Biogas
production: environmentally
friendly solution... and profitable!
Content:
Why biogas production? Well, one of the most serious issues regarding
ethanol production is the
stillage (vinasse) coming out from the distillation process.
Particularly,
vinasse has a heavy COD load. The value varies from one geographic zone
to another. But some can reach even 150,000 ppm COD. This, of
course, prevents distilleries from simply discharging it to bodies of
water.
What to do? Try anaerobic digestion.
Methane production trough anaerobic digestion is a partial solution,
though. It has to be combined with some other final disposal options.
Notwithstanding, the gas itself, can pay for the oil bill and an
alternate solution for the final disposal that best fits your
circumstances. Besides, it reduces significantly the organic load
before a secondary treatment. It can be said that this is the most
economical way to reduce pollution potential of any wastewater.
One proven application in our experience is the first plant of this
kind built in Nicaragua in 2002. This plant is still producing biogas
satisfactorily and... profitably. The volume of biogas produced here
amounts for more than 7,000 gallons of oil per day. Although the final
effluent from this methane digesters doesn't receive an extra
treatment, since it is used for sugarcane fields irrigation. In
Nicaragua, this utilization of digested vinasse is still allowed.
In Colombia, in the other hand, where legislation doesn't allow the
irrigation option,
there are some other alternate solutions applied. One of the most
common is composting. This is a low energy consumption alternative, but
the economical implications have to be analyzed carefully.
There are several kinds of wastewater treatment
technologies. The one we have found is the most
efficient is the UAC reactor. But you have to remember one thing...
methane digesters, as they are also called, are biological reactors and
its behavior is quite complex because it is always complex to work with
living organisms! Just like fermentation, by the way.
It needs expertise to manage this process in the most economical way
since the learning curve can last more than you wish!
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