A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were teste...A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were tested through chemical analysis, surface analysis, X-ray diffraction and FT-IR spectroscopy. The effects of various factors, such as dose, adsorption time and adsorption temperature, on phenol adsorption behavior were studied. The results show that the adsorption processes can be fitted to the isotherm Langmuir model very well. It was found that the adsorption process was strongly influenced by temperature and the optimal temperature for phenol removal was 40 ℃. The optimum adsorption time was 10 min, and desorption would happen afterwards. Between the models of Langmuir and Freundlich, the adsorption process of phenol onto magnesia fitted the Langmuir equation better.展开更多
Analysis on foulants shows that: the elements (except for C, H and O) in foulants formed during evaporating alkaline wheat straw black liquor are Si, Ca , K, Na, Mg and Al; Si and Ca account for about 36% of the weigh...Analysis on foulants shows that: the elements (except for C, H and O) in foulants formed during evaporating alkaline wheat straw black liquor are Si, Ca , K, Na, Mg and Al; Si and Ca account for about 36% of the weight of foulants; The organic ingredients amout to about 20% of the foulant; Rhodesite (Ca,K,Na)8Si16O40·11H2O is the main composition in foulants. The fouling mechanism of wheat black liquor is quite different from that of soft/hard wood black liquor, because the content of Si inside wheat straw black liquor is much more than that of soft/hard wood black liquor. Complex chemical reactions occur when evaporating wheat straw black liquor. The author considers that colloid H2SiO3 plays an important role in the process. The minerals produced by reactions between H2SiO3, with anion charges and positive ions, such as Ca2+, K+, Na+, etc. Further investigation on the process should be done.The fractal theory is used to analyze the fouling geometric texture. The fractal dimension values D of foulants are also calculated.展开更多
A novel vapor-liquid-solid circulating fluidized bed evaporator, meaning for enhancing heat transfer and preventing fouling, is applied to wheat straw black liquor, which is the primary pollutant in China’s papermaki...A novel vapor-liquid-solid circulating fluidized bed evaporator, meaning for enhancing heat transfer and preventing fouling, is applied to wheat straw black liquor, which is the primary pollutant in China’s papermaking industry. It is treated by alkali recovery, in which evaporation is a key process. The experimental results show that the vapor-liquid-solid three-phase boiling heat transfer coefficient is enhanced by 20%～40% than that of vapor-liquid two-phase boiling flow, also, the novel evaporator exhibits an excellent function of fouling prevention.展开更多
Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated l...Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated liquor and pulp of every cycles are analyzed respectively. Result shows that the content of lignin and organism in recycle black liquor and separated liquor increases faster in the first three cycles and then continues to increase slowly till four or five times, after that it trends to a stable state. The main organism separated from waste liquor of AS-AQ treated by sulfur dioxide is alkali-lignin, above 50% of total lignin in black liquor. The yield of pulp made from recycle cooking is steady, the hardness of pulp has a great improvement with recycle cooking. The brightness of pulp reduces correspondingly before bleaching, and after bleaching the brightness of pulp is relatively high and steady at the same sodium hypo chlorite dosage.展开更多
The principle and technique were reported here to produce lignin-based sand stabilizing material （LSSM） using extracted lignin from black liquor of straw paper mills. Field tests using LSSM to stabilize and green sa...The principle and technique were reported here to produce lignin-based sand stabilizing material （LSSM） using extracted lignin from black liquor of straw paper mills. Field tests using LSSM to stabilize and green sand dunes were started in 2002. The field experiment was carded out in August 2005 when the newly formed plant community was 3 years old. The results from the comprehensive field experiment demonstrated that unlike polyvinyl acetate or foamed asphalt commonly used for dune stabilization, LSSM was plant- friendly material and could be used in combination with seeding and planting of desert species. With the help of LSSM, the desert species （i.e., Agriophyllum squarrosum （L.） Moq. and Artemisia desertorum Spreng. etc.） could be used to form community in 2-3 yeas and to stabilize sand dune effectively. The newly formed community was sustainable under an extremely dry climate condition. The organic matter and total nitrogen in the soil increased significantly as the community were formed, while the change in P and K contents in the soil was negligible.展开更多
The measurement of lignin content in black liquid of straw AS-AQ by ultraviolet spectrophotometer(UV) is discussed in this paper. Different dilution multiple and contrast solutions have an effect on the measured resul...The measurement of lignin content in black liquid of straw AS-AQ by ultraviolet spectrophotometer(UV) is discussed in this paper. Different dilution multiple and contrast solutions have an effect on the measured results of the lignin content by UV. The calculation method for the absorption coefficient and the scanning spectrum property of liquor acidified by SO2 are introduced in this paper.展开更多
基金the financial support from the Natural Science Foundation of China (No. 20477041)
文摘A magnesia adsorbent was prepared from straw pulp black liquor and magnesium sulfate for the first time, and its adsorption of phenol from aqueous solution was examined. The characteristics of the adsorbent were tested through chemical analysis, surface analysis, X-ray diffraction and FT-IR spectroscopy. The effects of various factors, such as dose, adsorption time and adsorption temperature, on phenol adsorption behavior were studied. The results show that the adsorption processes can be fitted to the isotherm Langmuir model very well. It was found that the adsorption process was strongly influenced by temperature and the optimal temperature for phenol removal was 40 ℃. The optimum adsorption time was 10 min, and desorption would happen afterwards. Between the models of Langmuir and Freundlich, the adsorption process of phenol onto magnesia fitted the Langmuir equation better.
文摘Analysis on foulants shows that: the elements (except for C, H and O) in foulants formed during evaporating alkaline wheat straw black liquor are Si, Ca , K, Na, Mg and Al; Si and Ca account for about 36% of the weight of foulants; The organic ingredients amout to about 20% of the foulant; Rhodesite (Ca,K,Na)8Si16O40·11H2O is the main composition in foulants. The fouling mechanism of wheat black liquor is quite different from that of soft/hard wood black liquor, because the content of Si inside wheat straw black liquor is much more than that of soft/hard wood black liquor. Complex chemical reactions occur when evaporating wheat straw black liquor. The author considers that colloid H2SiO3 plays an important role in the process. The minerals produced by reactions between H2SiO3, with anion charges and positive ions, such as Ca2+, K+, Na+, etc. Further investigation on the process should be done.The fractal theory is used to analyze the fouling geometric texture. The fractal dimension values D of foulants are also calculated.
文摘A novel vapor-liquid-solid circulating fluidized bed evaporator, meaning for enhancing heat transfer and preventing fouling, is applied to wheat straw black liquor, which is the primary pollutant in China’s papermaking industry. It is treated by alkali recovery, in which evaporation is a key process. The experimental results show that the vapor-liquid-solid three-phase boiling heat transfer coefficient is enhanced by 20%～40% than that of vapor-liquid two-phase boiling flow, also, the novel evaporator exhibits an excellent function of fouling prevention.
文摘Thick black liquor, thin black liquor and solid state sodium hydroxide are added to the liquor treated by sulfur dioxide, then the blended liquor is used to recycle cooking of straw pulp. The black liquor, separated liquor and pulp of every cycles are analyzed respectively. Result shows that the content of lignin and organism in recycle black liquor and separated liquor increases faster in the first three cycles and then continues to increase slowly till four or five times, after that it trends to a stable state. The main organism separated from waste liquor of AS-AQ treated by sulfur dioxide is alkali-lignin, above 50% of total lignin in black liquor. The yield of pulp made from recycle cooking is steady, the hardness of pulp has a great improvement with recycle cooking. The brightness of pulp reduces correspondingly before bleaching, and after bleaching the brightness of pulp is relatively high and steady at the same sodium hypo chlorite dosage.
基金supported by the National Natural Science Foundation of China (No. 40675040, 30771687, and90302015)the National Basic Research Program of China (No. 2006CB400505)
文摘The principle and technique were reported here to produce lignin-based sand stabilizing material （LSSM） using extracted lignin from black liquor of straw paper mills. Field tests using LSSM to stabilize and green sand dunes were started in 2002. The field experiment was carded out in August 2005 when the newly formed plant community was 3 years old. The results from the comprehensive field experiment demonstrated that unlike polyvinyl acetate or foamed asphalt commonly used for dune stabilization, LSSM was plant- friendly material and could be used in combination with seeding and planting of desert species. With the help of LSSM, the desert species （i.e., Agriophyllum squarrosum （L.） Moq. and Artemisia desertorum Spreng. etc.） could be used to form community in 2-3 yeas and to stabilize sand dune effectively. The newly formed community was sustainable under an extremely dry climate condition. The organic matter and total nitrogen in the soil increased significantly as the community were formed, while the change in P and K contents in the soil was negligible.
文摘The measurement of lignin content in black liquid of straw AS-AQ by ultraviolet spectrophotometer(UV) is discussed in this paper. Different dilution multiple and contrast solutions have an effect on the measured results of the lignin content by UV. The calculation method for the absorption coefficient and the scanning spectrum property of liquor acidified by SO2 are introduced in this paper.
