Moisture analyser plays a key role in sustainable energy

A key energy company in Germany has chosen Michell Instruments’ Promet IS process moisture analyser to monitor moisture levels in biomethane before it is injected into the grid to ensure that it meets the correct quality standards.

Biomethane is a renewable source of energy that is produced from the breakdown of organic waste such as municipal waste, sewage, green waste, etc. The organic matter is converted into biogas using anaerobic digestion processes that use microbes in absence of oxygen. The biogas produced by this process then requires further treatment before it can be used as a biomethane fuel.

The biogas is saturated with moisture immediately after production and it also has other undesirable components such as CO₂ and other gases. Therefore, before it can be used as a fuel away from the production site, it needs to be scrubbed of the contaminants and dried. When it is destined to be upgraded to biomethane and injected into the grid with natural gas, precise measurements of moisture are vital as it will need to meet tight quality standards.

The advantages of biomethane are: it is sourced from organic matter that is readily available, which is a benefit for regions that don’t have access to natural resources such as coal and wind; the production of biomethane is claimed to be better for the environment as it basically uses the energy which is released during the natural decomposition of organic matter; and it can be used as an alternative source of energy for many fossil fuel and natural gas applications.

Many biogas plants use the biomethane on site to produce electricity or heat. For transmission into the local distribution network in Germany, the biomethane needs to meet the moisture levels permitted by the DVGW G260 Code of Practice. For distribution networks, this is 200 mg/m³ at less than 10 bar(g) pressure (267 ppm_V).

The Promet IS was selected for this task because it has a proven track record of monitoring moisture during the processing of natural gas, as well as for quality checks of gas in the network and transmission pipeline. The unit has an accuracy of ±1°C dewpoint and measures reliably in pressures up to 450 barg. It is certified for hazardous areas around the world, including ATEX, FM, CSA, IECEx as well as GOST.

Michell Instruments designs and supplies sampling systems fully equipped with filtration and sample conditioning to ensure reliable measurements and prolong the life of the sensor.

The Promet IS Process Moisture Analysers are heavy-duty, industrial hygrometer systems for measurement of high-pressure, process gases and vaporised liquids on natural gas platforms and terminals, petrochemical plants and industrial gas manufacturing facilities. The product combines the latest Michell Instruments moisture sensing technologies with sample conditioning system design engineering capabilities to provide a reliable and easy-to-operate, multichannel, online instrument for both flammable and non-flammable gases.

The Promet IS uses Michell Instruments’ ceramic moisture sensor, which is highly resistant to contamination and provides long-term stability in process applications. All Impedance instruments use Michell Instruments’ Advanced Ceramic Moisture Sensor technology. The Impedance hygrometers are rugged, low-cost, industrial measurement instruments for reliable moisture analysis from trace levels to ambient air conditions. They can be used in a wide range of gases, including hazardous area applications (flammable or explosive gases), and with many corrosive gases.

The sensors are also part of Michell Instruments’ sensor exchange program, which can reduce the cost of ownership. With the exchange program, a freshly calibrated sensor is sent out and swapped for the old sensor that is due to for recalibration, keeping process downtime to a minimum. Where traceability is needed, Michell Instruments provides a fast and efficient calibration service, with traceability to national standards.