Abstract

Abstract Calcium-looping process was simulated by solution of one-dimensional mass and energy balance equations for both interconnected fluidized bed reactors. Kinetics for the carbonator and calciner were derived from literature sources and were revised to include the effects of sulphation. The degree of apparent carbonation was compared to the actual level of carbon dioxide removal through a series of sensitivity analyses. It has been found that carbonation decreases with an increase in temperature. Sulphation increases with an increase in temperature. The activity of calcium oxide decreases with an increase in carbonation–calcination cycles. Neglecting the effect of sulphation during the design of the calcium-looping system leads to overestimation of active calcium particles that will react with carbon dioxide.

Highlights

  • 1.1 Background The commencement of industrialization saw the marked increase of greenhouse gases in the atmosphere compared to pre-industrialization levels

  • Calcium sulphate has a greater molar volume than calcium oxide, resulting in a sulphated layer forming on the outside of the particle, which prevents the uptake of carbon dioxide by the calcium oxide further inside the particle

  • The majority of the models proposed in literature have concluded that the calcium particles that react in the fast regime influence carbonator efficiency

Read more

Summary

INTRODUCTION

1.1 Background The commencement of industrialization saw the marked increase of greenhouse gases in the atmosphere compared to pre-industrialization levels. There are various methods of capturing greenhouse gases from the atmosphere, which include separation with sorbents or solvents, separation with membranes and separation by cryogenic distillation. In this project, the modelling and simulation of a calcium looping system for carbon dioxide removal from flue gases was considered. The calcium-looping method was proposed in 1999 (Shimizu, et al, 1999)and it is a method for carbon dioxide capture from flue gases using two coupled fluidized-bed reactors. It has been proposed in literature to design a model that considers the actual activity of the calcium particles in the system according to their carrying capacity, regardless of their preceding history of partial or full carbonation-calcination cycles. The heat exchanger design for the system is included in the chapter

LITERATURE REVIEW
Adsorption
Membrane separation
Carbonator
Sulphation
Sintering
MODEL DEVELOPMENT
Introduction
Effect of temperature
Bed mass versus number of carbonation-calcination cycles
Effect of changing carbon dioxide concentration in the flue gas
The mean temperature
Shell-side heat transfer coefficient
Findings
Conclusions and Recommendations
Full Text
Published version (Free)

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call