How the Bioreactor Works
This is how the Bioreactor works in a streamlined illustration. The CAD diagrams are also available here. This will function as an introduction to the general schema of the system.
The Bioreactor is at its heart a compost generator for producing high quality compost in a short amount of time. bootstrapped to that core is a power generation system located at the top of the tower. And above all of that is 1000L of rainwater in a tank that provides moisture and aquatic solvent for the entire process.
Part 1: The Compost Base
Let’s start with the compost base and the accelerant. Compost takes a few months for the microbes, temperatures, and biomass to achieve the proper temps and pressures to start the compost process. The bioreactor puts all of this in one place and adds an accelerant.
The body of the compost reactant base is set atop a concrete base and is actually a modified 1000L IBC tote (see image above). The plastic tote has a cap on top, a spigot at the base and an integrated steel cage. These are ubiquitous and cheap and that is why I prefer to use them.
The compost reactant base is modified slightly. The top of the plastic IBC tote has been removed to leave the tote open. The front of the tote has been cut open with a modified removable door for loading the compost reactant base.
The compost base is layered with the greens and browns as in traditional compost. The key here is the accelerant composed of ammonia, beer, and cola and added in 1 liter increments to 20 gallons of water once a week. As the accelerant percolates through the compost pile, it speeds up the composting process.
Part 2: The Water Collection Tower
Situated atop the compost reaction base is the bioreactor water tower. It sits with in the steel exoskeleton and serves to tie the entire tower together. It also holds 1000L of rainwater and like the compost reaction base has a built in spigot.
Housing the water tower at the top of the tower serves two very important purposes. Since the water tower never moves, it makes sense to store it at the top. The height of the tower allows the water to be pressurized as it drops to the ground 2.3 meters in the air.
With the water tower and its screw top filling access are situated at the top of the water tower. This is fitted with a cap and a pipe that makes refilling the tower with rain water easier and convenient. The steel frame of the water tower IBC is also a convenient place to mount sensors and equipment.
Part 3: The Energy Production and Sensor Deck
The top of the Bioreactor tower is home to the 200W wind turbines, The batteries and charge controllers, as well as the weather station and specific sensor arrays. Mounted from the top on the southern-facing side of the tower are the two 200W solar panels that capture solar energy. The sensor arrays cover temperature, humidity, solar LUX, barometric pressure, and CO2 levels.
In addition to the onboard energy generation, weather data, and sensor stack, the bioreactor also has a 5G and 4G repeater to disperse a wifi signal everywhere within a 5 meter radius. This allows me to use the bioreactor tower to broadcast and receive signals from the varis devices and sensors all around the bioreactor. It also allows me to upload data to the cloud and to watch YouTube videos on what to do next with my research.
Each of the wind turbines is mounted on a 2″ steel conduit pole strapped to the steel structure of the bioreactor. The steel conduit is threaded at the top, so that the wind turbine base can be screwed to the pole. A custom configuration would cost as much as the entire bioreactor steel frame; it’s crazy!
Off The Shelf Engineering
In total every part of the bioreactor tower is built from off the shelf resources. Most of it came from Menards with sensor and power generation and batteries coming from Amazon. The IBC totes formerly held dye for color-matched mulch and were quite affordable.
The lattice facing is a gift to my husband, Rick. He is not against the bioreactor, in fact most of the compost goes back to his formal gardens. He just wants it to look a little neater.
The tower has been working very well for two years. In that time it has produced nearly 4000L of high quality compost. All from resources that were culled and collected on site. The beer, cola and ammonia were the only resources that came from the outside and the cost for running the bioreactor over the previous two years has been minimal.
Two kegs of beer at a cost of $50. 24 2-liters of cheap cola at a cost of $24. and 12 bottles of ammonia at a cost of $22.
Add in the gas for the lawn mower, and a modicum of costs for batteries and AC to recharge rechargeable batteries for the sensors. And the final cost is a total of around $153 for running this system each year.
All of the water came from rainwater collected from the side of the house and collected in IBC rain barrels equipped with solar panels and water pumps. The water pumps run on demand when I turn them on and connect them to the refilling hose. The essence of renewable and ease.