Biogas from landfills has gotten a momentum lately, and several sources of it have been found potent: landfills, industrial operation, sewage treatment plants and agricultural residues. The happiness of promoting biogas from these resources is though shaded by the issues with a compound called siloxane.
Siloxane is a carbon-silicon compound found inside various chemical products on the market and then released into the air when methane is produced. Its existence threatens the biogas machinery, being able to cause serious damage.
The problem would not had been so severe if the agricultural sector wasn’t also involved lately. The U.S. government wants to promote biogas from dairy farms and other agricultural sources through a program called Agstar, to which siloxanes could constitute a roadblock. The issue arose when certain types of insecticides started being used in agriculture, thus letting the siloxane enter this system, too.
As any problem has its solution, this one too has one: Applied Filter Technology, Inc., a U.S.-based company, for example, sells a filter in the form of a graphite molecular sieve that catches siloxane and prevents it to build up into glassy formations that block turbines and grind down metal parts. Different other filters also exist on the market, such as PpTek.
The company had already been using their filter for about 14 years, but since they have been improving it and patented several other innovations related to biogas and various wastewater systems.
Biogas can be a serious source of profit and a true replacement for fossil-fuel derived gas. The stakes are high in this business and the future looks bright for it. The lesson that humanity should learn from the siloxane problem, though, is that we should be more careful when designing chemicals that could one day reach our foods or prevent us from recycling them – ever.