Search

In this paper, we have investigated the chemical adsorption behavior of O 2 on five types of organic sulfur (thiol, sulfoxide, thioether, sulfone, and thiophene) in polycyclic aromatic hydrocarbon (PAH) sheets using density functional theory (DFT) calculations. Here, the adsorption energy of O 2 -organic sulfur exceeds that of O 2 -PAH. Sulfone tends to be more favorable for oxidation reactions than other organic sulfur compounds and PAH by energy gap and deformation charge density analyses. A large charge transfer occurs between O 2 and organic sulfur compounds by charge analysis. A radical distribution function (RDF) analysis shows that O 2 /CO 2 /N 2 is preferentially adsorbed on nitrogen/sulfur/oxygen-containing functional groups in coal. To inhibit the reaction of sulfur-containing coal with oxygen, the physical adsorption of pure gas (CO 2 /O 2 /N 2 ) and binary mixed gases (CO 2 + O 2 /N 2 + O 2 /CO 2 + N 2 ) is conducted at different temperatures and geological depths using molecular dynamics (MD) and grand canonical Monte Carlo (GCMC) simulations. The adsorption capacities of five types of organic sulfur with respect to the pure gases decrease with increasing temperature and increase with increasing depth. For O 2 /CO 2 , CO 2 /N 2 , and O 2 /N 2 binary gas systems, the order with respect to adsorption amount is CO 2 > O 2 > N 2 . The factor of adsorption capacities is also evaluated, and the results show that pore volume plays a key role in adsorption behavior.

Catalytic fast co-pyrolysis of biomass and plastic is an effective method to achieve high-quality bio-oil production. In this work, (Ni)-MCM-41 catalysts with different Ni loadings were prepared and characterized in detail by using a variety of advanced analytical techniques, and the effects on the catalytic performance were analyzed by micropyrolysis with gas chromatography mass spectrometry (Py-GC/MS) and thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR) methods. The results showed that an appropriate amount of Ni addition can effectively modulate the physicochemical properties of MCM-41. For a Ni loading of 25.1 wt % (Cat-C), the catalyst showed an optimal catalytic performance, a decrease in the proportion of oxygenated compounds in the product from 35.6 (MCM-41) to 13.4%, and an increase in the relative total amount of olefins plus aromatics from 62.2 (MCM-41) to 84.6%. The excellent catalytic performance of Cat-C can be ascribed to a balancing of its proper physical structural properties, appropriate acidity, strong metal-carrier interaction, high metal dispersion, and excellent compatibility balance between active and acidic sites., Competing Interests: The authors declare no competing financial interest., (Copyright © 2020 American Chemical Society.)