Thermal treatment of Shengli lignite and subsequent oxidation

Li, Ya; Zong, Zhi‐Min; Zhang, Yangyang; Wei, Xian‐Yong; Zhu, Yu

doi:10.1016/j.jaap.2020.104810

Cited by 3 publications

(3 citation statements)

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“…LRCs inherently contain abundant aliphatic structures and oxygen-containing functional groups, which are helpful for their oxidation. Therefore, it is promising for producing carboxylic acids by oxidation of LRCs [5][6][7]. Benzene carboxylic acids (BCAs) are the fundamental raw materials for developing novel chemical materials and high value-added fine chemical products [8,9].…”

Section: Introductionmentioning

confidence: 99%

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Insight into Relationship between Thermal Dissolution of Low-Rank Coals and Their Subsequent Oxidative Depolymerization

et al. 2021

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Oxidative depolymerization of low-rank coals is promising for obtaining benzene carboxylic acids (BCAs). However, it is hindered by the low yield of BCAs along with a large number of alphatic acids. Thermal dissolution could modify the physico-chemical structural features of low-rank coals, which is expected to improve the oxidation of LRCs. In this paper, lignite and subbituminous coal were firstly subjected to thermal dissolution with cyclohexane at 250 °C for 2 h. Then, the raw coal and the corresponding thermal insoluble portion (TIP) were oxidized by NaOCl under the same conditions. The residual yields of TIPs oxidation were both lower than those of raw coals oxidation, indicating that TIPs were more easily oxidized than the raw coals. The yield of BCAs obtained by TIPs oxidation was above 19% higher than that from the oxidation of raw coals. Meanwhile, the selectivity of BCAs was improved in the resulting oxidation products from TIPs compared with that from the raw coals. The relationship between BCAs generation and thermal dissolution of low rank coals was investigated by ultimate analysis, Fourier transform infrared spectroscopy, and nitrogen adsorption-desorption analysis. The results suggested that thermal dissolution could enrich aromatic portion in the remaining TIPs, resulting in an increasing of the yield and selectivity of BCAs. Simultaneously, thermal dissolution raised the specific surface area and expanded the looser space structure of TIPS, which were beneficial for the sufficient collision between aromatic structures and oxidant, facilitating the oxidative depolymerization of TIPs. This investigation would provide a novel route for promoting BCAs production by mild oxidative depolymerization of low-rank coals.

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Section: Introductionmentioning

confidence: 99%

“…With increasing coal ranks from lignite to anthracite, the yield of BCAs and the selectivity of BCAs gradually increase. Therefore, enhancing the aromatic portions in LRCs through pretreatments would facilitate the generation of BCAs [6,7].…”

Section: Introductionmentioning

confidence: 99%

Insight into Relationship between Thermal Dissolution of Low-Rank Coals and Their Subsequent Oxidative Depolymerization

et al. 2021

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“…As for the molecular groups, Fourier transform infrared spectroscopy (FTIR) is a quick and helpful technique to investigate the molecular groups of fossil fuels. FTIR can recognize vibrational signals to identify the functional groups on the surface of fossil fuels. , In addition, X-ray photoelectron spectroscopy (XPS) can analyze the chemical property and quantitatively determine the content of functional groups of fossil fuels. ,, Thus, FTIR and XPS have been broadly applied to reservoirs to reveal their molecular groups. ,− For example, Wang et al (2017) performed FTIR to identify the molecular groups of coal dust. The results show that aromatic groups and aliphatic groups repel water, while the hydroxyl groups and carboxyl groups absorb water .…”

Section: Introductionmentioning

confidence: 99%

Unveiling the Changes in the Molecular Groups of Tight Sandstones in Response to an Electric Field

et al. 2021

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The electric field method proved in the lab and oil fields is an effective and fast way to significantly improve oil recovery, which can be applied to greatly realize the urgent-need requirements for energy, especially in tight sandstones. Generally, the changed molecular groups treated with an electric field modulate the wettability of reservoirs, affecting the final oil recovery. Herein, the investigation of the impact of the electric field on the molecular groups of reservoirs is imperative and meaningful. In this paper, tight sandstones were placed into a particular instrument and subjected to various strengths of the electric field. Nine treated powders and one untreated powder of tight sandstones were processed by Fourier transform infrared spectroscopy (FTIR) and Xray photoelectron spectroscopy (XPS) experiments. FTIR results show that the electric field decreases aromatic groups, C−O groups, COOH groups, and aliphatic groups, whereas it increases CC groups, CO groups, and OH groups. Interestingly, the changes in C−O groups, CO groups, COOH groups, and OH groups are all the competitive results of production and consumption during the treatment process. With regard to C−O groups and COOH groups, the consumption has an advantage over the production on the content of functional groups, and the situations for C=O groups and OH groups exhibit a contrary trend. The fitted result of XPS proves the fact that the electric field improves CO groups, OH groups, and COOR groups, whereas it reduces C−O groups, supporting that the molecular groups can be mutually transformed during the electric field treatment. The obtained knowledge is beneficial to the study of electric field-related technologies on the molecular groups of reservoirs.

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Effect of pyrolysis on Zhaotong lignite oxidation with aqueous sodium hypochlorite

Wang

Shen

et al. 2021

Carbon Resources Conversion

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Thermal treatment of Shengli lignite and subsequent oxidation

Cited by 3 publications

References 32 publications

Insight into Relationship between Thermal Dissolution of Low-Rank Coals and Their Subsequent Oxidative Depolymerization

Insight into Relationship between Thermal Dissolution of Low-Rank Coals and Their Subsequent Oxidative Depolymerization

Unveiling the Changes in the Molecular Groups of Tight Sandstones in Response to an Electric Field

Effect of pyrolysis on Zhaotong lignite oxidation with aqueous sodium hypochlorite

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