有机物电化学加氢的研究进展

氢能作为一种绿色能源,对其安全储存及运输是实现其多场景应用的关键。通过有机物化学储氢的方式有希望实现常温常压下氢气的安全储运。本文阐述了通过电化学方法实现有机物加氢反应的研究现状,介绍了电化学加氢的反应机理,并讨论催化剂与载体间的界面作用、催化剂的分散状态对电化学加氢反应的影响规律,基于传统的电解液体系及其局限性,介绍了通过分离电解和加氢过程或构造非液相体系提升电化学加氢效率的方法,同时提出了有机物电化学加氢的发展趋势和方向。     

丙烯醇在质子交换膜燃料电池反应器中的电化学加氢

利用质子交换膜燃料电池（PEMFC）原理，设计了PEMFC加氢反应系统装置，研究了PEMFC加氢反应器中丙烯醇的电化学加氢，实验表明，丙烯醇能够在极极转化为正丙醇，同时产生电能，并讨论了各种因素（温度，浓度，反应物流量，催化剂载量等）对丙烯醇加氢反应的影响。     

高密度燃料三环戊二烯加氢反应历程

三环戊二烯(TCPD)的加氢产物是具有重要应用价值的高密度碳氢燃料,本文对三环戊二烯的加氢反应过程进行了研究。采用气质联用、红外光谱和核磁共振对加氢产物进行表征,发现在加氢反应中TCPD的降冰片烯(NB)双键首先被饱和,生成中间产物 12,13-二氢三环戊二烯(12,13-DHTCPD),残留的环戊烯 (CP)双键需要在更高的温度和氢压下反应生成四氢三环戊二烯(THTCPD),即反应按照TCPD→12,13-DHTCPD→THTCPD的途径进行。利用密度泛函理论中的B3LYP/6-31G*方法对加氢过程进行模拟,证实TCPD中NB双键比CP双键更活泼,反应活性更高,并且NB双键加氢产物比CP双键加氢产物在热力学上更稳定,因此反应中NB双键优先反应,从理论上证实了实验结果。研究为三环戊二烯的两段加氢工艺提供了理论依据。     

含柴油的加氢尾油的裂解性能及经济评价研究

利用分析仪器和裂解炉模拟实验装置对4种原料[原料1(国内石化企业的加氢尾油)、原料2(合资石化企业含有柴油的加氢尾油)、原料3(国内石化企业含有柴油的加氢尾油)、原料4(国内石化企业的柴油)]的组成以及裂解性能进行了研究.裂解反应的实验条件:裂解炉出口温度为780～820℃,裂解炉出口压力为0.08 MPa,裂解炉停留...     

氧芴加氢裂化制邻苯基苯酚的工艺研究

筛选了氧芴加氢制邻苯基苯酚所用催化剂,优选4种催化剂,确定出加氢反应最适宜的温度、压力和空速,筛选出最佳催化剂。通过对氧芴加氢制邻苯基苯酚反应进行研究,确定出最佳反应条件:反应中心温度430℃,反应压力2.0MPa,质量空速0.05h~(-1)。利用GC对产物进行定性和定量分析,OPP收率为60.03%,BP收率为34.27%,DBF转化率可达97.76%。     

渣油加氢装置运行中存在问题及对策

渣油加氢处理的化学反应主要是渣油、催化剂、氢气发生的催化加氢反应,具体反应有加氢脱金属反应(HDM)、加氢脱硫反应(HDS)、加氢脱氮反应(HDN)、加氢脱残炭反应(HDC)和不饱和键的加氢饱和(芳烃、烯烃)反应等。本文主要探讨渣油加氢装置运行中存在的问题及对策。     

CO_(2)催化加氢制甲醇技术研究进展

CO_(2)的高效转化利用对缓解能源危机以及实现“碳中和”目标具有重要的战略意义。利用CO_(2)加氢制甲醇是减少碳排放、增加产品价值的一条重要途径。本文从CO_(2)加氢产物,CO_(2)加氢合成甲醇反应机理、催化剂和工艺几个方面论述CO_(2)加氢合成甲醇的研究现状,开发高活性的催化剂是CO_(2)加氢制甲醇实现工业化的关键技术手段。     

巴豆酸类共聚物分散剂的合成及性能

以过硫酸铵为引发剂,亚硫酸氢钠作链转移剂,由巴豆酸(CA)、甲基丙烯磺酸钠(SMS)、巴豆酸甲酯(MC)为单体合成共聚物CA-SMS-MC。通过单因素实验研究了过硫酸铵用量、反应温度对纳米二氧化硅分散液黏度的影响,正交实验结果表明最佳合成条件为:反应温度为90℃,反应时间是2.5 h,过硫酸铵为0.01 g(w=0.05%)、亚硫酸氢钠为0.1 g(w=0.50%)、单体质量为1.1 g(w=5.5%)、单体物质的量比4∶1∶2,红外分析表明该聚合物为CA-SMS-MC共聚物钠盐,此外,还进行了GPC、扫描电镜、粒径分布等测试。当共聚物的用量为0.5 g(w=0.60%)时,对纳米二氧化硅分散液的分散效果最好。     

壳聚糖与溴甲酚绿相互作用的电化学研究

利用线性扫描极谱法研究了溴甲酚绿(BCG)与生物多糖壳聚糖(CTS)的相互作用.在pH值为 4.5的Britton-Robinson (B-R)缓冲溶液中,BCG在-0.98 V (vs.SCE)处有一个灵敏的线性扫描二阶导数极谱波,当加入一定量的CTS后,反应体系的电化学信号发生变化.对结合反应条件和电化学测定条件进行了优化,计算发现加入CTS前后BCG溶液的电化学参数变化很大,表明两者反应生成了一种电活性的复合物.     

反应温度对浆状NiW催化剂加氢处理中低温煤焦油加氢性能的影响

采用完全液相法制备了以AlOOH-TiO_2为载体、Ni和W为活性组分的浆状加氢处理催化剂,以全馏分中低温煤焦油作为反应原料,考察了反应温度对浆状NiW催化剂的浆态床加氢性能的影响,并利用热重(TG)法、元素分析法、红外光谱(FTIR)法及气相色谱-质谱联用(GCMS)法分析了原料和反应产物的馏分分布及化学组成.结果表明:当反应温度为380℃时,催化剂具有较高的加氢性能,液体收率高达94.40%,氢碳物质的量比为1.56.本研究中萘的主要加氢路径可能为萘→苯基环烷烃(PCA)→苯基烯烃(PO),酚的主要加氢路径可能为酚(P)→苯(AB)→单环烷烃(MCA).在360℃~420℃温度范围内,升高反应温度有利于煤焦油中杂原子的去除及大分子的裂解,但不利于不饱和有机化合物的加氢反应.     

丙烯海松酸的合成研究

通过松香与丙烯酸的Diels-Alder加成反应制备了丙烯海松酸,考察了原料摩尔比对反应的影响。实验结果表明,随着丙烯酸用量的增加,产物的酸值和软化点逐步升高至不变;紫外光谱研究发现,随着丙烯酸用量的增长,枞酸型树脂酸相对含量下降,而海松酸型树脂酸的含量未见显著变化;气相色谱-质谱联用分析显示,在松香树脂酸与丙烯酸的加成反应中,树脂酸中的海松酸、异海松酸、脱氢枞酸等不参与反应,而长叶松酸、枞酸和新枞酸异构化为左旋海松酸,与丙烯酸发生加成反应;即使丙烯酸过量,长叶松酸和枞酸转化率最高也只可以达到91%和86%;研究还发现,加成产物丙烯海松酸有二种构造异构体,分别占丙烯海松酸量的20%和80%。     

单体酸组成分析及在润滑添加剂方面的应用

采用GC/MS方法测定了单体酸的主要组成:用甲酯化后的试样进行GC/MS分析,鉴定出肉豆蔻酸(12.16%)、棕榈酸(8.51%)、十八稀酸(25.53%)、硬脂酸(32.72%)等15种物质。从评价铝材轧制油添加剂的性能指标——相容性、润滑性、抗磨性、退火清洁性和抗氧化性5个方面,考察了将单体酸作为或加工成为铝材轧制油添加剂的可行性。     

Effect of bile acid feeding on hepatic steroid 12 α-hydroxylase activity in hamsters

The effects of feeding cholic acid, chenodeoxycholic acid and ursodeoxycholic acid on the activity of the hepatic steroid 12α-hydroxylase, gallbladder bile acid composition, fecal neutral sterol output, cholesterol synthesis and bile acid synthesis were determined in female hamsters. The 12α-hydroxylase activity was inhibited to 56% by cholic acid, to 62% by chenodeoxycholic acid, and to 78% by ursodeoxycholic acid compared with the control. Bile acid composition was altered by feeding of cholic acid and chenodeoxycholic acid to be rich in the given bile acids. Fecal neutral sterol output increased about twice by feeding chenodeoxycholic acid and ursodeoxycholic acid, whereas cholic acid had no significant effect. Body cholesterol synthesis increased to 217% by chenodeoxycholic acid and to 274% by ursodeoxycholic acid, whereas effect of cholic acid was not significant. Bile acid synthesis was suppressed to 48% of control only by chenodeoxycholic acid. A positive correlation between the 12α-hydroxylase activity and the bile acid synthesis was observed in the control, chenodeoxycholatefed and ursodeoxycholate-fed animals. In conclusion, ursodeoxycholic acid might have less inhibitory effect on the steroid 12α-hydroxylase and the bile acid synthesis than chenodeoxycholic acid.     

共轭亚油酸乙酯的合成

采用间歇式反应 ,以硫酸、磷酸、对甲苯磺酸为催化剂对共轭亚油酸乙酯进行了合成 ,并采用正交实验设计研究了物料比、反应温度、反应时间、催化剂用量对产品收率和品质的影响。硫酸、对甲苯磺酸催化活性佳 ,磷酸催化活性差。得到了如下合成工艺条件 :硫酸催化 ;n(共轭亚油酸 )∶n(无水乙醇 ) =1∶6;酯化反应温度 76℃ ;反应时间 1h ;催化剂用量为共轭亚油酸质量的 2 5 % ,收率可达 75 % ,产品w(共轭亚油酸乙酯 ) =77%～ 82 %。     

4种酸菜呈味成分的分析

为对比分析了4种酸菜中游离氨基酸、有机酸、核苷酸的含量及呈味特性,采用高效液相色谱仪对其进行分离鉴定,通过计算味道强度值确定了各呈味成分对酸菜滋味的贡献。结果表明:4种酸菜中呈鲜味的门冬氨酸含量最高,占总游离氨基酸含量的46.00%～53.21%,其次为呈苦味的精氨酸和呈甜味的丙氨酸;酸菜样品1、3和4中的乳酸含量最高,分别占总有机酸含量的41.69%、30.96%和38.76%,其次为乙酸、草酸;样品2中有机酸含量排名前3位的分别为草酸、乳酸和乙酸。样品1中核苷酸含量最高为0.0556 mg/g,其次为样品2中核苷酸含量0.0516 mg/g。味道强度值分析发现,4种酸菜中门冬氨酸、草酸、甲酸、乳酸、乙酸、柠檬酸、琥珀酸的味道强度值均大于1,对酸菜滋味的贡献较大。     

Hydrolysis of cellulose fiber in the presence of 12-tungstosilicic acid

Hydrolysis of cellulose fiber in the presence of 12-tungstosilicic acid was investigated, and the acid was found to show a higher catalytic activity than did hydrochloric acid at the same concentration of acid, although the ratio of the activities of 12-tungstosilicic acid to hydrochloric acid depended on the concentration. The influence of the ionic strength on the reaction rates was examined, and it was believed that the difference in the ionic strength between 12-tungstosilicic acid and hydrochloric acid at the same concentration of acid was one of reasons for the higher catalytic activity of 12-tungstosilicic acid. From the examinations of change in degree of polymerization of the cellulose fiber with the hydrolysis and adsorption behavior of 12-tungstosilicic acid by the cellulose, fiber, it was found that 12-tungstosilicic acid, in spite of its bulky structure, easily penetrated into the amorphous region of the cellulose fiber, as does hydrochloric acid, and catalyzed the hydrolysis of glucoside bond there.     

重结晶法制备高品质硝酸镍的工艺研究

硝酸镍作为一种镍盐广泛应用于分析,催化剂和电池生产行业,本论文以生产高品质硝酸镍为目的,提出了硫酸镍溶液→碳酸钠沉淀→硝酸溶解→结晶→硝酸镍产品的生产工艺。对工艺过程进行了探索,对工序过程中硝酸镍的杂质含量进行了检测。最终结果表明,采用该工艺可制备适合催化与电池行业应用的高品质硝酸镍产品。     

Effect of glucose administration on cholesterol and bile acid metabolism in rats

Glucose administered to fasted rats caused a marked stimulation in hepatic cholesterogenesis and cholesterol 7 alpha-hydroxylation, and an increase in biliary excretion of cholesterol and total bile acids. The excretion of cholic acid was not incluenced during the first few hr after glucose administration, but was significantly increased after 5 hr. Chenodeoxycholic acid showed a similar change, but the increase was only ca. one tenth of that of cholic acid. The excretion of deoxycholic acid was markedly increased by 1 hr, but gradually decreased thereafter. Pretreatment with neomycin abolished the increase in deoxycholic acid by fasting and glucose administration. Other bile acid components showed no significant change. It thus was presumed that cholesterol endogenously synthesized in the liver was metabolized mainly to cholic acid. In contrast, exogenous cholesterol was metabolized mainly to chenodeoxycholic acid. During the period of the acute enhancement of cholic acid formation from the endogenous cholesterol, biliary excretion of deoxycholic acid was increased. This probably occurred through the depression of 7 alpha-rehydroxylation of deoxycholic acid, or through the enhancement of microbial formation of deoxycholic acid in the lumen, and through the increase of intestinal absorption.     

丁二酸在环己烷,环己酮,环己醇中溶解度的研究

丁二酸是己二酸生产过程中,与己二酸和戊二酸一起共存于环己烷、环己醇和环己酮组成的混合体系中的一种副产物.为了提高己二酸的纯度,需要对丁二酸在环己烷、环己醇、环己酮中的溶解性能进行研究.本文利用常压固液平衡测定装置,对丁二酸在环己烷、环己酮、环己醇单一溶剂及其混合溶剂中的溶解度进行了测定.结果表明,丁二酸在环己酮和环己醇中的溶解度,分别为3.9784 g和1.2070 g,均大于1 g,属可溶范畴;在环己烷中的溶解度,仅0.0082 g,小于0.01 g,属于难溶范畴.在环己酮和环己醇的单一溶剂中,在20～50 ℃时,对丁二酸的溶解能力是环己酮>环己醇>环己烷;而在60～80 ℃时,则是环己醇>环己酮>环己烷.在3种溶剂的混合体系中,丁二酸的溶解度均随温度升高而增大;低于50 ℃时,随温度升高溶解度增大缓慢,在50～80 ℃时随温度升高增大较快.     

Pyrophosphatidic acid in mushrooms

The distribution of pyrophosphatidic acid in mushrooms was investigated. Total lipids of mushrooms were extracted from their fruit body, and the pyrophosphatidic acid fraction was isolated by DEAE-silica gel column and silicic acid column chromatography. The presence of pyrophosphatidic acid was tested by thin layer chromatography. Of the 43 species of mushrooms examined, the acid was found in 30. The pyrophosphatidic acid was identified by chromatography, IR spectroscopy and quantitative degradation with aqueous pyridine to produce phosphatidic acid. Chemically synthesized pyrophosphatidic acid was used as standard.