Articles & Case Studies
Laser gas detection success for Anglian Water Services
Posted: Monday 6th August 2012
Anglian Water Services (AWS) wanted to quantify methane emissions from their wastewater treatment processes. As these are less well understood and less well defined than indirect carbon emissions associated with electricity use, they set up a project to locate and quantify emissions from the processes at a wastewater treatment works. This was led by the in-house Innovation Team which undertakes research and development to deliver environmental benefit, cost saving and operational efficiency. In the three-month study they pin-pointed and quantified methane emissions around the plant, including those around secondary digesters, activated sludge plants, anaerobic digesters and gas holding tanks.
“We were able to successfully confirm patterns of methane emissions from activated sludge lanes, backing up results found worldwide by others studying similar trends in the literature. We were also able to use the TDL-500 probe to quantify methane emissions from the surface of secondary digesters.
“The TDL-500 was selected due to its accuracy in measuring methane with a sensitivity of 1 ppm. Its portability and ATEX certification were also vital in this project as it was used in potentially explosive zoned areas around anaerobic digesters. A critical benefit of the TDL-500 in this project was its ability to measure methane concentrations in two ranges (0-10,000 ppm and 0-100% volume gas). This was of great importance as gas emissions from various processes were analysed, all of which contained different concentrations of methane,” said Astrid Bosmith, Innovation Technologist with AWS.
AWS serves around 5.8M wastewater customers and operates 1,114 waste water treatment works.
The Geotech TDL-500 gas detector
Using laser spectroscopy technology, the Geotech TDL-500 can detect methane leaks in a range of applications, from natural gas pipelines to landfill or coal mining sites. The tunable diode laser provides total selectivity to methane with a sensitivity of 1ppm. ATEX certification to Zone 1 means it can be used in most hazardous areas, detecting methane leaks and their location with speed and precision.
The laser technology presents an advantage over FID devices as it does not need a hydrogen gas supply, avoiding transportation of hazardous gases. Fast response times mean less time spent monitoring and GPS is available to record leak position, set up routes and record readings. The TDL-500 offers portable laser leak detection as it is easy to carry for one person to use on foot and can work for 8 hours from a full charge. Users are likely to be involved with natural gas networks, landfill gas surface emission checking, biogas feeds to CHP engines, water treatment plants, momentary methane leak detection and sewerage system methane detection.
Wastewatertreatment sludge AD biogas monitoring and analysis
Wastewater processing gas leak detection with Geotech equipment is a very helpful addition for wastewater treatment site operators. Many of these already use Geotech portable and static biogas analysers to check biogas production volumes and quality ahead of using it in CHP engines to produce electricity and heat.