They arise through partial hydrogenation and/or isomerization of cis-unsaturated fatty acids from the feed by hydrogen produced during oxidation of substrates, with bacterial enzymes as catalysts.
Cars running on hydrogen produced from renewable sources are not yet commercially available, Mr. Garofalo said.
Next month, for the first time, city buses, built by DaimlerChrysler, are supposed to fuel up on hydrogen produced at the station through electrolysis.
A Shell station in Washington that opened a hydrogen pump in late 2004, to supply the demonstration vehicles that automakers traipse through the city, uses hydrogen produced cryogenically.
The hydrogen produced in this way is used to make ammonia fertilisers and to "lighten" heavy grades of crude oil.
In the more distant future, the US department of energy is examing whether giant stacks of efficient fuel cells could be run on hydrogen produced by pre-combustion CCS.
Mr. Wilmshurst said that since the March 26 document, engineers had calculated that the amount of hydrogen produced would be small.
The hydrogen produced would escape into space, and the O2 would react with the early reduced gases by reactions such as 2H2S + 3O2 = 2SO2 + 2H2O.
This doubles the estimate of hydrogen produced on Earth".
It was found that the amount of hydrogen produced decreases with increase in H2O partial pressure.
The hydrogen produced and consumed in the EH in Case 2 is given in Fig. 6.
