You don't need a combustible fuel-air ratio provided that the combustion doesn't need to be self-sustaining. Once the correct temperature is reached, any methane present will oxidise. The advantage of using a diesel engine is that it runs with minimal energy input as the temperature can be changed without irrecoverable energy input - the mix cools as it expands. I thought about using a jet engine - essentially an adapted turboprop or high-bypass turbofan, but I think it would be more lossy.
I don't agree that you'd be processing 'a few hundred cc'. I envisage building vast arrays of wind turbines, all connected to huge marine diesel engines. Why would you need a catalytic convertor? The CH4 just oxidises to H20 and Co2. I can see the benefit of a heat exchanger, and I already thought of that. I covered the issue of hydroxl radical - it's created by ozone photochemistry, so the best way to manipulate it seems to be by delivering ozone to the stratosphere. A 2009/1/28 dsw_s <[email protected]>: > > Compression ignition requires a suitable ratio of fuel to air. Even > if compression in a diesel engine perfectly removed methane from the > air, you're not going to process the atmosphere a few hundred cc at a > time. To remove methane from the air, I see two options: increase the > amount of hydroxyl radical if there's enough methane to deplete it, or > as you say build air-cooled CSP plants. For the CSP option you would > want a counter-flow heat exchanger and a catalytic converter on the > outgoing air. > > On Jan 27, 2:03 pm, Andrew Lockley <[email protected]> wrote: >> If you fixed up diesel engine to a wind turbine, you'd get compression >> ignition of any methane residue in the atmosphere, even without >> injecting any fuel. This would be expensive, but I think it would >> work. >> >> An alternative would be to pump air through concentrated solar power plants >> >> Any thoughts? We appear to need some bright ideas on methane >> remediation pretty soon. >> >> A > > > --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en -~----------~----~----~----~------~----~------~--~---
