Boosting value from Anaerobic Digestion: Optimisation strategies to improve ROI of your AD plant

Boosting value from Anaerobic Digestion: Optimisation strategies to improve ROI of your AD plant

Frank Wayman   0:45
Great. Thanks very much, Luke. I will just start sharing the screen.
OK.
So yes, today we're going to look at some of the issues that we've come across when we've been helping food and beverage and similar sites with their A D plants going to share some of the lessons that we've learned.
And that will hopefully help you improve return on your investment.
So who are we? So Alpheus are in the utilities sector. We are sort of water specialists, wastewater specialists. We will.
Operate, we will maintain, we'll do engineering design work, we'll also do consultancy. So yes, quite a quite a few things and we have quite an extensive client list.
Um.
Quite a few well-known names on there. I have been working for Alpheus for 20 something odd years. Ming has been there even longer than me, so Ming is also on the call. He's our engineering manager.
Uh, I'm technical manager based up in Scotland.
So that's enough about us. What about you guys? Couple of reasons why you might be here. One is that you've got an AD plant and it's it's built correctly, but you just cannot seem to get it to work properly.
Um.
There are a few reasons why that might be that we've we've picked up over the years and we'll share those with you. Or alternatively you've got an AD plant and it is working properly, but it's just not big enough. So we'll look at.
Both of those sort of sides of things the if you like the.
Tweaking the performance side, almost like the if you imagine like a Formula One team where you're trying to get an extra fraction of a second around off every corner and then you've got the more kind of fundamental OK, our plant is is is missing something which is stopping us from from getting what we want.
So what you're going to leave with, we will very briefly touch on some of the science, the the basics behind a DI will drill into a couple of more technical aspects though some key areas and tactics to improve the value that you get.
Where investment or operational changes could deliver value. Some real-life examples of optimization in action and and case studies are often one of the best ways to sort of see parallels between the sites that you operate and what other people are doing.
And we'll finish off with some bullet points to aid your performance investigation.
So first of all, then, what is anaerobic treatment of waste? It's where organic wastewater or organic matter is broken down in the absence of oxygen.
And.
Typically you will get fertilizer. If you're food and beverage industry, then you're you would be aiming to achieve pass 110 standard on your digestate and therefore it can be applied to land. The biogas is the other product you'll be putting that into.
A boiler typically, if you have a steam demand on site, or alternatively you'll be putting it into a CHP, you'll be getting hot water, maybe a boiler preheat, something like that. One thing that you might never have considered is upgrading the biogas to biomethane.
If you have a flight, a fleet of trucks or something like that, then commercial vehicle fuel is probably going to be of interest. Or alternatively, if you have a lot of waste, you'll be looking at gas to grid.
So opportunities come from understanding what it is you're trying to do to having that kind of bird's eye view. What is it we're trying to achieve here?
What is anaerobic metabolism then? So as I said, you're breaking down organic materials, the absence of oxygen and you're producing methane. It's a stepwise process and typically.
When this process doesn't work, you'll have a problem in either the red BLOB, which is methanogenesis, or in the hydrolysis BLOB, which is the the initial breakdown of larger macromolecules.
If you get those two ones right, then the other two steps, certification and a certification, they generally are quite trouble free.
So yeah, that's if we're trying to see what's going wrong, then it's those two steps that we really look at.
So in terms of the the technology that we're looking at, there are different ways to get anaerobic.
Metabolism to work on a engineering scale.
If you've got medium rate digesters, um, they're typically working.
You move up in terms of your biodegradability, then you might move to a granular type digester, an EGSB or sometimes called an ICX reactor as you increase in strength and concentration and solids.
You might need to look at an anaerobic MBR and this is where low rate digesters come in. And if you've got really strong, really rich, high solid feed, then you'll be looking probably at a what's called a dry digester. They're not really dry.
But um, dry digesters or continuously stirred tank sludge digests.
When you're looking at the type of digester that you've got, that gives you, if you like, a hit list of optimisation opportunities. So you would optimise A granular sludge bed bioreactor in a different way from a CSTR for example.
And us.
Probably makes sense. The more calories that you can remove. So in the wastewater industry, people talk about COD, chemical oxygen demand. It's another way of saying calories. So the more calories you can remove from the effluent.
The better it is and the better the performance is because those calories will have converted into biogas.
So in order to optimise what you've got, so this is if you like that analogy of the Formula One team that's trying to get an extra fraction of a second on every corner. And if you think of this in terms of efficiency, if you're getting 1 or 2% efficiency improvement at each step of the of the.
Way then actually those will add up. They will be cumulative.
Improvement or or even more, and we'll see those in the case studies later on.
So we're looking at what are the inputs, what equipment have you got? Are you measuring the right thing? How much energy are you using? What quality is the biogas? Is it? Is it actually good enough for what you want and.
A certain percentage of AD plants can actually pick and choose the wastes that they've got. So if you have a large site or if you've got neighbors or something like that, you've you've maybe got mixed-use site.
You can actually pick and choose which feeds you've got and you can say, all right, well, actually we'll have a bit more of this one because it's got the right minerals in or we'll have a bit more of that one because it it we really get a good boost of buying gas when we use that.
What is important is for good communication between the people that are making the waste and the treatment plant operators. I've seen a few instances where the people making the waste treat the AD plant as a dustbin.
And they will put anything that they don't want into what they perceive as the dustbin. It's really, really important. I cannot emphasise this enough to treat an AD plant as a production process. You are producing biogas, it is.
Important to the efficiency of your entire site that you put the right stuff in and you do not treat it as a dustbin.
Experience from a specialist support team. Uh, to help you get messages like that across.
So again, going back to that Formula One kind of team thing, what do you need to look at? What's your strategy in the lab is is the key question here.
So.
The analysis that you do does need to be tailored to the wastewater if you are have a connected to a very tightly controlled and very simple production process with only one product.
Then it wouldn't make sense to analyse the composition of the feed on a regular basis, but it probably would make sense to do some more sort of in-depth analysis on a say a seasonal basis just to look for seasonal variations in in things like that.
If, on the other hand, you've got a lot of mixture, it's possibly worth analyzing each of your of your feed streams to understand what do you get out of each one. Again, think of it as.
A roduction rocess, not as a dustbin.
Fostac ratio monitoring. I've got a separate slide on that is so important. I've got a separate slide for that micronutrients. I've actually got several separate slides for that because again it's super important. Take home is that.
If you over measure, it's obviously a waste of money and waste of lab resources. If, however, you under measure, then you will be more likely to have process upsets, process upsets with an AD system.
Tend to have quite big impacts, so that can really hit your profits.
So this is a picture of an auto titrator. An auto titrator basically does.
The analysis for you, it takes all of the difficulty out of titration and we use.
Sort of, I will say, I'm not going to say unskilled, but they're they're not laboratory specialist staff can use an equipment piece of equipment like this where you take 10 mill a sample, you dilute it with water, you stick it in the machine, you throw in a magnetic bead.
The number that you get out, it'll give you a single number, and generally speaking, a value of 0.3 or less is healthy, 0.4 or more is stressed. The equipment is cheap to buy, so one of these new is around about 3000 lbs.
If.
3000 lbs still sounds sounds too expensive on the second-hand market. You can get these for about half that price. About 1 1/2 thousand lbs needs to be used at least daily, possibly even twice a day. But the quality of the information, how it can tell you how healthy your process is.
I know I'm labouring the point about this machine, but we've been and we've looked at client sites and they some of them do not have an auto titrator and it is so important to have one.
On to the next thing then. So another thing we've seen on client sites is a lack of trace nutrient dosing. It's sometimes not appreciated at design time.
That the feedstocks on site do not have the necessary micronutrients in it. What do I mean by micronutrients? Well, methanogens are archaea. They're not bacteria. They evolved at a different time in the in the Earth's.
Development. You know, these are billions of years old and they evolved when there was no oxygen in the atmosphere. Excuse me, no, no oxygen in the atmosphere. The materials in the Earth's crust were different, so heavy metals were more prevalent than they are now. So what's what's happening?
Happened over time with geology and tectonic plates and everything else is that the heavier metals have actually sunk to the bottom and are now rarer. So the people talk about rare earth metals. The reason they're rare is that they're heavy. They've actually sunk out of the top layer of the Earth's crust.
So yeah, these archaea, they've got a metabolism that's quite unlike aerobic life forms. And if you look at the periodic table to the right, you'll see that I've highlighted that middle section, the transition metals.
If you want to go back to school and maybe you did higher chemistry or a level chemistry, you probably ignored this section of the periodic table. Why have I highlighted it?
It's because it's important. These transition metals have the ability to change their oxidation state, so they can, if you like, lend an electron or borrow an electron quite easily.
And the larger they are, the more shells of electrons they've got, and the more easy it is for them to lend an electron out to your metabolic process or to to borrow an electron back.
Um, in terms of the the metals specifically that I've highlighted.
So molybdenum. I always struggle with this molybdenum.
And or tungsten, you'll see they're stacked one on top of each other in the group of chromium at the top. These are vital for release of methane from a peptide called coenzyme M.
Molybdenum tends to be the predominant sort of form at.
More positive redox levels, so above -400 millivolts you're trying to get molybdenum chemistry if you have a more extreme environment.
In your digester and your redox potential is less than 400 millivolts then.
The tungsten catalyzed dehydrogenase enzyme will be the form that will be required, so.
A lot of people you don't sort of understand about the importance of tungsten. Fun fact for you, it is the heaviest element in the periodic table known to have a biological function. Some of these other ones then cobalt and selenium are essential for the metabolism of single.
Groups. So quite often in biochemistry, complex molecules are broken down in two carbon chunks. But if you have an odd number of carbons in carbon atoms in your molecule, then you need to do something with the single carbon groups and.
Cobalt and selenium are important for that.
Manganese, nickel, copper, zinc also have an important biological function. I think nickel is involved in the release of carbon dioxide from acetyl Co A and things like that. So these are all important and.
If these.
Micronutrients are not present, then the chemistry just won't work. It just won't get catalyzed.
Key point is that these trace metals may not be present in feedstocks derived from animals and plants, because animals and plants don't need these chemicals, these particular trace metals. Therefore, let's say you're processing.
Whey protein or something like that that will not have these trace metals in and you will have to add them.
How do you know if you need to add them? Well, you can get metals analysis done on your feedstock and you can see what it's short of.
If you.
Have the, you know, enough of a need for it, then gas chromatography.
It's quite an unusual technique, but I thought I'd share it just because it would allow you to see what's going on.
Typically a piece of equipment like this. So you've got a computer, you've got the gas chromatography machine with an auto sampler and stuff on it. You've also got a hydrogen generator on the side, which means that you don't need a hydrogen bottle. This just needs mains power and compressed air.
Everything else is on here. Second-hand price for this and I did check this about a week ago when I was preparing the slides around about 20,000 lbs.
You might think 20,000 lbs. Goodness me, that's a lot of money. But when you compare it with the price of vials, so a test kit for VFAS typically costs you about 5 lbs per tube.
So very quickly the cost of using Hack ****** test kits or or any other test kit, it ramps up really quickly if you have a site and you know maybe you've got sister sites nearby.
The idea of clubbing together and actually all working with gas chromatography does make a lot more sense.
What do you get if you process in this way? Well, you get a chromatogram out like this and it shows you. So if you run a test kit, it will say you've got VFAS of.
However, many 100 milligrams per litre, or maybe even 1000 milligrams per litre, depending on the type of process you've got. If you run a GC, you'll get different peaks. So all the different species of volatile fatty acids like acetic acid, propionic acid.
They'll all come out individually.
So a high C2 peak, that's acetate that indicates molybdenum or tungsten deficiency. That's if the other peaks are low, but that one's high if you have a disproportionately high peak at #2.
That's propionic acid that indicates cobalt or selenium deficiency.
If everything's high, that indicates some other matter. So you could have toxicity, could be nickel deficiency, overfeeding, too cold, too hot, wrong pH, all kinds of other things. But this allows you to see inside the process.
Um.
If it's not worth you getting this done, you know you're having your own equipment on site. If it's if you've got a fleet of AD plants, it might be worth strategically positioning a GC in the middle of everything. Or alternatively, you can get these things sent away and a external laboratory can do it for you.
So moving on to the engineering side, that's the that's the science bit over. I've just realised I'm running a little bit behind, so.
In order to maximise efficiency, there are certain engineering matters that need to be addressed. So your your temperature control needs to be really good. Your inlet needs to be well managed because.
What you put in affects what you get out, and boilers and CHP engines need a steady gas flow. If you have fluctuations in your input, you'll have fluctuations in your output. If you have fluctuations, then you're likely to need to flare off biogas rather.
Other than using it. Um.
Depending on what your heat requirements are on site.
I'll see your your.
Reactor, because it's biological, needs a nice steady temperature, typically between 35 and 3839 degrees use of heat pumps. So your your biogas, if you think of it, it's a high quality fuel.
But you're only needing waste heat to heat up to this kind of middling temperature, high 30s to to 40 degrees using heat pumps, heat recycles, all of these things.
Can save biogas. You don't. Using biogas to heat your digester isn't necessarily the best way to do it. You can use heat pumps to heat the reactor and to to maintain heat. Optimise the heat flows in and out.
That helps.
Cleaning up the biogas as well is important. Hydrogen sulphide can damage boilers and CHPS, and it probably doesn't need to. I don't need to labour the point. If you damage the CHP units, then that's obviously going to be expensive.
What do you do about it? Well, your treatment options are you could dose chemicals up front to reduce hydrogen sulfide formation, or you can clean up the biogas afterwards, and we'll look at that in the.
Case studies.
And we'll just rattle past that.
Obviously, once you've optimised your plant, then you can potentially import more waste, make more money, make more biogas.
If you are producing good quality digestate and you've got good, good quality granular sludge, you can actually sell it. Granular sludge is a commodity. If you can, if you've got a really stable system, you can sell it and it's quite valuable.
And if you are doing well and you're producing more biogas than you need, you can export these things. By far the easiest thing to do is if you've got a CHP engine, you can support, you can export electricity back to the grid, but if you've got neighbors, you can.
Sell them heat. You can transport off biogas by tanker. There's all sorts of things that could be done if you've got it.
Look at some upgrades which could become beneficial over time. So if you've got aging assets of poor performance, that's an ideal time to upgrade.
If you've had changes in your composition or production increases, again you could increase capacity.
Waste and byproducts. So depending on when your plant was built, the regulatory market for byproducts and waste has possibly changed. So it's worth having a look at that if your if your assets are coming to the end of their life.
Then it's a good idea to look at what you could use byproducts for.
And again, we've kind of labored that point, you looking at analysis and monitoring, what is it about your system which which doesn't work?
So on to some case studies, Haines Celestial, this company produces high sugar fruit based products. When we started our relationship with them, they had.
Very poor performance from their existing AD plant, high Mogden trade effluent costs and under UCHP they actually had more material that they wanted to get rid of and they couldn't do that. So they needed a capacity increase.
We carried out a feasibility study for them and proposed granular sludge ICX reactor with an increase in capacity installation of a gas buffer and this is something which.
Needs to be highlighted. Quite often when we've visited client sites there have been.
Components that have been missed out from a design, whether that's because of a cost cutting, you know, just to make the the investment a bit easier or something like that. But you usually pay in the long run if you don't install all of the necessary equipment like a gas buffer or a balance tank.
You usually pay for it in the end. Sugar extraction system we added and various other things. Again, micronutrient dosing.
An ICX reactor you've got if you like. I don't know whether you can see on the diagram that the the biomass is floating around as as distinct blobs that makes it easy to separate the biogas from.
The effluent from the biomass. So it's a biogas, biomass and effluent. You can separate really easily with this type of reactor.
Reactor.
Gas buffer, as I said, with any complex chemical engineering or process engineering system, if you don't have adequate buffering between the stages, you're always going to struggle.
Biogas production is never constant, so having a gas buffer in your process allows for a more constant flow to your CHP or your boiler systems, and that maximises biogas utilisation and minimises.
Buy gas wastage through SH through flaring.
Bit of a fun picture for you. So jam injection. So this is one of the products made on the Haines celestial site is is fruit jam. It was a waste stream identified by us as a useful extra feedstock. So we don't want to feed.
The AD system with jam all the time because that would give a fluctuating input. But as an occasional treat, if you like, for our archaea, it's allowable. So like a healthy balanced diet.
You know you can, you can top up with something like jam. We designed the reactor to accommodate that stream and because of the type of reactor it is, it was important to remove solids from the feedstock.
That extra load is used when the factory production is low, so we keep the jam to one side. When factory production drops off, we can add that jam into the feed process. We can maintain a nice high level of.
Biogas production.
So what does that lead to? Well, the target was an 80% COD removal. So removing 80% of the calories, we actually achieved 90% the reduced reduced discharge costs. We're meeting about 13% of the factory.
Energy demand.
The payback is reduced from 3.2 to 2.2 years.
And that over performance has actually made a a second CHP viable and further energy savings are expected. So that's a a good story.
All the way to the north of the country now to Glenmorangie and Taine. Taine is about. If you're not all that good with your geography of Scotland, it's about 3040 miles north of Inverness, so it's a long way north.
Their plant was an anaerobic MBR, so a different way of separating the solids from the biogas here. So the biogas separates off in the top of this tank here, which is their digester, and the solids are separated out with membranes, which you can see in the lower picture.
The issues that they had still running under commissioning parameters the site.
Needs to import gas. There's no gas pipeline. They're so far north. So they they get, I think it's compressed natural gas. It could be liquefied natural gas, not sure one of the two.
Distillery shutdowns have a huge impact on the AD plant, which means that when they are producing gas, it's at the wrong times.
And the gas wasn't particularly clean, so using a lot of chemicals. What did we do? Well.
There was an engineering step change required because the gas wasn't clean, they couldn't use it. It was causing degradation of the boilers, so a biogas scrubber was put in. So this is a biological scrubber that reduces.
Costs by was, you can see at the bottom of the slide over 2000 lbs a week, so that's very significant.
Other optimisations. So if you like that kind of Formula One style optimisation, working out what to do in terms of gaining an extra fraction of a second on every corner, we increase biogas output by about a third, so.
Now providing about 20% of the site's total gas demand up from 15%.
Uh, overall, we've saved the client well over 100,000 lbs.
Now this is pharmaceutical. It's not food and drink, but this comes from the the waste comes from a fermentation process and.
This is essentially semi food grade. It's kind of close to food, food equivalent. It's a different type of reactor. Again, this is a continuously stirred tank reactor, a very long retention time in here, very high strength feed.
High in solids. Um.
And you know a different type of type of arrangement. The site, as you can see by the wind turbine in the background, is very keen on sustainability.
So we've done the whole sort of Formula One thing here. We've optimised the process. We've managed to get about a 23% boost in biogas production, exceeded energy targets.
By well over 500 MW hours for the year. We've done that by cleaning out the digester tank. So the tanks that you saw in that picture about 15 years old and hadn't been cleaned out. So we.
Clean those out and that actually improves the the working volume of the tank, various infrastructure upgrades, feed management and on that site.
There was used to be a separate contract to running the CHP from the AD plant. By combining the CHP contract with the AD contract, that has really helped us to.
Optimize maintenance scheduling, for example on CHP. So we will see a production gap and we will maintain the CH PS during the production gap, whereas with an external provider of CH PS, it was when it suited them to do the maintenance.
That boost was achieved despite client production levels actually being lower than originally planned. So overall benefit to the client about 150,000 lbs annually.
All of these required feasibility studies. A feasibility study typically incorporates.
Looking at the project goals, assessment of existing infrastructure, analysis of options and best available technology, the finance stuff.
And we will produce a report typically with annexes and appendices showing flow charts and diagrams.
So final slide if you.
Going to look at a take a screenshot or or wait for the slide pack to become available. This is probably the nice simple thing to look at in order to improve your return on investment. Understand the underlying science, measure the right stuff.
Keep the process optimal. Put in the right chemicals.
On the design side, on the engineering side, look at the design, have key components been omitted to save capital cost, identify the bottlenecks, look for your opportunities.
And potentially increase in size if you can, because that dilutes your overheads.
I need a drink. It's time for some questions and I'm going to pass you back to Luke, I think.

Luke Morgan   39:32
Yeah. Thank you very much, Frank. Uh, really useful stuff there. Um, we've had a few questions that have come in already.

Frank Wayman   39:38
Luke, are you muted?

Luke Morgan   39:41
Um.
Can you hear? Can you not hear me at all?

Ming Zhu   39:47
I can. I can hear you, Luke.

Frank Wayman   39:49
Alright.

Luke Morgan   39:50
Oh, OK, cool. So we we have had a couple of questions already. The first one to give Frank a little bit of a break. We'll direct it to you Ming, if you don't mind. So the first one which came in is when considering an upgrade or expansion, what are the most common assumptions that end up being wrong?
And how does a feasibility study avoid this?

Ming Zhu   40:12
Thanks Luke, Luke for the question. So Frank just introduced me early on. So I'm the engineering manager at Alfis joined the company just a few years before Frank did. I'm responsible for a team of design and build.
Engineers, so involved in some of the schemes that Frank mentioned. When someone consider an upgrade or expansion, we always recommend a feasibility study to be carried out.
To find the the the optimal solution way forward because if we don't do that sometimes you end up with a wrong technology to start with. So just give some cases that we have worked on at the pharmacy.
Site that Frank mentioned to to be able to comply with the the forthcoming IED directive and upgrade will be required. So the initial thinking is for the existing plant which is a two stage.
Activate sludge process to have a tertiary filter to remove the solids, but we did a detailed feasibility study and concluded the best treatment technology and methods is to.
Treat high strength waste with membrane bioreactor and segregate the low strength waste to buy by the the main treatment. So that way we achieve the the the IED emission limits and with the the the best technology selection.
We also did a feasibility for a crisp manufacturing site up in in North. The client was considering solids digestion process to to treat their solid waste.
And then we did a a a study consuming the both the solids and the effluent arriving from the site and concluded that combining both the solids and the effluent with a CSTR type of eddy reactor is is the best form of treatment. So that's another change.
Of technology selection, we also carry out a detailed feasibility study for a waste reception reception centre, a major one up in Scotland and AD was not considered at all in their.
Consideration to upgrade the existing plant again to comply with ID directive and because of the the high strength of of the effluent they are getting, we consider that combining AD as a pretreatment.
With with MBR treatment at at the at the end is is the best form to to to go forward. So a a feasibility study really looks at all those different options and arrive at the the right technology.
I guess at more detail level looking at the the slides Frank mentioned about the hand celestial AD reactor often as Frank had mentioned as well the optimum temperature of the AD reactor is 35 to 37 degree. OK if you've got enough waste.
Heat to to to achieve that temperature, but the ICS director shown on the slides provided by Pax. They could have designed the A reactor to work between 25 and 30 degree, obviously with a larger reactor volume, but would save.
On the heating requirement, so if heating is expensive on your side, the option of considering a reactor at a lower temperature often is is the best way forward. So sometimes you always have assumptions at the beginning, but a feasibility study will will.
Look at all those aspects. So hopefully, Luke, I can answer that question OK.

Luke Morgan   44:34
Yeah. Thank you very much, Ming. We have had another question come in. I think this one's probably better for Frank. It's is there a standard tox screen for potential inhibitory compounds that may be present in an AD feedstock?

Frank Wayman   44:49
Could you just read the the first part of that question again please?

Luke Morgan   44:53
And is there a standard tox screen for potential inhibitory compounds that may be present in an AD feedstock?

Frank Wayman   45:03
So no, it's the.
If you go to a an external laboratory and say can you please screen for toxicity?
They will typically whether there are certain things which you can get. So you could get say by guess methane potential test and that will tell you how how good things are, but it won't tell you what.
The problem is um.
Generally speaking, you'll need a consultant to work with you. So if you if you think you've got something toxic coming in, it's probably worth going to an AD consultant and saying can you help us get the right analysis done by a third party?
Laboratory and and look for it. Identify what the problem is. You might then find that it's a simple enough test. You can then do that at your own sort of reception area and check that.
Whatever is a problem isn't coming through, but it's trying to standardize anything in the AD industry is quite tricky. You see this with people might have, say, standardized.
Nutrient mixes, yeah, they they work, but potentially they don't. They're not necessarily delivering what you need in an optimal way. But yeah, it's a good question.

Luke Morgan   46:43
Thank you. If anyone has got any others, please do put in their questions now. We have got one more for now, but if there's no others, we'll wrap up after this one. But the final question is you have highlighted the importance of trace metals dosing for good A D performance.
We we add a proprietary blend. How do we know if that is the best way to complement our feedstock and could we save money by adding individual chemicals?

Frank Wayman   47:12
Yeah, again. So could you save money? It all depends on how much you're paying at the moment and what a chemical supplier is prepared to charge you for what you're getting. However, again, you probably need to use a third party laboratory.
You could look at your digestate. So if you analyse your digestate, which you're currently adding metals to, if anything is particularly high in there. So you might go, oh, we've actually got a lot of molybdenum or we've actually got a lot of this and that and the other.
You might say, well, actually that's more than we need. We can cut back on on what we're adding.
If however you see, oh hang on a minute, one of the chemicals is only just present in the right amount, then it might make sense to add cut back on the on the mixture and just add the one that you need, in which case you you might well find that you asked.
They're capable of making a saving.

Luke Morgan   48:11
OK. Thank you very much. We've had one brief question which I can answer, which is will the slides be made available after the call? And yes, we will be sending you over a copy of the recording as well as the slides and the contact details to Frank and Ming. So yeah, I think there's no other questions in there. So thank you very much guys for the work that's gone into the presentation.
I hope that the console content has been useful for everyone. And yet, as I said, you'll receive a follow-up e-mail in the next couple of days with the recording slides and the emails of Frank and me. So thank you very much everyone and hope you will have a great rest of the week.

Ming Zhu   48:46
Thank you. Bye.

Luke Morgan   48:47
Bye.

Frank Wayman   48:47
Good. Thanks.

   48:49
Thank you.