So I had this idea...

[rusty70f100 1]

Now, I dont know how feasible or practical this would be.  It is just a crazy idea that passed my mind, and I thought you all might appreciate it, or at least get a laugh out of it.

 

A lot of the energy consumed in ethanol production is in heating the still, right?  Well, I had an idea on that front.

 

Solar power!  Now, I'm not talking about solar cells or electricity or anything like that.  Get ready for this:

 

A big reflective mirror.

 

It doesn't have to be perfect, heck, it doesn't even have to be glass.  Just something to focus sunlight down on to the boiler part of the still.  Have an automatically controlled set of shutters to control heating.  There you go.  Free heat, at least while the sun shines.  Conventional natural gas could be used as a backup.

 

So that's my crazy idea.  Would it work?

[cessna 9]

If you look on the Journey to Forever website they have plans for solar box cookers so people in Africa that can't scrounge up wood can still heat food. Probably growing algae for biodiesel would produce more fuel per acre, though.

[Greengenes 9]

At NREL (National Renewable Energy Lab) in Golden, CO.  they have a

device called a heliostat -- a series of mirrors that can focus the sun's

energy on a single spot and create some 1000 degrees(F) of heat.

 

I think this has even been perfected abit so the cost has come down

significantly, and it should be possible to try in almost any energy

intensive process ( like cooking tar sands, maybe ??) . 

 

For me, I think solar would be much more useful in displacing natural gas from

  the other lower energy tasks , such as the cooking or fermenting stages of ethanol

production.

 

Out here in Colorado , solar  would be a natural fit. In fact solar + methane digestors

should just about eliminate  the need for natural gas inputs. 

 

 

[mpersell 0]

Make it a combo to use solar when available and other fuels when necessary and you reduce requirements for the goal.

[hotrod 0]

That was discussed 30+ years ago, Solar power through direct solar heat is so obvious with regard to ethanol production and renewable fuels it is astounding that no one has built a plant that at least uses it as a partial heat input. Especially in the home still systems.

 

Cooking mash and distilling does not require high grade heat, A solar heat system that pre-heats a working fluid like water to near the boiling point and then just a bit of added temp from conventional sources is trivial to setup. It is basically the same set up you would use in a solar / water home heating system.

 

With thermal mass storage you can solve 24x7 operation and with only low solar concentrations, you can easily achieve temperatures in the 200 - 400 deg F range.

 

The problem is that the places like NREL and commercial systems either want to use "cutting edge" technology or do not want to take a risk on even a proof of concept system.

 

Absolutely everything necessary for a solar/thermal aided ethanol plant is off the shelf technology and has been for 20+ years.

 

I was drawing sketches of this sort of setup in 1973, just never had the money or land to build it.

 

 

Larry

 

 

 

 

[Guest colchiro]

Saw several shows on tv lately where they were generating a/c by burning garbage so would be a possible source of power for conversion on cloudy days. Doubt we have enough sunny days in the areas where corn is grown tho.

[Corey872 1]

There are a couple of plants in place using concentrated solar energy to generate power.  Most notably, just east of Barstow, CA in the Mojave Desert.

 

http://maps.google.com/maps?f=q&hl=en&q=barstow,+ca&ie=UTF8&ll=34.872526,-116.834471&spn=0.006716,0.009613&t=k&z=17&iwloc=addr&om=1

 

 

One possibility keeping this technology away from ethanol production, is that once you go to the trouble to set up the infrastructure...towers, mirrors, boilers, ect, you are pretty much geared to generate a lot of high grade power (electricity).  Ethanol could get by on pretty low grade "waste heat" - just a couple hundred degrees versus, 1000+ for a good electrical plant.

[hotrod 0]

Ethanol could get by on pretty low grade "waste heat" - just a couple hundred degrees versus, 1000+ for a good electrical plant.

 

Which makes it a perfect candidate for a bottom cycle energy recovery. You harvest energy from what would be unused waste heat from the primary process. I recall seeing a mention of a plan to team ethanol production plants with a large coal fired power plant and use the "exhaust" cooled steam as a power input before it is sent to the condensors to be turned back into hot water for boiler input feed water but I can't recall where I saw it.

 

Larry

[rusty70f100 1]

There's another great idea, coupling an ethanol plant with a power plant.

[BURNALCOHOL 0]

They call that a combined cycle plant.  Works good for gas turbines, but most Coal plants have to recover all the heat they can.

 

I guess a nuke power plant would be ideal for that application.  I think it is already being looked into.