Continuous Emission Monitoring Systems pt 2

 For part 2 on our CEMS episodes, Mike Wallis debunks more myths with Sean. Is a laboratory analyzer on par with their process counteparts? Who should design a CEMS? What type of field services are necessary to keep a CEMS in tip-top shape? Download and Listen to find out. 

Transcript

 [00:00:05.690] - Sean

This is a Yokogawa, Australia, and New Zealand podcast. Welcome back to Yokogawa Debunks conversations with industry experts to uncover the truth behind myths and misconceptions surrounding the industrial automation and industrial instrumentation space. I'm your host, Sean Cahill, and thank you for joining us today. And I would like to start by acknowledging and paying our respects to the traditional custodians of this land, to the elders, past, present, and emerging, on whose country this recording is taking place. Now, today, we'd like to welcome back Mike Wallis, who's manager for process Analyzer solutions at Yokokawa, Australia and New Zealand. Mike joined us in the last episode to discuss some of the misconceptions people have around continuous emissions monitoring systems, or CEMS for short. So, without further ado, welcome back, Mike. 

[00:00:56.010] - Mike 
Good morning, Sean. Thank you for calling me back. 

[00:00:58.960] - Sean 

Thanks, Mike. It's great to speak to you again. Now, I want to dive straight in and just want to pick up a little bit from where we're at the last episode. And at the end of that discussion, you mentioned RATA testing. So, I'd like to continue by looking into a little bit more. And one of the first things that comes to mind was that you mentioned that RATA testing involves third party and that they probably take samples and bring them to the lab and run analysis on those samples. Is that right? 

[00:01:28.650] - Mike 
Yes, Sean, that is quite correct. They may take the samples to a lab or sometimes they'll actually have portable laboratory analysis and actually do the measurements on site and in almost real time. So, it doesn't matter that the outcome is the same. It's basically about taking spot samples and getting results that are independently measured from the CEMS. 

[00:01:53.130] - Sean 
Now, that in itself leads to a bit of a misconception, which hopefully you can address here, that people out there say that laboratory analyzers and even the portable ones used in the rata tests should be used as a basis for CEMS measurements because they're super accurate and they're super sensitive. Therefore, they should be the reference. What would you say to them? 

[00:02:13.770] - Mike 
Well, okay, it's not difficult to make a cognitive leap that says that because the auditor uses a lab Analyzer, that a lab Analyzer is therefore appropriate to the CEMS measurement. And the lab Analyzer is certainly appropriate to making a CEMS measurement in the laboratory type of environment. However, you won't find those guys doing spot checks in owling gale out there in the pouring rain or some thrashing hail. But you might expect your CEMS to keep going when it's 50 degrees or whether it's freezing or when it's raining and 24 hours, seven days a week, 365 days a year. So as long as that process is operating, you expect that CEMS to keep running. So, lab analyzers, they're really suited to laboratory environments or at least mild ambient environments. Industrial analyzers, on the other hand, they're designed to run in a robust, reliable fashion for a long period of time. So, for process measurement, which is what a CEM is, it's probably more appropriate to consider process analyzers. So, while lab analyzers may be more sensitive and possibly even more accurate than process analyzers, you don't need to have minute levels of uncertainty In a CEMS measurement, what you need is to have good levels of reproducibility, good stability, and good robustness in the measurement. 

[00:03:36.930] - Mike 
By the way, typically a RATA or relative accuracy test audit has a bandwidth of about 10%. So, if you can get a correlation within 10% between what the spot sample sees from the lab analysis and what the CEMS are saying, that would usually be acceptable to the statutory authority. So that's not to say the process analyzers are not accurate or not sensitive. What we're saying is that they have an appropriate level of accuracy, an appropriate level of uncertainty, and an appropriate sensitivity for the requirements in the measurements that we're making. Because you have to select the Analyzer with regard to exactly what it is that you're measuring and what concentration of components it is that you're actually trying to measure, it still follows that a process Analyzer is going to be a better solution for around the clock process measurements than an adapted lab Analyzer. Nonetheless, it all comes down to competent design. Irrespective If you choose these lab analyzers and you put them in an Analyzer house with an air conditioner and you provide them with a laboratory type of environment, they'll probably work just fine, although you might just be adding unnecessary layers of complexity into the design by doing that. 

[00:04:50.540] - Sean 
Yeah, I'm looking at they're really not designed for the application. I mean, that's the point. 

 [00:04:55.090] - Mike 
Indeed. And that raises questions about who should actually design the systems in the first place. Now, there are some people thinking that they should be designed by qualified environmental scientists. Those tend to be the people who use lab analyzers. So, it does make sense at face value, but it's actually not that true either. From the CEMS vendor perspective, there's no requirement for environmental scientists to be involved in designing the CEMS. The end user may choose to have their environmental scientists look at it, in which case we're actually happy to collaborate with them to ensure that their concerns are fully addressed with respect to license conditions and other requirements of the statutory authorities. In regard to the CEMS execution, the CEM should be treated as any other industrial analytical measurement. That is to say, there should be a focus on accurately and reliably measuring a representative sample, in a timely fashion using equipment which can perform the required functions with minimal maintenance. 

 [00:05:53.990] - Sean 
Great insights there Mike. Now that also brings to mind another myth that we hear as well is that the same company that supplies the CEMS is also believed to be responsible for the RATA, so that there's less issues or discrepancies between the two. How do you see that? is it true? 

[00:06:13.290] - Mike 
Well, there's a bit of a temptation for the license holder to say, if we have the same people who built the CEMS, also bring in their lab analyzers and do the RATA. They'll know how everything works, so they'll know exactly how the cems works. They'll know how the lab analyzers work, they'll know how the RATA works, they'll have the whole picture. So, there's a potential that there could be a better outcome. However, there's also a little bit of a problem because the statutory authorities would generally shun that as embodying a conflict of interests. So, while some organizations certainly have the skills and experience to provide RATAs and CEMs, there is a perception of ethical problems. CEMS data in many cases are subject to public scrutiny. It's important that there is trust in the data. Avoiding perceived conflicts of interest not only helps keep the statutory authorities happy, it also helps to build public trust and increase confidence that these things are there for a good reason. Providing good data and that the operators are good corporate citizens. 

 [00:07:19.440] - Sean 
And it's also the brand, right? If you're conscious about the environmental impact of your operations, you communicate that to your community, you maintain your brand intact. And perhaps the employees of the companies could avoid being fined for not being responsible corporate citizens, as you mentioned. 

[00:07:35.610] - Mike 
Indeed. Now, of course we're talking about enforcement, but we're also talking about ethics and trust and being a good corporate citizen. And not everybody out there is always going to be a good corporate citizen. Unfortunately, that brings us to the next myth, which you might want to raise. 

[00:07:52.650] - Sean 
Absolutely. Well, that next myth is that the CEM supplier will force the end user to use their extensive workshop recalibration services to keep it valid. 

[00:08:02.200] - Mike 
Now, it's true that some equipment suppliers may not have fully site serviceable equipment or even people who can travel to sites to perform routine maintenance, let alone deal with breakdowns. Additionally, we've come across cases where even relatively simple analyzers, such as Zirconia oxygen analysis, can't have their cells replaced on site and have to be returned to a workshop. You can see it's certainly in the interest of the end-user to understand how their CEMS needs to be maintained and who will do the work. We're in the enviable position that we are able to be very flexible in this regard. As an example, if the customer doesn't want to be very involved in looking after the CEMS, we can provide long term support arrangements, or LTSA, to keep the system in tip-top shape. Alternately, the customer may prepare to have their own people look after themselves. In that case, we can provide from another suite of offerings. Now, those offerings, they can include formal and on the job training, transitional site services, remote support, and call out services as may be determined to best suit the prescribed requirements of the customer. One of the things that we've done in the past, by the way, which I understand has been quite successful, is transitional site services. 

[00:09:22.290] - Mike 
This is usually used by the larger customer who's got highly competent technical support people permanently engaged on site, and they're enthusiastic to look after the equipment. What we do in the transitional site services arena is we go to site, and we get the system running. During the commissioning process, we work with the customers people to bring them up to speed with on-the-job training, and then we come back and we continue that, and we work through a few maintenance sessions so they get to see how things are done and get practice and experience. And so, we hold their hand until they develop the confidence to take it over and do it themselves. And then we withdraw until we perhaps are needed for some major overhaul work or something like that going forward. 

[00:10:08.850] - Sean 
Okay, that's interesting. Well, look, I think we've covered a lot of misconceptions today for CEMS. I heard you mentioning earlier in the conversation about the two different types of installations that we can see as CEMS in, one being the Insitu and the other one being an extractive arrangement. There's also a misconception that in situ analyzers should always be used instead of extractive ones. I mean, what's your take on this? 

[00:10:33.090] - Mike 
Yokogawa are in the somewhat enviable position of having both insitu analyzers, such as our fully site serviceable TDLs 8100 probe type tuneable laser diode spectrometer and ZR series oxygen analyzers. But we also have a proven capability to implement extractive systems using analyzers such as the IR 202 or the IR 400. So there's no preconception on our part. We don't have a predisposition as to whether to use extractive or Insitu. What we have is an open mind to consider the many variables which will affect how an optimum cems design can be achieved. For example, say you have a remote site with three power generators, say, firing clean natural gas. The generators are lined up next to one another and the stacks are closed together. That arrangement might actually be best served by a three-channel extractive cems. Now, a different example requires the same measurement, but from a single stack, and the measurement is going to be close to the atmospheric discharge point. This particular stack, it's got easy access to a platform, has a few unused nozzles close to where the RATA Port is located. It's a clean burning process. There's no corrosives that are going to cause problems if it goes cold or during start up. 

[00:11:58.690] - Mike 
On balance, that particular installation may be better suited to using in situ devices such as the TDLs, which I mentioned. Of course, there's always other things that I mentioned earlier on in our previous podcast that still need to be considered. So, it's not a simple decision. It's a decision that with careful expectation, though, can yield a good outcome. 

 [00:12:21.420] - Sean 
Yeah, and everyone has their own opinion on CEMS and the number of variables to consider very clearly significant. I mean, that makes the decision of purchasing the CEM system more difficult for the end user than ever. 

 [00:12:33.830] - Mike 
Yes, it certainly can make it a more complicated process to make that decision. And unfortunately, this is very unfortunate. In a lot of cases, the customer will see the CEMS as an imposition. They'll see it as something that doesn't make money for them. It just costs money to maintain it. Perhaps it saves them from going outside their licensing requirements, which may stop them from being fined or having some unwanted public attention. Still, they don't see the thing as an investment. They really see it more as a cost. And that can be a problem because it can lead to decisions based around the cheapest bid rather than the best value type of approach. 

 [00:13:12.520] - Sean 
Okay, so you see then that there is a possibility of getting returns or having any value out of a CEM system outside of the EPA requirements, in your view, what are those extra benefits? 

 [00:13:23.490] - Mike 
Well, Sean, we live in an era that's extremely data rich, but in many ways information poor. Now, the idea that a CEMS can't help the end user to make money and the cheapest bid solution should be purchased is a really nasty myth because short term capital cost-based thinking can lead to poor medium and long term outcomes, particularly in the medium and longer term when the warranties have expired. Now, it may be possible to save some money in the initial purchase. However, a few points do merit some consideration. One of those is, could better measurements be used to optimize the process to improve the combustion, reduce fuel consumption, reduce pollution levels, or improve other outcomes such as refractory lining ducting, or process equipment lifespans? Will the more accurate, reliable measurement allow the operator to manage the process to its fullest potential? Will a less reliable measurement end up costing more because it requires frequent maintenance? Will the site be threatened with fines or shutdowns? Will the same supplier be around in 20 years? And will the customer view them as a partner successfully co-innovating their future? I'd like to expand on that last point a little bit. 

 [00:14:41.710] - Mike 
There are a great number of sites out there at the moment who don't really see any potential for a CEMS to give them any kind of a payback. They just see it as being right at the end of the process. Everything's already happened and it's too late to do anything about it. That view is certainly understandable. However, it does invite some deeper investigation. Recent developments in mining data, particularly those able to create complex, multivariable models that can simulate a process against a number of specified variables. Those models are proven to have a phenomenal capacity to actually lead to real world outcomes that reduce costs or improve profits. Yokogawa are confident that some of these models will be applicable even for the last measurement at the end of the street, which is the CEMS. So, I really do think there's a potential to reduce duck corrosion, to increase refractory life and to improve combustion optimization or gain other benefits. Even with data that seems at face value to be somewhat second hand because it's right at the end of the process, the number crunching that's available now can still do useful things with that data. 

 [00:15:57.270] - Sean 
Well, look, I think it's clear that people really haven't seen or realized the potential of how important these systems are to the plants. 

 I do hope with the information that we've shared today and in the previous episode have provided a bit more insight into the CEMS. So, Mac, I'd like to thank you for your participation today and also in the previous episode. I'd like to reach out with an invitation to join us again at some point in the future. 

 [00:16:24.470] - Mike 
Thank you, Sean. I'd like to say thank you very much for having me on the show and hopefully you've got good value from the chat. 

 [00:16:31.650] - Sean 
Thanks, Mike. And thanks to you, our listeners, for joining us once again. If you have any questions or particular topics you'd like to discuss, please contact us on Debunks@au.yokogawa.com and also, if you've enjoyed today's episode, please remember to like and share in your social media channels. We look forward to welcoming you back to future discussions. But in the meantime, stay safe and remember Yokogawa debunks.