Phillips 66® Lubricants designs high-quality Natural Gas Engine Oils (NGEO) to keep operations running smoothly in some of the most demanding environments. Our NGEOs protect engines in crude oil and gas transmission pipelines, electrical power generators, gas compressors, irrigation water pumps, well drilling rigs and more.
NGEOs are mainly used in reciprocating engine-driving compressors. These compressors are used to process natural gas for use in a variety of applications, including fuel for heating, cooking and even fueling certain vehicles. Natural gas is a clean burning, efficient fuel.
Gas engine oils have been around for decades. They differ from other lubricants, as they are specific for use in methane-fueled engines. They contain less sulfated ash and have a high amount of oxidation control for long-term service.
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The natural gas industry is moving to oil condition monitoring for more efficient operations.
Stationary NGEOs are generally categorized by their levels of sulfated ash. Sulfated ash is the residue left behind after the oil is burned and consists of the metallic-based additives in the oil. For NGEOs, this ash comes from calcium and magnesium-based detergents as well as zinc and phosphorus-based anti-wear additives. The detergent additives help to neutralize acids generated from the combustion process, whereas the anti-wear additives provide wear protection.
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The oil consumption and constant topping off of oil in these large engines make consistent monitoring even more important when assessing safe drain intervals.
The reason NGEOs are categorized by sulfated ash content is because natural gas engines rely on these ash deposits to cushion the valves to prevent valve recession. However, too much ash in the oil can lead to excessive buildup on the valves resulting in poor seating and eventual failure. Elevated ash levels can also lead to other combustion chamber deposits as well as deposits in after-treatment systems.
Monitoring additive metal levels in the oil will allow the operator to better assess drain intervals.
The most common type of NGEO recommended for four-stroke stationary natural gas engines today is a low-ash engine oil which will contain around 0.5 weight percent sulfated ash as measured by ASTM D 874. This level of ash is the perfect balance to cushion valves, protect the valve train and neutralize acids, but not lead to excessive deposit formation.
In the natural gas industry today, many operators have switched from set oil drains based on hours in service to condition-based oil drains based on oil condition monitoring through oil analysis. This is done to reduce costs by extending oil drains. This oil analysis will normally test for viscosity, metals, acid number and oxidation, with the condemnation limits focused on wear metals (iron, copper, lead), acid number and oxidation. While these are important to monitor, they may not provide the entire picture of the condition of the oil.
Monitoring additive metal levels in the oil, particularly calcium, magnesium, zinc and phosphorus can help give an indication of what is happening in the engine. Using this information along with wear metals, acid number and oxidation will allow the operator to better assess drain intervals.
Natural gas engines can be quite large and have larger reservoirs and higher oil consumption than mobile engines. They need to be topped off consistently to maintain the oil level. This replacing of consumed oil with fresh oil replenishes the additives which helps to prevent an increase in acid number and oxidation. Unfortunately, due to combustion blow-by, spent additives in the form of ash can migrate back down to the reservoir and, when combined with the fresh additives being added, can lead to an increase in the sulfated ash content in the system over time.
If the ash content of the oil rises too much, it can lead to excess deposits in the combustion chamber and after treatment system and, ultimately, valve failure.
Knowing these details and proper steps for monitoring additive metal levels can lead to extended service intervals and minimal downtime in stationary NGEO applications - and so can the El Mar® product line from Phillips 66® Lubricants.
Looking to the future of using landfills
Phillips 66® Lubricants is expanding into the landfill industry. Many landfills capture the methane created by the decomposition of waste. The methane is used to fuel engines driving generators to produce electricity - a win-win.
El Mar® LF-D Geo, for example, is a premium quality, next generation, low-ash, gas-engine oil designed for landfill gas applications. It is especially effective in controlling silica deposits formed during the combustion of siloxane gases found in many landfills.
El Mar® LF-D GEO has the capability to extend cylinder head and other engine component life. The combination of high-quality base stocks and enhanced silica deposit control helps reduce oil consumption - thereby resulting in lower operating costs for landfill operators.
Phillips 66® Lubricants is always improving our product line so customers can get maximum service life from their equipment. As we expand into other uses for NGEOs, we plan on being around a long time to support the demanding equipment and those who operate it.
For more information, visit www.phillips66lubricants.com or call (877) 445-9198.
