A fungus can't photosynthesize so there is inevitably an extra set of steps/losses. Sunlight -> plant -> dead plant -> fungus -> fuel Wouldn't you simply be better off simply burning the straw/woodpulp/etc waste material rather than feeding it to a fungus to make diesel?
No, you probably end up burning it to heat the greenhouses that the fungi is growing in! No doubt some set of EPA rules, tax credits and carbon tax will mean it makes financial sense to heat your pulp mill with coal/oil while turning wood pulp into diesel with fungus. Still, not as daft as using nuclear reactors in Afghanistan to make jet fuel from atmospheric CO2 and sewage. http://www.theregister.co.uk/2010/03/31/darpa_portable_fuel_reactors/print.html
That may be true. While a detailed study of the energy cycle would seem to be in order, I don't think we can assume that it would be a net negative.
I've been doing more digging on this. Montana State University has been granted a patent on the fungus (what?!) but will sell licenses for its use. So far, no description of the breakdown of hydrocarbon by-products, nor rate of production, nor of feedback mechanisms that might regulate or limit the digestion of cellulose. No description yet of a process to turn the off-gassed hydrocarbons into a liquid burnable fuel.
I don't see the problem here. There is presumably some fungus, that in the process of making more fungi turns cellulous rich tree droppings into simple liquid C-H compounds suitable for burning.
Not a problem, just questions. According to this publication, VOCs in the headspace above a sample grown on agar in a limited oxygen environment totaled about 80 ppm after 18 days. http://mic.sgmjournals.org/cgi/content/abstract/154/11/3319 I guess the operative word here should be "potential". It might be tempting to genetically modify the fungus to boost its ability to digest wood, but that might not be a good idea because this family of fungus is ubiquitous and can live inside living trees. If that should escape to the wild, there could be serious consequences involving forestry and food-crops.
More like: Code (Text): Sunlight -> | plant -> food | plant -> waste -> fungus -> fuel As long as the starting point for fuel production is cellulose waste that is currently considered as a negative good by-product of agriculture, there is no inefficiency here. As for burning this waste to produce power, it is a waste of good farmland. To make it a high-BTU fuel that can be burned to produce high-pressure steam, you have to dry it. It would be nice to be able to economically truck the waste to a nearby desert for drying. What kills that approach is that you have to truck it out of the desert for burning. Electrical generating plants need plenty of water. Some for making into steam, lots more for cooling the condensers.