Here's a fun fact from Ze-Gen, the company that turns landfill waste into commercially exploitable syngas by dipping trash into hot iron.

Over one billion tons of trash have already been "landfilled" worldwide so far this year, and it's not even Labor Day yet.

The U.S. alone produces more than 250 million tons of municipal waste a year. Fifty-five percent of it ends up in landfills, where it turns into methane. In most cases, that methane seeps into the atmosphere. Methane is a far worse greenhouse gas than carbon dioxide so it's a serious problem.

Landfill reduction and gas capture technologies have begun to increasingly proliferate in the past few years. A few companies, for instance, are turning manure into methane in California and Texas. The problem, historically, however, is that these technologies have been too expensive to compete with natural gas, but the cost differences are getting smaller. Turning landfill into gas also reduces the costs associated with building and managing landfills.

Ze-Gen, which raised $20 million in a second round earlier this year, claims it can make syngas for $6 per million British Thermal Units, or BTUs. Ze-Gen does not make methane. Instead, the iron dip process results in carbon monoxide and hydrogen that can be used on-site. In most situations, these syngases can be burned in the same sort of applications – the difference is that carbon monoxide and hydrogen don't work with conventional pipelines.

Ze-Gen has a pilot plant in New Bedford, Mass., but it is scaling up for large commercial systems in 2012.