Precise and safe: biogas odorization with gas flow controlled diaphragm pumps

Biogas – just like natural gas, oxygen, or nitrogen – is odorless, but potentially explosive and harmful. In order to reduce risks of gas usage to a minimum, gas consumers like Erdgas Südwest GmbH depend upon reliable odorization units that mix gases with strong-smelling substances like tetrahydrothiophene (THT). This is an important safety measure that permits responsible staff to notice leaks or defective systems quickly.

"Just recently, three of our biogas plants in Riedlingen and Laupheim were equipped with Lewa OD7 and OD60 type odorization systems," explains Karl-Heinz Brunner from the service team at Erdgas Südwest-Munderkingen. In this project quantity-proportional, gas flow controlled odorization systems were equipped with a diaphragm pump type MAH with solenoid actuator. A solenoid valve was built into the pressure line to prevent a backflow of odorant, which is often the consequence of very small stroke frequencies of less than ten pulses per minute.

Furthermore, the system is extremely precise: At a gas pressure at the injection point of six to twelve bar, at most 20 milligrams of odorant per rated cubic meter are added per hour. "The micro-flow meter KMM 1 also measures small volume flows at an error range of ± 1 percent, so the odorant is metered safely, proportionally, and economically," assures Walter Richter, odorization product manager at LEWA.