Low-temperature pyrolysis is the process where shredded waste is thermally decomposed. This process occurs at 400 to 850°C. The advantage of low-temperature pyrolysis, compared with conventional incineration, is, primarily, in its efficient prevention of environmental pollution.

Pyrolysis allows processing various waste components, such as for example tires, waste oils and plastics, sediments. There are no biologically active substances in the garbage after the low-temperature pyrolysis, so you can store the waste pyrolysis products without risk of harm to the environment. The produced ash has a high density and it substantially reduces the amount of garbage subject to further warehousing.

Thus, the advantages of low-temperature pyrolysis of solid domestic waste (SDW) include:

• easy storage and transportation of waste pyrolysis products

• a significant decrease in the volume of waste

• obtaining power that can be used for heating and electricity.

Units or plants involved in processing of SDW by means of  low-temperature pyrolysis, operate in many countries since the mid70s of the last century. It was the time when production of heat from rubber, plastic, and other wastes energy by low temperature pyrolysis was regarded as quite promising source of energy generation.

Japan has paid much attention to this technology. However, you must consider the fact that the countries with a developed technology of separated garbage collection strive to burn not all wastes by low-temperature pyrolysis, but only a certain part. Due to it efficiency of this method is much lower than in Russia, as our waste-processing factories burn mixed waste which contains many harmful substances.

First pyrolysis plants were built in Russia (in Kiev and Kazan) in the 70s. of XIX  century. Kerosene was mostly subjected to pyrolysis to produce gas for lighting. Later, it became possible to separate  aromatic hydrocarbons fromresin formed in the pyrolysis process. Pyrolysis has received extensive development during the World War I (1914-18) when there was a great need in toluene - raw materials for production of TNT.

After the invention of the process by German researchers Franz Fischer and Hans Tropsch , working in Kaiser Wilhelm Institute in 1920s, there was  a lot of improvements and amendments, and "Fischer-Tropsch" now applies to a large number of similar processes (’Fisher -Tropsch synthesis’ or ‘Fischer-Tropsch chemistry’)

The process was invented Germany (poor in oil, but rich in coal) in the 1920s to produce liquid fuels . It was used by Japan and Germany during World War II for production of alternative fuels.

The Fischer - Tropsch process is described in the following chemical equation

2 CH_4 + O_2 \rarr 4 H_2 + 2 CO
(2n+1)H_2 + nCO \rarr C_nH_{2n+2} + nH_2O

The mixture of carbon monoxide and hydrogen is called ‘synthesis gas’, or ‘syn-gas’. The obtained hydrocarbons are purified to obtain the desired product - synthetic oil.

Carbon dioxide and carbon monoxide are produced by partial oxidation of coal and wood fuel. This process benefits from ability to manufacture hydrogen or liquid hydrocarbons from solid materials such as coal, or solid carbonaceous waste of different kinds. Nonoxidative pyrolysis of solid materials produces syngas , which may be used directly as a fuel without  transformation as to. Fischer- Tropsch process may be used when liquid is required, similar to the fuel oil, grease or wax. Finally, if it is required to increase hydrogen production, steam shifts the reaction balance, resulting in production of carbon dioxide and hydrogen only. Fortunately, it is quite easy to shift  from gas to liquid fuels.