Emission Controls - Technical Thread

[CDK]

First of all, this is supposed to be a technical thread about marine emission control.
I have no friends in the luny bin so please stop comparing my ideas with those of K. or other members of the Enterprise crew.

Of course I should not have responded to FastFred's remark about 1000 years oil reserve. I am sorry, when provoked, sometimes I cannot keep silent. I have a very allergic constitution and react strongly to dust, pollen, bacterial toxins and stupidity.

See, I did it again....

Emission control has nothing to do with saving fuel or making cheap energy from water.

In my garage I have a Porsche 928, built in 1980. It has a large V8 engine with mechanical fuel injection. To comply with the Californian emission regulations back then, the Porsche engineers added a V-belt driven air pump (with air filter !) which fed fresh air to the first muffler. That way the exhaust gases were diluted to such an extent that the CO content was less than 2% at idle rpm.
Not exactly a price-winning concept, but an adequate solution for that era.

The Mazda RX-7 I owned in the 80's did things a bit better. It also needed a rich mixture for a vivid throttle response, so they used the Porsche trick but injected the air in a small reactor, well insulated and protected by heat shields. The excess fuel was burnt there so again it complied with emission laws. Not only at idle rpm but also at 3000 rpm: you could see the afterburner glow in the dark.

Now we are discussing marine emission control and have established that non of the automotive solutions can be used because we do not want scorching hot tin cans in our engine room. And without these, there is no way to treat the gases after they passed the exhaust valves.

So we have to investigate other paths.

Unfortunately marine propulsion has been exempt from emission laws until now, so we could keep using inefficient and polluting engines that would have been banned immediately when installed in a road vehicle. We were allowed to use dirty fuels in primitive engines, but it seems that we have been discovered now.

One way to improve emission figures is to use better fuels. There is no way to remove unwanted elements like sulfur from fuel once it has been produced because they are complicated organic molecules ( thiols among them) that cannot simply be washed out. But the oil companies can do that for us if we only insist on having sulfur-free fuel. And on large ships running on stuff we can hardly recognize as oil, the removal of sulfur and heavy metals can be done like in the refinery with high temperature/high pressure treatment.

So now that we have our clean fuel, let's focus on the engine.
While setting our boat in motion, it converts all long and short CxHx chains into CO2 and H2O as long as we provide it with enough oxygen to do so. More and more people are bothered by the CO2, but it is inevitable: if you have a lot of carbon to burn, CO2 is what you get. Going slow or not at all are the only options.
If there is insufficient oxygen (or too much fuel), like in gasoline engines, the combustion process is incomplete and produces carbon monoxide (CO) and unburt CxHx chains. Whatever leaves the exhaust without being fully oxidized do not contribute to the propulsion of our boat, has been paid for, but can never be collected again.

And that was what got me thinking about electrolysis of water. Adding a bit of extra oxygen and Hydrogen to the intake air may provide just what a gasoline engine needs to burn the fuel more effectively. The combination of H2 and O2 burns much faster than dynamite and has a much higher combustion temperature, that's why they use it to propel rockets. Adding it to the combustion air of a gasoline engine might be the solution to lower emissions.
But the answer cannot be expected from an amateur experiment. It involves exact analysis of the exhaust gases and measurement of the engine performance, facilities that are not at my disposal.

Lastly, there is also the problem of NOx emission, the inevitable by-product because we supply 80% N2 to the engine. That may also decrease if some H2 gas is present in the combustion chamber.

[FAST FRED]

"Where are you gonna get your oil for the other 985,5 years?"

Same place we got oil the past 5000 years , out of the ground.

The KNOWN reserves only cover where we have looked so far , and in many countries are considered "state secrets" , so we know little of the real resources.

Brazil "just" discovered a Saudi Arabia or 3 under deep water.

There is little question that eventually (the wait is over 150years so far) battery tech ( some type of efficient energy storage) will allow most motor vehicles to work from the clean Nuke base load.

Aircraft have over 500 years of fuel from coal , should nothing efficient come up in 500 years.

And of course we have been funding Fusion , clean energy at the Kolleges and research centers for 4 or 5 decades.

Politics shut down the US Super conductor super collider ( because it was in Texas) but the Euros have built a small scale copy , that may eventually get on line.

Although Whale Oil is a fantastic lubricant , and still used in the fine watch industry , its not burned as lamp oil, same with oil , we have hundreds to thousands of years of tar sands and shale oil (and plain old coal) but I expect the billion$ being dumped into research to have some use , eventually.

And we will no longer "need" oil as cheaper energy will be on the shelf.

To think scientific progress is over is the rawest form of STUPIDITY.

FF

[mydauphin]

I used to remove air pumps all the time from engines in the 70's and 80's. Simple reason, they reduce efficiency. The air pump is a parasite and the air inject into exhaust reduce engine ability to exhaust and therefore ability to breath. Much more can be achieve by properly sizing engines, gears and props to boats. Not very exciting but true. Must boats are setup wrong for efficiency. Also put boats on diets, a 100,000 lb that now weights 150,000 is a lumbering overreving fuel hog.

[Jimbo1490]

Why not just have the big ships run two fuels, their usual 'bunker' diesel for out at sea, and clean, low-sulfur diesel for when they get close to port, say 25 mile out? As I've pointed out, anthropogenic pollution is not really a problem for nature as a whole; nature copes with huge amounts of pollutants from natural sources all the time. The problem with anthropogenic pollution sources is that they tend to be concentrated in one area (like a port full of ships or a big city with many cars) and that these are the same areas in which humans live. So we get exposed to the high concentrations of pollutants, and this shorten lives.

A dual fuel system such as this would be simple and cheap to install.


Jimbo

Originally Posted by Jimbo1490

Why not just have the big ships run two fuels, their usual 'bunker' diesel for out at sea, and clean, low-sulfur diesel for when they get close to port, say 25 mile out?

A dual fuel system such as this would be simple and cheap to install.

Jimbo

This already is common practice in the merchant fleet! Many Ports do´nt allow the use of bunker C while maneuvering.

Regards
Richard

[mydauphin]

What is bunker fuel running for in the ports nowadays?

Originally Posted by mydauphin

What is bunker fuel running for in the ports nowadays?

MDO, or MDF marine diesel oil, marine diesel fuel, a low quality stuff. Bunker C is nothing else than refinery residue.

Regards
Richard

[mydauphin]

Anyone know price and can it be diluted by diesel and heat?

[CDK]

From the local oil company I downloaded spec sheets for their marine fuels in local language.

There are 4 distillates and 10 what they call remnant fuels.
The first group are DMX, DMA, DMB and DMC. They more or less resemble diesel road diesel fuel, but with a cetane index of 45, 40, 35 and ? for DMC. The viscosity is ascending, for DMB and DMC only a maximum value is given. Three out of four may contain used engine oil.

The second group are RMA-30, RMB-30, RMD-80 and so on, ending with RMK 700 for the heaviest.
Most are solid under 30 C. and may contain 10-22% free carbon, 0,15% dirt, 0,5% water and 3,5-4,5% sulfur. There are also limits given for vanadium, aluminum, silica, zinc, phosphor and calcium, plus 0,1% unspecified sediments.

This raises a few questions:

Why are there 14 different marine fuels?
Which criteria determine the type of fuel a large ship uses? Is that engine size, construction or do they simply use the cheapest type the engine will run on?

[mydauphin]

I know you guys are worried about pollution here, but I worry that prices of diesel will make my travels go by internet instead of by boat.
I am more worried about $10 a gallon fuel than about pollution,

So I am looking long term at either modifying some of my engines/generators for dual fuel, to something like diesel/bunker or my own refinery of waste oil/bunker fuel to a diesel mix. Biodiesel is also in idea mix.

Originally Posted by CDK

From the local oil company I downloaded spec sheets for their marine fuels in local language.

There are 4 distillates and 10 what they call remnant fuels.
The first group are DMX, DMA, DMB and DMC. They more or less resemble diesel road diesel fuel, but with a cetane index of 45, 40, 35 and ? for DMC. The viscosity is ascending, for DMB and DMC only a maximum value is given. Three out of four may contain used engine oil.

The second group are RMA-30, RMB-30, RMD-80 and so on, ending with RMK 700 for the heaviest.
Most are solid under 30 C. and may contain 10-22% free carbon, 0,15% dirt, 0,5% water and 3,5-4,5% sulfur. There are also limits given for vanadium, aluminum, silica, zinc, phosphor and calcium, plus 0,1% unspecified sediments.

This raises a few questions:

Why are there 14 different marine fuels?
Which criteria determine the type of fuel a large ship uses? Is that engine size, construction or do they simply use the cheapest type the engine will run on?

the latter...

CDK
DMA to DMX does not resemble road diesel! It is a Diesel fuel (better medium destillate) but not the "blend" we use in cars. You would kill a modern car engine using it.
The 4 common Qualities are IFO 180 and 380 at a viskosity of 180 and 380 centistoke respectively. Commonly known as "Bunker C" These fuels are solid below 30°C
And MDO MGO at far below 30 ct. These are single (not blended) medium destillates and residuals diluted, and stay liquid below 30°C. MGO 0.2 has about 4 - 6 ct as I remember.
MGO (Marine Gas Oil) is the highest common quality and usually the one used for mains on smaller vessels and / or for generators on larger vessels. You can burn MGO in almost all marine engines bigger than a truck diesel. (15 ltr. displ.).
Have a look at the prices:

http://www.bunkerworld.com/markets/prices/nl/rtm/

Marine (Residual) Fuel Oils Parameter Unit Limit RMA 30 RMB 30 RMD 80 RME 180 RMF 180 RMG 380 RMH 380 RMK 380 RMH 700 RMK 700
(Int. Bezeichner) IFO 180 IFO 180 IFO 380 IFO 380
Dichte (15°C) kg/L Max 0,960 0,975 0,980 0,991 0,991 0,991 0,991 1,010 0,991 1,010
Viskosität bei 50°C mm²/s Max 30,0 30,0 80,0 180,0 180,0 380,0 380,0 380,0 700,0 700,0
Wasser % V/V Max 0,5 0,5 0,5 0,5 0,5 0,5 0,5 0,5 0,5 0,5
Schwefel % (m/m) Max 3,5 3,5 4,0 4,5 4,5 4,5 4,5 4,5 4,5 4,5
MCR % (m/m) Max 10 10 14 15 20 18 22 22 22 22
Aluminium + Silizium mg/kg Max 80 80 80 80 80 80 80 80 80 80
Flammpunkt °C Min 60 60 60 60 60 60 60 60 60 60
Pourpoint, Sommer °C Max 6 24 30 30 30 30 30 30 30 30
Pourpoint, Winter °C Max 0 24 30 30 30 30 30 30 30 30
Total Sediment Potential (TSP) %wt Max 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1 0,1

Mydauphin
Biodiesel is your choice! None of the above mentioned is 1.st available for you, and 2.nd could meet your demand. Except you own a refinery.

Regards
Richard

[CDK]

Thanks for the education Richard.

Do you have any idea about the combustion efficiency of large engines that use RM fuels? If ships must change fuel type when nearing a port I suspect the combustion to be incomplete. Or is the pollution caused by fuel components that do not burn at all?

The combustion efficiency of those large monsters are the highest in our IC engine world. The largest MAN Diesel has a specific consumption of 162 g/kw only. And Bunker C has a high energy density. But it also contains a lot of chemical and solid crap that contributes to pollution. MDO by nature is a cleaner fuel `cos it is a destillate (middle dest.) whereas IFO 700 is the residue which no longer can be destilled to "higher" products. The 380 / 180 range is just a diluted IFO 700.

Regards
Richard

[fasteddy106]

You can take the bulk of the emission control devices from gasoline auto engines and put them on marine engines. It will raise the cost of the engine by several thousand dollars however. Mass air flow sensors, manifold absolute pressure sensor, camshaft and crankshaft position sensors, Evap canister and all of its various and sundry associated can be added. Plus all the temperature related sensors. They will have to redesigned for the marine environment so this will add to the cost in a big way. Think of all the wiring needed to be added, oh boy! You will need much bigger engine compartments and a secure environment for the computers to operate and monitor the engine. Because of the nature of water travel a secondary or limp mode will need to be added to the system in order to allow operation when some of the components inevitably fail and the engine shuts down because the computer gets confused and petulant by the incorrect signals it recieves from the sensors. The real function of all the sensors I just mentioned is to maintain the correct fuel mixture for temp and performance and are in addition to the sophisticated fuel injection systems modern autos have. With the exception of the evap system, the whole focus is on leaning out the fuel mix without causing excess combustion chamber temps that lead to higher nox. Nox on marine engines are beyond control with present technology. The heat is too dangerous to have on board so nox controls are a non-starter and further talk about them is silly and pointless. Besides nox gases from marine engines are a fraction of automobile engines because they run so much cooler so it would be like trying to stop West Nile Virus with a fly swatter, stupid and ineffective. About the same level of viability as painting your roof white to combat the AGW bogeyman, gee, wonder when they are going to start calling it AGC, (anthropogenic global cooling), crummy spring and summer here in the northeast, glad I'm out of the water for a year of redisign and repair.

[kistinie]

Originally Posted by FAST FRED

To think scientific progress is over is the rawest form of STUPIDITY.
FF

Nicely said.


Those that have noticed that recycled exhaust water was injected heated in the inlet of many modern car engines (Renault megane 2009, Golf TDI 2009....) for emission control purpose, are certainly sorry to see water is not available in sufficient quantity for a 20 to 30 % injection that would be much more adapted for a good emission control and fuel saving in the same proportion.

This may be the past as a smart solution exist to make de-mineralized water in large quantity with wind only....

Eole water

And you can drink it too :-))