I wonder how you will get all the hydrogen from the feed lots to all the hydrogen fueling stations to fill those FC SUVs.

If they just make methane they can fill the natural gas pipes and be CO2 neutral, the animals eat the plants.

Niel, anaerobic digesters are all over the country at dairy sites. I agree with you, providing power from these farms with net metering is a plus. Turn poo into power. Right now California has made cow poo methane digesters to power turbines into a state program. 600MW comes to mind. This is just another step in the right direction. Now just PHEV tractors :-) From Poo to Plows

is there a reason human waste cant be used for this
you always read about cow waste. our waste is already colleted at sewage plants ?

Kevin: Try these also.

http://www.greencarcongress.com/2006/09/nz_algae_biodie.html

http://www.greencarcongress.com/2006/06/nanologix_to_bu.html

http://www.greencarcongress.com/2006/06/petrosun_drilli.html#more

http://www.greencarcongress.com/2006/06/kwikpower_acqui.html#more

AlgaeCulture has a huge future! Three cheers

Most of the soft-skinned vegetables we eat at winter, like tomatoes and cucumbers, are grown in hot houses. In order to conserve heat at cold weather, hot houses are tightly closed, and plants very quickly adsorb most of CO2 available, inhibiting the growth. To alleviate this problem, so-called carbon fertilization is used widely, routinely, and quite for a long time. Exhaust from adjacent space heaters burning clean fuels (NG or LPG practically exclusively) is cooled and routed to hot house. Optimal CO2 level for tomatoes is 750ppm for cloudy day and 1000ppm for sunny day – about three times higher than current (already elevated) level of 340 ppm CO2 in atmosphere. Carbon fertilization increases harvest yield by about 20%:

http://72.14.253.104/search?q=cache:4jcqlg7Q3hMJ:oregonstate.edu/dept/NWREC/tomatogh.html+tomato+greenhouse+carbon+fertilization&hl=en&gl=ca&ct=clnk&cd=4

The biggest effect carbon fertilization has on trees, but all plants benefit from it. In closed environment trials, doubling of CO2 level in ground level air increases rate of growth for orange and coniferous trees by about 30% in wet conditions and up to 60% at dry conditions (due to reduced evaporation losses). For commercially grown wheat doubling of CO2 from pre-industrial 250ppm to 500ppm yields about 14% more grain.

Substantially higher biomass accumulation rates, attributed to increase of atmospheric CO2 from 250 to current 340ppm, are the main reason of substantial biomass growing rate increase in Amazon rainforest and in American coniferous forests. According to official data, during last 40 years standing tree mass in US forests increased 30%, mostly due to carbon fertilization, rather then re-forestation.

It is funny to think, that winter salad I eat is almost entirely built from captured fossil fuel carbon.

As I understand, algae has way higher efficiency of sun light utilization then any land-growing plant. Any numbers on it?

Technofixes are cheap & easy !
Real life is quite a bit more complicated, infinitely more complex. Before doing the technofixes there's a lot to fix first. The inhumanity, cruelty and horror is simply beyond belief. You simply don't know, are completely ignorant & un-educated, or ... don't care. But please take a look: www.meetyourmeat.org

I suspect these researchers are focusing on hydrogen only because that's where the grant money happens to be right now.

It's actually quite difficult to eliminate all traces of H2S from digester gas, which is why the preferred route in densely populated places like London or Paris is to dry the sludge and burn it to generate electricity. Instead of a steam cycle, you can also use a gasifier and a specially adapted stationary ICE. The waste heat from combustion is recycled to the drying process.

The fossil fuel consumption avoided is not really all that great. However, in terms of GHG emission reductions, it's far simpler and cheaper than trying to run FCVs on biohydrogen derived from the stuff.

Rafael:

Correction. Both primary (settled) and secondary (excess of aerobic activated sludge) are very difficult to dewater, hence drying it to the level when it will burn requires more energy than will be produced from it incineration. That’s why all sewage sludge is digested in anaerobic digesters. Digestion significantly reduces amount of sludge, and digested sludge is much easier to dewater on belt press (centrifuges were also used).

Unfortunately, sewage from big cities and industrial zones is still highly contaminated by heavy metals, which limits application of digested sewage sludge as fertilizer only to occasional non-agricultural uses, like one-time application when new trees are planted. Surplus of such sewage sludge is really often combusted – to minimize cost of waste disposal. Surplus of energy from combustion of still wet after all treatments sludge is minimal.

Andrey,
Algae adn cyanobacteria currently have yields of 50 dry biomass tons/acre/year yields. Up to half can be lipids/fats similar to vegetable oil. The remainder is mostly starches/sugar polymers and proteins. This comes out to ~6,600 gallons of oil to be converted to other fuels. Syngased biomass comes out to ~114 gallons/ton, and 2,850ga/acre ethanol.
_Solar to chemical energy conversion efficiency is ~2% when measuring the end results. Photosynthesis has a ~11% efficiency. The discrepancy is due to algae/cyanobacteria using most of the energy for growth, maintenance, and reproduction of itself.

u need help for that research?????????????????????????????????hydrogen tech!!!!!!!!!!!!!!!!!!!!!