Good Morning,

Recently we have been asked many questions about TBN and its relationship with various other parameters, especially in engine oil. To provide some scientific basis for TBN and TAN I have attached a recent paper on the topic by our Chief Chemist in Indonesia, Ibu Eka Karmila. Please don’t hesitate to call us to discuss further. But it seems that a healthy TBN is very important to the health of your engine. THEORY:

TBN ( Total Base Number) value indicates the alkali value of the additive in the oil. TBN values are the  amount of base required to neutralize  acid that is contained in 1 gram of oil, and conversion to mg of potassium hydroxide (KOH). This value is expressed in units of mg.KOH / g. Values for new oil in general is 6.0-13.0 mg.KOH / g.
When the number  is  below 50% of the originalTBN value, the acid neutralizing performance of oil is reduced and corrosive wear occurs. There are two main methods to determine TBN

1. Hydrochloric acid (ASTM 4739) and
2. Perchloric acid method (ASTM D2896).

Because perchloric acid method takes into account weak base numbers, a higher TBN is obtained. Therefore, it is necessary to establish which method of calculation is used. If the value of TAN is over the limit, the engine oil should not be used even if the remaining TBN value high. Sulfur contained in the fuel in the combustion process will oxidize (react with oxygen O2) to form gaseous SO2 (sulfur dioxide), and some will turn into SO3 (sulfur trioxide) if the combustion temperatures drop rapidly Furthermore, SO3  gas will react with moisture and combustion produced H2O to form sulfuric acid (H2SO4) which is very corrosive.

The resulting sulfuric acid may form within the combustion chamber and / or outside the combustion chamber. If the process takes place in the crankcase, during blow-by (leakage of combustion gases past the piston rings), sulfuric acid formed will contaminate the engine oil. As a result, the TBN value of oil drops and function and if lower enough acidic corrossion will occur.

TOTAL ACID NUMBER

Oxidation of the lubricant causes an increase in acid number( TAN) which results in corrosion of the

equipment.

• Trend
• of depletion of certain additive such as ZDDP, overbase detergent and rust inhibitor.
• Identifies the onset of basestock oxidation
• Measures the level of corrosive acids
• Measures the level of reserve alkalinity

TAN analysis was also used to detect the corrosive acid:

Notes on TAN Monitoring

• For Mineral – based turbine oils, an increase in TAN of just 0.01 mgKOH/g is cause for concern.
• In high temperature oils, acids from oxidation can vaporize or polymerize resulting in TAN being an unreliable indicator of oxidation. Solution is  to monitor oil oxidation by FTIR.
• Water is often the cause of acid formation. When water is mixed with oil, it gives the acids greatest corrosion potential.
• TAN measures acid concentration not acid strength
• EP and engine oil additive can interfere with TAN trending
• For mineral oils, a TBN above four isconsidered highly corrosive.

How to Monitor TAN trends

TBN :

Increasing TBN Trends Are Influenced by :

1. Makeup oil added
2. Loss of base oil volatiles

Decreasing TBN are influenced by:

1. Fuel/water dilution
2. Thermal Degradation
3. Reaction with acidic combustions products

How to monitor TBN Trends

STANDARD TEST IN TECHENOMICS :

Routine Oil Analysis carried out on equipment can provide maintenance personnel with the ability to improve availability rates on equipment, lower downtime and most importantly save companies extraordinary amounts of money that could be used on other maintenance requirements.

Background

In today’s manufacturing design process, enormous efforts are placed on producing cleaner emissions by having tighter, more precise engine tolerances, this creates extra horsepower and extended mileage on fuel and oil. These stringent guidelines and standards were introduced by governments and associated companies to ensure air pollution, fuel and oil usage would be reduced over time.

The necessity on such tolerances have placed enormous pressure on producing cleaner fuels and oils throughout the globe. Oil Manufacturers now have to ensure their products reach and meet a cleanliness standard, this can only be done by using Oil Analysis.

Equipment Manufacturers establish base line limits for each piece of equipment that are released for production. This is done by having scheduled samples taken on numerous equipment around the world and having the data sent back to the Equipment Manufacturers for analysis trending. After enough data sets have been achieved and a mathematical trend can be established, this information is then released as the OEM Limits for that equipment. Data sets that contain water, abnormal silicon results, fuel contamination and a few other sequences are discarded from the analysis trend to ensure a more accurate and repeatable result can be obtained.

Large companies that employ maintenance engineers to provide proactive and preventative maintenance strategies, trend and graph availability rates and produce downtime reports to senior management, these maintenance engineers have already done the hard yards and analytical background work to measure the cost effectiveness of an Oil Analysis program.

How money is saved

An example of costs savings on a single engine is as follows; say you spent $80,000 on parts or an engine replacement, an average oil sample cost you about $30 per sample, equipment usually gets sampled once a month, so you could sample that engine just over 222 times (18½ years) to equal that amount of money spent on the parts or engine replacement that may be needed. Based on this you can safely say, that Oil Analysis could have prevented or reduced the cost of the part or replacement within the 18½ years.

For example, Techenomics Australia sees anywhere from 3000 to 5000 samples per month that are indicating potential catastrophic failure and call for the piece of equipment to be withdrawn from operations and repaired immediately. A catastrophic failure will result in lost productivity, major inconvenience and unplanned costs of a failure as opposed to a planned service event to repair a failing component.

Across the range if only 10% of these potential failures are “saves” then that could amount to about a saving of $30 million. The cost of the analysis is about 0.1 cent per dollar of saving.

Conclusion

One thing is certain, Oil Analysis will find faults within the oil, whether it be wear, contamination, additive breakdown, acid or carbon build-up, viscosity or TBN loss. These are fundamental elements that need to be monitored constantly, they will need to be addressed whenever a change indicates a potential breakdown or failure of the lubricant or an internal component.

A well-established proactive and preventative maintenance program can save companies thousands on the bottom line. By being proactive and ensuring that lubricants and fuels are clean and fall within the standards, equipment components will last longer, reduce fuel and lubricant consumption, and overall, live a longer healthier life.

Oil Analysis can also provide insight information into the lubricants breakdown, possibly even identify other key indicators of the failure that if sampled and picked up earlier, may have prevented this failure from occurring.

Techenomics International is a lubrication and condition monitoring specialist, with over twenty years of experience, offering preventative maintenance tools, including Oil Analysis, to the mining industry and helping companies save millions.

Techenomics operates throughout Australia, Asia, Mongolia and Madagascar. Condition monitoring services include oil analysis, magnetic plug inspections, lubrication and filtration solutions for fixed and mobile plant, all of which will significantly extend the life of equipment, lower unscheduled downtime and most importantly decrease operating costs.

For further information and all enquiries please contact Sam, Email: sreejith.b@techenomics.com

For those in Indonesia and SE Asia contact Freddy, Email:  freddy@techenomics.com

For those in Northern Asia, Mongolia and Russia contact Sugraa, Email: sugraa@techenomics.com

For those in Turkey, the Middle East and Northern Africa contact Yasemin, Email: yasemin.fadil@techenomics.com

-ENDS-

For media enquiries please contact Brooke Tolar, DragonFly Public Relations on T: 0411 553 246 or

E-mail: brooke@dragonflypr.com.au

Eka Kamila, Chief Chemist , Techenomics Indonesia.

The following post is a precise of a research project conducted by Techenomics Indonesia’s chief chemist. A number of our customers regularly filter their hydraulic oil to extend lubricant life.

There is always a concern that aggressive filtration may affect the foaming tendencies. This work indicated that by regular top of with new oil can greatly reduce any foaming tendencies.

“Foam is a collection of small bubbles of air that accumulate on or near the surface of the fluid. Foam is an efficient thermal insulator, so the temperature of the oil can become difficult to control. The presence of air bubbles in the fluid can lead excessive oxidation, cavitation, the reduction of lubricating properties of the oil and hydraulics system failure.

The causes of  foaming are many, the most common include:

•                Water contamination

•                Solids contamination

•                Mechanical issues (causing excessive aeration of the fluid)

•                Cross contamination of the fluid with the wrong lubricant

•                Contamination of the fluid with grease

•               Too much antifoam additive, either by incorrect formulation or by incorrect reconstruction of the additive package

With the addition of top up, levels of foaming in the lubricant can be controlled, so as to minimize the volume of oil consumption and ultimately to reduce the cost of care units.

The result is expected to provide information for the reader to reconstruct the lubricant so as to provide good impact on engine maintenance.

Graph 1 : Top up effect against foaming tendency

Graph 2 : Top up effect against TAN value

Graph 3 : Top up effect against visco 100⁰C

Graph 4 : Top Up effect against Visco 40⁰C

Graph 5 : Top Up effect against Millipore test for insoluble

  Addition of top up 20%, can reduce the foaming tendency to 87.5% (normal limit). And future results of this study and subsequent research, will be grouped according to :

1. Unit
2. Oil type
3. Oil hours
4. Normal operation condition

This grouping is done to classify the top up so far the results vary, most likely be caused by :

1. Different units of large capacity and small capacity, which affects the load.
2. Type of oil, the additive composition of the various brands is very influential on the oil resistance.
3. Oils hours, use of long-terms and short term would have caused a different impact on the performance of existing additive in oil.
4. Abnormal operation conditions, over-heating, over-load, seal leaks and other”

Eka Kamila, Chief Chemist, Techenomics Indonesia.