Flow Measurement of Biogas

Biogas is generated from organic substances in the absence of oxygen. The sources can include: animal and human waste, dead plants, or any other decaying organic matter. Biogas is primarily composed of methane and carbon dioxide. Harvesting biogas from waste has two rewards, you get ‘free’ energy and you protect our natural resources by reducing greenhouse gases released in the atmosphere.

In this application, a palm tree plantation built their own biogas plant to utilize the vast amount of organic waste from their operations. To ensure efficiency, the company desired to measure the volume of biogas being generated. Measuring biogas can be complex because of the low operating

pressure, as low as 1.5 PSI at a point downstream of a blower. Biogas is also dirty and humid and has the potential to corrode metal components. Biogas is flammable, so hazardous certification is critical. As biogas is also compressible, the operational pressure and temperature must be evaluated to ensure an accurate flow measurement.

DOG Oscillation Flowmeter               PAS Pressure Transmitter                    TWL Temperature Transmitter

With oscillation principles and ample measurement channels, KOBOLD‘s DOG

Flowmeter is extremely dirt resistant. It also has a self cleaning effect making it ideal to handle dirty fluids like biogas. Because the DOG has no rotating parts, pressure drops are kept to a minimum with a maximum of 0.75 PSI drop at max flow, when the gas has the same density as air. it comes with ATEX II 1G EEx ia IIC T4 approval for hazardous applications. The paint is anti-corrosive To accommodate for process pressure and temperature variables, we installed a PAS Pressure Transmitter and a TWL Temperature Transmitter. Their outputs were connected to an external flow computer, along with the value received from the flowmeter.