Influence of Temperature and Citric Acid Presence on Impurities Removal of Spent Catalyst from Naphtha Hydrotreater (NHT) Unit by Ultrasound Method
Henry Wicaksana, Marthin Nathanael P, Prida Novarita Trisanti, Sumarno
Departement of Chemical Engineering, Faculty Technology of Industry, Institut Teknologi Sepuluh Nopember Surabaya, Jl. Arief Rahman Hakim, Surabaya 60111, Indonesia
*onramus[at]chem-eng.its.ac.id
Abstract
In petroleum refining processes, such as naphtha hydrotreater (NHT) unit, catalysts are important components to improve the yield of high-quality product. These catalysts are susceptible to inactivation caused by adsorption of sulphur (S) and by metals impurities, such as iron (Fe) and arsenic (As) from the process in a certain time. But the replacement of deactivated catalyst requires a large cost, so the regeneration of catalysts can be an alternative to reduce these costs. And ultrasound is an effective method for regenerating catalysts because the operating conditions and solvents are more environmentally friendly. The effect of ultrasound temperature and presence of citric acid on impurities removal of spent catalyst NiMo was investigated in this study. The mixture of the spent catalyst and 1% citric acid (1/20 (w/v)) was treated by ultrasound at 20% amplitude, 20 minutes and various temperature (30–70°C). After process, solid product was analyzed using Scanning Electron Microscopy (SEM) and X-Ray Fluorescence (XRF). The liquid product was analyzed with Atomic Absorption Spectroscopy (AAS). The content of S was decreased after ultrasound (from 17.3% to 3.8%). The optimum condition was achieved at 50°C and 20 min. Based on AAS analysis which showed Fe composition 73,20 ppm.
Keywords: Citric acid, Deactivation, Regeneration, Spent catalyst, Ultrasound
Topic: Materials Science