Performance Analysis of TiO2-Modified Co/MgAl2O4 Catalyst for Dry Reforming of Methane in a Fixed Bed Reactor for Syngas (H2, CO) Production

Arslan Mazhar,Salman Raza Naqvi,Faisal Mushtaq,Muhammad Hassan,Abul Kalam Azad,Mustafa Anwar,Sehar Shakir,Rabia Liaquat,Asif Hussain Khoja

doi:10.3390/en14113347

Abstract

Co/TiO2–MgAl2O4 was investigated in a fixed bed reactor for the dry reforming of methane (DRM) process. Co/TiO2–MgAl2O4 was prepared by modified co-precipitation, followed by the hydrothermal method. The active metal Co was loaded via the wetness impregnation method. The prepared catalyst was characterized by XRD, SEM, TGA, and FTIR. The performance of Co/TiO2–MgAl2O4 for the DRM process was investigated in a reactor with a temperature of 750 °C, a feed ratio (CO2/CH4) of 1, a catalyst loading of 0.5 g, and a feed flow rate of 20 mL min−1. The effect of support interaction with metal and the composite were studied for catalytic activity, the composite showing significantly improved results. Moreover, among the tested Co loadings, 5 wt% Co over the TiO2–MgAl2O4 composite shows the best catalytic performance. The 5%Co/TiO2–MgAl2O4 improved the CH4 and CO2 conversion by up to 70% and 80%, respectively, while the selectivity of H2 and CO improved to 43% and 46.5%, respectively. The achieved H2/CO ratio of 0.9 was due to the excess amount of CO produced because of the higher conversion rate of CO2 and the surface carbon reaction with oxygen species. Furthermore, in a time on stream (TOS) test, the catalyst exhibited 75 h of stability with significant catalytic activity. Catalyst potential lies in catalyst stability and performance results, thus encouraging the further investigation and use of the catalyst for the long-run DRM process.

Highlights

The rising concerns over greenhouse gas (GHG) emissions on global warming and climate change has motivated many industrial production facilities to reconsider plans on how to effectively control and recycle GHGs to produce synthetic fuels [1,2]
Syngas is considered the primary feedstock in the production of some important liquid fuels, such as ammonia and methanol, and it can be used as an intermediate resource to produce H2, synthetic petroleum, and hydrocarbon products [3,4,5]
The catalytic reforming technologies for syngas production, such as the steam reforming of methane (SRM) [6], partial oxidation of methane (POM) [5], and dry reforming of methane (DRM) [7,8], have gained much importance in recent years [9,10]

Summary

Introduction

The rising concerns over greenhouse gas (GHG) emissions on global warming and climate change has motivated many industrial production facilities to reconsider plans on how to effectively control and recycle GHGs to produce synthetic fuels [1,2]. The development of a catalyst with a high catalytic performance and resistance to coking is an important objective [20]. In this regard, catalyst performance depends on active metal and support properties, their interaction, and their catalytic behaviour. The strong metal–support interaction between the TiO2 support and metal exhibited a high resistance towards coke deposition while increasing catalyst activity and Energies 2021, 14, 3347 stability. The combination of TiO2 and MgAl2O4 as co-supports and Co as an active metal could enhance the CH4 and CO2 activation, resist carbon formation, and aid stability. The spent catalyst was characterised by XRD, SEM-EDS, and TGA to analyse the carbon formation during the TOS and to present a possible reaction mechanism

Synthesis of MgAl2O4 and TiO2 Nanoparticles

Experimental Setup

Catalytic Activity Calculations

Characterization of Catalyst

Reaction Mechanism