Instrument for benzene and toluene emission measurements of glycol regenerators

Abstract

We introduce an in-field and in-explosive atmosphere useable instrument, which can measure the benzene and toluene concentration in two gas and two glycol samples produced by natural gas dehydration units. It is a two-phase, on-line gas chromatograph with a photoacoustic spectroscopy based detector. The time resolution is 10 min per cycle and the minimum detectable concentrations are 2 mg m−3 for benzene, 3 mg m−3 for toluene in natural gas, and 5 g m−3 for benzene and 6 g m−3 for toluene in glycol. Test measurements were carried out at a dehydration plant belonging to MOL Hungarian Oil and Gas Company. Benzene and toluene emissions of gas dehydration unit are calculated from the measured values based on mass balance of a glycol regenerator. The relationship between the outdoor temperature and the measured concentration was observed which is caused by temperature-dependent operation of the whole dehydration unit. Emission decreases with increase of outdoor temperature.

Embedded system based data acquisition and control system for photoacoustic spectroscopic applications

“…In recent years the number of reported photoacoustic (PA) instruments to prove their applicability in various areas has been steadily increasing [1][2][3][4]. Amongst these instruments are those which were developed by our research group for various applications, including in the natural gas industry [5][6][7], airborne hygrometry [8][9], source apportionment of urban light-absorbing aerosols [10][11], measurements of gas permeability [12], and clinical research [13]. The main components of our instruments are basically always the same: a data acquisition and control system (DACS), one or more longitudinal differential detection cells [14], (a) modulated light source(s) which is/are either telecommunication-type diode lasers [15] or frequency converted Nd:YAG lasers [10] and gas handling units in various configurations.…”

“…In most cases, the DACS has various additional functions such as controlling the gas handling system and communicating with other instruments. Our recently developed systems [5][6][7][8][9][10][11][12][13] were based on a highly integrated target DACS. This system turned out to be one of the bottlenecks during the application developments due to its limited capabilities; therefore, a fundamental redesign of our DACS became essential.…”

Research on the influence of dimension and location of reflective film on the resonance frequency of quartz tuning fork

“…Photo-acoustic spectroscopy (PAS) is a unique spectral measurement method [1] that utilizes light absorption properties of the test object. The non-radiative deexcitation of energy absorbed by a sample is transformed into the heat energy due to the optical transitions.…”

“…Thus the effects of environmental and other frequency noise can be reduced for a narrow spectrum and a high qualityfactor.Therefore,it is suitable to be used as a detect ion sensor. The QTF dimensions are shown in Figure 2, where L is the total length of the tuning fork, 1 L is the length of the fork arms, h is the thickness of the arms, b is the width of the arms, and t is the gap between the arms. When the reflective film is pasted on the one arm surface of QTF, the direction of reflective film length is consistent with the thickness h of the arms.…”

Földgázipari káros emisszió mérésére, optimalizálására alkalmas műszerek fejlesztése

“…I have proved suitability of the further developed instrument under industrial conditions by measurements at a gas plant of MOL Plc. [87,88].…”