Guard Bed Material Development For Impurities Removal From Petroleum Feedstock

Abstract

Crude oil consist of impurities such as nitrogen, sulphur, metals, silicon etc. Nitrogen, sulphur and metals removal process are very deeply explore. Apart from above stated impurities halide and acid containing compounds causes corrosion problem in the pipe lines, reactors which contributes to catalyst deactivation. Corrosion is prevented by using phosphorus containing corrosion inhibitors. These chemicals form thin layer in between stream and metallurgy. During downstream processes of such streams can cause problem related to catalyst deactivation, lumping and pressure drop. Due to these reasons phosphorus removal from stream has become a research topic in recent year. Adsorbents are used for removal of impurities from hydrocarbon stream. There are mainly three adsorbents to remove phosphorus i.e., alumina, bentonite clay and magnesium silicate. Current research work will be on the synthesis, modification, characterization and evaluation of above adsorbents for phosphorus and other metal impurities. On the basis of literature survey, mainly four adsorbents were used for removal of phosphorus from petroleum feedstock. The adsorbents were characterized by X-Ray diffraction to identify the crystal structure and phases, BET surface area to find out the physical properties of adsorbents and Temperature Programme Desorption to know the strong and weak active sites. The adsorbents were evaluated through batch reactor and continuous reactor for adsorption process between adsorbents and petroleum feedstock (kerosene). Analysis of adsorbents were done by Fourier Transform Infra-Red to find out the quantity of phosphorus in liquid products and in feed, Induced Coupled Plasma was used to know the exact concentration of phosphorus in feed and on adsorbents, Nuclear Magnetic Resonance was used to identify the chemical shift of compounds and to identify the adsorption type (physical and chemical) on the adsorbents. The results of Fourier Transform Infra-Red, Induced Coupled Plasma and Nuclear Magnetic Resonance shows that the iron alumina and magnesium silicate adsorbents are the promising candidates for the removal of phosphorus from petroleum feedstock. Induced Coupled Plasma gave ~98% of phosphorus removal from feed and the adsorption capacity for trapping of phosphorus on iron alumina is 18% and magnesium silicate is 11%. The parametric studies was done through various parameters such as temperature, concentration and different adsorbents. The adsorbents studies were completed by using batch reactions, continuous reactions, adsorbent capacity and recycle data. The scope of this thesis is to understand the effect of adsorbents for phosphorus removal.