PEFTEC - Abstract

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Abstract Title: Direct determination of mercury concentration in crude oil, oil products, and hydrocarbon gases
Abstract Type: oral
Session Choice: Analytical Techniques:Elemental Analysis
Presenter Name: Mr Nikolay Ivanov
Company/Organisation: Lumex Analytics GmbH
Country: Germany

Abstract Information :

Detection and measurement of mercury in crude oil and natural hydrocarbon gas is a very important task due to technological and environmental issues. As a rule, natural hydrocarbons are a complex mixture of various organic and inorganic compounds. The conventional AA and AF analysis techniques necessarily involve the stage of mercury accumulation on a sorbent to avoid nonselective absorption and lower the limit of detection. The accumulation stage significantly increases the analysis duration and labor content.

The technique based on atomic absorption spectroscopy with Zeeman background correction (ZAAS) allows fast selective mercury determination in crude oil, naphtha, gas condensate, LPG, and natural hydrocarbon gas.

ZAAS complies with ISO and ASTM standards for mercury determination in natural gases. Furthermore, this technique enables direct continuous mercury monitoring in a gas flow. The limit of detection for direct analysis of methane gas is about 1-5 ng/m3 with response time of 1-10 sec. Direct determination of mercury in hydrocarbon gases was recently approved as a new Gazprom standard.

ZAAS facilitates the rapid determination of total mercury in crude oil using direct pyrolysis of liquid or solid samples. This versatile technology provides mercury speciation analysis of liquid hydrocarbons via measurement of volatile, water soluble (ionic), and particulate mercury. Experiments with continuous measurement of mercury in its gas phase releasing during gradual samples heating showed that it is possible to measure portions of mercury released during crude oil and condensate rectification.

A comparison of the crude oil, naphtha, LPG, and natural gas analysis data obtained using direct ZAAS and conventional gold trap based AAS, ICP, and INAA methods is given.