In order to reduce the viscosity of black liquor, a threefactor and three-level orthogonal experiment was employed to study the effects of alkali charge, maximum temperature and holding time at the maximum temperature on the viscosity of black liquor from wheat straw soda pulping by a simple heat treatment. While a fourfactor and threelevel orthogonal experiment was designed to study the effects of alkali charge, maximum temperature, holding time, and oxygen pressure on the viscosity reduction of black liquor from wheat straw soda pulping by an oxygen enhanced heat treatment. The results of variance analysis showed that the viscosity reduction of wheat straw black liquor by heat treatment with oxygen was much efficient than that of treated by simple heat treatment. The viscosity reduction was more prominent when the viscosity concentration more than 30 %. The critical concentration of black liquor treated by heat with oxygen, if compared with the similar heat treatment condition but without oxygen enhanced, increased by around 5 %. And the most remarkable factor which influences the viscosity reduction by heat treatment with oxygen was the maximum temperature. In addition, the optimal condition of heat treatment with oxygen was determined as follows: alkali charge on total solids content was 1.0 % (as NaOH), with maximum temperature of 170 ℃, holding time at the maximum temperature of 45 min and oxygen pressure of 0.7 MPa.
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References
[1]袁昊,乔炜,王继芬.草浆造纸黑液资源化工艺研究[J].上海第二工业大学学报,2005，22(2):15-17.
[2]朱焱，杨红刚,方继敏.草浆造纸黑液资源化治理工艺初探[J].安全与环境工程,2004,11(3):53-57.
[3]杨仁党,陈克复.造纸黑液降粘技术[J].中国造纸,2003,22(10):48-52.
[4]张效林,韩卿.麦草浆黑液降粘技术概述[J].西北轻工业学院学报,2002,20(3):97-99.
[5]刘福平，韩卿.麦草碱黑液降粘技术的研究[J].西北轻工业学院学报,1999,17(2):48-52.
[6]Pritham R, van Heiningen A R P, Kubes G J. Viscosity and thermal conductivity of black liquor[J]. Tappi Journal, 1993, 76(11): 175-179.
[7]Balzer D. Cloud point phenomenon in the phase behavior of alkyl polyglycosides in water[J]. Langmuir, 1993, 9: 33-35.
[8]Finch C A. Chemistry and Technology of Watersoluble Polymers[M]. New York: Springer, 1983: 193-197.
[9]Sandquist K. Rheological properties and evaporation of black liquor at high drysolids content[J]. Pulp & Paper Canada, 1983, 84(2): 30-35.
[10]Sderhuelm L. Factors affecting the viscosity of strong black liquor[J]. Appita, 1988, 41(5): 389-392.
[11]Harrison A. Frovifors mill installs new recovery technology to debottle[J]. Pulp & Paper, 1993, 67(13): 30-32.
[12]Vakkilainen E, Backman R, Forssin M. Effect of liquor heat treatment on black liquor combustion properties[J]. Pulp & Paper Canada, 1990, 100(8): 24-30.
[13]Soderlyelm L. Characterization of kraft black liquor with respect to evaporating and combustion[D]. Finland: Hilinki University of Technology Laboratory of Pulping Technology, 1988.
[14]马金霞,李忠正,翟华敏.麦草浆黑液加热处理[J].中国造纸,2001,20(3):67-68.
[15]石淑兰,何福望.制浆造纸分析与检测工艺实验[M].北京:中国轻工业出版社,2003.
[16]潘锡五.黑液粘度与黑液热处理[J].中国造纸,2001,20(2):48-52.
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