Solar panel recycling methods and equipment

Time：2022-12-12 16:16:30

In the electronic waste market, the number and scale of end-of-life solar panels is still insignificant, but its growth rate is the fastest. The industry is concerned that as the global green transformation accelerates and deepens, solar energy applications are becoming more and more widespread, and the disposal of the huge number of end-of-life panels will then become an unbearable burden for the solar industry. Usually in the case of maintenance to get, solar panel life can reach 25-30 years, or even longer. However, with the development of the solar industry, some cheap solar panels on the market may fail in as little as 5 years. But at the same time, because solar panels contain a lot of renewable materials such as glass, silicon, and aluminum, recycling of solar panels is on the agenda.

Solar panel recycling methods:

When recycling used photovoltaic modules, the modules need to be disassembled and the aluminum frame, glass and junction box removed to get the silicon wafers. Effective recycling methods for complete wafers include the "inorganic acid dissolution method" and the "heat treatment method". The latter is divided into "fixed vessel heat treatment" and "fluidized bed reactor heat treatment".

Inorganic acid dissolution method: nitric acid and nitrogen peroxide through a mixture of acid, under certain temperature and environmental conditions, after such a period of time to dissolve EVA, and glass industry classification. This method can maintain the integrity of the crystalline silicon wafer, but we need to further analysis of the silicon wafer structure processing.

Stationary vessel heat treatment: The pv module is placed in an incinerator with the reaction temperature set at 600 ° c for incineration. After combustion, the cells, glass and frames are separated by hand. The plastic material is completely incinerated by converting the various recycled materials to the appropriate recycling process.

Organic acid dissolution method: dissolving eva with organic solvents for the purpose of separating cell, eva sheet, glass sheet and backsheet. This method requires a long reaction time of about 7 days. In addition, eva swelling breaks the cell sheet and there is also the problem of organic waste liquid disposal, so this method is still in the laboratory research stage.

Physical separation method:The aluminum frame and junction box of the module are removed first, and then the frameless module is crushed to separate the tinned solder tape and glass particles, and the rest is ground again to get the metal, silicon powder, backsheet particles and EVA particles through electrostatic separation method. This is a more common and efficient way of recycling.

Processing process of waste photovoltaic panels:

One step is to disassemble the glass from the PV panel;

The second step is to disassemble and take off the backsheet and wires;

Three steps will be broken components, to remove the outside of the tempered glass;

The fourth step is the pyrolysis, the main purpose of this step is to dissolve the EVA;

This process enables 95% of the material in crystalline silicon PV panels to be split, sorted, processed and recycled: 2/3 of the glass is recycled into broken glass and sent to glass manufacturing plants; the aluminum frames are sent to aluminum refineries; the waste plastic can be used as fuel in cement plants; the recovered silicon can be reused in the precious metals industry; the remaining cables and connectors are crushed and sold in the form of copper beads. The end-of-life photovoltaic panels are disposed of in the interest of recycling.