In this episode of the Oil & Gas Measurement Podcast, host Weldon Wright is joined by Tony Mannion to discuss the challenges associated with CO2 measurement.

CO2 Measurement Challenges Show Notes, Links, and Insider Terms

• Tony Mannion is the NA Business Development Manager at Emerson. Connect with Tony on LinkedIn.
  • Emerson is a leading global technology, software, and engineering company providing innovative solutions for customers in industrial and commercial markets.
• ASGMT – The American School of Gas Measurement Technology is an annual three-day Oil & Gas Industry training conference, held in Houston, Texas each September. ASGMT is organized and hosted by an all-volunteer committee and offers a cost-effective training option for our industry.   In 2024, ASGMT offered over 150 one and two hour training sessions, with about one third of those being hands-on sessions, with the latest technology.
• “45 Q”  refers to the Section 45Q Tax Credits for Carbon Sequestration.
• Carbon capture and sequestration (CCS) technologies are intended to reduce carbon dioxide (CO2) emissions from fossil fuel-fired power plants, as well as other large industrial sources.
• Enhanced Oil Recovery (EOR) is a  “tertiary” oil recovery process where captured CO2 is injected into geological formations to assist in oil production.
• Triple Point – Defined in thermodynamics as the is the temperature and pressure point at which the three phases (gas, liquid, and solid) of that substance coexist in thermodynamic equilibrium.
• Critical Point – In thermodynamics, a “critical point” refers to the specific set of temperature and pressure conditions at which the distinction between a liquid and a gas phase disappears
• Supercritical Phase is a fluid operating at a temperature and pressure above its critical point.  In this range, very small changes in temperature or pressure and result in large changes in density.   The measurement of supercritical fluid can be difficult with many types of measurement equipment due to the difficulty in measuring or prediction density.    Coriolis meters measure and report directly in mass, simplifying the supercritical CO2 measurement challenges.

CO2 Measurement Challenges Full Episode Transcript

Weldon Wright: Welcome to episode 38 of the “Oil & Gas Measurement Podcast,” sponsored by GCI, the Gas Certification Institute.

For more than 20 years, GCI has been providing measurement fundamentals training in measurement standard operating procedures to the oil and gas industry. GCI’s instructor-led gas measurement and liquid measurement training classes, coupled with comprehensive measurement standard operating procedures, provide valuable tools for both back office and field personnel.

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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 another episode of the “Oil & Gas Measurement Podcast.” I’m your host, Weldon Wright, with FpvPrime Measurement Consulting. I’m here at the American School of Gas Measurement Technology, sitting in the middle of the exhibits hall, with Tony Mannion, the North American Business Development Manager for Emerson.

We’re going to talk a little bit about some of the challenges around CO2 measurement. Before we do that, Tony, thanks for being on the episode. Tell us a little bit about yourself.

Tony Mannion: Thank you, Weldon, for having me. I’ve been in the process control and automation industry for better than 30 years at this point in time, dedicated to flow for over 25 years. I’ve dealt with fluid flow of all types of fluids and all types of flow technologies over the years.

I’ve got an engineering background from Rochester Institute of Technology and worked for several suppliers of automation and process control equipment. I’ve been in a lot of different plants, seen a lot of different situations, couple of places I guess I would probably want to walk away from faster than I want to get involved with.

Recently, I’ve been really focused more and more on CO2, CO2 measurement, CO2 sequestration, the challenges. CO2 is not your typical fluid to deal with. I guess the nerd side of me gets interested in the eccentricities of CO2. It’s a dynamic fluid. It presents quite a few challenges when you start trying to get into the measurement aspects of CO2.

Weldon: Tony, challenges and nerd is OK. We like to say on this podcast that we geek out every now and then, so it’s OK. We do that some here. Before we start into this, I’ve had a couple of requests for the podcast to do some more information on CO2 and CO2 measurement.

A few episodes ago, we did one with Stephen Anson. Stephen talked about his work with API and the new coming API standards on supercritical fluid measurement and CO2 measurement. We talked about some of the terminology and all there, but we didn’t talk about the hardware, about what’s required, how we get there.

Before we go into that, one thing that our listeners might want to hear about is that we hear about 45Q, 45Q CO2, 45Q tax credits, but there’s not a lot of information with that. One of the few things I know about it is 45Q doesn’t tell us a lot about measurement. 45Q talks about metric tons. It doesn’t talk about any of the stuff we’re used to measuring.

Tony: Yeah, that’s correct, Weldon. It’s one of those areas where, if you look at just the general trend, you’ve got the socioeconomic portion, which is people are saying, “We need a greener society. We need to capture CO2.”

That all makes sense, but the economic piece that’s tied to that, is, as we know, you’ve always got to be able to justify the expense of capturing or doing any type of process or measurement system. Then the government’s involved, obviously.

This is where the 45Q comes in. Now, 45Q in general was derived many years ago, and then it’s enhanced through the Inflation Reduction Act. The idea, basically, being that the government will offer you tax credits in the form of X number of dollars per ton of CO2 captured. It’s based upon the weight of CO2.

Now, the variability in that and some of the questions that have popped up around 45Q, and some of this is being addressed under API of how we measure, the types of measurement, what’s involved with the measurement.

I’m not on the API committee — we have members on the API committee — so I can’t speak specifically to what’s going on with the API right now, but I know they’re heading towards from the measurement aspect. From the 45Q aspect, it just says so many dollars per ton is your credit, your tax credit, or so many dollars per pound.

There’s no delineation or explanation regarding the quality of the CO2 that’s being measured. You can take off takes of anything that’s dry CO2 or anywhere from 60 to 95 percent CO2. What you’re doing is you’re measuring the weight of the gas, the composition of the entire gas, and they’re recording.

That was the initial go around. They were trying to just submit that. Well, you can’t. If you’re collecting from several emitters and you are the person doing the trading and injecting it into the well let’s say, you’re not getting equal quality CO2 from different emitters.

How do you delineate as to how much of that credit do I give emitter A, versus emitter B, versus emitter C? I understand there’s discussions and I don’t know which regulatory agency will be involved, I’m assuming the EPA around what is the quality content of the CO2.

From all the indicators that I’m seeing, it should be 95 percent or better. I believe we as an industry should start to shape that and form that and define that so that we maintain consistency as we know if you jump back to just natural gas.

We have natural gas quality in the pipeline, and that has to meet a certain requirement for energy content. I drive a parallel with that, with CO2 and that if we’re getting government tax credits or there’s trading, there has to be consistency in the quality of that gas that’s in the pipeline.

As we all know, we’re better at defining what the needs of that gas is, how the gases operate. This industry should take the lead at defining what the quality of that gas needs to be or that CO2 needs to be in the pipeline.

Weldon: I think that statement is so true. We’ve seen this before in our industry. That’s just where we got to API, AGA and GPA midstream today. Way back in the early 1900s, the government said if the industry doesn’t figure out how to regulate itself and develop some standards, we’ll do it for you.

None of us want the government doing it for us. Our thing is, we as an industry need to figure this out, develop some agreement in the industry, develop some standards before the government steps in and starts telling us what those are.

Tony: I totally agree with that. There’s been a lot of advancements over in Europe, the European standards, and to driving the uncertainty aspect of the measurement. Primarily those are around classifications about uncertainty and measurement.

There also has to be that piece of the quality of the CO2, and I think that’s where we can get heavily engaged and start defining that so that there is consistency in what we’re measuring, what we’re reporting, what the government’s asking us.

At the end of the day, we’re the experts. That’s how we need to help and really get involved with the standards committees with any kind of other standards committees get involved from the gas industry in defining what those parameters are.

Weldon: So true. We’ve given our listeners a little bit of a, what is 45Q about and why we’re trying to get ahead of the government before the government tells us how to do our business. You want to talk to us a little bit about what the technologies are out there and what are the challenges those technologies are trying to get around?

What are they trying to address? Because we’ve talked about it a little bit, but CO2 is not your average animal when we put it in pipelines at the pressures we normally move it in.

Tony: That’s correct. If you tie this back to where the government involvement is with the tax credits, first of all, the tax credits are based upon weight of the fluid. Right away, we’re looking at certain types of technologies to utilize.

Now we’ve been utilizing orifice plates for years for CO2 injection into existing wells, but it’s all a volumetric based. It’s usually in a certain standards phase. We start talking about where a lot of the discussion, debate, and frankly, people not really understanding some of the aspects of CO2 is referred to something called the triple point.

That’s one of those phases where we like to refer to it as a squishy fluid. It’s a gas and a liquid. It’s both and neither at the same time. It wants to constantly change state. At that triple point the volatility, and maybe that’s not the right word, but small changes in temperature have enormous changes in density.

When you’re reporting weight, but you’re using a typical volumetric flow device, that’s where you get into to an issue. Because now you’ve got to go through and you’ve got to calculate with the pressure temperature, probably a densitometer, to convert that into a mass measurement of some sort or a weight measurement.

The CO2 is constantly changing state based upon the fluid dynamics. What we have found out and most people are starting to realize is that a Coriolis type of technology, it’s a direct mass measurement. As the fluid state changes, the Coriolis meter is designed to take that all into account and you’re reporting actual mass.

If we’re getting into talking, like I said, with the 45Q, if you’re getting into exchanging tax credits, now you’ve got a direct weight measurement or mass measurement of the fluid. You’re not having to do any calculations. You’re not introducing. other forms of uncertainty in your measurement, forms of error in your measurement.

The issue is that we’re starting to get into higher flow rates, higher pressures, things like that. Those are the things that you have to make sure that your Coriolis meters are designed for. Most of the systems I’m seeing are 600, 900 pound plus ANSI ratings. There’s Coriolis technology available to measure that.

Weldon: I know you mentioned earlier orifice and we’ve done orifice measurement for years. We’ve got 125, 135 years’ worth of experience there, but if we could put CO2 in a single state, a single phase, if you will, and keep it there, our office measurement might not be that bad, right?

Where we operate our pipelines so often is we want it as a liquid because it’s most efficient to transport as a liquid, but we don’t want to spend any more money than we have to on compression. We certainly don’t want to have to cool it before we put it in that pipeline, right?

We end up with so many of these pipelines that are operating right there on the edge and that’s where mass measurement becomes such a tool.

Tony: Yeah, that’s correct. If we’re talking about transportation and things like that, we ship CO2, and air separation companies generate CO2 and ship it in liquid form all the time. We know how to do that very effectively and efficiently.

The issue comes into when we’re getting into the recording for the government, based upon any type of weight, the mass measurement. It’s a weight measurement that the 45Q and the tax credits are tied to. There’s a lot of other, like you said, if we’re in a gas state, there’s multiple types of technology that we can use depending on the concentration of the CO2.

Certain types of technology, that’s what all these technologies have been developed over the years, right? There’s something lacks somewhere, something else fills that void. If I look at the value chain, and sticking not just to transmission itself, but from the portion of the tax, back to the tax credits, of where you’ve got emitters who are typically going to take their off take of CO2, which is going to be in a gas phase in the majority of instances.

They’re going to be putting that into some CO2 pipeline of somebody that’s going to be eventually sequestering that. They’re going to be responsible at that point for compressing it before injection into the well.

This is where you get all these potential different changes of state because you’re changing the pressure, you’re changing the temperature potentially from what the emitters are giving you versus what you want to inject in the well.

That’s where the challenge comes because you are going to potentially form a phase change or change of state in the CO2. How do you keep consistency in the measure from the emitters to the injection site, where I have to submit the records to the government for tax credits?

Then how do I go back and divvy up those tax credits, or trade those tax credits with the emitters with the right piece. That’s where I go back to defining what the quality of the CO2 is. Then the other issue that comes into play too, outside of the actual measurement with Coriolis is the effect of impurities in the CO2.

As we all know, moisture is a very dangerous thing in CO2, because get over certain percentages of water mixed in with CO2, it becomes carbonic acid. Now you have a whole metallurgical issue and deterioration issue. It can become a hazardous type of material to handle.

There are a lot of intricacies that are tied around with the CO2 measurement, especially when it gets into carbon capture. Pure CO2 that’s being generated by the Lindy’s and the air products of the world, they’re producing pure CO2. In a lot of cases, it’s medical or food grade CO2. That’s a completely different animal.

That’s usually transported in liquid phase. You don’t have to worry about things like impurities. When you’re putting it into a pipeline and generating it from a fertilizer plant, a chemical plant, a metals plant, or something like that, that we’re trying to capture this, now you have to be concerned with the effects of impurities in the CO2. How do you deal with that proportion?

Weldon: Some people say CO2 is not new. CO2 management is not new. We’ve been using CO2 injection for enhanced oil recovery for years, but nobody around cared what the quality of the stuff we put back in the ground was.

It came from maybe we have a field with high CO2 and produce natural gas, their treating process removed it. We took a stream that might be 50 percent CO2, might be 80 percent CO2, and we’re reinjecting that stuff back into the ground for enhanced oil recovery.

We didn’t care that much about analysis and that orifice meter or whatever was out there really did a good job. Today, when we talk about, we’re paying based upon the actual weight that we’re going to convert to, analysis becomes critical.

Depending on our technology, and there’s really in my old measurement guy view, there’s two different things out there. We can measure with something like an orifice meter.

If we’re a liquid state, if we’re up there in the squishy world, or if we’re solidly, wherever we are in that world, I hate that portion of the curve. If we’re up there, we can measure it with orifice measurement if we have accurate, real-time analysis data, especially that density.

Also, when you get into that supercritical state, little changes in impurities make density go wild. That becomes critical. Now, if we’re using a Coriolis meter, we still need the analysis, we still need to know about impurities, but that gets away from being a real-time issue, doesn’t it?

Tony: Yeah. If you look at the typical situation where you’re looking for impurity impurities or gas component content, gas chromatographs have always been used if you’re looking at custody transfer, fiscal metering skids. That’s fine, because there tends to be consistency in the natural gas composition, especially if it’s coming off of a pipeline.

CO2 is a little different. What we look at is not necessarily just a gas chromatograph. You have to look at something like a process gas analyzer so that you’re getting immediate analysis, real-world-time analysis.

The main impurities that you’re looking for and that we’re looking for in the content of the CO2 is things like H2S, carbon monoxide, oxygen, hydrogen, SOx, NOx, any methane content, and of course, water. Those are some of the main impurities that we work with.

There are all kinds of charts with acceptable limits of impurities within the CO2. That’s another piece, I think, that also has to be either addressed under the API standard or within our industry standard saying, “OK, we’ve got a 95 percent content of CO2, there’s acceptable limits in parts per million of these other impurities which will still maintain the quality of the CO2, but outside of that, we need to stop this,” or we need to do something with it, or filter it out, or however we handle those impurities.

Yeah, it needs to be a real-time measurement, which is better done with a process gas analyzer instead of our traditional gas chromatograph that we put on, which can have a measurement time or a cycle time of minutes, from when it takes a sample till it determines the content of the gas in the natural gas pipeline.

CO2, it’s really more along the lines of, it’s a “I need it now” measurement. It’s really a real-time process gas analyzer that needs to be attached to that stream.

Weldon: That makes perfect sense. With a couple of customers I’ve dealt with that have had orifice measurement, they’re typically, “We’re 99 percent CO2.” Well, that’s really great, and from the old-world gas analysis, a gas measurement standpoint, that was probably enough information.

Operating up there, if you get in any of the right or the wrong area of that phase curve, whichever we want to say it is, little changes can happen rapidly. Right?

Tony: Yes.

Weldon: A cooling fan coming on and off can throw you back and forth between phases.

Tony: To that point, it’s somewhat unstable at that point. When I talk about what they call the triple point, it is a very unstable fluid. It’s very much like ethylene.

We’ve utilized a lot of our background and knowledge throughout the years of measuring ethylene. With CO2, there’s a lot of physical dynamics that are very similar.

With CO2, yeah, that’s the issue. The main issue is — I think I mentioned it before — small changes in temperature. Like you said, something kicks on, the wind changes or the sun’s shining or whatever it might be, has dramatic changes on the density depending on what state or what phase that gas is at.

Yeah, everybody starts talking about supercritical and dense phase, and sometimes you have to bring that down as to, what are you really trying to do here? Is there an ability to maintain an envelope, to maintain within a certain phase? You keep a lot better consistency, and uncertainty in your measurement is reduced.

Weldon: Getting it there is always money from the operations side. That means if we’re going to get it there and keep it there, we’ve got to do it with a little bit of margin. In that margin is always a little bit more money, but we’re going to get there. We’re going to figure it out. We’re going to do it before the government tells us how to do it, hopefully.

Tell us a little bit about how y’all are putting these pieces together. What’s your equipment solution. How do you marry the right analyzers and the right equipment? I think we’re going to get to a Coriolis decision really quick here, but go ahead.

Tony: To your point, Weldon, yes. We highly recommend, if you’re metering it or you’re measuring anything and reporting it, similar to custody transfer or fiscal measurement, that’s the way I look at it, when I look at a system.

We’ll usually propose, in just about every instance that we’ve seen — people are very accepting of it — is what we call a 2-by-100-percent configuration, with a Z configuration. We’ll have the normal duty meter run. It would be a Coriolis meter.

Again, the use of a Coriolis meter I don’t have to worry about the pressure temperature compensation. I don’t have to worry about a densitometer. I don’t have to worry about additional equipment. We optimize it that way.

On the second stream, we’ll put a master meter, which is, again, a Coriolis meter, but it’s calibrated with more points when we do the initial calibration at the factory. That’s your reference meter, so that you can always switch over and put that in line through the Z configuration, as we call it.

What you’re doing is you’re checking your duty meter and validating your measurement through it. You can do that once a day, once a month, once every six months, whatever your requirement is based upon your total consumption rate or your processes or how you’re reporting it.

That also adds a backup to the government, its entities. I don’t know what will come into the phase, if it’s out west of the Mississippi and BLM steps in. There’s a lot of these entities that are unknown right now.

We’re proposing do this the right way, collect all the data that you can. The flow measurement is a Coriolis. Then we’ll put on a process gas analyzer and suggest with certain types of impurities. If the person does know the gas composition or the content or potential in contaminants or impurities, that’s always helpful.

Again, we need moisture, H2S, things like that, that can cause, potentially, real-world problems. We’ll always recommend that and always tie that in together with a flow computer and manage the whole skid package that way. We try to take into all the parameters of reporting and being able to generate reports out of that. That’s in a format that you can submit to the government.

Weldon: We think of natural gas being natural gas. If we’re in the midstream or the production world, we say, “We’re in this particular formation. All of our gas is kind of the same.”

When we talk about CO2 capture and eventual sequestration, we might have an installation that had one incoming customer, one source. It could be a methanol plant, or it could be agricultural digesters, whatever that source might be.

When you have a system that is multiple sources, an industrial plant…Maybe it’s fertilizer. Maybe it’s whatever. We have some agricultural plants over here. We have methanol, but all going into our same pipeline.

All of a sudden, what we end up with at the sequestration point that we have to divvy out, as you said earlier in our conversation, between our customers, that becomes more critical. We’ve got to watch it coming in and watch it going out.

Tony: Yeah, absolutely. That’s an exact point. I had this discussion with somebody about a year ago. The way they started off was just putting Coriolis meters, measuring the CO2, putting it in a pipeline. They were trying to do the jump on board and get the quick information, quick credits from the government.

I started to bring up that exact issue. This was a company that was doing post-compression. They were doing the sequestration into the cavern. They were going to own that. Then they were going to own the pipeline where it was coming in. That’s the exact question I asked. I said, “How are you measuring all the emitters, what they’re doing?”

They said, “They’re saying that they’re going to put Coriolis meters on it.” I raised the question. I said, “That’s all well and good because they’re going to be measuring weight.” I said, “How do you know that all these people that are putting CO2 into your pipeline are all putting in the same quality of CO2?”

I said, “There could be all kinds of garbage in emitter A. Emitter B might be very stand-up and say, ‘We’re making sure that we’re going to be delivering 95 percent,’ but how do you know that?”

They drove to push to own the input and the metering system into their pipeline, saying, “No. We’re going to put these in so that we can maintain the measurement of the quality of the CO2 that’s coming in at all of these entry points into our pipeline from all the emitters.”

Weldon: That’s very sound advice, Tony. I don’t know how anyone could do anything less. What I’m going to say seems awful counterintuitive to me, but EPA is kind of a known quantity for us right now. We’ve been there long enough with emissions. We kind of know what to expect out of the EPA.

When we start talking 45Q and tax credits, now, all of a sudden, we have the EPA, their focus on environmental. For these companies to get their paycheck at the end of the day, that is the IRS. The IRS is a whole different level.

We may find out that what satisfies EPA on analytical and those kind of issues may not be good enough for the IRS. They’re accountants. There’s no such thing as “We’re plus or minus some accuracy.” They want a number, and they want 14 decimal places sometimes.

Tony: I’ve run into a similar situation years ago, not necessarily with CO2 but a government edict and standard to measure the quantities of a contaminant. It was actually laughable from one point. We turned down the bid. I said, “No, we can’t bid this.”

The engineering firm came back. They said, “Why won’t you bid this? We need you to bid this. Nobody’s bidding this.” I said, “Where did this regulation, this measurement requirement, come from?” They said, “It’s a government spec, or it’s a government edict. I said, “The technology doesn’t exist to measure at that minimal of a level right now.”

I can’t remember exactly what the contaminant was, but it was some ridiculous amount, like 40 parts per billion, of some very, very small molecule. That’s the other reason I’m always pushing or trying to tell people that we as an industry need to help drive these standards, especially with the famous words, “I’m here from the government, and I’m here to help.”

If they define it, it’s going to probably be either something that’s so strict that we may not be able to measure that. Again, we’re the experts.

We need to get involved with the API, but we also need to get involved with any of the government agencies that are involved with this to define what it is that CO2 is, what are acceptable and what are measurable impurities, and to help to drive that standard across the board so that the IRS will hopefully become compliant with the other government regulatory agencies.

Weldon: IRS compliant. This is a lot of great information, Tony. I appreciate you doing this. We’re here at ASGMT, as I mentioned earlier, in the exhibit hall. Y’all may have heard some noise in the background. We’re not going to apologize for it because we’re enjoying ourself here.

This episode probably won’t come out for another month, but later today, you’re going to be doing a presentation, “Best Practices for the Design of CO2 Gas Metering Systems.” I’m sure you’re going to have a full room for that, Tony.

Tony: Hopefully, I will. It’s a few years doing it. The attendance every year seems to grow for the presentation. I try to keep it updated every year with any new information on either standards or things that are going on within the industry and what are the concerns around the measurements. It’s not the same old thing year after year. I try to update it every year.

Weldon: That’s great. Anything else you want to add before we go?

Tony: No. Weldon, I really appreciate taking the time to do this, appreciate you asking me. I believe I’ve got a passion for CO2 measurement and how it’s being done. I want to make sure that people understand it appropriately so that we get the right definition for this industry on how to handle and how to measure this.

Weldon: Thanks again, Tony. What you said there is so true. Passion is what makes this industry go. If it’s not people like yourself and the others here…When we look around the rooms here at ASGMT, we need more young folks in this industry.

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Weldon: We need young folks in. We need sharp minds. We need to get them hooked. We need them to develop that passion for the next generation of folks who are going to be doing this. Right?

Tony: Right.

Weldon: Thanks again, Tony.

Tony: Thanks, Weldon. I appreciate it.

Weldon: I want to thank each of you for listening. I hope you found this episode both interesting and informative. We’ll have a full transcript of this episode and Tony’s contact information in the show notes on our website, pipelinepodcastnetwork.com.

As always, if you have comments or questions about this episode, suggestions for new topics, or if you’d like to offer yourself up the podcast microphone as a guest, then send me a message on LinkedIn or shoot me an email at weldon.wright@fpvprime.com.

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