Electroremediation of deactivated catalysts from fluidised catalytic cracking for vanadium removal - the effect of a dual cathode chamber reactor

Abstract The aim of this study was to evaluate the quantity of vanadium removed through electrokinetic remediation applied to catalyst waste used in a fluid catalytic cracking process. In excess, vanadium affects process efficiency by reducing the catalyst’s activity, causing deactivation and reducing its useful life in petroleum cracking during refining. The electrochemical reactor used was composed of an extra cathode chamber coupled with an ion-selective cation exchange membrane, Nafion ®. The function of the cathode chamber was to increase the overpotential for a hydrogen reduction reaction (HRR) and the electric field to favour metal ion removal. Sodium citrate was used for electrolyte remediation (complexing vanadium) at 0.5 mol/L with an 11.0 V (ε =0.5 V/cm) potential applied. The treatment efficiency was analysed based on the vanadium ion concentration in the electrolyte collected. The results show that electrokinetic remediation using the dual cathode chamber yielded more metal removal and lower energy consumption.

摘要 本研究旨在评估流化催化裂化（fluid catalytic cracking）过程所用催化剂废料经电动修复（electrokinetic remediation）后所去除的钒总量。钒含量过高会降低催化剂活性，引发催化剂失活并缩短其在炼油石油裂化工序中的使用寿命，进而对工艺效率造成不利影响。本研究采用的电化学反应器由附加阴极室与阳离子选择性离子交换膜（ion-selective cation exchange membrane）Nafion ®耦合组成。该阴极室可提升氢还原反应（hydrogen reduction reaction, HRR）的过电位，并强化电场以促进金属离子脱除。实验以0.5 mol/L的柠檬酸钠作为修复电解液（用于络合钒），并施加11.0 V（电场强度ε=0.5 V/cm）的电位。研究通过分析收集到的电解液中钒离子浓度，对修复处理效率进行了评估。结果显示，采用双阴极室的电动修复工艺可实现更高的金属脱除率与更低的能耗。