Reliable biogas flow measurement without compromises

The biogas market has been booming for years. The gas obtained from the fermentation of energy crops, organic waste, liquid manure, sewage sludge or leftover plant materials can be used in a variety of beneficial ways – including fuelling vehicles or generating heat and electricity in combined heat and power plants. Various process parameters must be monitored around the clock for stable operation of a biogas plant: fermentation temperature, gas pressure and, primarily, the gas quantity produced.

The precise determination of the biogas quantity is a decisive criterion for evaluating the efficiency of a production plant and an indicator of an assured fermentation process. However, to date there have not been any flowmeter systems available on the market that were capable of reliably measuring the quantity of biogas. Now this gap is being filled by the Prosonic Flow B 200 ultrasonic flowmeter, developed especially for such applications. For the first time, this device makes it possible not only to measure the volume of biogas, landfill gas and fermentation gas precisely, but also the methane content directly in the pipe.

Unbeatable ultrasonic flow measurement
The ultrasonic flow measurement offers operators of a biogas plant many advantages compared to traditional measurement methods. Thanks to modern and innovative sensor technology, wet and dirty gases can be measured now with high accuracy even under greatly fluctuating process conditions with the Prosonic Flow B 200. The measurement is independent of the gas composition and even possible at very low gas pressures. A benefit that no other flowmeter has been able to match so far.

The Prosonic Flow B 200 from Endress + Hauser, is an industry-optimised flowmeter, which exhibits high measuring accuracy (1.5%) and a wide operable flow range (30:1). It causes no pressure loss and requires no maintenance once installed. The unit is available in diameters between DN 50 (2") and DN 200 (8") and can be used at gas temperatures of up to +80 °C and gas pressures up to 10 bar. As an intrinsically safe two-wire measuring device (Ex ia), the Prosonic Flow B 200 is especially suited for use in hazardous areas. Menu-guided local operation allows the user to optimally configure measuring points according to his or her requirements.

Methane content measurement directly in a pipe
Fermentation processes are not always uniform. The operating conditions, which often fluctuate, cause different methane content amounts (CH4) in the biogas, which must be monitored constantly. In addition to measuring volume flow, it is now for the first time possible to measure the methane content of a gas at the same time using the Prosonic Flow B 200, thanks to ultra-precise sound velocity measurement and an integrated temperature sensor.

This is a worldwide one-of-a-kind feature and opens up completely new perspectives for process monitoring. Since gas quantity as well as gas quality can be checked around the clock, a targeted reaction to disruptions in the fermentation process is possible at any time. As a multi-variable flowmeter, Prosonic Flow B 200 can also calculate additional characteristic values upon request such as the corrected volume, the heating output or the Wobbe index as a performance indicator for fuel gas quality.

N.B. E+H Ireland will be demonstrating the new Prosonic Flow B200 at the Energy Show on 28th & 29th March 2012, on Stand B5.