微细通道尺寸对甲醇水蒸汽重整反应性能影响

针对微细通道反应器内甲醇水蒸汽重整制氢反应,建立了二维稳态多组分传输反应模型.分析了通道几何尺寸的变化对产物的组成以及通道内部温度分布的影响.结果表明,通道长高比的增加能增强通道壁面与流体的换热性能,提高甲醇转化率和产物中氢含量,但同时也会造成产物中CO含量的增加,影响到质子交换膜燃料电池的正常工作.     

高温氢气处理对活性炭及钯炭催化剂性能的影响

采用高温氢气对不同活性炭进行处理,并分别采用比表面分析仪(BET)、红外光谱(IR)、氩气-程序升温脱附实验(Ar-TPD)和热重分析(TGA)对高温氢气处理前后的活性炭进行表征.结果表明,高温氢气处理对活性炭的孔结构和比表面影响较小,高温氢气处理后活性炭表面含氧官能团含量降低.以高温氢气处理后的活性炭为载体制备钯炭催化剂,催化剂上的钯的分散度降低,在粗对苯二甲酸精制反应中的初活性下降.     

吸附强化的甲烷水蒸汽重整制氢反应特性

在实验室固定床反应器上研究了采用复合催化剂的吸附强化甲烷水蒸汽重整制氢反应,对吸附强化制氢反应条件进行了考查,得到了实验室条件下的最佳反应条件为温度600～640 ℃,压力0.2 MPa,水碳比4～5.在600 ℃,0.2 MPa,水碳比5的条件下,吸附强化段H2含量高达95.39%,吸附强化段CH4转化率达到81.37%,相对于理论平衡值的吸附强化因子达到26.76%.     

生物质下吸式气化炉气化制备富氢燃气实验研究

以制取富氢燃气为目标,在自热式下吸式气化炉反应器内,进行了生物质下吸式气化炉富氧/水蒸气及空气气化的制氢特性研究。实验结果表明,与空气气化相比,富氧/水蒸气气化可显著提高氢产率和产气热值。在实验条件范围内,最大氢产率达到45.16 g/kg;最大低位热值达到11.11 MJ/m3。在富氧/水蒸气气化条件下,燃气中H2+CO体积分数达到63.27%—72.56%,高于空气气化条件下的52.19%—63.31%。富氧/水蒸气气化条件下的H2/CO体积比比值为0.70—0.90,低于空气气化条件下的1.06—1.27。实验结果证实:生物质下吸式气化炉富氧/水蒸气气化是一种有效的制取可再生氢源的工艺路线。     

固定化氧化亚铁硫杆菌处理硫化氢新工艺研究

用单一的生物反应器处理硫化氢时,微生物容易受到硫化氢的毒害作用而使细胞活力受损,废气处理效率迅速降低。为此,提出生物和化学二级反应器处理硫化氢的新工艺,并对微生物的生长、分布、最适工艺运行条件和影响因素等做了研究。结果表明,生物反应器中微生物对亚铁离子的氧化速率对硫化氢的去除效果有着重要的影响,二级反应器工艺大大提高了硫化氢去除效率,反应的主要产物为单质硫,同时便于对硫沉淀的分离,在操作温度31℃,pH值1.5—1.8,水力停留时间2.5 h,进气质量浓度8 g/m3,硫化氢承载负荷2 000 g/(m3.h)以下时,系统可以稳定运行,硫化氢的脱除率可达99%以上。     

化学沉淀稠油脱钙剂的研究

本文介绍了(NH4)2HPO4做为化学沉淀脱钙剂的室内研究,讨论了脱钙剂加入量、注水量、温度及混合强度对脱钙效果的影响。试验结果表明,在(NH4)2HPO4加入量为原油中Ca的摩尔数的6倍,注水量占原油量8%,反应温度100℃,乳化机搅拌8m in时,原油脱钙率可达90%,对普通碳钢无腐蚀作用。最后,提出循环沉降工艺是该技术的研究方向。     

铝及铝合金熔体净化剂研究进展

介绍了铝及铝合金熔体净化过程中气体净化剂、排杂熔剂、精炼剂、覆盖剂等净化剂的研究现状,并初步分析了其在铝及铝合金熔体净化过程中的基本原理,同时提出铝熔体提高净化效果的主要途径及铝熔体净化剂的发展方向。     

Hydrogen Peroxide and Calcium Chloride Added to Irrigation Water as a Strategy to Reduce Bacterial Populations and Improve Quality of Fresh Mushrooms

The quality and value of fresh mushrooms are often diminished by the presence of high bacterial populations that cause a brown, blotchy appearance. The objective of the present research was to evaluate the addition of hydrogen peroxide and/or calcium chloride to irrigation water as a means to reduce total bacterial populations on fresh mushrooms. Crops were grown using commercial mushroom growing practices except for the addition of 0.75% hydrogen peroxide and/or 0.3% calcium chloride irrigation water added to the crop starting 11 d after the casing layer was applied on top of mushroom compost. Irrigation water without the added treatments acted as the control. Mushrooms were aseptically sampled from the production beds for enumerating bacterial counts. Total aerobic bacterial populations were determined by standard microbiological plating procedures. Mushroom whiteness (L‐value) and color (delta E) after harvest and postharvest storage were measured using a Minolta chromameter. Harvested mushrooms were separated by treatment and weighed to record yield. Mushrooms irrigated with water (control) had 7.3 log colony‐forming units (CFU) of aerobic bacterial populations per gram of fresh mushroom tissue. Compared with the control, irrigation with 0.75% hydrogen peroxide and 0.3% calcium chloride reduced the bacterial populations on fresh mushrooms by 87% (6.4 log CFU/g). Irrigation with hydrogen peroxide and calcium chloride significantly enhanced mushroom whiteness after harvest as well as after 6 d of postharvest storage at 12 °C. The irrigation treatments did not have a significant effect on crop yields; hence, the addition of hydrogen peroxide and calcium chloride to irrigation water was demonstrated to have good potential as a practical strategy to reduce bacterial populations and to improve the quality of fresh mushrooms.     

二甲氨基丙基丙烯酰胺改性含氢硅油的合成

以氯铂酸-异丙醇为催化剂,二甲氨基丙基丙烯酰胺与含氢硅油为原料,在甲苯为溶剂的条件下,通过硅氢加成反应,将二甲氨基丙基丙烯酰胺接枝到含氢硅油侧链,合成了氨基改性硅油,其中甲苯的质量为含氢硅油与二甲氨基丙基丙烯酰胺质量总和的1.5倍,阻聚剂0.5%(对单体质量),n(含氢硅油)∶n(二甲氨基丙基丙烯酰胺)=1∶1.1,催化剂用量为反应物质量的50×10-6,120℃进行硅氢加成反应.并对其进行了红外光谱测试,结果表明:氨基基团已成功地引入到含氢硅油侧链上,合成了氨基改性硅油.     

铜离子对葡萄酒发酵中硫化氢产量的影响

以陕西泾阳县的小白玫瑰为材料,根据亚甲基兰比色法,在不同铜离子浓度条件下定量测定发酵过程中产生的硫化氢气体量,以及酒中残留的 S2-浓度。结果表明,发酵液中适当浓度的铜离子（0～0.8 mg/L）可以抑制发酵过程中硫化氢气体的生成,当添加 0.4 mg/L铜离子浓度时,综合效果最佳。