John D. Palazzotto

Design and Development of a New Landfill/Biogas Engine Oil for Modern, High BMEP Natural Gas Engines

The use of higher brake mean effective pressure (BMEP) engines in landfill or alternative gas applications has increased dramatically in the past few years. Operators are using these engines due to their ability to provide lower emissions coupled with improved economics for the end user due to the higher density or power output capability compared to an engine of similar size and displacement. Landfill gas (LFG) quality can vary greatly as well as the contaminant level due to the composition of the landfill. This environment poses unique challenges to both the engine and the engine oil, including shorter oil drain intervals, corrosive attack of engine components, with increased piston and combustion chamber deposits, to name but a few. Maintaining longer oil drain intervals minimizes unscheduled oil drains which can decrease the overall cost of the landfill operation. High BMEP engines provide higher power output but at the cost of increased maintenance in severe fuel applications. Excessive piston crown and combustion chamber deposits from landfill gas impurities can have a deleterious effect on engine emissions, which may lead to the inability to meet local emissions regulations. Engine lubricants must provide adequate oil life as well as minimizing deposit related issues that may negatively impact regular scheduled maintenance cycles, thus reducing engine downtime and increasing revenues. Traditionally, the approach has been that oils formulated for landfill applications used excess base reserve to sufficiently neutralize the acids being formed during the combustion process. Unfortunately, this approach increases the sulfated ash content of the lubricant which lends itself to increased ash deposits and negatively impacts the combustion dynamics of these high BMEP engines, which are sensitive to ash deposition. Based on requests for a longer life lubricant without compromising deposit control characteristics in serve landfill applications, a new product development project was specifically targeted for late model, high BMEP engines, which are prone to detonation and sensitive to ash related deposits. This paper presents the development bench testing, and proof of performance field evaluations of a new generation, low ash landfill gas engine oil.© 2011 ASME

Effect of Stationary Natural Gas Engine Oils on Fuel Economy

In order to investigate the possible environmental and economic benefits of lubricants optimized for stationary natural gas engine efficiency, a decision was made to develop a test stand to quantify the effects of lubricant viscosities and formulations on the brake specific fuel consumption.Many fuel economy tests already exist for evaluating gasoline and heavy duty diesel motor oils which have proven the benefit of fuel economy from different lubricant formulations. These engines would not be suitable tools for evaluating the fuel economy performance of lubricating oils formulated specifically for stationary natural gas engines, since there are significant differences in operating conditions, fuel type, and oil formulations. This paper describes the adaptation of a Waukesha VSG F11 GSID as a tool to evaluate fuel consumption performance. The performance of brake specific fuel consumption when using different formulations was measured at selected high loads and rated speed.The results of the testing program discuss the viscosity and additive effects of stationary natural gas engine oil formulations on brake specific fuel consumption. The results will detail the change in brake specific fuel consumption between natural gas engine oil formulations blended to varying viscosities and compared to a typical natural gas engine oil formulation with a viscosity of 13.8 cSt @ 100°C. The second portion of the test program explores the effect of different additive packages that were blended to the same finished oil viscosity.It was acknowledged that there were statistical differences in brake specific fuel consumption characteristics between lubricants different in viscosity and additive formulations.Copyright