Forced Unsteady State Operation of a Catalytic Converter during Cold Start-up for Oxidizing CO Over Pt/γ-Al2O3 Catalyst

Yogi Wibisono Budhi,Alimatun Nashira,Ade Kusuma Putri,M Shimada

doi:10.1051/matecconf/202133305003

Abstract

CO oxidation in the catalytic converter hasn’t showed best performance particularly during cold start-up, since the catalyst is not active during this period. The purpose of this experiment was to develop the forced unsteady state operation procedure of CO oxidation using 0.05%-w Pt/γ-Al2O3 and space velocity of 0.406 mmol/s/gram. The catalytic converter was gradually ramped-up, while introducing the feed gas containing CO in the air. The feed gas was modulated following a square wave model with switching time variation at 3, 6, 15, and 30 s and various operation modes. To gain the intrinsic reaction rate, the external mass transfer criterion was determined. Ramping-up the temperature from 50 until 150°C increased the CO conversion with different profiles between steady state and dynamic flow rate. The dynamic system with modulated CO feed flow gave lower light-off temperature and higher average CO conversion than the steady state system which gave light off temperature 115°C and average CO conversion of 48.86%. The switching time of 3 s gave highest average CO conversion during ramping-up, which was 79.35%. Meanwhile the dynamic operation system with modulated feed flow gave higher lightoff temperature and lower average CO conversion than steady state system.

Highlights

Environmental sustainability has been used as an indicator and a major concern of countries in the world nowadays as the huge increase of exhaust gas emission from various chemical industries and automotive vehicles (Shelef and McCabe, 2000)
The exhaust gas emissions from the automotive vehicle contain some types of substances that are harmful to human health and the environment, such as unconverted hydrocarbon (HC), carbon monoxide (CO), sulfur oxides (SOx), and nitrogen oxides (NOx) (Patel and Patel, 2012)
At the beginning of the reaction after the feed gas was introduced into the catalyst bed, the reactants were adsorbed over the catalyst surface

Summary

Introduction

Environmental sustainability has been used as an indicator and a major concern of countries in the world nowadays as the huge increase of exhaust gas emission from various chemical industries and automotive vehicles (Shelef and McCabe, 2000). The exhaust gas emissions from the automotive vehicle contain some types of substances that are harmful to human health and the environment, such as unconverted hydrocarbon (HC), carbon monoxide (CO), sulfur oxides (SOx), and nitrogen oxides (NOx) (Patel and Patel, 2012). Carbon monoxide is gas with high toxicity and highly harmful to human health such as circulatory system disorders (cardiovascular), nervous system (neurobehavioral effects), unconsciousness, and death as reported by Raub et al (2000). It was reported that 55-60% of CO gas emissions is caused by human activity emitted from automotive vehicles (Kašpar et al, 2003)

Methods

Results

Conclusion