Experiments and 3D Molecular Model Construction of Lignite under Different Modification Treatment

Zhijun He,Jihui Liu,Shuang Qiu,Yaowei Yu

doi:10.3390/pr8040399

Zhijun He, Jihui Liu + Show 2 more

Open Access

https://doi.org/10.3390/pr8040399

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Abstract

In this paper, Huolinhe lignite was selected as the lignite experimental sample, using microwave modification and ultrasonic modification separately as improvement methods. The three-dimensional molecular models of HLH before and after modification were established base on the parameters obtained by 13C NMR, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy (Raman), and Fourier transform infrared (FTIR). After the microwave treatment, the methylene carbon in the HLH coal sample structure mostly exists in the form of long straight chains, and after microwave and ultrasonic treatment, the -OH content of oxygen atoms in the coal sample increases, and form the CO- and the COO-. The proportion is decreasing. The models were adjusted and tested by the covalent bond concentration method and carbon chemical shift spectra calculation using Chemdraw software. A new method is proposed to study the structure and physicochemical properties of lignite modification from the molecular point of view through this study.

Highlights

In recent years, the shortage of high-rank coal resources has gradually become a prominent problem in industrial development [1,2]
Arash Tahmasebi [5] discovered that the content of some functional groups in pulverized coal particles decreased significantly after microwave irradiation, but the content of aromatic carbon and aromatic ring in lignite was not affected by microwave pyrolysis
The molecular formula of the three structures was determined by elemental analysis

Summary

Introduction

The shortage of high-rank coal resources has gradually become a prominent problem in industrial development [1,2]. The existing research focuses more on the optimization of modification processes and proposes new modification processes The mechanism of these processes were difficult to study by experimental methods due to innumerable coupling reaction pathways during the utilization of lignite [8,9,10]. The two-dimensional molecular models of HLH before and after modification were established based on the parameters obtained by a series of detection methods, and three-dimensional model is constructed. The two-dimensional molecular models of HLH before and after modification were established based on the parameters obtained by a series of detection methods, and three-dimensional. A new method is proposed to study the structure and physicochemical properties of lignite modification from the molecular point of view

Experiment

Results

FTIR Structural Parameters Analysis

Peak of 13C

Nitrogen

Raman Results

Model Construction

Verification of Model

C NMR simulation spectra of the three models are in good agreement with

Adjustment of Model

Construction of 33- Dimensional

Conclusions