Performance analysis of the gasification of spent pot lining (SPL) carbonaceous solid waste materials generated from the primary aluminum industry

Abstract

Spent pot lining (SPL) is a one of the most important carbonaceous solid waste generated by the primary aluminum industry during the manufacture of aluminum metal in electrolytic cells. The main objective of this study is to investigate the gasification performance of SPL to produce alternative syngas fuel. SPL gasification process model using Aspen plus software based on thermodynamics equilibrium approach was developed. The operating conditions of the gasifier were: gasification temperature of 900 °C, equivalence ratio of 0.3 and air is used as the oxidizing agent The investigation was carried out on four different grades of SPL: raw SPL, water washed SPL, alkali treated SPL and final treated SPL. Based on the gasification modelling and the simulation results, it was noticed that SPL gasification facilitates the formation of synthesis gas; mainly the formation of CO to a certain extent but with a low concentration of H2. Compared with conventional fuel (coal) gasification, the alkali treated SPL gasification recorded the ideal performance than that of other SPL fuels with values of hydrogen (H2), carbon monoxide (CO), cold gas efficiency (CGE), and carbon conversion (CC) of 1.43%, 41%, 58.5%, and 96.9%, respectively. The results show that the alkali treated, and final treated SPL materials can be used to produce alternative syngas fuel to displace fossil fuels.

Keywords

• gasification
• spent pot lining (spl)
• modelling
• simulation
• alternative fuels