Although ‘natural’, volcanoes produce vast amounts of CO2 and SO2, both gases currently being unwanted in the atmosphere in view of the anthropogenic excesses.

The STEP VLL concept is to tap into  those gases at source, ie while they are still in the base of the volcano.
Although technologically challenging, there are several advantages to this approach, namely the gases are concentrated (undiluted with air), hot and at high pressure (ie energy-rich)

With modern techniques, it is possible to drill horizontally as well as vertically, so enabling a rig to be located close to a volcano while still being relatively safe. By running hot, high-pressure gas through an expander/ compressor coupled with a cooler, liquid CO2 /SO2 can be harvested.

This is a far cheaper option than trying to separate dilute, cool CO2 from industrial exhausts; yet it is the same gas! A spin-off advantage is that by removing high-pressure gas from a caldera the possibility of an explosive eruption is vastly diminished.

• A suitable tap could prevent 100,000 tons of CO2 and SO2 from entering the atmosphere per year.

Building such machines would be viable for the existing drilling industry.

Once the tap is made, and the pipeline laid, the operation is relatively low-cost.

• Huge amounts of CO2 and SO2 are prevented from entering the atmosphere.
• The gases are reinjected into the ground at a distance from the volcano.
• Once the volcano is tapped, the hot gases provide most of the energy required for transportation to a geologically suitable zone.

• Such projects could be financed by a Carbon Tax; ideally through a "World Carbon Bank"
• Governments could buy in to such schemes; it's jobs for their industry and a way to be seen to be doing something!

• Development costs are estimated at $500 million
• A working plant would cost approx $500 million