SOLID WASTE TREATMENT CONVERTS ENVIRONMENTAL HAZARD INTO GREEN ENERGY
“Waste not, want not” is how the saying goes. Current solid waste treatment system turns this old chestnut on its head. For waste-to-energy technologies, solid waste serves as an input for electricity, steam, district heating/cooling or desalination. Having embraced waste incineration and “district heating” decades ago, Denmark and Sweden stand at the forefront of the waste-to-energy industry, pioneering new technologies for clean waste treatment and energy recovery.Israel enters the arena with publication of a preliminary tender for the construction and operation of the largest waste-to-energy facility in the Middle East.
Waste-to-energy is an energy recovery method, which has come to address a significant part of Europe’s energy needs. Approximately 50 million tons of solid waste are incinerated every year throughout Europe, an amount equivalent to the heating requirements for households throughout Scandinavia, Iceland, Estonia, Latvia and Lithuania. It is estimated that in Sweden alone, waste incineration generates as much energy as produced by 1.1 million cubic metres of oil, reducing CO2 emissions by 2.2 million tons annually.
Energy recovery adds a new dimension to waste disposal and treatment. Solid waste that cannot be recycled in an economic or environmentally sound way becomes a valuable local source of energy. The inclusion of waste-to-energy facilities in waste treatment plants reduces the need for landfill disposal to a minimum. In most cases, waste-to-energy facilities outperform alternative waste treatment processes with respect to carbon footprint and other negative environmental impacts.
DENMARK – TURNING STRAW INTO BLACK GOLD
Denmark is considered by some to have the most efficient waste management systems in Europe. It was the first country to ban the landfilling of waste suitable to incineration and remains a leader in waste-to-energy adoption, boasting more than 30 waste management plants serving more than 100 municipalities throughout the country. It is also a leader in biogas production, converting agricultural waste into energy and fuel.
The ribbon on Måbjerg BioEnergy was cut this past June. A collaboration between local farmers and energy supply companies, it is one of the largest biomass plants in the world. The plant will convert some 650,000 tons of biomass (manure from farms and waste from the local food industry) to 17.8 million cubic metres of biogas, supplying heat and power to northwest Denmark. While impressive in its own right, Måbjerg BioEnergy is just one of four pillars of a more extensive integrated waste-to-biofuel + energy initiative.
Launched earlier this year, the Måbjerg Energy Concept draws its inspiration from industrial symbiosis demonstrated at the DONG Energy Kalundborg plant. The envisioned complex integrates the newly inaugurated biogas plant with the existing Måbjergværket combined heat and power station, a planned ethanol production plant and planned biological waste treatment facility. The project creates synergies between its various components, in which waste from one sub-project serves as raw materials for another. The consortium behind the Måbjerg Energy Concept consists of the local utility companies Vestforsyning, Struer Forsyning and Nomi, which own 50% of the project and DONG Energy and Novozymes which collectively own the remaining 50%. The Måbjerg Bioethanol Plant will be constructed next to the biomass plant which will be expanded to accommodate new biomass inputs from the ethanol plant and waste management station. The plant will produce cellulosic ethanol from some 300,000-400,000 tons of wheat straw, using steam from the power plant. The residue molasses from the ethanol works becomes biomass for the biogas facility, while residue solid fibre is fed back for incineration at the power station.
The Måbjerg Waste Treatment Facility will use steam and enzymes to separate 50,000 tons of waste into solid and liquid parts. The liquid portion of the waste will be degassed in the biogas plant, while the energy will be recovered from the solid portion at the power station. The feasibility of the project is still being assessed, but it is anticipated that the project will be completed by 2016. It is estimated that some 50-70 million litres of bioethanol, 44 million cubic metres of biogas, district heating for 20,000 households and electricity for several thousand households will be generated from the integrated facility. Poul Ruben Andersen, Vice President for Bioenergy at Novozymes, believes that the Måbjerg Energy Concept could serve as a model for other countries. “Plants like this could be built all over the world, because they can use many types of waste inputs and produce many different kinds of output”.
SWEDEN’S NEWEST IMPORT – THE NEIGHBOUR’S GARBAGE Like Denmark, Sweden is on the cutting edge of waste management. The landfilling of organic waste has been prohibited in Sweden since 2005. More than five million tons of household and industrial waste is treated in Swedish waste-to-energy plants each year. Energy recovered from waste incineration provides heat to some 81,000 homes and electricity to more than a quarter of a million people.
Between recycling and waste-to-energy, less than 0.9% of municipal household waste ever sees the inside of a landfill. As a result of Sweden’s embrace of waste-to-energy technologies, it is anticipated that by 2020 the level of greenhouse gas emissions will amount to less than one quarter of what it was in 1990. Over the past 12 years, Sweden has more than doubled the processing capacity for combustible and organic waste to almost 6 million tons per year.
According to Avfall Svierge, the Swedish waste management association, studies show that Sweden’s energy recovery rate is the highest in Europe. Waste-to-energy currently accounts for over 51% of the treatment of household waste. Sweden’s waste-to-energy program has been so successful that its capacity to recover energy exceeds the supply of domestic waste.
To solve the problem, Sweden has started importing waste, primarily from its neighbour, Norway, for which waste-to-energy is less cost-effective. Avfall Svierge estimates that in 2011 a total of 813,000 tons of household and industrial waste was imported for incineration in Sweden. According to the arrangement, Norway pays Sweden to take the waste and agrees to take back the ash containing residual pollutants. Sweden enjoys the energy which is used for heat and electricity. Importing garbage is not seen as a long-term strategy for either Sweden or Norway, but rather a short-term solution to a temporary imbalance.
ISRAEL – BURYING THE LANDFILL FOR GOOD
Sweden may not be able to import garbage from Israel, but may be able to export expertise. Some 6.2 million tons of solid waste are produced in Israel every year, of which 4.8 million tons are municipal and commercial waste, and the remainder industrial waste. Today nearly 80% of Israel’s solid waste is landfilled while only 20% is recycled.
Israel’s Ministry of Environmental Protection (MEP) has adopted a master plan for solid waste management, which, among others, aims at attaining a zero-landfill future. Putting the plan into practice, the MEP in conjunction with the Accountant General of the Finance Ministry has issued a preliminary tender inviting Israeli and foreign companies to apply for pre-qualification for the construction and operation of a solid waste treatment plant in the centre of Israel. The projected facility is designed to handle 1,000 tons of sorted and mixed solid waste daily, twice the current garbage output of Tel Aviv, scheduled for completion by 2016.
According to the Ministry of Environmental Protection, the plant will be the largest such facility in the Middle East and one of the largest in the world. It is a public/private BOT project in which the contractor will build and operate the plant for a period of 25 years, after which it be transferred to the State of Israel. Rather than burning the garbage, the plant will use mechanical biological treatment with anaerobic digestion (MBT-AD) and closed composting technologies for waste treatment. It will produce biogas for electricity generation as well as high-quality compost.
The proposed facility will be Israel’s first waste-to-energy plant. For more information and to download prequalifying tender documents, contact Ms. Iris Giditz PPP-Waste.Service@inbal.co.il or phone +972-3-977 8753.