Behzad Ajamian - South Pars Gas Complex (S.P.G.C), Asalouyeh, Iran- Department of chemical engineering, Shahrood Branch, Islamic Azad University, Shahrood, Iran
Aliakbar Paraj - Department of chemical engineering, Shahrood Branch, Islamic Azad University, Shahrood, Iran
Bahman Mikaeili - South Pars Gas Complex (S.P.G.C), Asalouyeh, Iran

In fifth refinery of south pars gas complex, inefficiency of the filtration equipment is caused to severeaggregation of various precipitations with waxy forms in MEG regeneration unit packages. The mentionedproblems have serious damages to the internal packages body such as distillation columns, trays, reboilersand meshes. Such damages result in decreasing of heating efficiency of exchangers, reflux problems incolumns, producing purification percentage of lean MEG and pitting corrosion which are finally causedemergency shutdown and performing of maintenance overhaul for packages in during maximum sixmonths period time for at least 2 out of 6 MEG regenerator packages. Instrumental analyses were appliedfor characterization of sedimenated precipitations, their nature and origins. The obtained results are givenrespectively from thermal decomposition method to determine the hydrocarbons weight pecentage inprecipitations; inductively coupled plasma- optical emission spectroscopy (ICP-OES) which isdemonstrated elements of periodic table; X-ray diffraction (XRD) analysis is presented crystallographicstructure; Gas chromatography–mass spectrometry (GC-MS) for quantifying hydrocarbons compounds;Also, field emission scanning electron microscopy (FESEM) is applied to determine of shape and size ofsedimenated precipitation components. According to obtained results, the origin and nature of thesedimenated precipitation found.

MEG regeneration, Precipitations, Analytical methods, XRD, ICP-OES, GC-MASS