Enhanced CH4 Production from Corn-Stalk Pyrolysis Using Ni-5CeO2/MCM-41 as a Catalyst

Fang Huang,Meiting Ju,Weizun Li,Qidong Hou

doi:10.3390/en12050774

Abstract

Production of syngas from lignocellulosic biomass though pyrolysis is a promising solution for the large-scale utilization of biomass. However, current pyrolysis approaches suffer from the relative low product yield and selectivity, limiting their practical application. To solve this problem, a series of nickel-based catalysts including Ni/MCM-41, Ni-5CeO2/MCM-41, and Ni-5La2O3/MCM-41 were prepared and characterized by transmission electron microscopy (TEM), N2 adsorption–desorption, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and H2-temperature-programmed reaction (TPR) analysis. It was observed that the simultaneous addition of Ni and CeO2 to MCM-41 could increase the reducibility of Ni and the number of active Ni0 sites on the surface of the catalyst. Consequently, Ni-5CeO2/MCM-41 gave a CH4 yield of 14.6 mmol/g, which is remarkably higher than that (10.5 mmol/g) obtained in the absence of the catalyst. Meanwhile, the CO and H2 yields increased slightly, while the CO2 yield decreased slightly. Therefore, the improved CH4 yield and selectivity was mainly due to the increased decomposition of tarry compounds catalyzed by Ni/MCM-41 with the assistance of CeO2.

Highlights

According to Ministry of Agriculture of China, over 900 million tons of biomass stalk are produced every year in China, and around 60% of stalk is arbitrarily stacked, discarded, or burned as solid waste [1,2].The improper dispositions of lignocellulosic biomass caused serious air, soil, and water environmental problems
It was observed that the simultaneous addition of Ni and CeO2 to MCM-41 could increase the reducibility of Ni and the number of active Ni0 sites on the surface of the catalyst
Ni-5CeO2 /MCM-41 was prepared according to the following steps: firstly, 4.94 g of Ni(NO3 )2 ·6H2 O and 2.52 g of Ce(NO3 )3 ·6H2 O were added to 250 mL of deionized water to get a uniform solution, and 4.0 g of MCM-41 was added to the solution, followed by stirring for 1 h at ambient temperature

Summary

Introduction

According to Ministry of Agriculture of China, over 900 million tons of biomass stalk are produced every year in China, and around 60% of stalk is arbitrarily stacked, discarded, or burned as solid waste [1,2].The improper dispositions of lignocellulosic biomass caused serious air, soil, and water environmental problems. In order to alleviate these problems, the conversion of the biomass resource into alternative fine chemicals, bio-fuels, and novel materials is a sustainable and promising solution [3,4]. Numerous approaches, such as combustion, pyrolysis, pyro-gasification, fermentation, and catalytic conversion, were developed to convert biomass into value-added products [5,6,7,8,9,10]. Nickel-based catalysts are capable to reform tars and, decrease the need for their removal from producer gas [14]. Nickel-based catalysts are more economically viable than noble metals [15,16]

Methods

Results

Conclusion