In recent years, organic waste pyrolysis technology has been used more and more for its low pollution emission and high energy recovery rate. It can not only recover the metal in the PCB board, but also realize the resource utilization of the non-metallic components such as resin and glass fiber, which can be used to treat the waste PCB board.
Pyrolysis is a process in which the organic matter is heated to a certain temperature under the condition of oxygen or no oxygen, so as to decompose and produce gas, liquid (oil), solid (coke) and recover.
General process flow of PCB plate pyrolysis
First remove the components on the PCB board, and then crush the plate to a certain size into the reactor pyrolysis. Epoxy resin and other polymer materials are heated to a certain temperature under the protection of inert gas to produce thermal decomposition to produce low molecular weight materials. Condensation of the pyrolysis oil and gas from the reactor to obtain non condensable gas and liquid pyrolysis oil. The composition of metal and glass fiber does not change in nature, so it can be separated and recovered in the reactor as a solid residue.
The pyrolysis gases of pyrolysis products PCB were mainly composed of CO2, CO, HBr, lower aliphatic hydrocarbons and some low molecular weight aromatics. Pyrolysis gas has a certain calorific value, which can be used for heat recovery.
The composition of pyrolysis oil is complex, the boiling range is large, and the calorific value is high. Pyrolysis oil contains many valuable components, such as the reasonable recovery and utilization, which will greatly improve the economic efficiency of the whole pyrolysis process.
Recovery and utilization of pyrolysis oil
It is simple and feasible to use fuel as fuel when the scale is small and the oil production is low. Through the distillation of pyrolysis oil, get light naphtha, heavy naphtha, light oil gas and heavy oil and gas 4 fractions. High temperature has a high calorific value as low distillate fuel sold after moderate hydrogenation and deoxidation, dehydration at low temperature and light naphtha fractions of oil and gas can be used as the main component of gasoline and diesel oil recovery.
As an important organic chemical raw material, it is widely used in the fields of plastics, medicine, pesticide, dyestuff, paint and so on. These substances, such as the separation and extraction of the application, will be more valuable than pure fuel recovery. Wang Qing through the batch distillation experiment, explore the separation conditions of pyrolysis oil, isopropyl phenol and phenol in water, isopropyl phenol content of product obtained is not less than 90, with GB3079 - 1997 standard phenol. Iji and so on, using rotary kiln pyrolysis glass fiber reinforced epoxy resin waste, get high purity glass fiber, and it is used as epoxy resin polymer filler and insulation material recycling use, achieved good results.
