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To use sewage treatment plants adding bioreactors to make more biodiesel than America burns for transportation daily if done nationally.


Guidance on collaborative pilot

This is a pilot test of a new, collaborative approach for getting work done in the Climate CoLab. It will run during March and April of 2012.

Just like in the 2011 activities, anyone can create a proposal. But there is also a community proposal, where members are encouraged to work together in a collaborative way. Any member can contribute to the community proposal as long as they are logged in.

The community proposal is like a wiki, so the history of edits is tracked, and you can revert to prior versions of the proposal if desired.

Please also use the Comments to express your opinion on whether or not you would like to see this collaborative approach used in the Climate CoLab in 2012.

Feel free to organize the proposal as you see fit. One thought—it's good to have a brief summary of the overall proposal at the top, as an aid to readers.

Proposal Text


For where towns have them, using algae to purify city wastewater at the sewage treatment plant instead of using chemicals to precipitate the nutrients has a huge potential, they make full recycling of the water relatively cheap so that's part of this plan.

By purifying using algae you get a high-volume of biodiesel daily and a de-watered leftovers that are good fertilizer.

So, society is paying for water treatment during the entire process at this time, the wastewater can't be released because it causes algae blooms, so nearly all treatment is an expense. By purifying the water it reduces new fresh-water demand, then the biodiesel can be a revenue stream, and the pressed cakes sold to farmers & ranchers can be a revenue stream, a total reversal of the economy.

An example is Phoenix, AZ, produces 10M-gallons of effluent daily, this contains 41.5M-pounds of fertilizer worth $8.3M/day @ $400/ton, $3B/year in real value, effluent is about half in weight nutrients. So all this is what produces about 3M-gallons of biodiesel daily, 2gal/7L per person per day.

A fair price for this fuel is likely $1.25/gallon to local residents and still make a profit.

if you own a home on top of being able to purify rainwater from the roof, it recycles wastewater for the fuel & fertilizer, that's handy but the latter is like quantum leaps above in importance to farmers & ranchers as it constantly supplies a high volume of both for the small farm or ranch operator, it's huge on reducing ongoing expenses to handle fuel & fertilizer costs by producing it onsite from waste.

Well the same is true of a small town, if it has a sewage treatment plant this can make a big difference to create biofuel production from it for locals, most of the money going out of the area for transportation stays local, it's a big deal.

Category of the action

Reducing emissions from waste management

What actions do you propose?

The system is based on standard wastewater treatment, the first step solids removal, the secondary effluent is the algae food. So instead of pumping it into floccing tanks it's pumped in bioreactors, algae-growing units.

The algae harvest is fed to a biodiesel machine, and the priority of this system is full recycling of the water, exisiting methods use centrifuges to harvest, this leaves a slurry/slime that requires tanker-truck fleets, drivers, scheduling & delivery to local farmers, raising costs & carbon-footprint.

To avoid this is one reason to recycle the water and de-water any leftovers for fertilizer for farmers, this makes trucking them much less expensive and it's a better agricultural produce being dry to store and use on-demand.

So the project is to miniaturized the system to household-rural capacity and size so a small farmer can produce their own fuel and purify the wastewater from the farm. The average is about 7L/2gal of biodiesel per day per person on a city system, this is a lot of fuel, more than the USA burns daily for all types of transportation fuels for what a high-volume source of fuel this is.

To do this the main bioreactor design is a cube 1/2m on a side, insulated and full of glass plates to light the entire volume well, easy to aerate, everything is piped in and they stack to 6-7 high without external support. It takes 4-units to handle the ongoing waste per person so a family of four would have two stack in the yard.

Since these are semi-portable they got the attention of a rural utility in wastewater and farm spill remediation so there is an open offer from them to help develop the units to where they are reliable, robust and can certify for water recycling thus able to be sold in home & farm supply stores and approved under building codes, a key issue.

The harvesting method is the only research need, that's to avoid using centrifuges which are similar to floccing, it doesn't purify the water and leaves a slurry/slime needing trucking to fields. A final part of the biodiesel process is de-watering the leftovers to make a dry fertilizer.

This completes the system of using a resource we create daily to gain a biofuel that removes CO2 and emits O2 in enough volume to be a practical alternative for fossil fuels in IC-engines on the planet at any scale of need with my focus the household-rural scale this became a small unit that scales by adding more.

Also basic is the need for purifying water at a rural home from whatever source is there, rain, creek or spring. By having a system able to purify water for farm needs means you get fuel from the barn washdown and you get the water back to do it again.

Dairy cows are worth about 19L/5gal per day in biodiesel, pigs 11L/3gal. This type of system then can supply all the fuels needs from the sewage stream, and on a farm that is removing a huge cost-of-operation to pay only for the equipment to make the fuel.

Since agriculture uses a lot of diesel it's fitting their needs well to design systems for farm wastes that would include a parallel development of industrial hemp processing for both fiber and oils, it's a feedstock for biodiesel yet also cellulosic ethanol another aspect for needs of some engines. The CO2 aspect being that it's a crop that doesn't need pesticides or herbicides thus reduces farm carbon-footprint with a reliable crop for income.

Summarizing, this project is a product system that using algae to purify wastewater from sewage at household-rural as the primary role, but then produces methane from solids for shop or kitchen [not enough for hot-water for most homes], biodiesel from the effluent and then a machine to de-water leftovers that are good fertilizer.

Wastewaster treatment is a high-tech, ongoing industry, there are models of diverse sources of systems that can perform the needs except for the actual bioreactor that's not made to get the most oil out, it's made to clean the water. The typical large-scale bioreator recirculates the growing algae in a continuous bent tube for 2-3 days and then the batch harvested, this having the mentioned extra costs.

So a reason for the size of the cube is that processing is 4 steps and the water is cleaner each one so at the end of the 2.5-days the water can be filtered cheaply to return it to the fresh-water supply, this by continuous harvesting instead of a batch.

An aside, the units can be used in boats, likely spaceships as well but then would require artificial gravity for the aeration.

The product line then complete system sold from standard outlets with service-people for when something goes wrong, they won't be complex to operate but have chores to keeping them going, analogous to swimming pool care, a shut-down mode where growing would have to be restarted.

The intended result of doing this is to replace fossil fuels at the most basic level of living using waste as a resource cleverly with algae to support all the IC-engines with a low-carbon biofuel, made locally on any scale farm or city.

This means for existing treatment plants to add the bioreactors and algae processing to where the effluent is now sent to floccing tanks; these units stack & you can create structures for them so the footprint can be reduced by building more floors.

When a city converts it's processing to recycling the water so reducing new fresh-water demand, and a reduction in carbon-footprint by having local transportation running algae biodiesel and having a dry fertilizer on a trailer vs tanker-trucks of slurry/slime.

Since the CO2 removed making the fuel was local, when it's burn this should really help reduce overall emissions over a day, one must grow 24x7 to keep up with volume. Biodiesel made this way has about a 70-year period before it too becomes a fossil fuel. There is the need for reducing soots, and other harmful aspects but that's beyond the scope of this project.

Who will take these actions?

This is an independent, singular concept by an avocational industrial designer that pays bills as software contractor to software companies so only myself to begin with.

Where will these actions be taken?

Based in Bellevue, WA, USA.

What are other key benefits?

Recycling wastewater effluent for the water has been done at N. Lake Tahoe, CA, to prevent algae blooms in the pristine alpine lake, but this is too expensive using floccing.

The downside of algae are having to hold the water 2.5-days.

This system handles holding times, it's based on that as the bacteria and all need time to battle it out as well to reduce pathogen populations to where they are benigh.

My greatest hope is for small farms & ranches, they can invest in this equipment and make their own biofuel at home and run the whole operation, getting water to drink and fertilizer for fields.

This, then, can create a sustainable agriculture with the same tractors & machines being used, where all that cash going offshore to fuel them today stays in the community, enriching the tiny towns anywhere on planet earth.

For the cities, rank corruption will take the price up from my sense it should be $1.25/gallon since this is a public utility ...

Either way, the fuel will get burned immediately.

How much will emissions be reduced or sequestered vs. business as usual levels?

To answer this question precisely is beyond my resources; however, the principle of it is a coherent processing of our daily sewage using existing infrastructure to the large part, the source of nutrients are the value to grow algae in water supplied by the wastewater [mixing & dilution required for proper growth].

Thus these all relate to many environmental needs:

  • Recycling the water.
  • Gaining a high-volume supply of a biofuel that removed CO2 & emitted O2 to make it.
  • Gaining a high-volume supply of a high-quality fertilizer

Scaling globally the importance of this is that is takes a local resource and creates a local truly low carbon-footprint biodiesel that can be tweaked to run any IC-engine on the planet.

Then adding in my advocacy of industrial hemp for biofuels needs, beyond the project scope.

The atmosphere turns over fast enough biodiesel produced this way should be burned within 50-years, else it become more & more fossil and the reduction in CO2 no longer significant, a concern.

What are the proposal’s costs?

My design of a bioreactor is a key issue, 3D-CAD-CAM, 3D-printing prototypes. Mentioned is the rural utility to produce a robust, reliable, certified water purification system able to qualify for building codes with service-people support at enterprise level for distribution globally.

Time line

I still feel after some years now a two-year to the first assembly-line prototype, that is, it's built from sub-assemblies on an assembly-line to satisfy the mass-market home and farm supply stores is possible, and from my software experience multiply that by three, 3, for 6-years and we'll for sure be on schedule & budget.

There is perhaps some "basic research" missing, biological processing is the deal, not gene-splicing, finding what works from nature, then evaluating it.

With that provision, I still think it can go 2-years. By the time any money can possibly arrive, it's just getting faster to prototype.


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Stand on the concept's merit, studied sewage treatment in the 70's, visited Tahoe's plant back then.