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From Waste-to-Energy Revolution
Thứ ba, 16/09/2014 - 14:13
Sweden is well ahead of all countries in successfully designing and implementing urban the waste-to-energy (WtE) plan, a process of generating heat and/or electricity from incineration of waste.

Sweden has been pioneering sustainable urban waste management for decades. Now they have embarked on the Zero Waste Revolution. Sweden is well ahead of all countries in successfully designing and implementing urban the waste-to-energy (WtE) plan, a process of generating heat and/or electricity from incineration of waste. Heat or electricity may be produced as a result of direct combustion or the process may produce a combustible fuel like methane or ethanol. 

Today, 99 per cent of all household waste in Sweden is reused, recycled or composted. Only 1 per cent of 4.4 million tonnes of household waste reaches its landfills or dumpsites. Not only are they running their power grids from their own waste, they import over 800,000 tonnes/year of trash from neighbouring European countries like the UK, Ireland, Norway and Italy to use in their power plants. So Sweden generates heat and power for its buildings from trash and gets paid to do it!

How is it done?

Sweden has established an advanced trash sorting method. It is producing energy from things that otherwise would be discarded — animal waste or unicellular waste like algae. About one million households are heated by biogas, produced from 99 per cent of the country’s household trash; 3,00,000 households are powered by it. In 2013, Sweden produced 25.5 gigawatts of energy from renewable resources. In 2014, it is expected to produce 26.6 gigawatts.

Households are responsible for separating and depositing waste at available collection points, which as a rule cannot be over 300 metres from every doorstep. From the collection point, it undergoes one of these waste treatment methods — material recycling, biological treatment, energy recovery. Only remains that cannot be reused or converted into energy reach landfills. Landfilling of organic or combustible materials is strictly prohibited.

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Waste sorting and collection bins near homes, apartment buildings and residential complexes

Waste treatment is either performed by municipalities themselves or outsourced to another municipality or a private company. While some municipalities still have manual waste collection systems, trash bags are being replaced with collection bins, and manual pickup and transportation is being replaced with automated underground vacuum refuse collection and container systems. 

There are two kinds of vacuum refuse collection systems: stationary and mobile. In the stationary system, refuse is collected by air into an automatic vacuum system. It is transported through underground tubes, which connect the waste drop chutes to large containers that are placed in a terminal. The containers are collected by load carrying vehicles. The mobile system uses air to collect waste and a storage tank is positioned under each drop chute. The tanks are connected together via an underground pipe system. The vehicle connects to the docking point for emptying, the vacuum system is switched on and air propels the waste from the storage tanks to the docking point and into the vehicle.

Sweden’s 2020 vision is Zero waste. It wants to reduce emissions by 40 per cent compared to 1990’s, produce 20 per cent more renewable energy and at least 10 per cent of vehicle fuel from renewable resources.

Newindianexpress.com