稻秆相变储能建筑板材的性能研究

利用稻秆浸渍并装载相变材料Na2SO4.10H2O溶液,以改性水玻璃胶结合含相变材料的稻秆,通过模压成型制备稻秆相变板材,再将该板材插入带有槽型孔的混凝土砖中,得到相变砖,测试了板材及相变砖的各项性能。结果表明：稻秆定型相变板材1次涂膜封装后抗拉强度为0.44 MPa,燃烧等级为FH-1,3次涂膜封装后30次相变循环后的质量损失仅为1.9%;板材插入混凝土多孔砖中保温性能优劣顺序为：插入稻杆相变板〉插入稻杆板〉原混凝土多孔砖。     

小麦秸秆催化液化工艺研究

常温常压下小麦秸秆催化液化制绿色化学品。分别研究了小麦秸秆在甲醇、乙醇、丙三醇和丁醇中的液化效果,考察了甲醇和苯酚的混合体系下液化时间与不同催化剂对液化产率的影响。结果表明,常温常压下,4种醇对小麦秸秆的液化产率的高低顺序:甲醇>乙醇>丙三醇>丁醇,甲醇的液化产率最高,达到17.23%,可以作为木质素液化的有效试剂。甲醇和苯酚混合液化体系的液化产率可达到24.52%,以对甲苯磺酸作为催化剂液化产率可达到28.40%。     

稻秸秆/玉米淀粉胶复合材料的制备及性能

以玉米淀粉为原料,H2O2为氧化剂,制得氧化玉米淀粉胶。利用模压方法制备了稻秸秆/玉米淀粉胶复合材料,基于正交试验方法,研究了原料配比对复合材料的密度、抗压强度、吸湿性及可降解性能的影响。结果表明:稻秸秆/玉米淀粉胶复合材料密度随稻秸秆含量增加,先升高后降低;当稻秸秆含量为16.3%时,复合材料密度最小;随玉米淀粉胶含量增加复合材料抗压性能降低。当稻秸秆∶改性淀粉∶玉米淀粉胶∶滑石粉∶碳酸氢氨的质量比为6∶9∶15∶5∶1时,复合材料抗压强度较高。稻秸秆/玉米淀粉胶复合材料在潮湿环境下的降解性能良好,但与聚苯乙烯泡沫塑料相比易吸潮。     

PBAT/棕榈酰氯酯化改性秸秆粉复合材料制备与性能

以棕榈酰氯为酯化剂改性秸秆粉,探究了不同酯化反应条件下秸秆粉取代度的变化,并对改性前后秸秆粉进行了傅里叶变换红外光谱测试及接触角测试,进一步验证了酯化反应的成功.制备了基于聚己二酸/对苯二甲酸丁二酯(PBAT)和改性前后秸秆粉的复合材料,考察了秸秆粉的不同酯化处理条件对复合材料拉伸、冲击性能的影响,通过对比可得,当反应...     

生物质半焦CO2气化反应动力学研究

采用热天平研究生物质半焦CO2气化反应动力学特性。考察半焦粒径、热解制焦温度以及热解制焦气氛对气化反应碳转化率的影响。采用随机孔模型、未反应芯缩核模型和混合模型对生物质半焦气化反应速率随碳转化率变化的趋势进行拟合,并求出半焦气化的动力学参数,结果表明随机孔模型的拟合效果最好。     

Thermophilic dark fermentation of untreated rice straw using mixed cultures for hydrogen production

Biohydrogen production from untreated rice straw using different heat-treated sludge, initial cultivation pH, substrate concentration and particle size was evaluated at 55 °C. The peak hydrogen production yield of 24.8 mL/g TS was obtained with rice straw concentration 90 g TS/L, particle size <0.297 mm and heat-treated sludge S1 at pH 6.5 and 55 °C in batch test. Hydrogen production using sludge S1 resulted from acetate-type fermentation and was pH dependent. The maximum hydrogen production (P), production rate (R_m) and lag (λ) were 733 mL, 18 mL/h and 45 h respectively. Repeated-batch operation showed decreasing trend in hydrogen production probably due to overloading of substrate and its non-utilization. PCR-DGGE showed both hydrolytic and fermentative bacteria (Clostridium pasteurianum, Clostridium stercorarium and Thermoanaerobacterium saccharolyticum) in the repeated-batch reactor, which perhaps in association led to the microbial hydrolysis and fermentation of raw rice straw avoiding the pretreatment step.     

Effect of enzyme addition on fermentative hydrogen production from wheat straw

Wheat straw is an abundant agricultural residue which can be used as raw material to produce hydrogen (H₂), a promising alternative energy carrier, at a low cost. Bioconversion of lignocellulosic biomass to produce H₂ usually involves three main operations: pretreatment, hydrolysis and fermentation. In this study, the efficiency of exogenous enzyme addition on fermentative H₂ production from wheat straw was evaluated using mixed-cultures in two experimental systems: a one-stage system (direct enzyme addition) and a two-stage system (enzymatic hydrolysis prior to dark fermentation). H₂ production from untreated wheat straw ranged from 5.18 to 10.52 mL-H₂ g-VS⁻¹. Whatever the experimental enzyme addition procedure, a two-fold increase in H₂ production yields ranging from 11.06 to 19.63 mL-H₂ g-VS⁻¹ was observed after enzymatic treatment of the wheat straw. The high variability in H₂ yields in the two step process was explained by the consumption of free sugars by indigenous wheat straw microorganisms during enzymatic hydrolysis. The direct addition of exogenous enzymes in the one-stage dark fermentation stage proved to be the best way of significantly improving H₂ production from lignocellulosic biomass. Finally, the optimal dose of enzyme mixture added to the wheat straw was evaluated between 1 and 5 mg-protein g-raw wheat straw⁻¹.     

机械搅拌转速对稻草厌氧消化性能的影响

以稻草为原料,采用批式厌氧消化,研究了4种搅拌转速(40,80,120,160 r/min)对稻草厌氧消化产气情况、组分变化和系统稳定性参数(pH值、碱度和氨氮)等的影响。结果表明,搅拌转速对稻草厌氧消化的产气性能有显著影响。80 r/min的厌氧消化效果最好,单位VS产气量为430.6 ml/g,分别比40,120和160 r/min提高了23.6%,11.4%和18.3%;80 r/min和160 r/min的消化时间T80均为46 d,分别比40 r/min和120 r/min缩短了20 d和3 d。搅拌转速为80 r/min时,厌氧消化反应器既能保证良好的物料混合效果,又能维持系统的稳定和较高的微生物活性,其TS,VS降解率均高于其他搅拌转速的反应器,产气性能最好。     

玉米秸秆酶解糖化液乙醇发酵的工艺优化

利用从4组混合乙醇酵母中筛选出的优势混合酵母,对玉米秸秆酶解糖化液的乙醇发酵工艺过程进行了优化试验。试验结果表明,管囊酵母和酿酒酵母组成的混合酵母具有较高的乙醇发酵能力,经60 h发酵,乙醇浓度最高可达12.55 g/L,乙醇产率为最大理论值的68.63%。根据对糖化液乙醇发酵的二次回归正交组合优化试验,当发酵温度为28.0℃,初始pH为5.2,接种量为8.1%时,实际乙醇浓度最高可达13.03g/L,乙醇产率为0.36 g/g,为最大理论值的70.59%,与所得乙醇发酵回归方程预测值基本相符。     

四乙酰乙二胺(TAED)对稻草高得率浆双氧水漂白的影响

研究了四乙酰乙二胺(TAED)作为活化剂对稻草高得率浆双氧水漂白的活化效果,并在TAED的作用下以漂后白度为指标考察不同条件对活化效果的影响,以此确定最佳漂白条件。结果表明:最佳漂白工艺为浆浓10%,时间30min,温度70℃,TAED与H2O2摩尔比0.5,NaOH用量4%,H2O2用量6%,Na2SiO3用量3%,MgSO4用量0.05%;在该条件下,漂后浆的白度值为52.4%ISO,比原浆白度增加值可达38.6%ISO,比单纯的H2O2漂白提高了7.8%ISO。