ORIGINAL RESEARCH ARTICLE
DETERMINATION OF MERCURY IN ACID GAS TREATMENT PROCESS
AND ITS ENVIRONMENTAL IMPACTS
1,2
El-Feky, A.A.,
1,*
Mohamed B. Masod, and
1
Faramawy, S.
1
Egyptian Petroleum Research Institute, Cairo, Egypt
2
Department of Physics, College of Science, King Saud University, Saudi Arabia
ARTICLE INFO ABSTRACT
Mercury occurs naturally in unprocessed hydrocarbon streams, which can damage the equipment
and contaminate the treatment fluids as well as pose a health risk to workers and the environment.
Mercury was determined in all stream fluids for sweetening process (Benfield solution process)
and composition analysis also determined to evaluate the performance of the process. Fourteen
samples were collected from natural gas, Benfield solution, water, sludge and solid samples.
Mercury was measured on-site for gas streams using cold vapor atomic absorption (CV-AAS)
technique. Total Hg concentrations were measured for liquid streams and solid samples with AAS
after digestion with a different technique. Vent gases (composed mainly of carbon dioxide) have
high Hg concentration reached to 21.6 µg/Sm
3
for Train2, emitted to the atmosphere without
treatment. This study suggests that separate carbon dioxide and install Claus process for remove
H
2
S and periodically monitor Hg for the treatment process and environment. Moreover, mercury
contaminates the Benfield solution where the total Hg concentration of rich Benfield solution
reached to 175.4 ng/g for Train2 but the lean Benfield solution free of mercury due to the
regeneration process. Although water collected from reflux is condensed water, but it has high
mercury content reached 122.1 ng/g for train1. Finally, solid and sludge samples collected from
regeneration package contain mercury sulfide, which reached to 8.2 weight% of sludge sample.
Therefore, the workers when cleaning the vessel from solid and sludge must take all safety
precaution.
Copyright ©2017, El-Feky et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use,
distribution, and reproduction in any medium, provided the original work is properly cited.
INTRODUCTION
Natural Gas is a vital component of the world's supply of
energy and considered as an environmentally friendly clean
fuel, offering important environmental benefits when
compared to other fossil fuels. The superior environmental
qualities over coal and crude oil are the negligibility of sulfur
dioxide and carbon dioxide emissions. This helps to reduce
problems of acid rain and greenhouse gases (Mokhatab, 2006).
Egypt’s estimated proven gas reserves stand at 77 trillion cubic
feet (Tcf) and the fourth‒largest amount in Africa (EIA, 2015).
Natural gas is a mixture of hydrocarbon and non‒hydrocarbon
compounds (impurities). The hydrocarbon compounds
normally found in natural gas are methane, ethane,
*Corresponding author: Mohamed B. Masod,
Egyptian Petroleum Research Institute, Cairo, Egypt.
propane, butane, pentane, and small amounts of the heavier
hydrocarbons that are mainly hexane, heptane, and octane.
Some aromatics can also be present such as benzene, toluene
and xylenes. The non‒hydrocarbon gasses are nitrogen, carbon
dioxide, helium, hydrogen sulfide, water vapor, and other
sulfur compounds such as carbonyl sulfide and mercaptans
(Speight, 2007). Mercury is also being present in produced and
processed natural gas, hydrocarbon liquids and wastewater in
various forms. The mercury removal unit (MRU) must be
installed in gas plant even for the low concentration levels of
mercury, especially when the gas processing plant consists of
the aluminum heat exchanger. Raw natural gas must be
processed before moving into high pressure pipeline systems
for use by consumers. Natural gas processing means the
separation of undesirable components, such as water, acid
gases (CO
2
and H
2
S) and heavy hydrocarbons. This is in order
to facilitate its transportation and meet specifications for
commercial use.
ISSN: 2230-9926 International Journal of Development Research
Vol. 07, Issue, 11, pp.17246-17252, November, 2017
Article History:
Received 16
th
August 2017
Received in revised form
27
th
September, 2017
Accepted 03
rd
October, 2017
Published online 30
th
November, 2017
Available online at http://www.journalijdr.com
Key Words:
Mercury,
Carbon Dioxide,
Sweetening Process,
Vent Gas, Natural Gas,
Benfield Solution.
Citation: El-Feky, A.A., Mohamed B. Masod, and Faramawy, S. 2017. “Determination of mercury in acid gas treatment process and its environmental
impacts”, International Journal of Development Research, 7, (11), 17246-17252.
ORIGINAL RESEARCH ARTICLE OPEN ACCESS