Automatic Optical Measurement and Control of Benzene and Benzenoids in Natural Gas Pipelines

Abstract

The presence of benzene and similar aromatic compounds in civil environments is due to anthropic actions but also to natural sources. Natural gas consists of a gas mixture where benzene and related compounds are usually presents. Thus, the detection of these compounds in natural gas pipelines is of the utmost importance as well as the control of the concentration level, which must remain below the limits consented by law. In this regard, it is of striking interest to engineer devices able to detect these compounds by automatic and continuous remote control. Here, we discuss the application of an optical device designed for the measurement of sulfured odorizing agents in natural gas pipelines aiming at the detection and the measurement of benzene, toluene, and xylenes (BTX) in the same contexts. The instrument consists of a customized UV spectrophotometer connected to an automatic control system able to provide in-field detections of BTX through a continuous and remote check of the gaseous mixture. Relatively to benzene, the instrument is characterized by values of LOD (level of detection) and LOQ (level of quantification) equal to 0.55 and 1.84 mg/Sm3, respectively. Similar limits are found for toluene and xylenes (LOD of 0.81, 1.05, 1.41, and 1.00 mg/Sm3 for toluene, meta-, ortho-, and para-xylene, respectively).

Research on Signal Feature Extraction of Natural Gas Pipeline Ball Valve Based on the NWTD-WP Algorithm

“…When reconstructing a single branch of the eight end node coefficients in the third layer of the wavelet decomposition structure tree, the signals in the frequency range of the corresponding single branch are extracted. L 30 represents the reconstructed signal of the end node coefficients low (3,0); H 31 is the reconstructed signal of the end node coefficients high (3,1); and so on for the rest of the nodes. The reconstructed signal to be analyzed, y(t), is shown in Equation (2).…”

“…Natural gas is the widespread energy source that is widely used for civil purposes due to its advantages in green environmental protection, economy, security, and reliability. Pipeline transportation has become the main means of transportation of natural gas by virtue of its advantages of low loss, safety, and reliability [ 1 , 2 , 3 ]. The high-parameter and large-diameter natural gas pipeline transportation system is constructed in order to improve the efficiency of natural gas pipeline transportation and reduce the costs of transportation.…”

“…L n1 represents the reconstructed signal of the end node coefficient low (n,1); H n2 is the reconstructed signal of the end node coefficient high (n,2); and the rest of the nodes are recursive. The reconstructed signal y(t) to be analyzed is shown in Equation (1), where y(t) is the original signal.…”