Zero carbon biodiesel calcs

Here are a few numbers that show the potential of the biodiesel production system shown here:

This system has the potential to operate with net zero carbon emissions.

In Sonoma County, CA, the census statistics show that there are between 800-900 restaurants operating in the county at any given time. Over all those restaurants, the average fry oil use is 10 gal/week. Based on this range, that total oil use of the restaurants in the county use runs around 500,000 gallons of oil per year. This does not include company commissaries, hospitals, etc, which would boost the total considerably. We found that the local school bus fleet uses about 80,000 gallons per year of petrodiesel. If the school buses were run on B20 (20% biodiesel), only 16,000 gallons per year of biodiesel would be required.

For sunflower crops, I found that the yield runs 1500-2000 lbs of seed per acre. The oil content varies between 40% to about 43%. This comes out to 80-100 gal of oil per acre, based on 0.92 specific gravity of sunflower oil.

So, to raise enough sunflowers to supply the oil needs of the county’s restaurants, you would need roughly 5,000 acres. I like the idea of going cradle to cradle on this, so the “oil coop” would rent the oil to the restaurants, would help them with maintenance, etc. Shepherd the oil through the whole life cycle, so the biodiesel feedstock would be high quality.

If the amount of ag waste from the harvest, pressing, etc. from the sunflowers, along with the waste glycerine from biodiesel manufacture was processed in an anaerobic digester, you would get a significant amount of biogas. From another project, I estimated that the biogas generated from the yard waste in the county would be enough to supply all the municipal facilities in the county: swimming pools, buildings, etc. This is a tremendous resource. If you just took the hulls and crushed seed residue left over from the oil crush, it’s over 2,000 tons from each crop. This could produce over 6,000,000 cu.ft. of biogas. And that’s at the low end.

One of the features of this system is that each element can be added independently, and the system will stand alone. For instance, waste vegetable oil can be used to make biodiesel, without the local production of the oil itself. The point is that the entire system will be zero carbon, if implemented properly.

To implement an entirely zero carbon system, the sunflowers must be raised using biodynamic techniques so they don't require any fossil fuel related fertilizer. If irrigated, the irrigation pumping must be done using renewable energy. Any farm machinery must be run on biofuel. All transport links in the system should be done using vehicles powered by biofuel from the system. Biodiesel processing must be done using renewably generated electricity. These steps could be taken without a significant cost impact