it becomes “interchangeable” with geo-sourced natural gas. The methane content must be concentrated to approximately 90%, inserts reduced to acceptable limits, and toxic and\or damaging contaminants removed.
• RGN Feedstocks: The biomass that is the raw product used in the production of RNG. Common sources are:
  • Landfill Gas – The natural deterioration of the garbage in landfills releases a variety of gasses that must be collected to prevent them from reaching the atmosphere. While large amounts of methane are present, undesirable and/or toxic gasses may also be produced.
  • Digester Gas – Anaerobic (without oxygen) Digesters that produce methane gas from various biomass sources, such as human sewage, cattle, and swine feedlot waste, and non-woody plant material
• Siloxanes are a class of compounds having a short repeating unit of silicon and oxygen atoms (either in a chain or a ring) with organic side chains. They are not found in geologically sourced natural gas, but they are a common contaminate pervasive in RNG sourced from landfills.
  • Siloxanes are non-toxic and are frequently used in food processing and preparation. They also appear in cleaning agents, cosmetics, personal care products, lubricants, car wax, and many other consumer and industrial products. When burned, they create silicon dioxide, which is basically sand as a hot gas. As it cools, it is deposited on the interior surfaces of engines, burners, and turbines, reducing efficiency, and eventually damaging the equipment. Even small amounts of siloxanes in the natural gas stream are damaging, since the effects are cumulative over time.
• Anaerobic Digestion is a process through which bacteria break down organic matter—such as animal manure, wastewater biosolids, and food wastes—in the absence of oxygen. Anaerobic digestion for biogas production takes place in a sealed vessel called a reactor, which is designed and constructed in various shapes and sizes specific to the site and feedstock conditions

What is Renewable Natural Gas Full Episode Transcript:

Weldon Wright: Hello and welcome to Episode 21 of the “Oil & Gas Measurement Podcast,” sponsored by GCI, the Gas Certification Institute, which has been providing measurement training, standard operating procedures, and consulting services to the oil and gas industry for over 20 years.

GCI proudly partners with Muddy Boots Online, offering measurement and operations professionals a true unified, cloud based field operations option. Visit GasCertification.com to find out how Muddy Boots can streamline your field operations.

Announcer: Welcome to the Oil & Gas Measurement Podcast, where measurement professionals, Bubba geeks, and gurus share their knowledge, experience, and likely a tall tale or two on measurement topics for the oil and gas industry. Now your host, Weldon Wright.

Weldon: Hello and welcome to Episode 21 of the “Oil & Gas Measurement Podcast.” I’m here with Dr. Diane Saber, President of REEthink. Diane, how are you today?

Diane Saber: I’m doing very well. Thank you, Weldon. Thank you for having me on.

Weldon: Tell us a little bit about yourself, Diane, and what you do and what REEthink does.

Diane: A little bit about myself. I have been working with the natural gas industry since about 1994, but I’ve been working in the area of energy pretty much since I graduated from college. After college, I worked for Union Oil, Union 76, in their chemicals department. I was a salesperson. I did a lot of technical work for them.

At that time, there was nothing close to renewable natural gas to speak about. Through all of the work that I had done through a number of years, I ended up working then, eventually, after I got my PhD, for Fluor Daniel, a big consulting house, and Ebasco, another big consulting house that dealt with hazardous waste.

My PhD at Minnesota really focused on hazardous waste. It was, in fact, a PhD that looked at bacteria that degraded xenobiotic or difficult to degrade compounds. In fact, my specialty is chlorinated compounds, believe it or not.

I took that information, and I started to develop some techniques and approaches that might be applicable for using bacteria to clean up hazardous waste sites. The word “bioremediation” hadn’t been developed yet.

In fact, that word came out of my laboratory at the University of Minnesota. We tried a whole bunch of different things to try to use bacteria to clean up hazardous waste. A couple of those ideas are still in use today.

I really focused on hazardous waste for many years, until about 1994, when I decided to go over to the Gas Technology Institute, which, at the time, was called the Institute of Gas Technology, and start to work on applications of microbes to hazardous waste particular to natural gas.

That would be associated with a process which is no longer used to produce a gas like product. That process is called manufactured gas or town gas production. It’s a great, great product that really took the world, frankly, from the age of coal into the Industrial Revolution.

Finally, gaseous fuel could be brought to an industry. An industry could predict and be very secure with having a product that was reliable, for its day. It was from that application that you really got industry cranking around the world.

Weldon: So many people, Diane, especially the younger couple of generations in our industry, they have no idea what town gas or manufactured gas is. That’s something that is not taught in our classes. Most of our college classes dealing around oil and gas production don’t touch on that.

There’s a lot of folks out there, generations of folks out there, that have never really known this concept of manufactured gas.

Diane: It really is interesting, especially, as we’ve known, in this industry, the last 20 years, 15 years in particular, we’ve had a lot of really seasoned professional experts in the industry and just walking the path of natural gas as an industry across the world, they’ve all retired.

Even verbally or the legacy being passed down, just in stories of what it was like working through what would be the ’40s and ’50s into the ’60s, is gone now. It is a shame.

There was a big energy transition away from wood and coal to manufactured gas. Then, of course, the next big transition was from manufactured gas to natural gas, which is what we use today.

You’re exactly right. Was it perfect as an energy product? No, it wasn’t. It caused a lot of us a lot of problems with hazardous waste but it was better than coal. The days of Dickens were gone when manufactured gas became a reality.

Weldon: I think that we’re going to build on one word you said there. We had manufactured gas and we moved to natural gas, meaning coming right out of the ground, right?

Diane: That’s exactly right.

Weldon: We may need to polish it. We may need to remove a few heavies for it, but it’s a natural product, right?

Diane: Yes.

Weldon: I know where your direction is headed lately. Has been around renewable and alternative gas sources. Tell us a little bit about what your work has been and what your focus has been lately around these renewable natural gas products.

Diane: Sure. What’s of interest here is…I’m a microbiologist. I specialize in bacteria that degrade compounds or create compounds through their natural actions. The fact of the matter is bacteria, no matter what they eat as a fuel source, they leave behind a fingerprint. That fingerprint is pretty pronounced.

In fact, there is fingerprinting of manufactured gas waste that if you extrapolate that or use the techniques, you can actually fingerprint gas, as well, using almost the same techniques.

About the year 2004, ’05, or ’06, I started to see a transition with the industry, going away from understanding natural gas and perhaps looking at new, innovative gas sources.

You have to remember, and you probably remember it, Weldon. Remember at that time shale gas had not really hit the United States yet. Everybody was a little concerned about natural gas sourcing worldwide. Before the United States entered into the shale gas era, we were quite dependent on other sources for our gas. That made us dependent and vulnerable.

When shale gas hit, there was still some excitement about understanding new sources, but this renewable natural gas came to the forefront afterwards. It would be, more or less, in 2012, 2011.

Using those exact same techniques and some of the approaches, I started to look for, once again, fingerprints associated with what would be renewable natural gas, as we call it.

What we’re actually talking about is biomethane. That is anaerobic, or without oxygen, degradation of organic compounds and bacteria under natural circumstances through a consortium of works in action. They work together as an uncooperative team.

They produce methane. They also produce a lot of carbon dioxide and other constituents. That methane could be used as a substitute gas for natural gas, which is in our system.

When I was at the Gas Technology Institute, I took the responsibility to try to understand if we were to transition to more of a renewable product, what would it look like? Did it look like natural gas? What did it chemically look like?

Weldon: I think, Diane, that 2012 is the date you’re throwing out there. That’s when we started into this concept of renewable natural gas.

If we roll the clock back 10 or 15 years before that, we really have this concept of, let’s just say, biomethane translated into landfill gas in the early days. That was really the only place we got it from.

Maybe a few cities were using a little bit of digester gas internally for fuel, but landfill gas, they looked at cleaning it up and putting it into our system as a way of getting rid of contaminants, of hazards they had in the process.

It really wasn’t intended to be a replacement fuel. Almost all of that early landfill gas went into gathering systems, where we had gatherers and processors that knew how to clean up. They knew how to test. They knew how to monitor gas.

We were also diluting very small quantities in the massive gas from a production field, right? Today, that has really shifted. I know there’s a lot of concern. This is why I met you initially, was in the AGA, the American Gas Association, meetings in the transmission management committee as we talked several times through some of the issues around specifications.

I know in our industry we’ve never thought of our gas quality as product specifications, right? We had maximum inerts, maximum CO2, maximum nitrogen.

We had minimum BTUs, but we’ve thought of it as a full fledged specification of what are all the things that have to be in our gas, what are the things that can be in our gas, and what are the things that can never be or can never be in certain concentrations?

I know that’s what a lot of your work has been around. Can you talk to us a little bit and tell some of our listeners about what are those concerns companies are seeing, especially when this biomethane is getting introduced into the distribution system level instead of into our gathering systems?

Diane: Sure. I’d be happy to. Natural gas, what we were describing a little bit before, natural gas came to be a product that was used, starting probably in the 1920s, 1930s. At that time, it was replacing manufactured gas. They knew how manufactured gas performed. Can you imagine that transition? That was probably a tricky one, as well.

As, little by little, they understood the performance of natural gas, they knew it was more predictable because the product itself is very predictable. There’s this whole aspect to understanding natural gas that falls into the historical category. Historically, we’ve known it to perform this way. Historically, we’ve had problems with this or no problems with that.

What was interesting about understanding natural gas, it was only a little later on where various companies who had new sources came online…They needed to define what a common goal or a common specification or tariff, as we call it. It would be suitable for a new producer coming onto the natural gas line.

What’s really amazing, though, Weldon, to me is that you have gas all across North America, if not all the way down through Central America, as well, that’s exceptionally consistent. We have a gas product that falls within a certain range in its heating value, certain range within its inerts concentrations, and so on and so forth.

That was both purposeful, but also it was also a matter of understanding that product really well through years and years of applications.

When we talk about a new energy product such as biomethane, we have to have a full understanding of what it is and what it isn’t. When we talk about what it is, what I just described a couple of minutes ago, is very applicable.

It is a product that contains quite a bit of methane. However, in its natural form it’s not a lot of methane. It can be anywhere from 40 to 65, 68 percent methane. There’s a lot of other stuff in there because bacteria, which degrade organics, when they produce this raw biogas, it isn’t to meet any natural gas spec. It’s just nature.

They also produce a lot of inerts with that.

The goal, then, was to take this raw gas and define what it needs to be that might be suitable for an introduction to a natural gas pipeline grid. Immediately you can see, well, we’re going to have to strip out a bunch of stuff. We’re going to have to strip out some inerts, a lot of inerts. We’re going to have to strip out carbon dioxide and oxygen and nitrogen, for sure.

You’re also going to have to strip out that awful compound, hydrogen sulfide. Can’t have that in there. There’s hydrogen sulfide in raw biogas.

Then, there’s also this aspect of stripping out or getting rid of any moisture, because moisture’s really…That’s really problematic when it comes to corrosion in a pipeline. You have to make it a dry gas.

Then, there’s this other stuff that might be in biogas. That gets back to what you were talking about before. Where did the biogas come from? Did it come from a landfill? Did it come from an anaerobic digester that might be used on a farm?

You know, farms use digesters all the time. They don’t talk about renewable natural gas. What they’re talking about is waste minimization of manure because they really don’t want to have manure on their property any more than they need to have. It can be considered environmental…a black eye.

They have to worry about the runoff from manure. They want to contain it as much as possible. They digest it and at the end they’re not necessarily looking for biogas, but they are looking for a substrate or an end product that can be used back on their crops again so they recover the nutrients.

They also can get some bedding material from the bottoms of the tank. It runs the gamut. You have the not so clean sources of landfill all the way to the pretty, really, really clean sources of waste that comes out of animals or animal manure.

Weldon: That’s one of the things that I was surprised about. I grew up around agriculture. I actually worked for a municipality in a public utility for a while. They were actually using a little bit of digester gas for the power generators in their own wastewater treatment plants.

When you talk to people about the sources of RNG, of renewable natural gas, and you say, “Well, there’s gas from landfills, wastewater treatment plants, digesters on farms,” immediately they turn up their nose and they go, “Oh, wastewater treatment plants and farms, that’s awful.”

The farms are probably the cleanest form of biogas we get, right? With digesters at wastewater treatment plants being the second. The worst is probably landfills, isn’t it?

Talk to us about some of those bad things that come out of the landfills. Those tiny percentages of stuff.

Diane: Yes, you’re absolutely right.

What I always say when I give a talk to groups is, “Just imagine everything you’ve thrown out in your life. Everything that’s gone out in the garbage.” I bet you’ve thrown out a lot of stuff that you didn’t eat for a meal, but I bet you’ve also thrown out empty bottles or nearly empty bottles of products that you use for personal hygiene or for cleaning around the house.

Sometimes we inadvertently throw out some empty bottles and nearly empty bottles of chemicals we use around our house, as well as sometimes people – we know this – throw our fuel oils or spent oil from their car, or even pesticides, herbicides, and products that you would use on your lawn.

All of that goes into the garbage can. It gets picked up by the waste company, gets thrown into a landfill, and it stays there until somebody pokes a straw into it and starts letting that gas or volatile compounds come out the top.

For sure there’s going to be methane in there, but also anything that you throw out in the garbage, if it has got a low vapor pressure, then it’s liable to come out as well.

Weldon: Exactly. I think that’s what scares some of the folks in the industry more than anything else. We understand methane, we understand CO2, we understand water, we understand oxygen. Water, that’s the easy stuff to get out. We could dry gas out. We know how to do that.

In the processing world, we’ve been dealing with removing CO2 and even nitrogen, although it’s a little bit harder. We can get that stuff out of our natural gas. We know how to concentrate and get around that, even oxygen. We don’t like oxygen, but we know how to get it out of our gas.

Those other compounds, especially stuff in those smaller concentrations that cause problems down the road, those are things that we’re really uncomfortable about. The majority of tariffs, the majority of our gas contracts for purchased gas, they don’t contain anything for these small concentration contaminants. The siloxanes is probably…Am I pronouncing that right?

Diane: That’s right. In fact, siloxanes are really a problem. Americans – well, all of us in North America – love siloxanes because it imparts a shiny or a slippery look to various applications. For instance, we use it in hygiene products because it makes our hair shiny. It’s used in soaps because it has a nice feel to it.

It’s used in cleaning products because it’s able to make the liquids more of a surfactant feeling. As well as it seems to work a little bit better when you have additional siloxane added when you have bubbling situations. It’s also a defoamer. We use it quite a bit in North America, in all of our products. It, of course, goes out in the garbage or the wastewater.

Weldon: We use it in makeup. We use it in hair products. It’s even used in some food and some food prep products. That makes it sound like it must not be toxic. It must not be too bad. It’s really not us that it hurts. Is it?

Diane: No. You’ve got it.

Weldon: What happens when we burn it?

Diane: You’re absolutely right. The rubric or the matrix that I always look at are three things. Are the compounds that are found in the gas of concern to the human health and the environment –     that would be us or the environment – by way of emissions from burning of the gas?

Is it of concern to pipes, pipeline integrity? Does it impart any properties that might cause problems for the insides of the pipe. The third aspect is, does the compound impact the end use equipment?

Siloxanes, your example – it’s a great one – doesn’t do anything for human health and the environment. It’s completely inert to us. It’s basically a compound that’s got a little bit of sand or silicon attached to it. Doesn’t do anything to the pipeline integrity.

But, when you burn the compound, the alkane and the oxygen come off. That silicon is deposited on the burner tip. Over time – maybe you’ve seen it even – you see a white or a glassy surface building up around a burner tip. That’s from siloxane buildup. It’s a glassy buildup.

What that does is it makes a burner tip, especially high energy efficient burner tips, get smaller and smaller and smaller. That’s really dangerous for keeping a burner light going or an appliance or…

Weldon: Or depositing inside of a turbine.

Diane: Yes, exactly.

That’s a problem for the end use equipment. There’s other things in RNG, or biomethane, as I like to call it, that are problematic. That would be chlorinated and fluorinated compounds. Of course, chlorine and fluorine, they’re problematic for human health and the environment.

Also for pipeline integrity. If it’s mixed with hydrogen or a source where that chlorine could bind to a hydrogen, you have hydrochloric acid, or hydrofluoric acid if the fluorine breaks off the parent compound. That’s an acid that could deteriorate the inside of the pipe. Similarly, in the end use, you don’t like having those compounds around.

Another one we have to worry about – probably, you’ve talked about this before – is gas companies use odorants so that we, as humans, detect methane in our homes or in our environment. We’ve tuned ourselves to understand, “Oh, that’s the smell of natural gas.” That’s because of the odorant we add.

We don’t want to add any compounds from RNG or from biomethane that would cause that odorant to be masked or changed a little. That’s a problem to us because we’re so accustomed to that smell that if it changes just slightly people may not notice there’s a leak in their house so they’ve got a problem somewhere.

That’s another important element. We also…

Weldon: We also…I’m sorry. Go ahead.

Diane: I was going to say the other thing is metals. There were metals we don’t want in that gas, either.

Weldon: There’s metals in a lot of things in our environment that we don’t want in these days. It falls into that same category as microplastics. We didn’t realize we were doing bad for so many years, right?

Diane: Yes.

Weldon: Backing up to what you said just a couple of moments ago, when we look at these other compounds, these other things that are in our natural gas, we don’t know what to do with them as an industry. For instance, one of the concerns out there…You talked about masking our odorants or changing the smell of our odorants.

We see some literature out there. I’m not sure I believe the validity of some of this literature, but we see stuff that tells us that, hey, some of this RNG is actually creating a need for higher concentrations of odorants. That’s something that sets off the klaxon bells and the alarms in a hurry for your people in the LDC world, right?

Is that something that’s been well quantified or is it still something we’re trying to figure out?

Diane: Boy, you just gave me a topic that I could speak about for a while. This is a hot button item right now. It’s so disconcerting that we’re hearing not just in the United States, but all across North America this incidence of needing more odorant than gas systems have ever needed before.

Not everybody odorizes at a certain level. It depends on if you’re a local distribution company or a transmission company. If you’re a local distribution company, the amount and the type of odorant you use is really, really important.

You don’t see many gas companies or local distribution companies just adding odorant willy-nilly, left and right, just because things aren’t quite right if there’s too much odorant added, that can cause problems, as well. Too many people consider, “Maybe there’s a leak in my house. The smell is just too strong.”

Yet, we’re facing circumstances where we’re not quite sure…Is it the performance of the odorant or is it there’s something in the gas. What you’ve brought up is, actually, a bridge between renewable natural gas or biomethane and natural gas.

Natural gas supplies are changing, as well, on top of everything else. It’s changing. I mentioned it before. It’s changing because of shale gas. We’re just poking our nose into what is shale gas really like.

What do we have to use? How do we use shale gas? How do we refine shale gas? What is its characteristic different from what is considered traditional natural gas sources that we’ve known for many, many years until shale gas came along?

One thing is pretty clear. Shale gas has got many more heavy hydrocarbons associated with it. We feel that it’s a hotter gas coming out of the ground, so you have more ethane, propane, and butanes plus.

If that gas is not refined, so those nice products are taken off and used in other circumstances or sold at a higher premium. If it’s not refined, it ends up in the line.

In general, the burden of natural gas and the odorant together causes the odorant, we think, to be a bit overwhelming. Some odorants can handle that bombarding of compounds more than others.

That’s the place that we are with respect to research. Where would those compounds come from renewable natural gas? There are a ton of small compounds that are really not of any environmental concern. They’re not a concern to the pipeline or the end user, but they might be a concern because they’re overloading the odorant which is in the gas.

You have to think of it like a sponge. The odorants are like a sponge. It’s sucking up all these little compounds. It’s trying to protect the system from being overloaded by compounds that might give problems to people being able to recognize smells.

If the odorant is overwhelmed over time, you’ve either got to add more odorant or you’ve got to make sure that those little compounds are gone. They’re stripped out of there.

Honestly, that’s where the research is right now, is we’re trying to understand what is causing this funny space of not enough odorant. The smell is slightly different sometimes in RNGs coming into the system, as well as shale gas.

Weldon: Fascinating, Diane. Unless you’re in the local distribution world and unless you’re one of those guys that’s actually in charge of this, maintaining odor injection, filling those tanks…

Very few people in our industry, nobody on the upstream part the industry, almost nobody in the gathering and processing industry, and very few people in the pipeline transportation industry have any idea how small the concentration of odorants are in our gas.

This is not something that we’ve blended 10 percent, or 1 percent, or even 1/10 of a percent with something with our gas so we can smell it. Those are really factionals down at the part per million or maybe even hundreds of parts per billion level that we, as humans, can smell.

It doesn’t take a lot of something to absorb or mess with to overwhelm those odorants.

Diane: Absolutely. In fact, there’s studies that have been done by Chevron and others that have been developing and perfecting blends for various companies where the company will come back and say, “Your odorant is degrading. It’s not there. Something’s wrong with the odorant.”

They’ll run tests and the odorant is just as strong as when they put it in the pipe. There’s something else going on. We recognize that. We’re not quite sure what it is, but we’re looking for that opportunity to do a real world test.

Weldon: Maybe our noses are getting worse. That could be a possibility, too.

Diane: Maybe. Anytime you do…It’s a funny thing, you bringing this up because anytime you’re interfacing with humans, humans…Our habits are so different. Our physiology is so different. We eat different foods across North America.

Our lifestyle patterns are different. Every single one of those aspects has an impact on our olfactory system. When we create an experiment, you can just imagine…What would you consider standard? What would you consider your control? What would you consider your outlier? Those are tough questions.

They’re also expensive questions. We have to really make sure a study is good before we start interacting with humans because, boy, that’s something, right?

Weldon: I’ve probably spent 30, 32 years in the industry before I knew that there’s companies that manufacture tests. There’s distribution companies that routinely test their employees to verify their sense of smell to the odorant in natural gas.

There’s kits where you sit there and have them sniff this. Have them sniff that and make sure that your employees in the field, everyone in the local distribution system, is charged with lead detection at some level or another…To make sure they can smell the odorant.

There’s a lot of pieces there. When we start talking about messing with that natural gas…Again, backing up from that whole path. We started with manufactured gas, town gas, which was relatively low BTU by our standards, right?

We moved to gas oil gas, which was pretty predictable just out of the ground. Then, we started capturing natural gas produced coincidental to oil and gas production. That got us some liquids, but there’s not huge quantities of that.

Then, we got into a shale place. Some of them, like you said, are very high in natural gas liquids. That removing, stripping down, or processing to keep us that that BTU value we want, that’s been key.

Then, when we look at RNG, and I think most of the folks in our industry are aware of this, we’re worried about keeping that heating value up, especially with the CO2 that can be in there.

Then, and I don’t want to start you off on a whole another tangent, but talk to us briefly, maybe five minutes or so, about what happens when we start looking at hydrogen because hydrogen, of course, is another piece to this renewable natural gas or alternate natural gas puzzle.

Hydrogen very much takes us back to the world where we’re potentially looking at a whole lot lower BTU product to deliver to the end user.

Diane: That’s correct. Hydrogen is a field that there still are so many unknowns when you look at it in 360 because right now, as I said, this industry, our industry, natural gas, is…Even before natural gas, manufactured gas, we learned through many, many years of experience the performance of that product in general and specifically when it came to certain industries.

When we start to bridge into hydrogen, we don’t have that 360 experience at all. We still don’t know basic things about how it impacts our pipes, especially if they’re metal pipes. If they’re plastic pipes, plastic pipes are joined, and are interfaced with pieces of equipment which are metal.

Hydrogen and metal, it’s a tricky space. We don’t know how those interfaces are going to perform in the short, medium, and long term, as well as just calibrating everything against hydrogen.

Then, there’s this whole aspect of something we just talked about, odorant. Hydrogen is the lightest, fastest element we have. It’s the first on the periodic table. It’s quite wily. It’s a speedy thing. It’s speeding all over your pipe. It doesn’t necessarily follow that pathway that we all know to be natural gas, which is CH4.

Methane’s a bigger molecule. It’s slower. It’s got different characteristics. Hydrogen would outrun it. What happens if there’s a leak? Does the hydrogen way outrun any methane that might come out as well or does it, in particular, outrun the current set of odorants that we have at our disposal, which were crafted around the characteristics of natural gas or of methane.

We have to think how or is hydrogen going to react the same way as we are expecting with methane. Intuitively, it wouldn’t, right? It’s really different.

As well, when we get to using hydrogen, we probably will have to talk about storage of hydrogen. Will it be stored the same way as methane is stored or natural gas is stored? When we pull the gas out of the ground or storage fields, will it act the same? Do we have the same characteristics?

There’s a lot of unknowns right now. In particular, I love the thought about the things we really know and we’ve taken as common knowledge. Everybody knows this.

We’re going to have to reethink, do we really know it with respect to hydrogen. Easy one is odorization.

Weldon: Odorization, that’s a new one. I hadn’t thought about that piece of the puzzle. I know that there’s many pieces that fit even around the mundane world of measurement. Most of the concern out there is with what’s going on with our metals, with our pipe, in particular, with our joints, with our fittings.

What’s going on with our seals? Just from a measurement side, there’s other subtleties that I don’t think we’ve even begun to look at yet. Maybe some of the ultrasonic manufacturers have. When you start looking at that small molecule that races down the pipe as you put it.

As we put higher and higher concentrations of hydrogen into a natural gas mixture, all of a sudden the development of flow profiles in our meter tubes is not the same.

We’ve relied on that drag up against the side of the pipes, help us develop that profile that we’ve built our orifice flow equations with that we’ve calibrated our other meters to. Even that changes. There’s a lot of moving parts here.

We’re going to have to spend a lot of years figuring out how to do that well, how to do that safely. That doesn’t mean we’ll take that time. It means we should, might be the better word for it.

Diane: Yeah. You know that in the space in particular that you work in, and that’s really the analytical space, that’s going to be an interesting one as well. Our industry I say it’s like a man made, a natural wonder.

Man Made wonder of the world. The pipeline network we have across North America, bridging into South America is fantastic. What is going to be problematic is, and when we start to use that network and not understand how it’s going to perform, when something that we’ve known for so long has had the characteristics that we’ve needed for what it needs to perform.

That’s pretty much taking natural gas or manufactured gas from one point to another. You start adding hydrogen and we don’t know how it’s going to perform. Are the flow patterns going to be the same? Is it going to be as predictable and is it going to be as safe as it is right now? I think those are the big questions that we have outstanding.

Weldon: Diane, you’ve given us a lot to think about. You may even give a few of my listeners some nightmares. We appreciate everything you’ve shared with us. If any of our listeners have more questions, if they need to talk with the Reethink, give us your contact information again.

Diane: Sure. REEthink, by the way, is a company that works specifically in the area of writing specifications for renewable natural gas or biomethane. We also write verification and monitoring programs specific to renewable natural gas projects.

Real briefly, those two are interconnected. Making the gas is one thing, but checking and make sure it’s the quality that it needs to be safe to get to the pipeline is a whole nother thing.

It’s REEthink with two Es, R E E T H I N K. My email is Diane.Saber@Reethink.net. You can find our website at reethink.net. The office number is 847 400 7789. Please feel free to shoot questions. I’m always interested in helping and this has been great, Weldon.

Weldon: Thank you so much for taking the time to do this. I know you’re in popular demand and you’ve been in a lot of places. You were in Sweden three weeks ago?

Diane: Berlin.

Weldon: Berlin. Were you in Canada?

Diane: I was in Natural. In fact, this is really interesting. The Bureau of Normalization of Quebec, the BNQ, is a normalization group for the province of Quebec. They have created a national standard. This is a group effort that takes into account all of the natural gas companies, transmission and local distribution, as well as RNG producers, regulatory bodies, government and so on.

We’re creating spec or I’ve been leading the effort to create a national spec that hopefully will come down here to the United States as well soon. We’ll all be speaking with common knowledge.

Weldon: Thanks again for all your time, Diane. I certainly appreciate this and look forward to seeing you at a conference or an AGA meeting again soon.

Diane: Thank you, Weldon. Have a great day.

Weldon: I want to thank each of you for listening, and I hope that you found this episode interesting and informative. If you did, please share our podcast with your coworkers, your boss, and others in the industry. We will have a full transcript of this episode along with Dr. Saber’s contact info, in the show notes on our website, pipelinepodcastnetwork.com.

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Transcription by CastingWords