Micro-metering pump for gas odorisation

Jon Lawson

According to the German Energy Agency (dena), biomethane production in Germany may increase as much as 10 times over – from currently 9 terawatt hours to about 100 – by 2050. What is more, natural gas is the most important energy source for private households and accounts for 44% of the heating market.

Before natural gas or biogas is fed into commercial supply networks, it must have an odorant added to it. Odorants serve as a warning in case of leakage.

Since the last few years have been marked by a trend toward decentralised production, Lewa has added the MAH 4 size to its micro-metering pump portfolio as a proactive measure for meeting the expected increase in demand. The new unit can be used for odorising with mercaptans or tetrahydrothiophene at a throughput rate of up to 12,500Nm³/h. The pump covers the flow range from 200 to 250ml and can be used as a cost-effective solution in accordance with DIN-EN 1333 for gas networks up to PM 16.

“Back in early 2018, we started getting more requests for odorising gas volumes of approximately 12,500Nm³/h, to the point where it just made sense to design a pump specifically for that amount,” says Walter Richter at Lewa. “The right way for us to respond to this trend was to add an intermediate size, the MAH 4, to our hydraulically actuated and solenoid-driven micro-metering pumps from the MAH, MBH and MLM series. The new size meets the requirements for this range exactly.”

The new unit closes the gap between the MAH 3 and the MAH 5 – something that had previously been done using the larger MLM 15 series. However, the stronger stroke solenoid made that design over-dimensioned and less cost-efficient in some cases. Neither the MAH 3 nor the MAH 5 units from the same series were cut out for the job. There was always one of two problems: either they could not manage to pump at the required output of 16 bar, or they could manage a sufficient flow rate at 600ml but were not designed for the necessary discharge pressure.