Heat, power, fuel from waste, the run is on

Post date: Mar 18, 2010 10:17:18 PM

Innovators

are racing to glean heat, power and fuel from waste, seeking big rewards

and subsidies for technologies which have a history of failed projects,

drawing skepticism from some analysts.

Governments

are sweetening waste-to-energy technologies with incentives, to try and cut carbon emissions, boost domestic renewable energy supplies and dispose of waste more cleanly.

Wood steam turbine

Even a very simple process burning wood to drive a steam turbine is three to four times more expensive per unit of energy than a conventional gas power plant, say experts, although some developers may earn a "gate fee" for disposing of the waste.

SYNGAS

One new approach is gasification, traditionally applied to coal, where waste is heated with only little oxygen to produce a high-energy gas containing hydrogen and other chemicals. That so-called syngas in theory can be cleaned and mixed with natural gas, or else burned in engines rather than used to drive steam turbines, and capture more energy than incineration. Problems with gasification at the small scale have included sticky tars which clogged machines, and at the larger scale variable waste which led to unpredictable results in power production, and especially engines. "The country is littered with failed gasification projects"

Gasifiers for poultry litter