Method of catalytic oxidation of lignite using oxygen as oxidant at atmospheric pressure

Patent metadata

Field	Value
Publication number	US-10160712-B2
Application number	US-201615548100-A
Country	US
Kind code	B2
Filing date	Dec 7, 2016
Priority date	Jun 1, 2016
Publication date	Dec 25, 2018
Grant date	Dec 25, 2018

Abstract

A method of catalytic oxidation of a lignite using oxygen as an oxidant at atmospheric pressure is provided. The method includes the following steps, pulverizing the lignite to 200-mesh or less; drying the pulverized lignite at a temperature of 80° C. in vacuum for 10 h; weighing 0.5 g of the dried lignite and sequentially adding 10 ml of acetic acid, 0.5 mmol of a catalyst and 0.15-0.25 mmol of a cocatalyst into a round-bottom flask filled with the oxygen, keeping oxygen pressure at 0.1 MPa, reacting at a temperature of 80-120° C. for 4-12 h; using oxygen as the oxidant to catalytically oxidize the reacted lignite at an atmospheric pressure of 0.1 MPa; filtering after the reaction is finished; decompressing the filtrate to remove the acetic acid, adding a small amount of ethyl acetate to dissolve, and using an excess CH 2 N 2 /ether solution to esterify for 10 h at room temperature; and analyzing the esterified product through a gas chromatography-mass spectrometer.

First claim

What is claimed is:

1. A method of catalytic oxidation of a lignite using oxygen as an oxidant at atmospheric pressure for mildly oxidizing the lignite using the oxygen as the oxidant under the action of a N-hydroxy amide catalyst and a metal salt or a metal oxide cocatalyst, comprising:
pulverizing a lignite to 200 mesh or less;
drying the pulverized lignite at a temperature of 80° C. in vacuum for 10 h;
weighing 0.5 g of the dried lignite;
sequentially adding 10 ml of acetic acid, 0.5 mmol of the N-hydroxy amide catalyst, and 0.15-0.25 mmol of the metal salt or the metal oxide cocatalyst into a round-bottom flask,
wherein the N-hydroxy amide catalyst is one of compounds consisting of N-hydroxy o-sulfonyl benzimide, N,N-dihydroxy pyromellitic diimide, 1,3,5-trihydroxyisocyanuric acid, N-hydroxy-N-methylbenzamide, 3,5-dinitro-N-hydroxy-N-methylbenzamide, and 1-hydroxy-2,2-diphenyl-3-indolone, wherein the structures of the compounds are as follows:

and
wherein the metal salt or the metal oxide cocatalyst is one of cobalt acetate, manganese acetate, copper acetate, iron acetate, and manganese dioxide;

connecting a tee joint to an upper orifice of a condenser pipe, replacing oxygen in vacuum for three times to fill the round-bottom flask with the oxygen and keeping the oxygen pressure at 0.1 MPa, and then reacting at a temperature of 80° C.-120° C. for 4-12 h and observing the reaction conditions;
using the oxygen as the oxidant to catalytically oxidize the lignite at an atmospheric pressure of 0.1 MPa;
filtering after the reaction is finished;
decompressing the filtrate to remove the acetic acid, adding a small amount of ethyl acetate to dissolve, and using an excess CH 2 N 2 /ether solution to esterify for 10 h at room temperature; and
using a 0.45 μm filter paper to filter, and analyzing the esterified product through a gas chromatography-mass spectrometer.

2. The method of the catalytic oxidation of the lignite using oxygen as the oxidant at atmospheric pressure according to claim 1 , wherein the amount of the lignite is 0.5 g, the amount of the N-hydroxy amide catalyst is 0.5 mmol, the amount of the metal salt or the metal oxide cocatalyst is 30%-50% of the amount of the N-hydroxy amide catalyst based on a molar ratio, and the total yield of a coal acid is 66.21%-85.47%, wherein the yield of a benzene carboxylic acid is 22.58%-28.85%.

Assignees

• Univ China Mining

Inventors

• Liang Jing
• Yang Huihui
• Wei Xianyong
• Zong Zhimin

Classifications

• B01J31/04

  containing carboxylic acids or their salts {(B01J31/0277 - B01J31/0298 take precedence; multi-metal carboxylate complexes like Pd (II) acetate, i.e. Pd3 (OAc) 6 or Cr(II)acetate, i.e. Cr2(OAc)4 B01J31/2226)} · CPC title

• C07C51/21 Primary

  with molecular oxygen · CPC title

• C07C55/02

  Dicarboxylic acids · CPC title

• C07C65/21

  containing ether groups, [IMAGE cpc-sch-C07C-0958.gif] groups,[IMAGE cpc-sch-C07C-0959.gif] groups, or[IMAGE cpc-sch-C07C-0960.gif] groups · CPC title

• C07C63/06

  Benzoic acid · CPC title