When waste at the end of a journey is no longer recycled and ends up in landfills, it does not just steal space. An ecological ordeal begins, such as those we observe at Taverna del Re, one of the landfills of southern Italy, or the many in difficulty around Rome.
Unless stringent and in any case never completely inert, waste in landfills is a great source of methane, the greenhouse gas 86 times more harmful than carbon dioxide. The exponential growth of landfills (just outside New Delhi there is literally a mountain of waste more than 60 meters high, and laconically renamed "Everest") makes things worse.
A startup plans to eliminate thepollution vaporizing waste to transform it into fuel and clean energy. Sierra Energy, this is his name, raised 33 million dollars from the BEV, Breakthrough Energy Ventures. BEV is the Bill Gates fund which also includes investors such as Richard Branson and Jeff Bezos.
The company does not aim to replace recycling and composting, but "only" to manage the millions of tons of waste that currently lie in landfills. "Let's take what we can't handle anymore," says Mike hart, CEO of Sierra Energy.
The system is able to process practically everything, even medical or hazardous waste (I doubt the radioactive ones). “We bring these materials to around 2300 ° C, twice the core of a volcano and much more than twice the size of an incinerator. At this temperature everything is broken down at the molecular level ".
How it works
The technology called FastOx makes use of a special modified blast furnace. By introducing pure oxygen into the apparatus, the process starts a chemical reaction with the carbon present in the waste, increasing the heat. "Vaporizing waste does not require energy supplements from the outside," Hart points out. "It's a simple carbon-oxygen chemical reaction."
The system uses steam to regulate the temperature, with a circuit that feeds itself with the introduction of landfill materials. Any metal inside the waste melts and can be reused.
Unlike keeping them in landfills, vaporizing waste does not create methane thanks to the very high temperature: the steam generates only carbon monoxide and hydrogen. Unlike an incinerator, FastOx does not produce emissions: all the gas produced is collected to be involved in a wide range of reuses: electricity (with gas turbines), aircraft fuel, fertilizer. It is clear that when used as a fuel there will be emissions, but they are about 20 times lower than their fossil equivalent. Even the hydrogen produced by the process can fuel vehicles without emissions.
The pilot plant
After 10 years separately testing more and more demanding pilot projects, the company's partners now work together and have focused on a new plant. It is located at a base of the US Army in California, and in the first presentations it showed how the process can produce both fuel and electricity (at full speed the "vaporizers" will do one or the other thing).
Given the costs of storing landfills, a system like FastOx that quickly gets rid of waste also allows significant savings.
The landfills themselves can turn into real power plants, vaporize waste and sell the energy produced by the vaporization process. The "vaporizers" could also act as a bridge solution to avoid the disastrous incineration and its deadly nanopowders.