BAUER technology used in climate-friendly geothermal projects

Geothermal energy is among the most eco-friendly sources of renewable energy. Virtually inexhaustible, its impact on the landscape is low and it has no negative effects on the natural environment. 

Geothermal energy is a virtually inexhaustible source of renewable energy. Theoretically, the energy stored in the top three kilometres of the earth’s crust alone would meet all our energy needs for around 100,000 years. But there’s a problem; bringing this heat to the surface, in the form of hot water, from depths of up to 2,000 metres poses a real technological challenge: 

The boiling point of a fluid increases as its pressure is increased and superheated water is liquid water under pressure at a temperature higher than the normal boiling point of 100 °C. When the pressure is reduced the water flashes to steam. Superheated water pumped from the ground at temperatures of 175 °C or more can be flashed to steam in a separator or flash tank to drive a turbine directly. But how does the hot water get to the surface?  

By lowering a drill pipe or coil-tube into the well and pumping compressed air through them, the well can be pumped by so called “air-lift pumping”. The density of the water column is significantly reduced with air bubbles. The air-froth is light enough to reach the surface and cause the well to flow. Once the well starts to flow, warmer water from depth reaches the surface and it will start flashing, causing the well to spontaneously flow. 

A successful air lift requires approximately 10 to 20m3 air at 100 bar per hour. As the Geothermal Power Plant is located in a very isolated area , the BAUER high pressure compressors, two GIB 26.7-132 units, have to be moved from area to area on demand. Packaged in containers, they are transportable by truck. North Japan is a sparsely populated and remote area, rich in geothermal hotspots, but also notorious for its extreme climate. With this in mind, the geothermal plant operators chose BAUER compression systems, knowing their reputation for performance and reliability around the clock under even the harshest environmental conditions.  

Ralf Deichelmann 

20.04.2016_V3