Each day, the world produces some 5.5 million tons of waste. During the period of a year, that adds up to more than 2 billion tons of solid municipal waste, much of it taking up space in landfills and producing carbon emissions as it rots away. By 2050, the World Bank estimates that the problem will be even worse, reaching 3.4 billion tons of annual waste — a 70 percent increase.
As nations around the world confront all of that household refuse and unused industrial material, new technologies are turning this liability into an energy asset. Power is being generated from semisolid waste discharged from urban incinerators or industrial plants, liquid waste such as domestic sewage and excess gas produced in refineries.
Solar, wind and hydro power may grab the headlines as clean energy solutions, but steadily, waste is a source of renewable, low-carbon energy. With 6% annual growth, the global waste-to-energy (WTE) market is expected to exceed $35.5 billion by 2024, led by the Asia-Pacific region where adoption of these novel technologies is projected to expand rapidly.
Asia’s leading role
Today, incineration is the most widely used technology in waste management to prevent the costly transport of refuse to landfill sites. But throughout Asia, governments are extremely adopting greener and more innovative approaches.
Japan was a very early adopter of WTE technologies and proceeds to lead the way; it processes about 70 percent of its municipal solid waste in WTE facilities. But China is making big strides as its economy and population continue to develop and its government transitions to cleaner energy. The power demands of the world’s most populous country are increasing rapidly, along with mounting domestic and commercial waste. Heavy investment in renewable energy technologies, buoyed by government policies that encourage sustainable development, is driving China’s WTE sector.
In 2020, the southern city of Shenzhen is scheduled to start operating the world’s largest waste-to-energy plant, with an expected daily incinerating capacity of 5,000 tons of the city’s trash. The incinerator’s residual heat, once captured, is used to drive a turbine, generating electricity. According to the project’s architects, the process should halve the amount of carbon dioxide typically released from landfill sites.
The Shenzhen facility is just the opening for China, currently the fourth largest WTE user after Japan, Europe and the United States. China’s growing awareness of its waste’s environmental impact is spurring policies that promote efficient, cost-effective solutions. By 2022, the Chinese government plans to build 300 dedicated WTE plants throughout the country — double the number of current facilities.
Converting a variety of waste
While the U.S. continues to lag in WTE, the European market is growing. Producers in Europe are adopting initiatives to process different types of waste, including solid or semisolid, excess gas and heat. In Turkey, for example, the country’s largest egg producer has installed an Organic Rankine Cycle (ORC) system from Turboden, a company within Mitsubishi Heavy Industries Group. The system converts chicken manure into electricity and hot water, creating clean energy out of unwanted waste.
A similar system is in operation in Russia but with a different source. Rather than solid or semisolid waste, international oil and gas company Lukoil uses a Turboden ORC system to process residual heat from flare gas to provide electricity and hot water for the oil refinery. This is usually burnt off at the top of a torch. During each hour of operation, the system prevents 720 kilograms of CO2 emissions from reaching the atmosphere.
And at ORI Martin’s steel plant in northern Italy, ORC turbines capture residual heat from the manufacturing processes, producing enough energy to power and heat part of the industrial city of Brescia. Such innovative projects represent a continuing shift in attitudes toward cleaner, more sustainable production. As more governments and private operators acknowledge the need for alternative waste management, creative solutions like these might become the norm around the world, combining the future of waste and the future of energy.