European nations treat their solid waste to keep as much of the organic component of it as possible out of landfills. This is a high priority for the UK as they must reach Government recycling targets that are intended to assure compliance with mandatory landfill diversion rates, as set by the EU Landfill Directive.
How can we reliably keep organic refuse out of landfills and close down many completely? The answer to this is composting. Composting is the best way to return left-over organic waste back into the nutrient cycle. It also replaces conventional fertilizer and improves the soil, minimizing crop pests, and retaining more water in the soil, which then means less watering is needed.
So composting is a good way to divert waste from landfills, but is there actual demand for the vast volumes that would be generated from the very large fraction of our municipal solid waste that consists of organic material? It seems improbable that gardeners and farmers would require as much compost as can be made from the enormous supply of organic material thrown away each week.
The good news is that composting can take the form of anaerobic digestion, which ultimately produces Methane (CH4) gas. CH4 is a cleaner-burning fuel that could help undergird a more sustainable economy with a smaller carbon footprint, as an in-between step in the transition to a hydrogen economy.
Our present carbon-dependent economy does indeed suggest the need to increase methane production. The fact that CH4 can be processed further into biofuels such as methanol and biodiesel bolsters this suggestion. Methane production would help to move us away from dependence on oil as our fuel source – and toward freedom from fossil fuels.
Nonetheless, the adoption of composting to develop CH4 would probably occur slowly rather than suddenly. In addition, while many nations, such as the UK, are currently composting with immense success, composting by itself will not take us to sustainability.
It is well understood that we urgently need sustainable, renewable fuels to curtail our use of oil and reduce the pace of anthropogenic climate change. By building on our progress with household organic garbage and by beginning to compost commercial and consumer wastes, we begin to engender the overall acceptance of organic waste processing in place of simple landfilling as the standard. More and more companies are entering the anaerobic digestion market place, and these endeavors will certainly grow and multiply, further driving the acceptance of this practice.
However, typical composting requires energy. As a net contributer of GHGs (green house gases), it is still not particularly sustainable as a solution for dealing with Municipal Solid Waste. Moreover, it is not necessarily the best option for dealing with organic refuse, which is often inundated with contaminating material.
How then can we adapt composting to be at least Carbon Neutral and allow these newly emerging companies to expand their growing skills in biowaste processing?
Anaerobic Digestion is a good solution.
The technique of anaerobic digestion (composting in the absense of oxygen) uses organic waste to produce methane gas. CH4, a sustainable source of energy, can be used in generators to produce electricity. Doing so reduces the carbon footprint of energy production, uses solely renewable source materials, and replaces petroleum as an energy source. This, in turn, helps to mitigate climate change.
Put all this together and we have a bona fide contribution to sustainability — contributing to a life without anthropogenic climate change, and without imperiling the lives of subsequent generations from global warming.