Mercury (Hg) is a naturally occurring element found in various geological formations, including those where natural gas is extracted. As a result, mercury is naturally present in trace quantities in fossil natural gas. While present in small amounts, mercury can cause issues in gas processing and transportation, and poses potential health and environmental risks, as outlined by the Minamata Convention on Hg.
Mercury is also found in landfill gas. It comes from many sources, including fluorescent bulbs, thermometers, batteries, latex paint, dental amalgam filling capsules, and contaminated plumbing. Mercury scrubbed from coal power plant exhaust can also be dumped in landfills. Some studies have found that the concentrations of mercury in landfill gas are comparable to those found in the exhaust gas of coal-fired power plants.
Like siloxanes, mercury in landfill gas that has been upgraded to RNG and injected into the natural gas pipeline can have significant impact downstream to equipment, pipeline integrity, and also personal health. For these reasons, pipeline and utility RNG gas quality specifications typically set limits on mercury concentrations and require periodic sampling.
The big question – Is periodic sampling enough? An increasing number of pipeline operators and utilities believe the answer is no and are installing online mercury analyzers to continuously monitor incoming RNG from producers. They understand that a landfill is comprised of many wells of varying ages, that each well may contribute a wide range of mercury concentrations, and that depending on which wells are in operation, the mercury concentrations in the landfill gas can fluctuate significantly. As a result, periodic mercury sampling and analysis may not sufficiently assess the risk to their network.
Ohio Lumex has been at the forefront of online continuous mercury monitoring. While initially developed for monitoring the emissions from coal-fired power plants, and later to continuously monitor mercury in natural gas feeding LNG plants along the Gulf Coast where mercury can lead to severe damage to aluminum cryogenic heat exchangers, Ohio Lumex is now providing a solution to many natural gas pipelines and utilities who choose to continuously monitor RNG injecting into their system.
Our sustained focus on research and development, drive to innovate, commitment to quality, and dedication to supporting our customers has allowed us to become a recognized leader in the field of gas analysis, including the design, manufacture, and distribution of state-of-the-art continuous gas analyzers and integrated monitoring systems, onsite field service and sampling, and comprehensive laboratory analysis. Have a question or need additional information? Reach out to our team. We’re here to help you find the right monitoring solution for your needs.
