Sludge Digestion Biogas Analysis and PPC Compliance

Switched on Blackburn - seen live in Warrington. It is that quick. United Utilities’ bosses are impressed. It was the first time they had seen their own data on methane gas output live and on-line from their anaerobic sludge digesters 40 miles away. “We could have been on the other side of the world - anywhere with Internet access, fixed or mobile and a secure logon,” said Adam Guest, operational scientist, who added, “We set up the equipment and I went home, logged on and there it was, on screen, on display and working away.” Adam Guest is not alone in checking gas output levels remotely. Operational staff now can do as well. The static gas analysers continue to collect and transmitted data every 15 minutes.

Adam Guest had looked around for a supplier of wireless, unmanned remote operation, transportable, continuous gas analysers which handled several gases and auto purged. UU selected the Geotech-Landtec Automatic Extraction Monitoring System (AEMS) package. Its development was originally fuelled by the demands of CDM carbon credit trading.

United Utilities’ methane comes from anaerobic sludge digesters which feed a combined heat and power (CHP) engine. Optimising methane production is one driver of this development, especially as UU is also monitoring its Advanced Enzymic Hydrolyser in Blackburn. Another imperative is its need to comply with new Environment Agency legislation. Because sludge is transported and United Utilities is processing waste it will have to comply with Integrated Pollution Prevention and Control (IPPC).

The analyser has had positive response from everyone who has used it with the benefit of continuous analysis, measurement and data logging to help with ‘tuning and tweaking’ production to optimise sludge treatment and methane output. Colin Greenhalgh, UU’s wastewater treatment specialist, said, “We placed our order with Geotech and we are very pleased. The equipment will be absorbed into UU’s Integrated Performance Management (IPM) system and is consistent with the IPM approach of making key operational data available anytime anywhere to help us ensure consistent effective and efficient operation of our assets.” More: www.geotech.co.uk