The BioBox is a micro-biogas-digester for (sub)urban households and for people who want to recharge the batteries of their gadgets with bio-energy!!!
Please see the picture (where it says: fantastic picture), to get a shortcut.
1. An average household in the UK produces some 4 kilogram of food
and kitchen waste per week
2. from this, you can in theory, using a set of off-the-shelf components, draw 12,000 watt hours of energy per year, if you convert the waste into biogas and then into electricity
3. this biobox is for (us) wealthy suburban people in the 'highly developed world', it is an object like a micro-wave oven; but the inspiration comes from micro-digesters as used in many developing countries
4. it is about the size of an old table-top computer (bit larger), and deserves a nice design
Ok, so you drop in your kitchenwaste, which follows the following parcours:
-it gets shredded and mixed with water
-this sludge falls into a simple digester that is mildly heated (see below)
-the biogas thus produced is burned in a simple bunsen-burner type device
-this flame heats an external combustion engine (stirling), which powers a generator
-the electricity thus produced is stored in a battery
-plug in your cell phone, iPOD, epilady or any gadget, and charge the battery
Simple. Elegant. Maybe efficient.
-you recuperate some of the heat of the stirling, to heat the digester >> you use the water tank as a cooling medium to cool the stirling's top-side; this slightly heated water is perfect for the digester's temperature needs
-12,000 watt hours per year equals around 3333 fully charged iPOD batteries, or 6666 fully charged cell phone batteries!!
Note on a current event that influenced this little idea: a community here in Belgium has stopped collecting organic waste (which households had to put in the green box), for the simple reason that the council calculated that it took too much energy to collect this waste, separate it further, and digest it to produce biogas. The community explained this to the people, who were adviced to use the organic waste to make their own compost.
For those who don't want to bother, they can now throw their kitchen waste in the ordinary bag.
Mind you, Flanders is world record-holder when it comes to smart waste management. But after decades of experience with many different systems, some communties have come to notice that the energy balance doesn't work out.
Of course, this all depends a bit on the location and the circumstances. But still, this came as quite a shocker to (us) the greenies.
I made a fantastic picture of the BioBox that charges gadgets.