The methane hydrate is crushed and separated from the majority of rock and stone offshore, before being pumped as a slurry to an onshore base for final processing. Most of the detritus is returned to the seabed; however some of the inclusions within the hydrate can be rich in valuable minerals, and are separated and retained during the centrifuging process.

The miners can work a coastal plateau of say 500m deep at a rate of 10kms per week, producing an average of 40 MSCM of gas per day. This avoids an equivalent GHG emission of 350 million tons of CO2 per year (using a methane/CO2 ratio of 22), hence attracting a healthy ‘Carbon Mitigation’ bonus, while generating clean energy to support a population of 5-15 million people.

The miners lay pipelines behind them as import/ export arteries: - a hydrate slurry (MHS) line and a Compressed Natural Gas (CNG) line. Because hydrate occurs in patches over natural methane vents, any active methane-producing structure will be tied into the CNG line by a subsea wellhead, providing ongoing methane production with concurrent GHG mitigation.

Onshore the MHS is purified for export. Methane, because of its low boiling point, is a difficult gas to transport. LNG (Liquefied Natural Gas) has to be cooled to -160ºC for shipment. This is expensive and energy profligate. Methane Hydrate, by comparison, can be shipped at -15ºC using conventional cold-storage technology.

Alternatively the hydrate can be transmitted as a slurry by pipeline to nearby cities where it provides simultaneous fuel, water and cooling. The technology described, although novel, is not significantly removed from current offshore practice.

Impact

• Natural gas for local use at 50 million sM3/day. (Compare UK usage of 200 million sM3/day)
• 300 thousand tons/day Methane Hydrate Slurry to local cities, equivalent to 25 Gigawatts energy.
• Cooling to local cities, equivalent to 170 Megawatts energy.
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• resh water to local consumers at 260 thousand M3 per day
• 7 thousand tons/day of valuable minerals to local industry.
• 910 thousand tons/day of export quality Hydrate equivalent to 170 million sM3/day of Methane.

Practically

• Building such machines would be viable for the existing offshore industry.
• The technology is transferable to less-developed countries.

Environmentally

• Avoids risk of catastrophic methane release equivalent to over 2 billion tons/year of CO2 (at 22)
• Substitutes for potential use of fossil fuels equivalent to 200 thousand tons/day Oil equivalent.
• The miners are powered by harvested methane. Resulting CO2 is locked up in the deep ocean.
• Harvesting coastal hydrate would satisfy world energy requirements for the next 100 years with negligible carbon emissions.
• Vulnerable coastal shelves could be worked out within this time, focus could then move to deeper waters if hydrate still needed.

Socially/ Politically

• Such Machines could bring clean energy to developing countries.
• 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!

Economically

• Development costs are estimated at €500 million/li>
• A working prototype would cost a further €500 million
• Brazil could subsequently build a family of such machines for €5 billion
• New Orleans is costing this much, just to repair the damage!!