Improving sulfur recovery operations with processes based on novel CO2 over SO2 selective membranes and its combinations with SO2 over CO2 selective membranes

A method for processing sulfur dioxide emissions from a sulfur removal unit for improved operating conditions when treated streams are recycled to the sulfur removal unit, the method comprising the steps of:

• introducing an SO2 emissions stream to an SO2 removal system, the SO2 removal system comprising an SO2 selective membrane, operable to separate sulfur dioxide and carbon dioxide, wherein the SO2 emissions stream is saturated with water and further comprises sulfur dioxide and carbon dioxide;
• separating sulfur dioxide and carbon dioxide in the SO2 removal system by the SO2 selective membrane;
• generating a CO2 removal system feed stream from the SO2 removal system;
• generating a low SO2 discharge stream from the SO2 removal system;
• introducing the CO2 removal system feed stream to a CO2 removal system, the CO2 removal system comprising a CO2 selective membrane, operable to separate carbon dioxide and sulfur dioxide;
• separating carbon dioxide and sulfur dioxide in the CO2 removal system by the CO2 selective membrane;
• generating an SO2 rich recycle derived from the CO2 removal system, such that the SO2 rich recycle has a higher concentration of sulfur dioxide than the SO2 emissions stream, and further such that the SO2 rich recycle has a lower concentration of carbon dioxide than the SO2 emissions stream;
• and
• generating a CO2 waste gas from the CO2 removal system.