Jeff Frusha

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since Jan 15, 2014
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Recent posts by Jeff Frusha

paul wheaton wrote:Some of my gobbledygook about the dailyish ....

If anybody spots a bump in the road, or something that might improve anything about the dailyish, please speak up!

No link to sign up...  Just loops to the give-away.
Hi Mike,

TH Culhane shared a link to the SolarCities Facebook group ( ) .  I was unaware of this thread, but have had a lot going on, both personally and with the goat farm I live on, in the intervening time, since your initial post.

I am currently in the process of working out a timeline to construct 3 of the Puxin 10 Cubic Meter ADs with a site manager.  Those 3 will be in series for a combination of reasons:
1) Increased total Hydraulic Retention Time (HRT)
2) Increased total quantity of biogas
3) To explore the potential to naturally upgrade Biogas to Renewable Natural Gas standards (pipeline injectable grade).

So, to simplify that, Input 'A' gives Biogas 'B' from #1, about 1/2 'B' from #2, about 1/4 'B' from #3.  So, 1.75 x 'B' biogas available, due to triple the HRT from 1 'A' input.

Biogas has roughly 50% of the heat value that pipeline grade Natural Gas has.
1.75 x 2 = 3.50  is the total expected heat value, as RNG, compared to a single unit of feedstock 'A', by only FEEDING 'A', by providing a longer (3x)HRT AND some additional MECHANICAL steps.

The final effluent will have a much lower BOD/COD (Biological/Chemical Oxygen Demand), so, it is more environmentally friendly.

Even if the RNG system fails to fully achieve the expected upgrade, the simple increase in quantity of biogas can be worth the increased system complexity and the RNG upgrading can be readily eliminated.

In addition, my methodology eliminates compressors, by utilizing much simpler pumps for liquid circulation.

Jeffrey L. Frusha
Head of R&D
LoneStar BioGas
1411 Gravel Pit Road
Seguin, Texas 78155
3 years ago

paul wheaton wrote:

Made of concrete.

My position ...  and I suspect that there are many schools of thought in this space ...  is that "appropriate technology" will minimize cement and plastic.  

I would guess that depends on how long it is intended to last.  

The HomeBiogas system is plastic and may have a boxed shelf-life total of 15 years and an in-use life expectancy of up to 15 (without mishaps).

A properly made Concrete structure is durable and not readily damaged.

Currently, there are ferrocement Oil Barge, the S.S. Peralta (1919 - WWI), and Liberty Ship hulls (WWII) in Canada being used as parts of a floating breakwater.

Part of the upgrade levels is to eliminate PVC inlet and outlet pipes, plus replace the FRP dome with a concrete cap, to increase longevity.

At current expected price equivalents, the HomeBiogas system (XL has a 6 cubic meter capacity) and regular replacements reach price parity within about 50 years, whereas a 100+ year long potential of a single Concrete Anaerobic Digester would be considered permanent.

There are several ways to keep an Anaerobic Digester warm.  Easiest would be to place it below the frost-line and to utilize grains as part of the feedstock, generating heat from within.  Next would be a greenhouse.  Beyond that, it will take a powered system that needs monitoring and maintenance.

A Class and build with, say 20 Operators and 10 Builder/Operators could cover the costs at reasonable rates.

Something to mull over, at any rate.

Jeffrey L. Frusha
3 years ago

Starting up a nonprofit in Texas.  Bought a set of molds that are in Washington State and I have to go get them, bring them here.

Puxin Hydraulic 6 and 10 Cubic Meter volume Anaerobic Digester.  
Made of concrete.

Estimated build time 4-5 days (split 2 & 2-3), over a week+

There are only 3 sets of these molds currently in the US.  The other 2 are on the East Coast in Pennsylvania and Florida and owned by SolarCities (Prof. Thomas H. Culhane, USF).

3 possible build levels:
1st-level upgrade*
2nd-level upgrade*
      *Additive Patents Pending

2 certification levels:
Trained Startup/Operator (class participant)
Experienced Builder & Startup/Operator (hands-on)

**Additive Patents reduce total internal volume slightly, but aid ease of operation and increase overall efficacy and efficiency

Jeffrey L. Frusha
LoneStar BioGas (pending 501(c)(3))
1411 Gravel Pit Road
Seguin, Texas 78155
3 years ago