The ultimate form of the ‘recycle, reuse’ concept: Landfill mining. Digging up landfills for extracting solid waste and recycling the usable materials and converting the organic material into usable fuel. A Belgian company Advanced Plasma Power is planning to extract a 16.5 million tonnes of solid waste from a landfill which has been in use since the 1960s. Several other European companies are analyzing the feasibility of such projects.
Advanced Plasma Power (APP) is planning to excavate 16.5 million tonnes of solid waste from a landfill site near Hasselt in eastern Belgium. The project which will span up to 30 years would convert the organic waste into usable fuel gas (practically methane) through its Gasplasma technology. The project would generate enough fuel to power a 60 MW power plant capable of supplying electricity to 60,000 homes.
One of the common technologies to convert organic waste into fuel is the gasification process. It involves heating up of the organic waste at very high temperatures to breakdown the high-energy chemical bonds and convert it into usable gaseous products which chemically resemble natural gas gas or methane.
The conventional gasification plants, however, have lower operating temperatures, this limits the concentration of hydrogen in the fuel gas which, in turn, reduces its calorific value and the efficiency of the power generator into which it is fed. The conventional gasification process also generates several non-usable, non-recyclable and hazardous by-products which need to be sent back to the landfill.
APP’s Gasplasma technology solves most of these problems.
It uses a fluid bed gasifier operating at 900°C which breaks down the synthetic gas produced after the thermal decomposition of organic matter. The high temperatures increase the concentration of hydrogen in the gas which increases its calorific value. The gas is then fed into generators which now have an efficiency of close to 40 percent as compared to 20 percent achieved using fuel gas from conventional gasifiers.
Because of the high operating temperatures the more resistant waste products like tar, char and ash are either broken down into simpler products or their volumes are reduced significantly, thereby reducing the amount of products going back to the landfill.
Energy From Waste
As the population and consumption rates increase the amount of waste generated is also increasing every year. The municipal solid waste which used to be dumped into the landfills is now becoming is big problem due to land crunch. The developed and developing countries are suffering from this problem alike. Several countries like the UK now impose taxes on dumping wastes into landfills in order to encourage recycling as the land for disposal is running out fast.
Chris Dow of Closed Loop London described the situation in an interview in 2008.
Just imagine the resources that are lying in those landfills—it could be incredible. But the insane thing is that we are talking now about investing millions into tapping into a resource under the ground, when the real tragedy is that every week we’re still dumping tonnes and tonnes of plastic into more landfills. It’s an act of vandalism against the environment.
We must realize that waste is not waste but an energy resource which meeds to be utilized not only to meet the growing energy demands but also because we are running out of solutions to dispose it. Not only municipal solid wastes but liquid effluents from industries and domestic wastewater too have significant energy resource.
Wastewater can be used for producing biofuels and electricity. Solid wastes can be converted into gaseous fuels and biofuels. Plastics and construction materials worth billions of dollars can be extracted from the landfills and reused. The list of products that be extracted by waste-utilization is almost endless.
The views presented in the above article are author’s personal views and do not represent those of TERI/TERI University where the author is currently pursuing a Master’s degree.