RE: aerobic vs anaerobic--look hard"Anaerobic digestion is a bacterial process that is carried out in the absence of oxygen. Anaerobic digestion generates biogas with a high proportion of methane that may be used to both heat the tank and run engines or microturbines for other on-site processes. In large treatment plants sufficient energy can be generated in this way to produce more electricity than the machines require. The methane generation is a key advantage of the anerobic process. Its key disadvantage is the long time required for the process (up to 30 days) and the high capital cost."
Finally a good point on this board.
However....the gas produced wouldh have a mx calorific value of 500-700 btu per cubic foot in comparison to natural gas at 1000 btu per cubic foot.
The gas produced is extremely wet and requires drying. The particles "left over" have a very heavy "sulphur like" material that coats and addheres to the boiler internals.
The digesters would have to be investigated if they were constructed to ASME standards bearing sufficient pressure ratings. Remember IBR does not operate the digester internals on a pressure basis however the steam jackets obviously do.
The methane (basically) would have to be recovered and stored. It seems the only REALISTICAL solution for IBR would be the installation/modification of their existing equipment to realize a true ROI.
However, energy recovery has been suggested to the manager at IBR. The average true (not smoke and mirrors) ROI would be expected within1 year with net savings of 20k per annum subject to their cost on natural gas and their OPERATIONAL HOURS.
try a website called heatsponge.com. Look at online performance review.
anyways it is a good thought, I firmly believe that with VSD's VFD's economizers, steam turbines rather than prv's this companies bottom line would shoot through the roof.
You perform these modifications, use the N Van plant as a true show piece and customers would flock in droves to their doorsteps.
Think about it, business groups simply want to see their roi. Increase their ROI and they would lookj harder wouldn't they.
Check out that web
good starting point
ICE