Industrial emissions

Carbon oxides such as SO₂, NO₂ and CO, as well as hydrocarbons—compounds consisting of carbon and hydrogen—emitted from chemical industrial estates enter the human body via the respiratory tract and can seriously endanger human health. Acidic pollutants, along with SO₂, NO₂ and other substances, can also cause corrosion to industrial materials, equipment and building infrastructure, thereby adversely affecting the production, installation, commissioning and operation of precision instruments and equipment.

Furthermore, the monitoring and regulation of various parameters during industrial production processes are of paramount importance. Real-time online monitoring of process changes, detecting specific chemical substances or physical states to obtain process information such as reaction status, uniformity and concentration, can effectively optimise production stages, improve product quality and quantity, thereby achieving objectives such as reducing energy consumption and saving materials.

Take the ethylene cracking furnace as an example: ethylene is a commonly used raw material in the production of industrial goods and is itself an important petrochemical product, produced by the cracking of hydrocarbons at high temperature and low pressure. The feedstock for ethylene cracking is light oil; the crack gas produced consists of non-condensable gases such as hydrogen, nitrogen, oxygen, carbon monoxide and carbon dioxide, as well as hydrocarbons ranging from C1 to C6. The analysis of crack gas composition is of great significance for the control and adjustment of process parameters; amongst these, the ethylene yield is a key indicator for measuring the depth, capacity and efficiency of the cracking process, making its accurate measurement particularly important.

Sampling points for mass spectrometers can be positioned along industrial ethylene oxide production lines (top); comparison of data obtained from online dynamic sampling of industrial ethylene production (bottom)

Emissions of volatile chemical products (VCPs) enhance ozone formation and modulate urban chemistry. In addition to industrial emissions, the volatile chemical products (VCPs: volatile chemical products, such as perfumes, cosmetics, detergents and other everyday household items), are also a significant source of volatile chemical pollutants in urban atmospheres.

The ProC-TOF mass spectrometer mobile laboratory has conducted a more systematic study of the interrelationships between VCPs, traffic sources and urban population density.

The ProC-TOF clearly illustrates, based on mobile monitoring data spanning thousands of kilometres, the concentrations of anthropogenic VOCs in the areas surrounding various cities. These pollutants originate not only from common urban traffic sources (such as benzene and other aromatic hydrocarbons) and the household product indicator D5-siloxane (a common additive in skincare products), but also from monoterpenes. The latter generally originate from vegetation emissions and are also commonly used as fragrance additives in consumer products.

Monitoring of toxic volatile organic compound (VOC) leaks:

As long as chemical production facilities exist, there is a potential risk of toxic VOC leaks. Various types of sampling devices are available, including vacuum canisters (Summa canisters), VOC alarms, or purge-and-trap systems. The collected samples must be sent to an environmental laboratory for analysis.

Currently, many enterprises use electrochemical sensors to provide real-time indication of whether target molecules exceed predetermined concentration levels. Another quantitative method involves using open-path Fourier transform infrared spectrometers to determine whether VOCs remain within warning thresholds; however, neither of these technologies can provide the high temporal and spatial resolution required.

ProC-TOF Online Environmental Mass Spectrometer: This environmental mass spectrometer can monitor over 100 sampling points within 20 minutes and detect specific substances with an accuracy ranging from 0.01 to 1 ppm. Thanks to its speed and accuracy, it can monitor short-term leaks in all critical areas and provide accurate 8-hour time-weighted average exposure data.

Detectable Substances: Detection limits range from 0.01 to 1 ppm; detectable substances include:

Acetone, acetonitrile, acrylonitrile, benzene, butadiene, carbon disulphide, carbon tetrachloride, chloroform, chlorobenzene, cyclohexane, dichloromethane, dimethylacetamide (DMAC), dimethylformamide (DMF), dioxane, epichlorohydrin, ethylbenzene, ethylene oxide, Freon, hexamethyldisilane, hydrogen cyanide, bromomethane, methyl ethyl ketone, iodomethane, methyl isobutyl ketone, methyl methacrylate, 1-methyl-2-pyrrolidone, methyl tert-butyl ether (MTBE), propylene oxide, 2-isopropanol, styrene, tetrahydrofuran, tetrachloroethylene, toluene, trichloroethylene, vinyl acetate, vinyl bromide, vinyl chloride, xylene, etc.