Application of a New Method in Identifying the Sludge Deposits from Refineries and Gas Plants: A Case of Laboratory-Based Study

Abstract

This article reports the application of a new method in identifying the accumulated sludge deposits (e.g., oily sludge, water sludge, and filter sludge). The method is an excellent approach for identifying the inorganic materials found in sludge deposits generated in refineries and gas plants. The phase identification and quantification on inorganic material in the form of corrosion products are important to facilitate chemical cleaning and prevent the reoccurrence to stop the generation of sludges. Therefore, the authors developed a new method to separate the inorganic materials from the hydrocarbon of the as-received sludge samples from the fields. When the sample preparation was taken with great care, the results revealed that this method is fast and can accurately identify very small quantities (>0.5 wt%) of sludge deposits present in the sample. Additionally, if the color of the dichloromethane soluble part collected is changed, it indicates the presence of hydrocarbon in the sludge. Thermal gravimetric analysis results revealed that the sludge contained approximately 3 wt% of inorganic compound, 25 wt% of water, and 72 wt% of hydrocarbon. Subsequently, gas chromatography mass spectrometry analysis results revealed that the type of hydrocarbon was diesel with the C10-C27.

Characterization of Sludge Deposits from Refineries and Gas Plants: Prerequisite Results Requirements to Facilitate Chemical Cleaning of the Particular Equipment

“…Clay minerals normally found with sandstone materials [2] along with the type of hydrocarbon that presents at the sludge deposits can guide the engineers at the affected refinery and gas plants to overcome the problems by devising appropriate corrective procedures. The main objective of the present study was to extend the new method developed by Sitepu, Al-Ghamdi, and Zaidi (2007) [1] to particularly and accurately examine the phase composition of inorganic materials (non-soluble or nonhydrocarbon) that were built up in the different equipment at refineries and gas plants -(a) a regeneration overhead acid gas condenser located at the low-pressure gas treating unit, (b) water draw-off pumps suction strainer for pumps and water recycle pump in a gas plant, and (c) condenser, inside vessels of inlet head, and head coiler tube of the sulfur recovery unit (SRU) -using advanced XRD [3][4][5][6][7][8][9] and Rietveld method [10][11][12][13][14][15][16][17][18], which are well-known techniques, both for identification of phases and for the quantification [19][20][21][22][23][24] of all the identified phases. Subsequently, when the types of International Journal of Corrosion 3 the hydrocarbon were required by the field engineers for the particular deposits, the authors independently analyzed the dichloromethane soluble part.…”

“…The sludge deposits that frequently accumulate inside the equipment used in the oil industry can cause failures and temporarily shut down the refinery and gas plants [1]. Sitepu, Al-Ghamdi, and Zaidi (2017) successfully experimented to separate the inorganic materials (i.e., the insoluble part or non-hydrocarbon) from the hydrocarbon (dichloromethane soluble part) of the sludge deposits that were collected from the diesel oil tank in a refinery and accurately identified and quantified the very small quantity of inorganic materials, Figure 1.…”

“…Sitepu, Al-Ghamdi, and Zaidi (2017) successfully experimented to separate the inorganic materials (i.e., the insoluble part or non-hydrocarbon) from the hydrocarbon (dichloromethane soluble part) of the sludge deposits that were collected from the diesel oil tank in a refinery and accurately identified and quantified the very small quantity of inorganic materials, Figure 1. They showed that the X-ray powder diffraction (XRD) data consisted of iron oxide corrosion products in the form of goethite [FeO (OH) Zaidi (2017) [1] showed the relationship between their XRD phase identification results of the sludge samples that were generated in the particular equipment in refineries and gas plants, and the nature of the corrosion and scale products, Table 1.…”

“…Subsequently, Sitepu, Al-Ghamdi, and Zaidi (2017) [1] described that the gas chromatography mass spectrometry (GCMS) analysis results of the hydrocarbon (dichloromethane soluble part) showed diesel with the carbon range (C10 to C27), which suggests the minor portion of the oil-based type of sludge deposits was a diesel. Additionally, thermal gravimetric analysis (TGA) yielded that weight percentage (wt%) of inorganic compound, water, and hydrocarbon soluble were 3 wt%, 25 wt%, and 72 wt%, respectively.…”

“…Additionally, thermal gravimetric analysis (TGA) yielded that weight percentage (wt%) of inorganic compound, water, and hydrocarbon soluble were 3 wt%, 25 wt%, and 72 wt%, respectively. Knowing which phases and their wt% were involved in the inorganic 2 International Journal of Corrosion Table 1: Summary of the identified phases of the inorganic materials (i.e., the insoluble part or nonhydrocarbon) separated from the hydrocarbon (dichloromethane soluble part) of the sludge deposits, and its nature [1].…”