The average proportion of all odor/foul odor complaints in the chemical industry from 2018 to 2020 was 8.5%. In the past three years, the number and proportion of complaints in the chemical industry have shown a significant downward trend, with the number of complaints decreasing from 16315 in 2018 to 4937 in 2020, and the proportion of complaints decreasing from 10.7% in 2018 to 5.3% in 2020. This is related to the introduction of a series of policies and standards for VOCs control in recent years, as well as the increasing requirements for VOCs control in enterprises. However, due to the low odor threshold of odorous substances, even if VOCs control standards are met in industries such as daily chemical, fertilizer, and pesticide manufacturing, further in-depth odor control is needed to meet odor control requirements. There are many categories in the chemical industry, and in 2020, complaints mainly came from specialized chemical products, basic chemical raw materials, daily chemical products, fertilizers, pesticides, coatings, and ink manufacturing. Among them, there were 873 complaints about the manufacturing of daily chemical products, with 212 companies being complained about; There were a total of 820 complaints about fertilizer manufacturing, among which 534 companies were complained about, accounting for 7.2% of the total number of fertilizer manufacturing enterprises in China; There were a total of 578 complaints about pesticide manufacturing, involving 218 companies, accounting for 14% of the total number of pesticide manufacturing enterprises in China. The problem of odor pollution in the fertilizer and pesticide manufacturing industry is quite common.

The distribution of foul odors in chemical industrial parks is widespread, and the development of industrial parks has solved some long-standing problems of foul odor pollution. However, at the same time, some parks have caused large-scale and widespread pollution due to centralized production and emissions, leading to an increasing trend of foul odor pollution in the surrounding areas. Some areas have more prominent problems and have received widespread attention from the government and various sectors of society. Therefore, the current chemical industrial park needs to be able to monitor the odor and peculiar smell of the entire industrial park in a timely manner, achieve over limit warning, and combine relevant traceability analysis results to solve the gas pollution problem in industrial parks or odor pollution source areas. From the perspective of technical means, it can solve the problems of insufficient odor detection methods and inability to collect and retain samples in a timely manner, and solve the drawbacks of traditional gas sampling and detection.

Our company's German AIRSENSE online odor concentration monitoring system OLFOSENSE product can effectively monitor environmental atmospheric odors and odor monitoring. It consists of a combination of multiple sensor arrays, including 4 types of MOS metal oxide sensors, 1 type of PID photoionization detector, 2-4 types of electrochemical sensors, etc. Combined with AIRSENSE software, it has popular algorithms such as K-NN (Euclidean distance, Mahalanobis distance), DFA discriminant function analysis, PCA principal component analysis, LDA linear discriminant analysis, PLS partial least squares, etc. The results can display single gas concentration values of hydrogen sulfide/ammonia, VOC total organic volatile matter, or user selected single concentration values of odor gases (1-2 types), as well as dimensionless odor concentration OU values, on-site or remotely. The monitoring center can view real-time and historical monitoring data through the network. Hundreds of units have been installed nationwide, and the stability of the equipment is highly valued by customers.