Showing posts with label NOx. Show all posts
Showing posts with label NOx. Show all posts

Friday, April 10, 2009

Nitrogen Enriched Gasolines – What Are They and What Do They Do

Nitrogen Enriched Gasolines – What Are They and What Do They Do

Shell Oil has recently begun advertising their Shell V-Power “Nitrogen Enriched” Gasoline.
Why would nitrogen improve the cleaning performance of gasoline detergent?

Here are some facts to consider:

1. The earth’s atmosphere is approximately 78% nitrogen
2. Nitrogen is an inert gas that is not combustible
3. Nitrogen atoms are larger than oxygen atoms
4. Nitrogen when combusted with fuel and Oxygen creates Nitrogen Oxides (NOx)
5. NOx when combined with Volatile Organic Compounds (VOC’s) creates petrochemical smog.

Shell claims that fusing (their term) nitrogen with their detergent creates a more stable, longer lasting detergent that will be more effective in preventing gunk (their term) deposits (my term) from building up on the valves and other combustion chamber areas.

It would seem to me that adding Nitrogen will make the combustion process less efficient and could possibly lower combustion temperatures. This would seem to be the opposite of the desired effect.

It would also seem that adding Nitrogen could raise the NOx emissions from the engine which would tend to increase smog production, again the opposite of the desired effect.

I definitely applaud the idea of raising detergent levels in all gasolines. This is a quick and inexpensive way to reduce emissions and improve fuel economy.

The whole Nitrogen thing is nothing other than another marketing ploy. Shell and many other refiners have attempted to convince the consumer that they are doing something unique and wonderful, when in reality they simply want to sell more and or charge more than their competitors.

Shell needs fewer “Cutesy” TV commercials and more science, or at least they should provide some documentation to support thier claims.

If you want to do the best thing for your gasoline powered vehicle, look for fuels containing “Top Tier” fuel additives used at the manufactures “Top Tier” levels or simply purchase and regularly use aftermarket “tank additives” that meet or exceed the “Top Tier’ requirements.
This together with proper maintenance will ensure peak performance and minimum emissions from your engine.

Please let me know what you think, post your comments, ideas, and suggestions here.

Diesel Doctor
Copyright 2009 – William Richards

Friday, March 6, 2009

Natural Gas as a Transportation Fuel – A Cautionary Note

Natural Gas as a Transportation Fuel – A Cautionary Note


Natural Gas is currently being promoted as a domestic clean, safe, and cheaper alternative to petroleum fuels.


Some thoughts for your consideration.


Natural Gas as domestic source of energy. The US currently imports approximately 16% of its natural gas. Some comes to us by pipeline and some in the form of LNG via ship. Increasing the use of natural gas to replace petroleum fuels simply shifts our imports from one product to another.


Currently the US uses approximately 22% of our natural gas to create electricity. This is a poor use of a valuable resource for a need that has many other fuel sources available. If this was replaced by wind, solar, nuclear, and a future renewable bio-source (see previous article: The Richards Cycle) you could eliminate our imports.


Natural Gas as a clean motor fuel. Compressed Natural Gas (CNG) and Liquefied Natural Gas (LNG) both reduce certain emissions however they are not as clean as some would have us believe. If you look the whole basket of emissions that come out of the exhaust on an internal combustion engine, a 2010 Selective Catalytic Reduction (SCR) Diesel engine actually is less polluting than an equivalent CNG or LNG engine.


While I believe you can safely use CNG and LNG, it requires more training and much greater diligence on the part of drivers and operators vehicles and fueling stations. It is important to remember that it can take far longer to fuel LNG and particularly CNG fueled equipment. This long fueling cycle can lead to lack of attention and added expense in fueling equipment.


Natural Gas as cheaper alternative. Many people incorrectly try to compare a gallon of diesel to a gallon of LNG or a gallon of CNG. While the price per gallon of the LNG and CNG may appear to be cheaper, you need to consider the energy in the gallon. For example a gallon of diesel contains approximately 139,000 Btu’s of energy, while a gallon of LNG contains about 73,500 Btu’s, and CNG works to about 34,750. In short it takes about 4 times the space to store an equivalent amount of CNG as compared to diesel.


The other concerns with vehicles powered by CNG or LNG are that they are far more expensive to purchase, for example a school bus built to run on CNG can be $30,000.00 to $40,000.00 more than its diesel counterpart.



Also when you purchase a vehicle powered by CNG or LNG you locked into one supplier for all fuel system and some engine components for ever. There is virtually no secondary supplier compatibility. You limit the range and usefulness of the vehicle due to limited ability to refuel that vehicle away from its domicile. Lastly, you have to be concerned about the value of those vehicles when it comes time to trade or sell them. In many cases this limited resale market can make a used vehicle worthless.


There is an important and growing place for alternative fuel vehicles and equipment. It takes visionary leaders with long term commitment and very deep pockets to make a change to this type of equipment successful.


You can get more information on this and other fuel related subjects at: http://www.lcbamarketing.com and click on Fuel School Articles.

Please comment here and share your thoughts, ideas, and suggestions.


Diesel Doctor



Copyright 2009© - William Richards

Monday, February 9, 2009

UREA use in 2009 and 2010 Diesel Vehicles

Urea Use in 2009 Light Duty and 2010 Medium and Heavy Duty Diesels
Hold on, here comes the next big change in diesel engines. Starting with the automotive market in 2009 and then with virtually all of the medium and heavy duty diesel vehicles in the 2010 model year, diesel engined vehicles will require an additional fluid to operate.

These vehicles will require an “aqueous urea solution” as defined by ISO 22241-1 using test methods described in ISO 22241-2:2006. This is a solution of 32.5% Urea in deionized water.
This Urea solution is used as part of a Selective Catalytic Reduction (SCR) system to reduce the NOx emissions of diesel fueled engines.

These systems require that a tank of the Urea solution be installed on the vehicle. The Urea is meter injected into the exhaust stream after the turbocharger where the exhaust heat will convert it to ammonia which is then used by a special type of catalytic converter to significantly reduce the formation of NOx. This system will function as long as there is Urea available.

This is a complicated system with maintenance requirements, cold weather operability issues (Urea freezes), and quality concerns.

There is a wide ranging debate on what type of driver information systems are to be required, what will happen if the system runs out of the Urea solution, and where Urea will be available.