Enclosed Aerated Composting -Shipping Container

Topic Type: 
Idea

Enclosed aerated composting vessels are efficient in processing organic wastes, but expensive and site specific. Given the glut of shipping containers (thanks to trade deficits) why not re-purpose these and convert them into mobile enclosed aerated vessels. And why stop at just replicating the typical vessels, when a few further simple mod's could capture all the products of aerated composting - namely heat and CO2 production. My idea would create a way to transport food wastes from urban centers to a small farm in a delivered "composting pod" which in addition to getting the valuable end products, could serve as a significant revenue source to a small farm in the form of tipping fees paid by waste haulers.

The mod's to a shipping container are beyond simple: 1. Mount perforated tubing on the inside base of the container. At the farm, these pipes would be hooked into a external squirrel fan to force air into the waste/compost; 2. Mount tubes to side and top inside panels, much like a solar thermal collector to act as a heat exchange. At the farm these would be attached to a pump and h2o tank and heat exchange; 3. Mount a auger (i.e. -a pole digging auger) to a track running down the top panel of the container - and at the farm attached the auger motor to periodically mix the compost. To mitigate leachate from leaking into the soil, the container would be dropped off on a concrete pad, but with a slight slope (horizontally & vertically) to cause any leachate to flow to a directed collection point/drain. To treat compost odors, the wastes would be mixed with a minimum of 5% by volume of biochar and surrounding the container would be a "biofilter dock" of 2'-3' of a biochar/compost mix (held in a wire mesh/ steel frame structure). Simple -- no brilliant new technology, parts from Home Depot, Lowes, etc.,....and inexpensive. And it takes up a footprint, even a small farm could accommodate.  Four 40 ft containers of 8' x 40' plus dock structure plus a generous amount of circulation space would still take up less than 3,000 sq ft (under 1/10th of an acre)

Consider the potential revenue boost to a small farm. A 40' container holds (at 90% capacity) roughly 67 tons of food wastes. Enclosed aerated composting typically processes wastes into compost in 28 days - meaning there are 12 cycles per annum for each pad. Waste haulers pay an average of $50/ton to deposit food wastes at compost sites, so for a 4 unit site that translates into $13,400 per month or $160,800 per year --- perhaps a little bit better than the revenue from a 3,000 plot of corn. And, incidentally, it's also not too bad for the environment.

I forgot to mention two by-products of composting that are often overlooked - heat and CO2 emission. Normally, CO2 emission wouldn't be considered a beneficial by-product, but what if this warm CO2 laden gas were ducted to bubble through a tank of spirulina algae, provide the spirulina its needed carbon and warmth. I read somewhere this algae is good...something about high protein.  Speaking of high protein, one of the challenges of raising black soldier fly larvae or even crickets is the need to provide a warm climate during our colder northeastern months, economically. The heat from the compost could vent into the vertical insect ranches producing protein feed year round. Notwithstanding the FDA's refusal to sanction insect derived livestock feed, it happens to be what pastured chickens eat as well as fish in the wild. I've never heard of anyone using processed soybean meal as bait for trout fishing - but what do I know.

Well, I thought I'd provide proof of my mental incompetence by dashing this off. On the limited risk of someone actually understanding the above, and finding some small part interesting enough to comment...rant.. etc... I'd love to your thoughts.