In Soviet fiction has been described by light control project rubbish — load it into the rocket and send the sun to burn it. Not cheap, but a good idea.
At the Institute of Electrophysics and Electric Power Russian Academy of Sciences under the leadership of Rutberg (about awarding him the prize "Global Energy" journal "Science" wrote in N2) established industrial plasma generator in which to process household waste used low-temperature plasma-chemical process. Thus not only be disposed of waste, but also produces electricity. The project plant for processing of municipal solid waste was submitted for examination to the Fund "Skolkovo". Academician Yevgeny Velikhov, Chief Nuclear Technology Innovation Fund, has given a positive opinion by offering the industry's first model built on the territory of Skolkovo.
— Now we are working closely on this issue with the fund, — Said the deputy director of "Plasma-chemical technology" Sergei Terekhov. — There is a protocol, signed by all parties. If all goes well, by the end of the year will have the first incarnation — not even in the metal, probably, but at least at the beginning of construction. And then a year later the plant can be built.
Kills all known dioxins
Now incinerators are not able to provide a complete combustion of the waste due to a relatively low temperature — 800-1000 degrees. Therefore, in the atmosphere emitted tons of harmful substances, including dioxins, posing a serious threat to all living things. Industrial filters that can completely clear the smoke from harmful contaminants, science has not yet invented.
Rutberg plasma generator creates a working region of the reactor with temperatures of 1200 to 2000 degrees, which is in the process of pyrolysis (thermal decomposition) and plasma gasification of organic waste. As the plasma gas is air and water vapor. During pyrolysis of organic synthesis gas is formed — mixture of carbon monoxide and hydrogen (CO and H2), while continuing combustion which produces carbon dioxide and water.
Working body of the plasma generator is a plasma torch — a system of electrodes, creating an electrical arc which heats the gas to the ionized state. The installation consists of a column reactor, which are located in the middle of the plasma generators, and the top of the ground and backfilled with granular organic waste. Getting inside the reactor, organic undergoes a process of gasification. The obtained synthetic gas can be supplied as a gas turbine, which produces electric current and used for production of liquid fuel and hydrogen. Non-combustible residues in the form of a glassy slag fall down.
— The plasma is generated in the plasma torch at a temperature of 2 to 6,000 degrees — Explains the principle of operation of the generator academician. — Two thousand — is at least six — this is usually the maximum, although it can be more necessary. In principle, the low temperature plasma — a couple of thousands to a million degrees, high — hundreds of millions of those temperatures that exist for fusion reaction or in the center of the Sun. We operate with temperatures that correspond to the surface of the sun — it is precisely about 6000.
Since the reactor falls relatively cold material (organic waste), plasma diluted therein and the internal temperature drops to approximately a thousand degrees — from 1200 to 1800. This is sufficient to support the process of plasma chemical reactions, but do not waste unnecessary energy. The temperature not lower than 1200 is required to avoid conditions for the formation of dioxins. Therefore, the plasma jet emitted by the generator is controlled so that the temperature of organic compound is within the range — can enlarge above is not necessary.
— The generator is supplied protective working gas, that is, the same air, — Says Rutberg — to limit the scope of arcs, where the temperature may be ten, twenty, thirty thousand degrees. Air is blown through them, part of which is on the edge of protecting walls of the generator — in the end, all mixed and a working temperature of the plasma.
Mobile electric arc
The most wear parts torch — electrodes. In the plasma generator, manufactured by foreign firms, regardless of what they are made of alloys, the electrodes are destroyed for 200-400 hours. In the plasma torch Rutberg, through a special organization combustion mode when the arc is not tied to a single point, and moves in a magnetic field, the resource is increased to two thousand hours, at least up to a thousand. In addition, cost and ease of manufacture designed Institute electrodes substantially less foreign counterparts. They are used either pure copper or copper powder with an iron compound.
Replacing the electrodes in the plasma torch is not a technological problem — according to Rutberg, it can be done literally in five minutes, without any prejudice to the generality of the process. Since the inside of the reactor column is quite a large mass of material, it heats up and cools inert.
— You can turn off all at least for half an hour, — He says. — As the process of heating plasma reactor could take a whole day, and cools it about the same. It is time. Second, you can change the electrodes in series, as the plasma torch in the reactor one — they are two, three, maybe four. In general, we look forward to the time of continuous operation of the plant in 8000 hours — that is, to stop it to prevent possible once or twice a year.
— Of the one hundred percent of the waste after processing at sorting line, — Says Dmitry Aronin, CEO of "Plazmotehnicheskie technology" — that is, after the selection of useful things that can be recycled — it's metal, paper, glass, plastic — is of the order of 25-30% of organic matter that has to be put somewhere. All of this organic matter can easily be used for gasification in plasma-chemical reactor. From what it recycled remain 5-7 percent vitrified slag which can subsequently be used in road construction.
That plant, which "Plasma chemical technology" are ready to put the now able to process 12,000 tons of material per year and will produce up to 2 megawatts of power. About half of the electricity produced will be wasted on heating of the working zone of the reactor and maintain the process — so that the sponsors are counting on the net benefits not less megawatts of electricity per hour. By heating the water in the cooling station will produce heat energy and which can be used for heating. Is produced in the syngas can be the raw material for further processing.
— Of synthetic gas we can get anything, — Says Rutberg. — Mozhem pull hydrogen — and the cheapest in the production of hydrogen will. Can burn in a gas turbine, under the pot to get the energy and can produce alcohols and diesel fuel. Unfortunately, we have not developed in Russia catalytic production, but abroad have proven technologies. They can be used to receive and ethanol, and methanol.
Skolkovo will not leave garbage out
— But the main thing is, — Said Aronin — and the fact that the chimney of our processing plant debris will fly only CO2 and H2O — carbon dioxide and water. Those dioxins and furans, which notorious for all incinerators are excluded. Therefore, we proposed to fund "Skolkovo" to put the first plant for plasma chemical processing of municip
al solid waste on their territory. The parameters of the future city suit us. On average, a person produces about half a ton of garbage a year. If the population of Skolkovo will be 20-25 thousand people, as now planned, it is a plant with capacity of one and a half tons per hour will solve the problem of garbage disposal in full.
Such plasma chemical industries in the world yet. The existing plasma generators, says academician Rutberg, used on other technological principles and long obsolete. However, in St. Petersburg, already operates an experienced plazmogeneratornaya installation capacity of up to 200 kilograms of waste per hour, which is practiced by all processes.
There are also talks with foreign companies. Philipp Rutberg told that, for example, have shown interest Icelanders. The coastal waters of the island are contaminated household plastic — it brings Atlantic currents.
— Plastic as raw material for the plasma reactor is ideal. The larger plastic, the better. Because it is close to the energy content coal. That is all that plasma-chemical recycling of plastic that floats in the ocean, would be the best way to solve this problem.
The magazine "Kommersant Science», № 4 (4), 25.07.2011