Reduction of Carbon Emission From IC Engines

The injection of air/oxygen into the exhaust stream has been tried, with the net result of creating headaches for car owners when those systems fail.

Yes it was sort of cheap for the car makers to do however, it only created the illusion that the exhaust was "cleaner" by diluting the exhaust not removing the harmful components of that exhaust.

A properly tuned and maintained motor will be enviromentally cleaner and more economical to one that has been neglected. Most of the "smog" systems in place are to compensate for poorly maintenaned engines.

Response 1 says that modern cars have O2 sensors and some action is taken. I wish I knew what action. What I felt was when the fuel is ignited - the heat results in expansion of the air. Hence quantum of air molecules must remain the same, but oxygen content must be increased. When we use oxy-acetylene torch, just by increasing oxygen- we get higher temperatures and flame quality can be controlled. Same effect must be seen even in IC engines- we must attempt to increase oxygen injection- deliberately.

Response 2 to the thread - is talking of injecting O2 in exhaust - which is little use in improving power of the engine. It may help to reduce carbon emission at a cost- which is not acceptable to the customer.

Thank you for elaborately and eruditely tracing the developments in IC engine.

I also thank you: nice summary / chronology.

I do think Exhaust Gas Reticulation should be Exhaust Gas Recirculation --at least, that's always the way I saw / heard it.

I believe M S DIVEKAR is talking about improving combustion efficiency by increasing the oxygen content of the charge by controlled injection of oxygen. Nobody seems to have cottoned on to this yet, and all are going off at tangents. It seems to make sense to me, I'm just unsure about costs, payback, etc. I eagerly await a post that will earn a GA from me.

OK,

Who says, " Nobody seems to have cottoned on to this yet,"

It's done every day.

It's called nitrous oxide injection.

It's not cost effective, nor practical. If it were it would be more wide spread.

N₂O? Naw, how about a much more reliable and productive HHO generator?

Hey Holzfeller: Where is my GA for the oxygen injector idea?

I was driving down the street the other day, and saw a '70^s station wagon that looked like it had been salvaged from the junk yard.

In the dirty rear window was a small sign extolling the virtues of using water for fuel. I smiled.

Poor mixtures produce CO. Lead sickens children. High temperatures produce NOx. That's why we have smog doodads.

**But are we assuming that within that the oxygen content is also constant in the air?**

The oxygen sensor is present to detect the amount of oxygen in the air that is being sucked into the cylinder.. so how does this affect the performance or emissions..? well, based on the percent of oxygen present, the driving conditions etc. the ECU decides on the amount of fuel to inject into the cylinder, so that combustion takes place as close as possible to the stoichiometric ratio for the fuel.

"The oxygen sensor is present to detect the amount of oxygen in the air that is being sucked into the cylinder.."

No, the oxygen sensor measures the amount of oxygen in the exhaust gasses. The computer used this information to adjust the fuel/air mixture and spark timing, among other things.

I some how think many-times people rush to respond. Holzfeller at 9 has correctly said that what am talking about is injecting intentionally certain amount of O2 to improve burning as well as power output. Basically PV= constant curve will not change. Hence will power output increase??? But carbon emission should come down. For changing PV curve- we should look at my other blog.

And where do you get this Oxygen to inject? Is it produced by some means? Is it under pressure created by some process? What's the carbon cost of making that "bottle" of oxygen?

Injecting oxygen does not "improve burning." It simply allows for burning more fuel, thereby creating more CO2. (NO2 injection is done for this reason. It can increase the power of an engine temporarily, while over-stressing it.)

This combination of statements is wrong: "Hence will power output increase??? But carbon emission should come down."

If there is no fundamental redesign of an engine, adding more oxygen to burn more fuel creates more CO2. If power increases, CO2 increases.

Perhaps you are confusing the slang "carbon" (to mean CO2, a greenhouse gas) with solid carbon: coal, soot, etc?

For the last several decades, all cars sold in the developed world have had catalytic converters with oxygen sensing. In this closed loop system, precisely the correct ratio of fuel to O2 in the air is maintained at all times other than at startup and full throttle.

To increase power while reducing CO2 requires a change in the efficiency of the engine, which requires re-engineering the engine. For example, to produce 20 hp, a Prius engine uses less fuel, (and creates less CO2) than a Porsche 911 engine does to produce the same output.

You'd find a combustion text helpful, provided you actually read it. Search for John Heywood.

good Moronic, I gave you a GA

If you inject more gas (not gasoline) into an engine than it would normally- naturally aspirated- receive, you will get more power because the pressure inside the cylinder will increase above "normal" due to the additional expansion WITHOUT increasing the CO2 and likely DECREASING the NOx because the temperature of the flame will be lower.

YES- this will likely overstress the engine and might cause serious damage, BUT it will reduce CO2 (and NOx) while it is working.

This is NOT a recommendation to do such a thing, just an engineering discussion of how it could work.

Indeed, contributors to this thread seem to be mostly missing the point entirely, or dismissing it offhand without explanation.

The key questions are:

· Is there any benefit to increasing oxygen content of the charge?

· Is there any possibility of a feasible way of doing it?

· Is it worth pursuing?

We already know of many methods that have been proposed & tested (injection of nitrous oxide, water, hydrogen peroxide, HHO, etc) and, for various reasons, none seem to be ideal at the moment. So do we just all agree that IC engines are as good as they'll get ("perfect in the combustion department") and desist from flogging the dead horse or, in fine engineering tradition, do we look to see if the benefits could justify seeking alternatives?

Straight (pure) oxygen injection does a wonderful job of turning precisely machined pistons into little round blobs of aluminum, as well as reconfiguring all sorts of internal engine parts.

The oxygen sensor monitors the O2 content in the exhaust, delivers that data to the onboard computer, which uses that, along with other input data to adjust engine performance operating parameters.

I think injecting oxygen that way would increase the cylinder temperature. Especially if the engine was not running at optimal....which is pretty much usual. The high temperatures would cause more nitrous oxide pollution, assuming that it did not simply burn through the cylinder head. Injection of oxygen would be quite dangerous to the engine components I would think. Perhaps you meant "fresh air" instead of "oxygen". Since nitrous oxide is more dangerous than carbon dioxide to the environment, I have always heard that anything which would LOWER the cylinder temperature would be better. To illustrate this, Alcohol in the fuel, for instance, lowers the temperature, reduces no2 pollution, and prevents icing. It also raises the price of bread. Alcohol always has a bit of water in it, which allows a little bit of h2o to go into the combustion mix, which turns to steam, and re-burns carbon monoxide, cleaning the whole system by burning the exhaust. So you see the usual answer is to lower the temp, not increase it. The trace amounts of water in the fuel does the same job that your oxygen injector would do, and requires no changes to the engine.

Stratified charges (which we now have in most ic engines) allow more non burning air into the cylinder which helps to cool the cylinder head and provides air to reburn the exhaust in the catalytic convertr, which reduces the CO to CO2. I suspect that your idea of injecting oxygen might have already been done by the invention of stratified charges.

Your question was, "would this be the answer to reduce carbon emissions"? The short answer is no, it will not. In fact, the high cylinder temperatures will increase nitrous pollution, and increase global warming and air pollution.

Your second question "would adding oxygen to the mix cause the engine to run better in a polluted environment", I would say, it would have to be VERY polluted! Like, running in a closed garage. The answer is of course "yes". Adding air to a fire makes it burn better. Hardly rocket science. But I don't think that you were looking for a way to run an engine in a closed garage. But that IS what you suggested in your post. Oxygen levels DO vary from place to place, the O2 sensors adjust for that already.

The third question, "would adding oxygen to the mix" be a low cost simple solution to the burning problem facing the world today? The answer is an unqualified no. It will not. The internal combustion engine is 19 century solution to a 21st century problem. It has been refined to death, and even if there was a sudden increase in its efficiency it would still be an unsuitable engine as far as the environment is concerned. Even burning pure hydrogen will result in NO2 pollution.

Good post though. made me think. I am totally looking forward to the engine experts here on CR4 to tear this comment to shreds! I will admit up front that there has been some over-simplification here...grin!

The only way to reduce the carbon emissions is to burn fuel that does not contain carbon. So that pretty much leaves you with something like hydrogen, if you also want to reduce NO emissions you have to use an oxidizer that does not contain nitrogen, so out with the atmosphere, in with pure oxygen. Gee, why not just use a fuel cell? Greater efficiency, the only thing going out the tail pipe is water?

Lots of discussions on how to get more power out of an engine, and a couple will actually allow reduction of CO2 because they will use some other product to help create the pressure that drives the pistons, BUT- as noted by a couple of others, when you burn carbon, you get CO2. Usually- if you are getting more POWER from an engine, you are usually burning more fuel and getting more CO2.

If you burn anything that is not carbon- you don't get CO2.

If you burn anything using air for the oxidizer, you will get NOx.

If you don't use a mixture of nitrogen and whatever to oxidize, you won't get NOx.

Let me summarise my own way of what I have gathered from discussions so far.

Since air is used NOx (is poisonous & polluting & undesirable) is formed & not due to fuel - at high temp.

Carbon in exhaust is due to fuel - not burning. If possible we should avoid.

Given the above- we should try to use pure oxygen (let us not debate on cost, where to get, etc NOW). Avoid Nitrogen while burning. When the air to fuel mixture is ignited- what really expands is air. Fuel only helps to increase temperature of air in a short time.

If my summary is right - I will think over other avenues- including use of closed loop (like in refrigerators) nitrogen free gas.

Your summary assumes that there is significant unburnt carbon in the exhaust. Modern ic engines are so efficient these days that the vast majority of fuel actually is burned. If you perfectly tuned the engine, and extracted every bit of energy out of the exhaust, it would not increase the power available by more than a few percents.

You are correct, there are other avenues. The world will belong to the person who will get fuel cells to work on raw biodiesel. There is your closed loop!

Thank you very much for your very elaborate explanation. For sure it has to be nitrogen free burning.

My other blog related to splitting the 4 stoke IC engine into one piston type inlet/ compression & followed by rotary type to draw power over almost 350 Degrees rotation continuously stands. This one was related to the fuel type.

Is your "invention" anything like two stroke blown diesel? It uses pistons and a blower.

Thank you very much for your very elaborate explanation. For sure it has to be nitrogen free burning.

This is an odd juxtaposition of thoughts. Did you think I was suggesting that "it has to be nitrogen-free burning"? What could possibly give you such an idea? That is not at all what I was suggesting. I was suggesting that you learn about engines before trying to fix them.

This one was related to the fuel type.

If that's the case, then why are you focusing on the oxidizer and not the fuel? Are you thinking of air as a fuel?

My other blog related to splitting the 4 stoke IC engine into one piston type inlet/ compression & followed by rotary type to draw power over almost 350 Degrees rotation continuously stands.

What do you mean? Obviously it "stands"... that goes without saying. CR4 does not remove old threads. If you come back in 3 years, that thread will still be there, making as little sense as it does today.

You have not defined what sort of "carbon" you want to reduce as an engine emission. Do you mean CO2, the gas? Or do you mean carbon particulates, i/e smoke. The causes and solutions are different: For the first, burn less fuel... or burn a fuel that does not contain carbon. For the second, implement the controls that have already been developed.

I am an electronic engineer.

Almost anything in the world as we know is analog. But Electronics has successfully used digital technology almost everywhere. It further involves amplitude, frequency or pulse width modulation etc and ultimately what we experience is analog. My thoughts originally went in this direction - why IC engines can't be digital. I studied that a 3 cylinder 800 CC car engine uses 200 CC 3 No's cylinders. We as customers are told that if we drive around 40 to 50 KMs - the engine is efficient. When we use digital technology we can get higher efficiency over much wider range of operation. Digital is more efficient then analog or linear technology anyway. Hence I was thing we should use say 25 CC engine, 50 CC engine, 100 CC engine and then 200 CC engine. Depending on speed and power needs one could fire only 25 or 25 +50 or 25 +100 or 25+50+100 and so on . We can use all combinations. So your problem of using different engines for different target applications is solved. We should even get rid of teh reduction gears and drive directly. We could further use modulation etchniques etc for speed erduction.

Basically let teh world get ready to dupm the present 4 stoke iC engine, use concepts of binary and digital electronics etchnology. Swicth to piston cum rotary engine. We could tehn look at ways of avoiding air for cumbustion etc.

But we msut agree to dump 4 stoke iC engine first.

If I have read your answer correctly (and thats a big IF!) you are suggesting that you use fewer cylinders for lighter loads. Damned if I can figure out what you mean by "rotary" though.

Oh well, no doubt you have a good grasp of the concept. You have not really explained it well enough on this post for me to make a decision one way or the other. Possibly, you don't want anybody to steal your idea, but you still want to talk about it. Okay then. I won't supply money for you to make it into a reality though. Good luck with that.

Personally, I don't know why we don't use more Stirling Engines. They seem to be the perfect engine...runs on cow shit and scrap paper. But you say, its not as efficient as a gasoline engine. (argueable) Well DOOOOOD! Why are you talking efficient! It runs on cow shit and scrap paper! Good lord. Solve the global warming problem over night! How ya gonna beat cow shit and scrap paper! I live for the day that airplanes will fly using their own paperwork as fuel!

But anyway, good luck with your digital rotary combination thingamagiggy. Put up a video of it operating on youtube. Really love to see what you come up with!

Right now - I am touring and will return to my home town & my own computer after about 4 to 5 days. After that I will share more details with sketches. I am in Bangalore , India. So logistics of working arrangement has to be looked into.

I posted this in a thread relating to engine efficiency and what not and feel its well worth repeating here again.

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Theory theory theory and pretty lines on paper blah blah blah.

I have yet to ever see that solve any problems faced by the daily reality that if no one builds it/ has tried to build it/ has built it no one will know if it actually works or not. This issue relating to how to make an engine more efficient or how can we make it whatever comes down to some apparently poor overall understandings of how form follows the intended function.

There are a few basic criteria that need to be addressed before anything can be designed and so far they rarely ever come up in these topics or debates which means these need to be solidly answered before any realistic design can be made.

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1. Why do you want it more efficient? To save fuel/money or some other reason?

2. What standards do you want it to meet? Peak energy conversion efficiency or peak cleanliness of combustion byproducts?

3. What is the intended application and operating conditions? Steady fixed load rate or highly variable operating conditions?

4. Who or what is the target market or intended application? Do you want to pull a 20,000 pound trailer up a 6% slope into a 40 MPH head wind with a with a 600 HP F550 super duty truck or do you want to get 100MPG on gasoline with a 500 pound 15 HP econocar?

5. Who's standards or specifications will dictate the design? Is it going to meet the maximum efficiency levels possible with practical design or meet some clueless halfwit requirements placed on it by uneducated politicians or similar parties?

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Here is the problem of the first part. Internal combustion engines can be made far more efficient at turning fuel energy into usable mechanical energy but at some point the design, manufacturing, and operational costs start to outweigh the financial savings gained by using less fuel. So do you make the system less efficient but save over the long term on operating costs or do you find a cheaper/more cost effective alternative for one or more components related to this problem?

Here is the problem for the second part. Do you save money and fuel by making the energy conversion operate at its peak efficiency or do you make it work at its "cleanest burn rate"? Peak engine energy conversion efficiency and peak theoretical combustion cleanliness are not the same thing. Thats why GM vehicles have crappy efficiency numbers, they are that way because of emissions standards numbers not fuel efficiency numbers.

Here is the problem of the third part. What application or working conditions are you targeting? Freight hauling is a steady continuous load that does not require large changes in speed or overall working conditions so those engines can be designed to work at a optimum efficiency level simply do to having a very narrow range of intended working conditions. They only run at one narrow output range and do very little stopping between destinations. Commuter vehicles however are in a constantly varying working environment. They have to work with continually changing loads and conditions.

Here is the problem with the fourth part. What is the application? That is it nothing else. There is no single design that can ever meet all the variables and working conditions needed by everyone and everything.

Here is the problem with the fifth part. Internal combustion engine efficiency for vehicles can and at one time did run at higher fuel to mechanical conversion efficiency numbers than they do now. Clueless twits in politics and environmental organizations placed rules and demands on how clean is the exhaust over how little fuel is used to do useful work. That is what comes out the tail pipe became more important than the money in your pocket going out.

As someone who has gotten of his butt, or at least I raised a cheek and grunted a little, relating to more realistic issues of this topic I see these are what need addressing first!

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In summation clean burning is not efficient burning. To reduce CO2 output the only solution is to reduce the usage at the input by converting more of fuel energy to mechanical motion opposed to political based theoretical ideals that don't necessarily add up in reality to anything that could be remotely called a positive gain.

I have great regard for your understanding of the subject- I think you really are an EXPERT in this field- while I AM A NOVICE - trying to come up with some new ideas.

I believe in one thing - John F Kennedy once said "America will land a man on the moon" and NASA took several years to translate that political statement into action. So as scientists- let us work towards a solution. It challenges everyones brains and keeps us active.

I do notice that you are highly knowledgeable - regarding IC engines for different target markets etc. When Carnot developed his theory - there was no specific target market. So I am trying to suggest ideas at that level.

I am convinced that my piston-cum-rotary engine called 2Px350R with existing fuel will develop more power = less pollution per kilometers. Regarding reducing NOx or carbon emission at tail pipe needs more understanding on my side.

"You say I started out with practically nothing, but that isn't correct. We all start with all there is. It's how we use it that makes things possible." -- Henry Ford

There is an air to fuel ratio that engine manufacturers tune an engine to run at. That is using 21% Oxygen content. if you change the oxygen content, you will need to change the air to fuel ratio to match. The changes will cancel each other out.

How much oxygen do you want to carry on board? Do the math. A 3.0 liter engine about 175 cubic inches, times 1/2 of 2,500 RPM equals 127 cubic feet per min. Or, 12152 cubic feet of air ingested in an 8 hour drive. How often do you want to fill the oxygen tan k?

I thought this thread was exhausted...

I originally started discussion on reducing pollution due to NOx and unburnt carbon from fuel- by trying to inject oxygen. There seem to be practical difficulties.

Then the discussion has turned my original thought on engine design itself. I will start a new blog and then revert to fuel related issues later.

Kindly participate in a new thread http://cr4.globalspec.com/thread/66304.

This is in response to comments by tcmtech at 34 and by Yusef1 at 39.