Both gasification and plasma gasification need to heat garbage at high temperature in a closed combustion chamber. This process takes place with almost no oxygen, and the organic components in the garbage will not be burned, but will be converted into synthetic gas of carbon monoxide and hydrogen. After the gas is filtered, the chemical components can be "washed" to remove toxic molecules and gases, and then burned to generate energy or converted into fuels such as biogas, ethanol or synthetic diesel. After this process, the last thing left is to clean up the dust, filters and chemicals left behind, and after treatment, they can be sent to be buried or discharged into the sewer.
In the past, the method of garbage disposal was to burn in an incinerator to generate steam, drive turbines and drive generators to generate electricity. Comparatively speaking, gasification generates more energy than burning a certain amount of garbage. In addition, if ultra-high temperature arc plasma is added to syngas, more energy can be generated.
Plasma gasification is to evaporate garbage at a higher temperature, so that more organic garbage can be gasified. The temperature can reach 10000 degrees Celsius, while the ordinary gasification temperature is only 1600 degrees Celsius. Another advantage of plasma gasification technology is that high temperature will not turn garbage into fine ashes, but glassy solids, which can be used as fillers in construction industry in theory.
The United States, Canada, France, Britain and Portugal have all established pilot plants for garbage gasification technology, most of which use plasma gasification technology. There are two commercial plasma garbage gasification power plants in Japan. However, these pilot gasification plants focus on treating domestic waste rather than generating energy from it.
However, IST Energy still believes that the scale of the gasification pilot plant is too small. For example, its closed non-plasma "Green Energy" system (GEM) can treat 3 tons of municipal waste every day, and the released gas can generate energy for a building accommodating 500 people.
Although there are more and more pilot projects of waste gasification power plants around the world, not everyone welcomes this "ideal" of environmentalists. Opponents believe that the process of garbage gasification is not clean, which is far from environmental protection in terms of energy consumption and pollution discharge, and this method may also "fan the flames" for wasteful social atmosphere.
In the process of gasification, organic matter will produce toxic waste gas when heated at high temperature. It is also said that the chlorine gas produced in the process of garbage gasification may cause additional problems under the condition of high temperature and lack of oxygen in plasma gasification.
The early exploration and practice of garbage gasification are often destructive in environmental protection and capital, and the methods of garbage gasification have been vilified, including the toxic gas leakage accident in wheelie bins Gasification Power Plant in Karlsruhe, Germany. The factory was temporarily closed in 2000 and officially closed in 2004.
Opponents also believe that gasification will still produce carbon dioxide. NeilTangri of the Global Incineration Technology Alliance said that the gasification power plant only added a layer of Phnom Penh to the incinerator. He said: "There is an intermediate process of garbage gasification, but the final result is incineration."
There is also a green "proof" question about garbage gasification, that is, compared with other garbage treatment methods, the efficiency of pilot factories and stations in generating energy and minimizing greenhouse gas emissions.
A recent study by TellusInstitute, an independent think tank in Boston, concluded that although the energy per ton of garbage is five times higher than that of landfill, the landfill method of methane recovery system emits 2.5 times less carbon dioxide than the combustion of gasification mixture.
In short, it will take some time to achieve the comprehensive effect of garbage removal. At present, garbage gasification is not a panacea to solve garbage disposal and energy problems, and only time will tell the answer.