When waste at the end of a route is no longer recycled and ends up in landfill, it doesn't just steal space. An ecological ordeal begins, like those we observe in Taverna del Re, one of the landfills in southern Italy, or the many in difficulty around Rome.
Landfill waste, unless subjected to stringent treatments and in any case never completely inert, is a large 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, 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 no longer deal with,” 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 external energy supplements,” Hart points out. “It's a simple carbon – oxygen chemical reaction.”
Environmental impact
The system uses steam to regulate the temperature, with a circuit that feeds itself with the introduction of landfill materials. Any metal within the waste melts and can be reused.
Unlike keeping it in landfill, vaporizing waste does not create methane thanks to the very high temperature: steam only generates 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), jet 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. The hydrogen produced from the process can also power emissions-free vehicles.
The pilot plant
After 10 years spent separately testing increasingly challenging pilot projects, the company's partners are now working together and focused on a new plant. It is located at a US Army base in California, and in early presentations it has shown how the process can produce both fuel and electricity (when fully operational the "vaporizers" will do one or the other).
Given the costs of storing landfills, a system like FastOx that quickly gets rid of waste also allows significant savings.
The landfills themselves can transform into real power plants, vaporizing waste and selling the energy produced by the vaporization process. The “vaporizers” could also act as a bridge solution to avoid disastrous incineration and its deadly nanodust.
