Sensors monitor underground gasification process

Sensors monitor underground gasification process

A cost-effective technique that uses a distributed-temperature-sensing (DTS) fiberoptic system will monitor the in situ conversion of coal into gas in a 600-m-dee¥subterranean well. Developed by York Sensors (York, England) for trial in Spain, the system uses specialty fiberoptic cable to withstand reaction-zone temperatures that can reach 1100°C. The DTS system incorporates an optical time-domain reflectometer, microprocessor, and one to six sensors consisting of loops of standard telecommunications-grade multimode fiber to measure temperatures at 1-m intervals down the well. Within 20-30 years, the underground coal-gasification process is expected to recover gasified coal from closed pits.