麦草浆DEP漂白过程中污染物产生规律研究

研究了麦草化学浆DEP漂白过程中麦草浆性能变化情况,以及漂白废水中污染物生成规律,并建立了二氧化氯用量、纸浆得率等因素与漂白废水中污染物发生量的相关关系式。结果表明：随着二氧化氯用量的增加,漂白废水中CODCr、BOD5、AOX发生量都逐渐增加,并且这些污染物发生量与二氧化氯、得率和白度等有密切的关系。     

纤维素原料生产酒精糖化工艺的研究

以玉米秸秆为原料研究稀酸预糖化-酶糖化法发酵生产酒精的工艺,考察了工艺条件对纤维素出酒率的影响。稀酸预糖化具有打破秸秆结构的效果,但会伴随纤维素的损失,为了提高纤维素利用率,必须优选最佳工艺条件,经试验确定：预糖化过程固液比1∶9,硫酸浓度1.5％(w/w,与原料质量比,下同),140℃条件下预糖化1.5h;酶糖化过程底物浓度25%,pH5.0±0.1,加入1%的纤维素酶,糖化时间72h;此工艺条件纤维素糖化率可达83.82%。该条件酶糖化液发酵生产酒精,纤维素出酒率可达40.69%,发酵液酒精浓度6.20%vol。     

Organic solvent pretreatment to enhance enzymic saccharification of straw

Enzymic saccharification of wheat straw in the absence of any pretreatment was only about 20 %. Acid hydrolysis did not improve the overall cellulose enzymic breakdown, nor did pretreatment by flash autohydrolysis under pressure or sodium chlorite delignification. When wheat straw was treated with N-methyl-morpholine-N-oxide (MMNO) at J20°C for 20–30 min, this treatment and subsequent enzymic hydrolysis produced carbohydrate conversion of 73%. Similar results could be obtained by treating straw with 0·1 M sodium hydroxide. When MMNO treatment was combined with any other pretreatment, the saccharification yield was greatly enhanced. Nearly quantitative conversion was obtained by swelling straw in 0·1 M sodium hydroxide followed by MMNO treatment. The results show that lignin content of plant material does not represent the limiting factor to enzymic saccharification.     

添加助剂的非木浆二氧化氯漂白

研究了添加醛类助剂对非木浆二氧化氯漂白的活化效果。在ClO2脱木素（D）段添加1.0%～1.5%的甲醛助剂,可以有效地促进和改善ClO2脱木素的速率和效率。与对照样相比,ClO2脱木素（D）后和碱抽提（DE或DEP）后纸浆的卡伯值均有所降低,ClO2的实际消耗量增大,表明甲醛对ClO2脱木素有较好的活化作用。除了甲醛以外,乙醛、乙二醛、葡萄糖等醛类或醛糖也可以起到一定的活化效果。甲醛的活化效果与未漂浆初始卡伯值的高低有关。未漂浆初始卡伯值越高,甲醛对ClO2脱木素段的活化效果越好。对原浆卡伯值为21.7的烧碱-蒽醌法麦草浆,在D段添加1.5%的甲醛助剂,采用DEPP漂序,可使漂白终点白度达到81.8%,比对照样提高了2.5个点,部分强度指标有所下降。     

不同催化剂对麦草组分乙醇溶剂热分离效果的影响

高效清洁的纤维生物质组分分离技术是生物质深度精炼和高值化利用的前提。乙醇溶剂高温热分解是一项极具前景的生物质组分高效分离技术,催化剂的加入可以明显加快脱木质素效率。本研究在麦草乙醇溶剂热分离过程中加入催化剂,探讨了催化剂乙酸、MgCl_2、H_3PO_4以及3种催化剂与H_2O_2组成的二元催化体系对麦草组分分离效果的影响。结果表明,H_2O_2的加入对乙酸、MgCl_2催化半纤维素的脱除有明显的提高,而对木质素的脱除影响不显著; H_2O_2的添加对于H_3PO_4催化来说,木质素脱除率有明显的上升,而半纤维素脱除率则保持较高水平。当反应温度190℃、催化剂浓度0. 02 mol/L、H_3PO_4/H_2O_2质量比为5∶5时,木质素脱除率由单独H_3PO_4催化的80. 99%增加到88. 64%;半纤维素脱除率为68. 99%。     

草类原料爆破法纸浆抄造高强瓦楞原纸

稻麦草采用爆破法制浆新技术,纸浆得率高,成本低,污染少,用于抄造高强瓦楞原纸,裂断长和环压强度指数都可超过瓦楞原纸国家A级标准。该新技术为稻麦草原料在造纸工业中提供了新的出路,非常适合在我国稻麦草生产区的小型纸厂推广。     

乙醇及发酵废液预处理秸秆条件的研究

利用酒精厂的乙醇发酵废液对小麦秸秆进行预处理,处理液仍在本厂回收后再利用,这样有助于降低预处理成本,促进纤维素乙醇的发展。经实验,处理小麦秸秆的最佳条件为乙醇、杂醇油体积比为1∶1,处理温度110℃,处理时间为200min,处理后的秸秆酶解率达到83.3%,比直接酶解高出近50%,但由于纤维糖化液中抑制发酵成分的存在,使得发酵的酒精度只有6%左右。     

Sulfite-Formaldehyde Pulping and Oxygen Delignification of Wheat Straw

In this study,wheat straw pulp was prepared by sulfiteformaldehyde(SF) pulping combined with oxygen delignification to develop a sustainable methodology for chemical pulping of straw materials.The bleachability of oxygen-delignified SF pulp was also evaluated by hypochlorite bleaching.The results indicated that the Na_2SO_3 charge played an important role in lignin removal during SF pulping as well as oxygen delignification.The efficiency of oxygen delignification of wheat straw SF pulp was markedly high.After the oxygenation stage,the Kappa number decreased by over 50%(the original Kappa number of SF pulp was lower than 30) when the Na OH charge was in the range of 3%~5%.The optimal conditions for preparing bleached pulp via combined SF pulping and oxygen delignification involved the use of 12% of Na_2SO_3 and 3% of Na OH,respectively.Pulp with relatively high brightness,a low Kappa number,as well as an acceptable viscosity could be obtained when oxygen-delignified SF pulp was bleached with hypochlorite under a low active chlorine dosage.     

Research State of Disposable Non-plastic Straws

The continuous production of disposable plastic straw places a high demand on global petrochemical resources and a significant environmental burden. Biodegradable and eco-friendly straws have therefore been studied and produced worldwide. This article briefly introduces the characteristics of paper straws and polylactic acid (PLA) straws, and focuses on edible straws made using, e.g., hydrophilic colloids, zein, and starch. Raw-material selection, preparation methods, advantages, and defects of straws are summarized, to provide a reference for the development and research of eco-friendly straws.     

魔芋超强吸水剂的生物降解性能研究

采用霉菌侵蚀法和土壤掩埋法对自制的吸水性材料魔芋超强吸水剂(KSAP)的生物降解性能进行了研究.结果表明,KSAP在霉菌侵蚀和土壤掩埋的条件下均具有可生物降解性,它的使用可减少环境污染.