Care to comment Jtabeb

[flintlock]

Re: Care to comment Jtabeb

Hope in one hand and .....

[jtabeb]

Re: Care to comment Jtabeb

JT,
I think you have made an error in your calculations

There are 4047 sq m in an acre. The surface of the earth on the average recieves 4800 wh of energy per sq m ~ 0.13 gallons of gasoline.

So the maximum amount of enrgy at 100% efficiency of conversion would be 4047*365*0.13 = 192,000 gallons of gasoline per acre. However photosynthetic efficiency on the average is only 4.5% -- which leads to a theoretical production of 8641 gallons of gasoline per acre per year. This would be for pond algae. Bio reactor algae I believe could possibly ~ double this. However, there appear to be problems of scaling with the bioreactors -- for example fouling of the tubes by algal growth itself -- which would require frequent cleaning of the bioreactor tubes -- which would cut into the net energy out.

Yes, you are correct. ( I was wrong in my calculations)

See my "Me A Culpa" down a bit on this thread.

[GRG55]

Re: Care to comment Jtabeb

Yes, you are correct. ( I was wrong in my calculations)

See my "Me A Culpa" down a bit on this thread.

Don't sweat it jtabeb. We're chalking it up to repeated exposure to high G forces...

[Rajiv]

Re: Care to comment Jtabeb

JT

I still think Algae bioreactors are a potential solution, but just a bit further down the Peak Oil timline. Gives us enough time to perfect the technology, and to reduce the costs.

Any sustainable economic solution has to go back to relocalization. That is where I believe that both Algal fuels/raw materials, and photovoltaic cells will play their role -- I posted the Rose Street Labs blurb some weeks ago. They are getting efficiencies of 25-30%, with a potential of hitting 70% -- That has to count for something.

[thriftyandboringinohio]

Re: Care to comment Jtabeb

JT

I still think Algae bioreactors are a potential solution, but just a bit further down the Peak Oil timline. Gives us enough time to perfect the technology, and to reduce the costs.

Any sustainable economic solution has to go back to relocalization. That is where I believe that both Algal fuels/raw materials, and photovoltaic cells will play their role -- I posted the Rose Street Labs blurb some weeks ago. They are getting efficiencies of 25-30%, with a potential of hitting 70% -- That has to count for something.

I agree for another reason. Not only will alternatives get cheaper, but oil will get more expensive. I think the shift will be gradual, like the transition from horses to autos.

[ggirod]

Re: Care to comment Jtabeb

Here's another military fuel source. This one seems farther along the development process and appears to produce quite a bit of everything we need.

Ten percent of what emerges from the reaction vessel is "ash" which can be used as raw material for cement or asphalt. The rest goes into a distillation column of a fairly standard design, where the remainder of the slurry is separated out into its various levels. Seventeen percent of this is water; fourteen percent is "producers gas" which is used to run an on-site turbine to generate 2.5 megawatts of electricity, 1.5 MW of which is needed to run the plant. The remaining liquid (accounting for 59% of the original feedstock) separates into 8 parts Naphtha, 24 parts Kerosene, 45 parts Diesel, and 19 parts Fuel Oil. (The discrepancy of the remaining 4 parts for a 100% total is because the weight of the fuel is different. If you calculate the real weight of the fuel you get a complete weight balance).

Naphtha is used primarily as feedstock for producing high octane gasoline. Kerosene is the typical feedstock for making jet fuel but is also commonly used as a heating fuel. The diesel that emerges from the process is classified as #2, of ASTM standard level D975, which is the commercial diesel fuel specification. (Ref.) The fuel oil that emerges from the bottom of the column is classified as #4 fuel oil of ASTM standard level D396, which is the commercial heating oil specification. (Ref.)

You would think from these descriptions that we are talking about the products emerging from an oil field refinery, but instead we're describing the fuels emerging from what hitherto has been piled in a heap of trash and dumped in the ground or incinerated or "accidentally" dumped at sea. And who verified these input/output production volumes and qualities? The U.S. government! Not bad. (Kudos to them for actually doing something deeply significant.)

Trash to fuel with a 25 million price tag for the gadget and a three year payback should work until people quit producing quite so much trash. Then they will probably need to grow biomass to feed it.

[thriftyandboringinohio]

Re: Care to comment Jtabeb

Here's another military fuel source. This one seems farther along the development process and appears to produce quite a bit of everything we need.

Trash to fuel with a 25 million price tag for the gadget and a three year payback should work until people quit producing quite so much trash. Then they will probably need to grow biomass to feed it.

I remain skeptical. This is in the tradition of trash-burning power plants, although this one gasifies incoming waste and condenses it into fuel for use elsewhere.

1. Pilot demonstrations gloss over the realities of incoming waste to the grinders with carefully selected garbage. In real life people throw away bowling balls, big bench vises, spools of steel cable, and cans of ether starting fluid. The trash grinders constantly jam, break, and explode. Downtime becomes uneconomical while lines of refuse trucks stand and wait.

2. In real life trash contains halogens that end up as emissions of dioxin, furan and other toxic substances. Water and air pollution are a big challenge.

It’s funny that the pilot plant is in Pasco Washington, literally next door to Hanford. In Hanford are 177 underground tanks containing 53 million gallons of the most toxic waste on earth – many serious scientists describe this waste with the term “witches brew”.