Ammonia (NH3) is one of the most highly produced inorganic, synthetic chemicals & is critical in manufacturing fertilizers. There are numerous large-scale ammonia production plants available worldwide and, as per the 2016 report, produced a total of 144 million tonnes of nitrogen. Ammonia plants are an essential part of the chemical industry, providing a vital source of nitrogen for fertilizers and other industrial applications. In addition, there are numerous critical applications used in ammonia plants, need specialty lubricants to run the machine. However, the machinery used in these plants is subject to intense stress and high temperatures, which can lead to wear and tear on components. To ensure that these machines continue to operate at peak efficiency, it is essential to use the right lubricants.However, today’s effort is to address investigating lubricant failures on Ammonia plants. But before going ahead with different cause of failure of a lubrication system, we need to understand A lubricant’s function and characteristics to enhance the machine durability and reducing overall plant maintenance cost.
A Lubricant’s Function And Characteristics For Ammonia Plants:
Table of Contents
A lubricant’s main function is to reduce friction and wear on moving parts, which helps to extend the lifespan of equipment and increase efficiency. Some of the characteristics of a lubricant are:
- Lubricating properties: A lubricant should have good lubricating properties, which means that it should reduce friction and wear on moving parts.
- Viscosity: A lubricant should have the appropriate viscosity for the specific application. Viscosity is a measure of a lubricant’s resistance to flow.
- Thermal stability: A lubricant should be stable at the temperatures at which it will be used, and should not degrade or lose its effectiveness due to high temperatures.
- Chemical stability: A lubricant should be chemically stable and should not react with other substances present in the equipment.
- Compatibility: A lubricant should be compatible with the materials of the equipment and with any other lubricants or fluids that may be present.
- Pour point: A lubricant should have a low pour point, which means that it should flow easily at low temperatures.
- Flash point: A lubricant should have a high flash point, which means that it should be able to tolerate high temperatures without catching fire.
- Rust and Corrosion inhibitors: A lubricant should have rust and corrosion inhibitors properties which can help prevent rust and corrosion of metal parts.
- Anti-wear properties: A lubricant should have anti-wear properties, which means that it should protect moving parts from wear and tear.
- Cleanliness: A lubricant should be clean and free from contaminants that can cause damage to equipment.
Lubrication System Failure Reasons in Ammonia Plants:
- Insufficient lubrication: This can occur if the lubrication system is not properly configured or if there is a malfunction in the lubrication pump. To avoid this, regular maintenance and inspections of the lubrication system should be performed to ensure that it is working properly.
- Contamination of lubricant: This can occur if foreign particles or fluids enter the lubrication system. To avoid this, proper filtration and seals should be used to prevent contamination.
- High operating temperatures: High temperatures can cause lubricants to degrade and lose their effectiveness. To avoid this, proper cooling systems should be used and the lubrication system should be designed to operate within the recommended temperature range for the lubricant being used.
- Lack of proper lubricant selection: Using the wrong type of lubricant for the specific application can lead to failure. To avoid this, proper lubricant selection should be done based on the operating conditions and the materials of the equipment.
- Lack of proper lubricant storage: Lubricants can degrade if they are not stored in the proper conditions. To avoid this, lubricants should be stored in a cool, dry place, and away from direct sunlight or other sources of heat.
- Improper lubrication practices: Incorrect lubrication practices, such as over lubrication or under lubrication, can lead to failure. To avoid this, proper lubrication practices should be followed as per the manufacturer’s instructions.
How To Avoid Lubricant System Failure And Lubricant Degradation In Ammonia Plants?
To avoid lubricant system failure and lubricant degradation, the following steps can be taken:
- Regular maintenance and inspections of the lubrication system: This includes checking for leaks, proper functioning of pumps and valves, and ensuring that the lubrication system is properly configured.
- Use proper filtration and seals: This will help prevent contamination of the lubricant by foreign particles or fluids.
- Use proper cooling systems: This will help keep operating temperatures within the recommended range for the lubricant being used.
- Proper lubricant selection: The lubricant should be selected based on the operating conditions and the materials of the equipment.
- Proper lubricant storage: Lubricants should be stored in a cool, dry place and away from direct sunlight or other sources of heat to avoid degradation.
- Proper lubrication practices: Follow the manufacturer’s instructions for lubrication practices, such as the correct lubrication frequency and the correct amount of lubricant to use.
- Use the right lubricant for the specific application: Avoid using wrong lubricant that may not be suitable for the specific application.
- Regular oil analysis: Regularly monitoring and analyzing the lubricant sample can detect any issues such as contamination, oxidation, thermal degradation, and wear debris, which can help prevent lubricant failure.
Best Lubricating Oil Can Be Used In Ammonia Plant?
The best lubricating oil to use in an ammonia plant would depend on the specific conditions and requirements of the equipment in the plant. However, some lubricants that are known to be compatible with ammonia and commonly used in ammonia plants include:
- Synthetic lubricants: These lubricants are specially formulated to withstand the harsh conditions of an ammonia plant and are highly resistant to oxidation, thermal degradation and chemical reactions. They are also suitable for high temperature and high-pressure applications.
- Mineral oil based lubricants: These lubricants are made from petroleum-based products and can provide good lubrication for equipment in an ammonia plant. They are also less expensive than synthetic lubricants.
- Inhibited mineral oil-based lubricants: These lubricants are mineral oil-based lubricants with added corrosion inhibitors to protect the equipment from corrosion.
- Polyalphaolefin (PAO) lubricants: These lubricants are synthetic lubricants made from a synthetic hydrocarbon base stock. They are more thermally stable and have a higher viscosity index compared to mineral oil-based lubricants.
- Phosphate Ester based lubricants: These lubricants are synthetic lubricants made from synthetic esters. They are highly resistant to oxidation and thermal degradation, and are also suitable for high temperature and high-pressure applications.
It is important to consult with the equipment manufacturer and the lubricant supplier to determine the best lubricant for the specific application in an ammonia plant. The lubricant should be compatible with the materials of the equipment and should be able to withstand the specific operating conditions in the plant.
What Are The Symptoms Of Poor Lubrication in Ammonia Plants?
Symptoms of poor lubrication can include:
- Increased friction and wear on moving parts: Poor lubrication can cause increased friction and wear on equipment, leading to increased wear and tear and a shorter lifespan for equipment.
- Increased noise and vibration: Poor lubrication can cause increased noise and vibration in equipment, indicating that something is not functioning properly.
- Increased heat: Poor lubrication can cause increased heat generation in equipment, which can cause damage to equipment and lead to reduced efficiency.
- Reduced efficiency: Poor lubrication can cause equipment to work less efficiently, leading to reduced productivity.
- Leaks: Poor lubrication can cause leaks in equipment, which can lead to contamination of the lubricant and further damage to equipment.
- Smoke or burning smell: Poor lubrication can cause the equipment to overheat and produce smoke or burning smell.
- Unexpected shut downs and breakdowns: Poor lubrication can lead to unexpected shut downs and breakdowns, causing production downtime.
- Metal-to-metal contact: Due to poor lubrication, the lubricant film may break down and cause metal-to-metal contact, which can lead to severe wear and damage.
- Dark, cloudy or dirty lubricant: Poor lubrication can cause the lubricant to become dark, cloudy, or dirty, indicating that it is contaminated and no longer effective.
It is important to address these symptoms as soon as they are noticed, as poor lubrication can lead to significant damage to equipment and increased maintenance costs.
What Are The Causes And Effects of Deterioration or Contamination of Lubricants In Ammonia Plants Resulting Failure of Machine Parts?
Effects of Lubricant Deterioration or Contamination Include:
- Reduced lubrication: The lubricant’s ability to reduce friction and wear on moving parts is reduced, leading to increased wear and tear on equipment.
- Increased friction: Contamination can cause abrasive particles to be present in the lubricant, increasing friction and causing further wear on equipment.
- Reduced efficiency: Degraded or contaminated lubricants can cause equipment to work less efficiently.
- Reduced lifespan of equipment: The increased wear and tear caused by degraded or contaminated lubricants can lead to a shorter lifespan for equipment.
- Increased maintenance costs: The need for more frequent repairs and replacement of equipment can increase maintenance costs.
- Production downtime: Lubricant failure and equipment failure can cause production downtime.
Causes of Lubricant Deterioration or Contamination Can Include:
- Exposure to high temperatures: High temperatures can cause lubricants to degrade and lose their effectiveness.
- Exposure to water: Water can cause corrosion and rusting of metal parts, and can also dilute or emulsify lubricants, reducing their lubricating properties.
- Exposure to air: Oxygen can cause oxidation of lubricants, leading to thickening, hardening, and loss of lubricating properties.
- Exposure to contaminants: Foreign particles or fluids can enter the lubrication system and contaminate the lubricant, reducing its effectiveness.
- Improper storage: Lubricants can degrade if they are not stored in the proper conditions.
- Lack of proper filtration: Lubricants can become contaminated if they are not properly filtered.
- Lack of regular oil analysis: The regular oil analysis can detect any issues such as contamination, oxidation, thermal degradation, and wear debris, which can help prevent lubricant failure.
However, with each failure mode, there are associated conditions (such as temperature or contaminants) and outcomes (for example, tar deposits, coke, or sludge) that can aid in the identification of the failure mode. The outcomes or deposits are essential in determining how a lubricant degraded if a root cause analysis was performed for that component.
Additionally, oil analysis tests can be done to recognize failure modes either before or after the failure. While there are many oil analysis detection methods, not all can be carried out on a single component. Therefore, there must be a strategic selection of oil analysis tests that can form a baseline suite that will enable end-users to identify and possibly rectify issues in the lubricant before it fails. From the research conducted, it can be deduced that a primary suite of tests should include; Linear Sweep Voltammetry (Remaining Useful Life Evaluation Routine), Acid Number, Fourier Transform Infrared, Viscosity, Quantitative Spectrophotometric Analysis / Membrane Patch Calorimetry / Ultra Centrifuge, and Rotating Pressure Vessel Oxidation Test. These can aid in identifying the type of degradation and can be used in the root cause analysis to determine corrective actions to avoid future failures.
Root Cause Analysis of a Lubricant Failure:
It has been determined that while root cause analysis is a powerful tool, it is not always applied correctly when investigating lubrication failures. The five phases of data collection, assessment, corrective actions, informing, and follow-up are quintessential stages that must be adhered to during an investigation to identify the reasons for a lubricant failure. The first two stages of data collection and assessment form the basis for determining the reason/s for failure. As such, close attention to areas of data collection such as the lubricants, filters and separators, deposits, oil analysis tests, sump conditions, lubrication system, and system parameters must be observed during the investigation. Similarly, verifications of insufficient or excessive lubricant volume, wrong or contaminated lubricant, lubricant failure, and abnormal wear debris generations must be examined thoroughly during the assessment stage. It is believed that if industrial plants properly employ root cause analysis, then there will be a marked decrease in failures.
How to Reduce Machine Downtime Cost due to Lubricants Failure:
Any failure within industrial plants leads to unplanned downtime, which incurs a cost to the organization. These costs are significantly high, and methods to avoid these are usually employed. However, if proper condition monitoring techniques such as oil analysis are not adequately applied in the appropriate frequencies, failures can occur without sufficient warning. If root cause analyses are also not conducted, then the failures become repetitive and are never solved. It has been found that with ammonia plants, some of the basic suites of tests are not adequate to identify impending failures.
The deposits formed in most ammonia plants typically consist of primary amides, carboxylic acids, and ammonium salts. Therefore, to identify the onset of a typical lubrication failure for an ammonia plant, the user should test for the presence of carboxylic acids and monitor the condition of the lubricant in service with the use of Viscosity, Acid Number, Membrane Patch Calorimetry, Remaining Useful Life Evaluation Routine, Rotating Pressure Vessel Oxidation and Fourier Transform Infrared tests.
Suppose the service of chemical filtration is available to the end-user. In that case, this should be employed to remove the carboxylic acids from the lubricant since these initiate the reaction with ammonia to produce varnish or sludge within the system.
Root cause analysis is imperative to identify the reasons for lubrication failures, and these should be performed before assigning blame to ammonia gas/liquid in a system.
What Are The Safety Guidelines Keep In Mind During Lubrication for Plant Maintenance?
When performing lubrication for plant maintenance, it is important to keep the following safety guidelines in mind:
- Use the proper protective equipment: This includes gloves, goggles, and respirators to protect against exposure to lubricants and other chemicals.
- Follow proper handling procedures: Lubricants and other chemicals should be handled in accordance with the manufacturer’s instructions and safety guidelines.
- Keep lubrication area clean and well-ventilated: Lubrication should be performed in a clean, well-ventilated area to reduce the risk of exposure to lubricants and other chemicals.
- Store lubricants and other chemicals properly: Lubricants and other chemicals should be stored in accordance with the manufacturer’s instructions and safety guidelines, in a cool, dry, and well-ventilated area.
- Follow proper disposal procedures: Lubricants and other chemicals should be disposed of in accordance with local, state, and federal regulations.
- Always be aware of the fire hazards: Lubricants, especially those with high flashpoints, may pose a fire hazard. Follow proper precautions, such as using fire-resistant lubricants, and always be aware of the potential for fire.
- Follow lock-out tag-out procedures: Always follow lock-out tag-out procedures to ensure that equipment is properly de-energized before performing maintenance.
- Use appropriate precautions when working with pressurized systems: Always wear the appropriate personal protective equipment and follow proper procedures when working with pressurized systems.
- Be aware of the risk of slips, trips and falls: Lubrication areas can be slippery, so take care to minimize the risk of slips, trips and falls.
- Be aware of the risk of electrical hazards: Always be aware of the potential for electrical hazards when working on equipment, and take proper precautions to avoid contact with live electrical parts.
By following these safety guidelines, you can minimize the risk of accidents and injuries and ensure that lubrication is performed safely and effectively.
You can also read below articles for more information.
Sanya is the Founder of Strategic Reliability Solutions Ltd based in Trinidad and operates in the capacity of Managing Director and Senior Consultant. She works with global affiliates in the areas of Reliability and Asset Management to bring these specialty niches to her clients.
Sanya possesses a strong engineering background with a BSc in Electrical & Computer Engineering and MSc in Engineering Asset Management. After completion of her thesis “An investigation into the root causes of lubricant degradation in critical equipment in an Ammonia complex”, she was made aware of the plight that reliability faces within and outside of the Caribbean. As such, she decided to ensure that every attempt was made to make reliability the backbone upon which the industry operates by forming Strategic Reliability Solutions Ltd.
Sanya has worked in the lubrication industry for the past several years and has used her engineering background to assist various industries with lubrication related issues both locally in Trinidad and Tobago, regionally and internationally. She has solved lubrication problems and provided training in the Automotive, Industrial, Marine, Construction and Transportation sectors.