It is interesting in two ways. Grass does extract Co2 from the air, and builds it into the grass itself
but quite slowly
In this PDF, while not the latest, page 7 has some figures for CO2 absorbed per hectare for varying types of vegetation that I imagine are a good starting point.
Of course you do need quite a lot of forest and even more bush or grassland and if yo u make gas from it and burn it later you have not really won, but you are not making it worse either.
That proposed test generator making 'gas for 4000 homes' from 3000 Acres is presumably absorbing at the 'prairie' sort of rate, perhaps 1 tonne CO2 per ha per month. Now to me 3000 Acres as an area is a touch under half that in ha - perhaps 1250ha or about 12sq. km (e.g. a 3km by 4km rectangle) so something over 1000 tonnes of CO2 per month. Now CH4(~16 grams per mol) is lighter than CO2 (44g/mol), so you are making perhaps 300 tonnes of methane per month.
that is a lot of joules even so.
Mike.
It is interesting in two ways. Grass does extract Co2 from the air, and builds it into the grass itself
but quite slowly
In this PDF, while not the latest, page 7 has some figures for CO2 absorbed per hectare for varying types of vegetation that I imagine are a good starting point.
Of course you do need quite a lot of forest and even more bush or grassland and if yo u make gas from it and burn it later you have not really won, but you are not making it worse either.
That proposed test generator making 'gas for 4000 homes' from 3000 Acres is presumably absorbing at the 'prairie' sort of rate, perhaps 1 tonne CO2 per ha per month. Now to me 3000 Acres as an area is a touch under half that in ha - perhaps 1250ha or about 12sq. km (e.g. a 3km by 4km rectangle) so something over 1000 tonnes of CO2 per month. Now CH4(~16 grams per mol) is lighter than CO2 (44g/mol), so you are making perhaps 300 tonnes of methane per month.
that is a lot of joules even so.
Mike.
