Pyrolysis is a process of decomposition of raw materials (wood, household garbage, etc.) under the influence of temperature 450º and practically in the absence of oxygen. In this process, the formed pyrolysis gas, liquid products (wood tar, etc.) and solid products (charcoal).
The pyrolysis process is divided into several stages:
· drying, where fuel moisture is removed and it is prepared for the next stage;
· dry distillation or pyrolysis. Raw materials are burned at a certain temperature and lack of oxygen with the formation of gas, liquid and solid products. The first known use of pyrolysis carried out in the 19th century, the raw material was the wood of deciduous trees, and the сentral product of this combustion was acetic acid;
· the combustion residues occurs in the upper chamber of the boiler at a high temperature and absence of oxygen. Gases formed in the process, pass through a zone of high temperature and reaching the output of the box, mixed with secondary air.
In the process of pyrolysis of different amount of substances, it depends primarily on raw material and temperature at which the pyrolysis.
There are two types of pyrolysis:
1. Low-temperature pyrolysis takes place in the temperature range of 450 – 900º. The application process at these temperatures gives a little gas and a large number of resins and solids. With increasing gas temperature leads to much more.
2. High temperature pyrolysis is temperature controlled above 900º. At this temperature, the production of gas is maximum, and the number of other wastes are minimal. Therefore, high temperature pyrolysis more efficient and productive.
Any the unit the main element is the reactor. The reactor itself consists of a shaft furnace and svalsat. In the reactor are as follows, in the upper chamber receives raw materials where under the influence of temperature it is dried and warmed up. Further, the raw material under gravity through solsuite goes down, where the pyrolysis. To protect the environment from leakage of harmful substances, is a multi-phase cleaning process. First, from the reactor smoke is distilled in a waste heat boiler, then in a special dryer and finally get to the canister. After the canister is formed, the suspension is again returned to the dryer and have clean gases into the atmosphere.
Modern the unit is equipped with automation, so the process of pyrolysis of combustion easy to manage. Automated units are simple and convenient in operation, more economical and reliable.
Pyrolysis is used in the home for space heating and hot water, as well as in the industry to produce thermal energy, and various other chemical products. The disposal of solid waste in this way – it turns out waste and promote the rational use of natural resources. The products of this process are safe and environmentally friendly, they can be used as fuel or raw material in industry.