Black Liquor Treating of Wheat Straw Pulping Using Microwave Radiation

2014 ◽  
Vol 997 ◽  
pp. 279-283
Author(s):  
Ming Xian Cui ◽  
Wei Song
Keyword(s):  
Activated Carbon ◽  
Reaction Mechanism ◽  
Wheat Straw ◽  
Microwave Radiation ◽  
Organic Pollutants ◽  
Microwave Power ◽  
Black Liquor ◽  
Effective Factors ◽  
Wheat Straw Pulp ◽  
Combined Action

This paper describes the method of treating wheat straw pulp black liquor with microwave radiation. The granular activated carbon and CuO are used as a catalyst.Effects of effective factors such as the total amount, ratio, microwave power, time on treating process are studied. The reaction mechanism is also researched. The results indicate that the oxidative decomposition process of lignin or organic pollutants is combined action of activated carbon and CuO absorption-degradation with microwave induced oxidization. This approach is easy to operate, quickly to treat, completely to react and no new pollutants. So it is used to treat black liquor of containing organic pollutes which is hardly degraded.

Kinetics Research of Wheat Straw Atmospheric Pressure Pulping with Microwave Radiation

2012 ◽  
Vol 610-613 ◽  
pp. 1726-1730
Author(s):  
Hong Zhu ◽  
Hong Xu Qiao
Keyword(s):  
Activation Energy ◽  
Wheat Straw ◽  
Microwave Radiation ◽  
Atmospheric Pressure ◽  
Lignin Content ◽  
Removal Rate ◽  
Black Liquor ◽  
Alkali Concentration ◽  
Paper Pulp ◽  
Lignin Removal

The lignin removal of pulping process is left in black liquor, and with relation to the paper pulp lignin. The higher the black liquor lignin content is, the bigger the lignin of paper pulp is removed. This paper analyzes the delignification mechanism of wheat straw atmospheric pressure pulping with microwave radiation. The relations of black liquor lignin content and alkali concentration to pulping time are described in detail. The results show that delignification process is divided into two stages: quick stage and residual stage. The lignin removal rate in the first stage is much higher than the second stage, that is, lignin has been removed more sufficiently after quick stage. In first stage, reaction order of delignification is 1.0, and 0.7 with respect to OH-, the activation energy is 38.62 kJ • mol-1. The latter delignification also belongs to the first-order reaction and 4.4 with respect to OH-, the activation energy is 75.56 kJ • mol-1. Apparently, residual stage needs to consume large amounts of energy to removal lignin.

Study on Optimal Condition of Activated Carbon Prepared by Microwave Heating from Shot Coke

2014 ◽  
Vol 936 ◽  
pp. 1809-1815
Author(s):  
Ying Fei Hou ◽  
Ya Ya Gu ◽  
Qing Ping Mou ◽  
Gang Yao ◽  
Jian Hui Zhang
Keyword(s):  
Activated Carbon ◽  
Optimal Condition ◽  
Microwave Heating ◽  
Surface Area ◽  
Microwave Radiation ◽  
Microwave Power ◽  
Bet Surface Area ◽  
Benzene Adsorption ◽  
Iodine Adsorption ◽  
Radiation Time

The activated carbon was prepared from the Jing Bo shot coke using KOH as the activation agent by microwave heating. The effect of microwave radiation time, the microwave power and the ratio of activation to shot coke on the properties of the activated carbon were investigated in detail. The result showed that the optimized condition of preparation of activated carbon is as followed: the ratio of activation agent to shot coke is 3:1, the microwave power 900 W and the microwave radiation time is 40 min. In this condition, the BET surface area of the activated carbon is 2668 m2/g; the iodine adsorption value 2281 mg/g and the benzene adsorption value 1368 mg/g.

The Effect of Microwave Treatment on the Hydrogen Peroxide Bleaching of Soda-AQ Wheat Straw Pulp

2011 ◽  
Vol 236-238 ◽  
pp. 1307-1312
Author(s):  
Chao Jun Wu ◽  
Chuan Shan Zhao ◽  
Jun Li ◽  
Ke FU Chen
Keyword(s):  
Hydrogen Peroxide ◽  
Wheat Straw ◽  
Fiber Length ◽  
Weighted Average ◽  
Microwave Treatment ◽  
Arithmetic Average ◽  
Peroxide Bleaching ◽  
Bleached Pulp ◽  
Infra Red ◽  
Wheat Straw Pulp

In this paper, the effect of microwave treatment on the hydrogen peroxide bleaching of Soda-AQ wheat-straw pulp was investigated. The results showed that microwave treatment could increase the brightness of the hydrogen peroxide bleached pulp. The fiber coarseness of microwave enhancing peroxide bleached pulp was higher than that of the peroxide bleached pulp. However, the arithmetic average fiber length, the length weighted average fiber length and weight weighted average fiber length of the former was lower than that of the latter. Fourier transform infra-red spectroscopy (FTIR) and X-ray diffraction (XRD) spectra showed that CrI(%) crystallinity of microwave enhancing peroxide bleached pulp was similar as that of the peroxide bleached pulp but all higher than that of the Soda-AQ wheat-straw pulp. N·O′KI infra-red crystalline index of microwave enhancing peroxide bleached pulp were lower than that of the peroxide bleached pulp. The FTIR spectra of lignin showed that the microwave treatment had some influences on the methoxyl and phenolic group in lignin.

Purification of pulp mill condensates by an adsorptive process on activated carbon

Holzforschung ◽  
2019 ◽  
Vol 73 (6) ◽  
pp. 589-597 ◽  
Author(s):  
José A.F. Gamelas ◽  
Sofia M. Rebola ◽  
Margarita G. Evtyugina ◽  
Valdemar I. Esteves ◽  
Dmitry V. Evtuguin
Keyword(s):  
Activated Carbon ◽  
Volatile Compounds ◽  
Water Cycle ◽  
Black Liquor ◽  
Pulp Mill ◽  
Dimethyl Disulfide ◽  
Pulp Mills ◽  
Wide Range ◽  
New Process ◽  
Pseudo Second Order

Abstract In order to close the water cycle in pulp mills with condensates instead of fresh water, the malodorous/hazardous volatile compounds and colored substances have to be removed by appropriate efficient methods. In the present work, the condensate from the evaporation of black liquor (BL) from a kraft mill was purified by a batch adsorptive process by means of commercial activated carbon (AC). The effluent was found to contain a wide range of aromatic and organosulfur volatile compounds, including toluene, ethylguaicol, syringaldehyde, dimethyl disulfide (DMDS), dimethyl trisulfide (DMTS), 2,3-dimethylthiophene, benzothiol and benzothiophene derivatives. Methanol was the major volatile organic component in the condensate (201 mg l−1), which was, however, poorly adsorbed on the AC surface. Aromatics and organosulfur contaminants were adsorbed almost completely in 2–5 min at 23°C under the optimized AC load (900 mg l−1). The treatment allowed the elimination of up to 99% of the obnoxious odor, color and turbidity of the condensate. The adsorption equilibrium followed the Langmuir model and the pseudo-second-order kinetics. The new process could be incorporated in the pulp mill with relatively low additional reagent costs.

Preparation, characterization and application of lignin-based activated carbon from black liquor lignin by steam activation

2013 ◽  
Vol 228 ◽  
pp. 1074-1082 ◽  
Author(s):  
Kaifang Fu ◽  
Qinyan Yue ◽  
Baoyu Gao ◽  
Yuanyuan Sun ◽  
Liujia Zhu
Keyword(s):  
Activated Carbon ◽  
Black Liquor ◽  
Steam Activation
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