Biogas

The federal Government have recently announced a plan to get more gas from the Australian fields sold onto the Australian market. Meanwhile there is a push for all new homes to have electric induction cooktops to reduce the overall gas consumption. The older homes that were never wired for high current cook tops will have to use gas a lot longer or face costly re-wiring. One way we can reduce our dependency on fossil fuel gas is to produce our own from household bio wastes and humanure. This would have the added benefit of vastly reducing landfill emissions as the waste currently ends up as a potent greenhouse gas (methane) in the tip anyway. There are many ways to build a home biogas digester, but not many safe ways. Dealing with a flammable gas means a very professional approach needs to be taken. I heard about a system where a large plastic lined pit was built at the beginning of a driveway to a rural western property. The owner collected road kill kangaroos and filled the pit, then put a heavy plastic sheet over the top with rocks and earth to seal it. He ran a long pipe back to his caravan and cooked on the resultant gas. Probably not great if you left the gas on but it did work, and sometimes simple is best. I have seen many biogas digesters in different countries around the world and they all serve their purpose. Most are on a community scale with the local piggery or dairy contributing the effluent for digestion. Removing the sulphides from the gas is the greatest technical challenge. Sulphides can create acidic conditions that eat away at gas jets and other components. This can be done by percolating the gas through a sodium hydroxide solution but then that needs to be disposed of at the end of its usefulness. There are biogas composting toilets on the market right now, very efficiently designed and safe, however as yet not accredited for use in NSW. If we are going to be able to effect sustainable change, legislation needs to adapt away from the nanny state and give us opportunities to buy well engineered solutions. In the meantime, an anarchistic approach should be taken! The existing legislation does allow for owners to build their own waste management facilities without the need to have it accredited by NSW health. Anyone who wants to go down this path should reach out and I would be happy to act in a design capacity. Weirdly an owner built system has more chance of getting approval than a tried and tested commercial design without accreditation. I would love to see the day when my On-site Sewage Management System (OSMS) designs are not hindered by unreasonable guidelines that prohibit local entrepreneurial talent. My original pre-cast concrete composting toilet design cannot be sold anymore due to councils not getting behind my product.