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Waste gas abatement a safer solution for solar

Hazardous materials and chemicals can make manufacturing photovoltaic solar panels dangerous work. But waste gas abatement systems are helping to improve safety throughout the production process.

Gas abatement technology can make manufacturing solar panels safer
Gas abatement technology can make manufacturing solar panels safer

The production of solar cells employs dangerous and environmentally harmful substances, which require abatement. German firm DAS Environmental Expert (DAS), said the solar industry’s entire process chain generates waste gases and waste waters that are contaminated at varying degrees with silicon or metal dusts.

Abatement is required by law. But with the drive for grid-parity putting the PV industry under high cost pressures, demand for standardised production processes and facilities is mounting.

DAS said: “The safety of the production line must be guaranteed at every step and in every operating situation.”

The Union of Concerned Scientists (USC) said: “The manufacturing of photovoltaic cells often requires hazardous materials such as arsenic and cadmium. Even relatively inert silicon, a major material used in solar cells, can be hazardous to workers if it is breathed in as dust.”

DAS says integrated abatement solutions for the photovoltaic industry are characterised by equally high proficiency in treatment of contaminated waste gases as well as waste waters. At the same time, all components need to harmonise and be compatible.

DAS specialises in developing point-of-use (POU) abatement technology. Critically, POU application ensures immediate abatement. However, rather than just relying on adapting equipment from other fields of use, the company says the technology develops specific solutions personalised to each customer’s application, while ensuring they are economical as well as reliable.

“Most of the volatile organic compounds do not only have bad odours, many of the substances are also toxic and harmful to the environment,” said DAS.

The company says organic compounds are used as auxiliary substances in the solar industry. They are essential for the production of printing paste that is used for the deposit of the strip line in the production of crystalline solar cells. This printing paste is deposited on the surface via screen printing, before the paste is baked in a special furnace. This is when the organic compounds condense and are exhausted into the Fab exhaust.

DAS says its JUNIPER system “reliably and cost effectively” solves this problem. It separates condensable organic compounds from exhausts in manufacturing plants of the photovoltaic industry.

JUNIPER is capable of handling waste gas flows up to 600m3/h. Due to its small footprint, the device can be installed in either the Fab’s basement, or in close proximity to the manufacturing systems where the dangerous vapors are generated.

Meanwhile, DAS has launched Styrax, a system designed specifically for disposing dangerous substances from chemical vapor deposition (CVD) process waste gases.

DAS says the CVD process, through chemical reaction during the gas phase, creates a thin layer on a substrate surface.

“The process uses a variety of gaseous substances that are in part toxic, highly flammable, highly explosive, or climate damaging,” the company says.

The system is based on burn/wet technology, during which waste gases are burnt from top to bottom. A fluid film prevents corrosion and deposition of particles in the reactor. In a washing column next to the reactor, reaction products are absorbed and particles suspended. The cooled and cleaned air is then released through the system’s roof.

Guy Davies, director of the company’s waste gas abatement business unit, said: “We specifically designed Styrax for typical applications in the semiconductor industry. However, we see many crossover applications in the photovoltaic industry that do not require large systems.”

DAS says the system runs on diverse fuel gases and scrubber liquids and is characterised by “a long maintenance cycle, high uptime, high abatement efficiency and is easy to maintain”. And, due to prolonged service intervals, it “provides the customer with lowering operating costs”.