Pyrolysis technology development pyrolysis, an ancient industrial production technology, the technology used in the first dry distillation of coal, the resulting coke products mainly as a smelting of steel fuel. With the development of modern industry, the application of the technology has been expanded, is used for heavy oil and coal gasification. In the early 1970s, the impact of the global oil crisis on the economies of the industrialized countries made people increasingly aware of the importance of developing renewable energy sources, which began to be used for the recycling of solid waste. Waste incineration: garbage perishable, the release of stench, resulting in difficult transportation and storage difficult; garbage in the chloride combustion of corrosive hydrogen chloride; incineration power generation efficiency of only 10-15%; produce dioxin; incineration ash containing Heavy metals, easily lead to secondary pollution. To this end, people carried out the waste pyrolysis, gasification research and practice.
Pyrolysis principle pyrolysis in the industry, also known as dry distillation, is the organic compounds in the absence of oxygen or oxygen under the conditions of the use of heat to the compound of the compound key broken by the large molecular weight of organic matter into small molecular weight fuel gas, liquid (Oil, grease, etc.) and coke and other solid residues in the process. (Organic acids, aromatics, tar) + solid (carbon black, slag) + organic liquids (organic acids, aromatics, tar) + solid (carbon black, slag) Compared with the incineration, the pyrolysis of the organic matter in the garbage into fuel gas, fuel oil and carbon black-based storage of energy, is the endothermic process; due to hypoxia decomposition, less exhaust, help to reduce the atmosphere Environmental pollution; waste sulfur, heavy metals and other harmful components are mostly fixed in carbon black, due to maintain the reductive conditions, Cr3 + will not be converted to Cr6 +; NOx less; pyrolysis equipment is relatively simple. The study shows that the amount of pyrolysis flue gas is 1/2 of incineration, NO is 1/2 of incineration, HCl is 1/25 of incineration, and dust is 1/2 of incineration.
Pyrolysis process Solid waste pyrolysis process is a complex chemical reaction process, including macromolecules bond fracture, isomerization and other chemical reactions. In the process of pyrolysis, there are two kinds of intermediate products in the process of change, on the one hand, from macromolecules into small molecules or even gas cracking process, on the one hand there are small molecules polymerized into a larger molecular polymerization process. The pyrolysis process includes lysis reaction, dehydrogenation reaction, hydrogenation reaction, condensation reaction, bridge bond decomposition reaction and so on. Different types of waste, different pyrolysis conditions, pyrolysis products are different. The proportion of plastic and rubber containing large waste of its pyrolysis products contain more liquid oil, including light naphtha, tar and aromatic hydrocarbon oil mixture. Living garbage, sludge pyrolysis products are less. Tar is a brown black oily mixture, from benzene, naphthalene, onions and other aromatic compounds to the main bitumen, and other containing free carbon, tar acid, tar base and paraffin, naphthenes, olefins compounds.