Hazards and purification technology of characteristic gases in commercial kitchens

Against the background of increasingly stringent global environmental protection supervision, the problem of characteristic gas pollution generated by commercial kitchens is receiving great attention from the international community. At the beginning of 2025, the "Urban Microenvironment Pollutant Report" released by the European Environment Agency clearly pointed out that gases such as volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) emitted by the catering industry have become an important source of urban photochemical smog and fine particulate matter pollution, among which restaurants, barbecue restaurants and other places have a particularly prominent contribution rate.

The characteristic gases in commercial kitchens mainly come from the cooking process. When barbecue restaurants grill meat over charcoal, high-temperature cracking of fat will produce polycyclic aromatic hydrocarbons such as benzopyrene. These substances have been listed as Class 1 carcinogens by the International Agency for Research on Cancer. Long-term exposure will increase the risk of respiratory cancer. During the stir-frying and frying process in restaurants, cooking oil and ingredients undergo oxidation and decomposition reactions at high temperatures, releasing volatile organic compounds such as aldehydes and ketones. These not only have a pungent smell, but also form photochemical smog with nitrogen oxides in the atmosphere under the action of ultraviolet rays, exacerbating urban air pollution.

In response to the hazards of these characteristic gases, a number of international regulations have been issued to control them. For example, the U.S. Environmental Protection Agency (EPA) has set strict limits on VOCs emissions in the catering industry, requiring new catering venues to install standard gas filtration systems; Tokyo, Japan, stipulates that barbecue restaurants and other venues must be equipped with purification equipment that can effectively remove polycyclic aromatic hydrocarbons, and regularly test and publicize emission data.

At the technical level, a mature solution has been formed for the filtration of characteristic gases in commercial kitchens. For large molecular organic pollutants such as PAHs, efficient activated carbon adsorption technology is a common method. High-quality activated carbon filter elements have a developed pore structure and a specific surface area of ​​1000-1500m²/g. They can firmly lock PAH molecules through physical adsorption, and the adsorption efficiency can reach more than 90%. At the same time, in order to avoid saturation failure of activated carbon, some advanced equipment is equipped with an adsorption saturation monitoring function, which can remind you to replace the filter element in real time.

For volatile organic compounds, photocatalytic oxidation technology performs well. This technology uses ultraviolet rays to irradiate titanium dioxide catalysts to produce highly oxidizing hydroxyl radicals, which can decompose VOCs molecules into harmless carbon dioxide and water. In practical applications, photocatalytic oxidation is often used in combination with electrostatic purification. The particulate matter in the gas is first removed by an electrostatic field, and then VOCs are decomposed by photocatalytic oxidation. The purification efficiency can be increased to more than 95%.

In a high-end restaurant renovation project in Berlin, Germany, a four-stage filtration system of "pretreatment + electrostatic purification + photocatalytic oxidation + activated carbon adsorption" was adopted. Before the renovation, the restaurant's VOCs concentration exceeded the local standard by 3 times, and the PAH concentration also exceeded the standard. After the renovation, the VOCs concentration dropped to below 0.5mg/m³, PAHs were almost undetectable, and the number of complaints from surrounding residents dropped by 100%.

Effective filtration of characteristic gases in commercial kitchens is not only a basic requirement for catering companies to comply with international environmental regulations, but also an important measure to protect the health of employees and surrounding residents. Choosing appropriate purification technology can reduce the harm of characteristic gases from the source and help the catering industry achieve green and sustainable development.