In March 1986, a bungalow next to a landfill site in Loscoe, Derbyshire was destroyed by an explosion. Succeeding measurements revealed that landfill waste was producing 150 to 200m3 of gas for every hour. This incident set off a major change in the way the waste industry managed and regulated the gases produced at landfill sites and subsequently resulted in landfill regulations of 2002, especially LFTGN03: the Guidance on the Management of landfill Gas.
The regulations explain the control and management of landfill sites, and outline landfill gas as being all the gas produced from landfill waste. This comprises gases originating from both chemical reactions and chemical volatilization from the waste as well as gases produced by biodegradation of waste. The regulations specify that for each landfill site, a gas management strategy must be implemented. This would ensure that landfill gas is collected from all landfills receiving biodegradable waste and the collected landfill gas is properly treated and used; the collection, use and treatment of landfill gas is needed and should be accomplished in a way, which minimizes deterioration or damage to the environment.
Mature landfill gas mainly contains Methane (CH4) in the range of 40% to 60%, along with carbon dioxide (CO2). This gas may also include different amounts of atmospheric oxygen and nitrogen that have been drawn into the landfill. Since CH4 is a greenhouse gas which is 21x more detrimental to the environment than that of carbon dioxide, changing CH4 to carbon dioxide through burning is believed to be more advantageous to the environment. Moreover, carbon credits are created by determining the amount of CH4 burnt and these can then be traded to achieve a valuable revenue stream. In addition, CH4 serves as a useful fuel and can be utilized to power gas generators to generate heat and electricity.
Appendix F of the regulations explains infra-red measurement as the principal method of quantifying CO2 and CH4 on landfill sites.
In 1956, Edinburgh Instruments’ founder published a paper on the design and development of infrared band pass filters that form a critical component of contemporary IR bench sensors. This technology was commercialized by Edinburgh Sensors over the last four decades, resulting in a reputation for long term stability, precise, reliable and low maintenance gas sensor products. Over the last 10 years, these products have been widely used by major landfill gas analyzer developers and were deployed on landfill sites across the globe.
OEM Sensing Solution
Edinburgh Sensors’ Gascard NG is a perfect OEM sensing solution designed for measuring CO2 or CH4 (Figure 1). It is easy to integrate and available with a 0% to 100% range for both CH4 and CO2. The OEM sensor includes features such as extensive temperature compensation and on-board barometric pressure correction, making it suitable for installations in different climates across the world.
Figure 1. Gascard NG OEM gas detector
The Gascard NG sensor comes with different interface options, such as true RS232 communication, analogue 4-20mA/0-20mA/0-5v, serial interface for interfacing relay alarms and optional on board LANsupport. The on-board firmware is capable of supporting a contemporary graphical display or a conventional 4 segment LCD.
OEM Evaluation and Support
Edinburgh Sensors offers an evaluation kit for OEM development. This kit contains a Gascard NG sensor, a relay board, and a sophisticated graphical display interface (GUI), enabling easy assessment of the Gascard NG functions.
Besides OEM gas sensors, Edinburgh Sensors has been offering gas monitors, which are built on its proprietary infrared sensor technology, for a number of years. In fact, innumerable gas monitors have been deployed across the globe and are being extensively used in landfill applications.
Figure 2. Guardian NG gas monitor
Edinburgh Sensors’ Guardian NG gas monitor (Figure 2) is being assessed by several clients operating within landfill applications. This wall-mounted sensor comes in a rugged IP54 enclosure with a sample pump and an integral power supply. These features make it possible to collect samples remotely from more than 30m away. The gas monitor can be configured to determine 0% to 30% of CO2 or 0% to 100% of carbon monoxide (CO).
Other features of the Guardian NG gas monitor include a precise pressure and temperature compensated measurement of the gas concentration through 4-20mA (or 0-20mA) and RS232 interface, and a GUI with password protection. The GUI not only shows the compensated gas measurement, but also displays control of the gas monitor alarm functions and calibration.
Edinburgh Sensors supplies advanced sensor products that provide fast, precise, reliable and continuous measurements day after day. The company’s engineers provide technical support and one-to-one customer service during the entire assessment and system integration process.
This information has been sourced, reviewed and adapted from materials provided by Edinburgh Sensors.
For more information on this source, please visit Edinburgh Sensors.