The US Composting Council Conference, held in Santa Clara, California, was an excellent source of the latest research and updates on the composting process and the use of compost. There is increased interest in the US on source separation of food scraps. Worldwide, there is a continued interest in diversion of organics from landfill. This is a good thing. There were many vendors with compostable products, including bags, cups, and flatware.
Of particular interest was the panel of leading composters and anaerobic digestion developers who spoke at the plenary session. We heard that anaerobic digestion and biogas production is the way of the future – its the right thing to do. We heard that it is currently not economically viable, but the time will come when the costs will decrease. We heard that relying on grants for capital construction of anaerobic digesters is a good thing. This is of particular interest to me because as a microbiologist, I was trained in the last era of anaerobic digestion, and have actually built a small scale unit. They work, but the real question is the economics of the process!
Last October at the Biocycle conference on anaerobic digestion, some of the European speakers addressed their concern of what would happen if their countries withdrew their subsidies for anaerobic digestion. What this means is that even with higher landfill tipping fees and higher energy costs, anaerobic digestion still had to be subsidized by the taxpayers. So, the costs haven’t come down yet…
I’d like to see some more real data on the economics of this process. We know that after anaerobic digestion, the material still needs to be composted. There will also be nutrient rich liquids to manage. This will also cost money. Simply saying that this is the right thing to do is not a logical rationale for using tax payers dollars to fund these processes.