Siloxanes are manmade by-products created as a result of a variety of combustion processes. They are difficult and expensive to measure due to the complex and varying gas matrices. Those concerned with siloxane levels include landfills and wastewater treatment plants that use biogas to generate electricity or upgrade the biogas to Renewable Natural Gas (RNG) for direct injection into a natural gas pipeline or Compress Natural Gas (CNG) for use as vehicle fuel.
When combusted, siloxanes convert to SiO2, which deposits as essentially a layer of glass inside the engine cylinders used to produce electricity at biogas electricity generation facilities or RNG-fueled vehicles. These deposits degrade engine performance and will eventually cause damage to the engine if accumulation is left unchecked.
Renewable Natural Gas (RNG)