Bioethanol from Wheat Straw?

Question

Wheat straw is a very cheap source of carbon that could be transformed (by microbial means) to ethanol. What are the major obstacles faced in the large-scale production of bioethanol from wheat straw? And also, which of the 3 production steps (Pretreatment, Saccharification, Fermentation) is the most costly one?

Answer 1

Actually, biomethanol is better, it doesn't require sugars because it uses an anaerobic process instead of the aerobic process that requires high value feedstocks. Why not use wheat grass or prarie grass instead? And WHY use large scale systems? This would be a GREAT family farm product.

Answer 2

The largest obstacle is finding the technology to convert it to fuel.

Answer 3

Ethanol as all alcohol comes from sugars. The starch in the must first be turned in to a use able sugar. The problem with straw is there is not much starch in the plant that can be used.

Answer 4

Of course it's money that is the major obstacle.  I would think that the Pretreatment would be the most costly because you have to manipulate it.

Answer 5

Just being able to grow enough of it is an issue.  Look how many acres we have now that goes into grain for consumption.  Where would be find the land to be able to grow more to turn into fuel.  That is the biggest problem.

The most costly step is actually the production of the wheat itself.  This is traced to the costs of diesel for running all the farm equipment.  That is a currently overlooked problem with the efficiency of corn based ethanol.

Distillation is also a very costly step because most companies use fossil fuels (generally natural gas) to heat up the mixture to the appropriate temperature to boil the ethanol away from the water.  This step generally has to be done 3 times to ensure purity.