Kai Låtun, VP Sales & Marketing, Yara Marine Technologies AS presentation during the 2015 GREEN4SEA Forum.

In the presentation “SOx Scrubbers – a profitable investment ?”, Mr Latun looks at under which conditions the profitability of a scrubber investment should be evaluated. He gives some concrete examples of scrubber installations onboard vessels, and illustrates how to calculate paybacktime for a scrubber investment based on realtime conditions. He also reviews the costs of alternative consumables needed during scrubber operations.

Yara Marine Technology, used to be known as Green Tech Marine, founded in 2010. Yara Marine Technology has supplied scrubbers since 2012 so it has tens of thousands of operating hours on scrubbers and experience on it. It is also now part of the Yara Group, which is a large Norwegian cooperation with turn over around $15,000,000,000/year and about 10,000 employees. 

First of all I would like to say that I’m very happy about the presentation from Lloyds before, because he showed you a chart with green, yellow and red lines, when does it pay to have a scrubber. And being a scrubber supplier, we have very often come across this question. So, we have simply developed a calculator, where you can put your own values. What I’m going to do is to take you through that calculator and show you how simple it is to get a general idea. It’s not the answer to everything, but for initial investigations, whether you should do something or not, this is a very useful tool.


Sox Scrubbers - A profitable investment?

As mentioned before, you need to input some staff, in order to have an idea whether it pays to invest in scrubber technology. To do that, you should go to a scrubber manufacturer and ask instead of guessing on the equipment cost. You can ask many of us. You also need to establish the installation costs. Now it is very often something that yard can answer. (I’ve heard anything, from 50% of the equipment cost- no ship-owner is believing at all-to twice the equipment cost) So for the sake of the exercise, I put in 75% of the equipment cost as installation cost you see up here top. Then, it’s your own internal interest level. What’s your requirement, what interest level do you calculate in your company? I can’t answer that. You can put it in. Then, as also mentioned previously, a very important issue is how long, how much do you sail in an ECA. Then you need to input sulphur content in the fuel and cost level of MGO and the HFO. The example above is not a surprise. It’s a vessel that it is in ECA zone in northern Europe all year round. It has a fairly large engine configuration. We are talking here about 1 main engine and 4 auxiliary engines, (28-30MW of engine power install), the average load on this vessel through 365 days is 22 MW and when they are, as mentioned, in coastal waters, manoeuvring, where there is no discharge allowed, and the have to operate in close loop, they have an average load about 6 MW. And there is about 120 days of those. So 1/3 of the operating time is spent in no discharge waters. Then, finally, this owner has to know this specific fuel consumption, as fuel oil consumption, for the vessel. It has to be an average number. It is so easy to come up with and if you ask engine manufacturers they often give you a number that is slightly lower than real life shows. But some number has to be put in.

I hope you are all clear on the preconditions and your payback time for investing in a scrubber. Under these conditions, payback time is less than a year. So we are in the green range. But from this tool, you can input your own values and you can check for yourself. Interesting enough, as I said, it is very often difficult to know how many gr/kwh that your engine is consuming in terms of fuel. What you very often do know is how much fuel I buy for that vessel through the year, so therefore there is a variety in calculator. You recognise all the data, but what is in here instead of this specific fuel oil consumption is your tonnage of fuel per year. With this calculate you can play around those specific parameters for your vessel or your vessels and get some sort of idea. I stress, it is not the final answer. But it will tell you if it is interesting to start looking at this. Because it’s very hard, when everybody else says if you are 25% in the ECA it’s not value, it doesn’t pay. If you are 40%, it may be pays well.


Sox Scrubbers - A profitable investment!

With this tool, you can check also if you have to use an alkaline to operate in closed loop, because the water is losing its buffering capacity; its capacity to take up SOx. We would strongly recommend not looking at caustic soda as an alkaline for the reason stated before. Caustic soda is harmful. The alternative, magnesium oxide is completely harmless. A second point, which is just as important, is that your consumption of magnesium oxide is much less. I am not going to details why, I am not a chemist, they can tell you why. It is much more efficient agent than caustic soda so your consumption in terms of volume is about ¼ of what it could be with caustic soda. So the higher efficiency also yields a lower storage space requirement on board for your alkaline when operating in closed loop. Prices of those two alkaline are historically fairly similar but caustic soda is very up and down than magnesium oxide has been doing. But they are more or less on the same price level the cost saving by using magnesium oxide in this vessel that I gave you example for is actually quite substantial as you can see from the calculation you save about 200000$ per year for that specific vessel but again that’s something that calculator come up with if you inpur your own values

MgO Advantages

  • Safer handling due to mild alkaline properties compared to NaOH, Ca(OH)2, Na2CO3
  • Much Lower Operational Cost than caustic soda/NaOH
  • And NaOH normally requires fresh water for mixing


  • Higher efficiency
  • Low storage space requirement onboard
  • Lower MgO quantities result is less solid waste, hence less disposal cost
  • No or limited price fluctuation

Now, let’s take a ro-ro vessel or something like that, that is going in a liner around the world and that gives you slightly different figures. Let’s say that also for a ro-ro vessel, its load is 22 MW, is quite realistic, the distribution of engines is quite realistic, all the parameters are quite realistic.  Of course a vessel like this, it trades 80 days inside an ECA, at least pre 2020, (when we get to 2020 EU will implement a 0.5% limit on the sulphur so all European waters will be 0.5% regardless of what IMO is doing). The scenario would be for pre 2020. For this ro-ro here, I’ve used again the variety where we have the specific oil consumption, but this ro-ro would obviously sail with 3.5% sulphur. For that vessel with 80 days in an ECA and 40 days in near coastal waters (Belgian coasts, port of Bremen, Eindhoven, Hamburg, maybe some ports in the Baltic Sea). Well, this in an ocean going ro-ro that she would go to the Baltics, typically stop at Rotterdam or somewhere. So for this vessel you see that the return on investment is like 4.5 years.


Sox Scrubbers - A profitable investment!

In conclusion, there is no set equation that can give you a general answer.  You have to input your own values.


Above article is an edited version of Kai Låtun presentation during the 2015 GREEN4SEA Forum

You may view his presenation video by clicking here

Click here to view all the presentations on this GREEN4SEA Forum


About Kai Låtun

VP Sales & Marketing, Yara Marine Technologies AS

Kai has gained an education from Norwegian Technical University (NTNU) and London Business School. He has 30 years’ experience in shipping-, offshore- and telecom industries, whereof last 7 years he is expert in marine emissions and air abatement challenges, specifically working with NOx and SOx abatement equipment.

In the starting, I was forthright with you propecia before and after has changed my existence. It has become much more fun, and now I have to run. Just as it is incredible to sit.