首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 109 毫秒
1.
中国石化石油化工科学研究院历经20年,成功开发出己内酰胺绿色生产技术,建成3套20万t/a工业生产装置、多套工业装置正在建设中.己内酰胺绿色生产技术包括:钛硅分子筛与浆态床集成用于环己酮氨肟化合成环己酮肟;纯硅分子筛与移动床集成用于环己酮肟气相重排;非晶态合金催化剂与磁稳定床集成用于己内酰胺精制.工业实施后,装置投资下降70%、生产成本下降10%、原子利用率由60%提高到90%以上、三废排放是已有技术路线的1/200、无副产物硫酸铵.己内酰胺绿色生产技术产生了重大的经济效益和社会效益,践行了绿色化学的理念,是绿色化学的成功范例.  相似文献   

2.
自我国第一套流化催化裂化装置于1965年实现工业化以来,先后开发出沸石催化剂-提升管催化裂化、渣油催化裂化、催化裂解、变径串联提升管催化裂化和正在开发的高选择性催化裂化;经历了催化裂化装置从无到有,技术水平由低到高,装置规模和加工能力从小到大,研究思路从跟踪模仿到自主创新,取得了巨大的成就,已跻身国际先进水平.到目前为止,全国催化裂化装置总加工能力已达到近150 Mt/a,其中渣油占催化裂化总进料约40%,所生产的汽油和柴油组分分别占全国汽油和柴油成品总量的70%和30%左右,所生产的丙烯量约占全国丙烯总产量的40%.同时,此催化裂化装置还可为烷基化装置和醚化装置提供原料.这些成果对我国炼油行业加工重质原料、提高轻质油收率和改善产品质量,进而提高经济效益起着举足轻重的作用.  相似文献   

3.
在磷含量1.34%下,采用分步浸渍法按磷添加顺序不同制备了3种改性催化剂:MoP-Ni/Al2O3、Mo-NiP/Al2O3、Mo-Ni/PAl2O3.通过X射线衍射(XRD)、程序升温脱附(NH3-TPD)、程序升温还原(H2-TPR)、氮气吸附等技术对催化剂进行了表征.以新疆中低温煤焦油为原料,考察了不同磷改性方式对催化剂加氢脱氮(HDN)性能的影响.结果表明,适宜的磷添加方式能够改变催化剂的酸性分布,提高10~13 nm加氢脱氮有效孔的比例,并且减弱活性组分与载体的相互作用,同时使得活性组分更易被还原,进而提高催化剂加氢脱氮性能.加氢脱氮活性顺序为Mo-Ni/PAl2O3(74.36%)>Mo-NiP/Al2O3(72.74%)>Mo-Ni/Al2O3(71.72%)>MoP-Ni/Al2O3(56.13%).  相似文献   

4.
采用完全液相法以不同的铜源和锌源为原料制备了CuZnAl催化剂,在浆态床反应器中考察了其催化合成气合成乙醇的性能,并采用XRD、H2-TPR、NH3-TPD-MS及BET技术对催化剂进行表征。结果表明,以乙酸铜替换硝酸铜,抑制了热处理过程中Cu2O的还原,提高了催化剂的比表面积,为催化剂具有较高的乙醇选择性提供了适宜的酸中心和孔径,其总醇选择性达45.6%,总醇中乙醇所占比例达28.7%。  相似文献   

5.
多道检测—激光诱导荧光猝灭法测定食品中磷   总被引:1,自引:0,他引:1  
利用激光诱导荧光 二极管阵列检测 计算机联用装置 ,对磷钼杂多酸 罗丹明 6G荧光猝灭体系进行了研究 ,建立了一种测定食品中磷的新荧光光度法。试验表明 ,该法具有较好的灵敏度、选择性 ,检出限为 0 .1ng·ml- 1,加标回收率为 90 .6%~ 10 9.0 % ,相对标准偏差为 1.3%~3 0 % ,用于食品样品中磷的测定 ,结果满意  相似文献   

6.
在程序升温热解反应装置上,研究了低氯煤中添加不同氯含量(质量分数0.1%、0.3%、0.5%)的CaCl2对煤热解过程中汞析出规律的影响。实验结果表明,温度是影响汞析出的关键因素;随着氯添加量的增加,Hg2+析出比例呈上升趋势,且汞的最佳析出温度降低,汞的释放率也有所降低;随着热解气氛中O2比例的增加,Hg2+比例也略有增加;较高的升温速率能加快汞的释放,也能提高Hg2+的比例。低氯煤中添加氯化钙能够强化单质汞的氧化。  相似文献   

7.
用对称性匹配微扰理论(SAPT)对C_2H_2与X2(X=F,Cl,Br,I)相互作用进行了量子化学研究.优化所得的4个稳定复合物相互作用能在-3.276 8~-10.639 5 k J/mol之间.自然键轨道(NBO)理论分析表明,形成复合物分子间的电荷转移量都很少,在0.002 3~0.013 2之间.SAPT2能量分析显示,从F到I,静电能和诱导能先增大后减小,交换能和色散能逐渐增强,相互作用能依次增强.复合物稳定构型的相互作用能中静电能占主导作用,对吸引能的贡献比例在C_2H_2 F2中最大(57.3%),在C_2H_2 I2中最小(49.7%);其次为色散能,在吸引能中所占的比例在21.9%(C_2H_2 F2)~31.2%(C_2H_2 I2)之间;诱导能在吸引能中所占的比例最小,均小于20.7%.  相似文献   

8.
用对称性匹配微扰理论(SAPT)对C2H2与X2(X=F,CI,Br,I)相互作用进行了量子化学研究.优化所得的4个稳定复合物相互作用能在-3.276 8~-10.639 5 kJ/mol之间.自然键轨道(NBO)理论分析表明,形成复合物分子间的电荷转移量都很少,在0.002 3~0.013 2之间.SAPT2能量分析显示,从F到I,静电能和诱导能先增大后减小,交换能和色散能逐渐增强,相互作用能依次增强.复合物稳定构型的相互作用能中静电能占主导作用,对吸引能的贡献比例在C2H2…F2中最大(57.3%),在C2H2…I2中最小(49.7%);其次为色散能,在吸引能中所占的比例在21.9%(C2H2…F2)~31.2%(C2H2…I2)之间;诱导能在吸引能中所占的比例最小,均小于20.7%.  相似文献   

9.
文献[1]介绍了磷钨钒光度法快速测定碳钢、低合金钢中0/01%~0.50%钒的测定方法.本文在此基础上经试验发现,紫红色低价磷钨钒吸收光谱曲线与文献[1]有区别;另外通过降低体系酸度,提高了配合物的稳定性和灵敏度;利用高氯酸热氧化性在挥铬的同时将钒氧化为高价V(V),使操作更简便、快速,通过实际标样分析结果良好,能满足实际生产的需要.  相似文献   

10.
采用溶胶-凝胶技术研究了ZrOCl2·8H2O掺杂对磷硅酸盐凝胶质子导电性能的影响. 结果表明, 掺杂ZrOCl2·8H2O能提高磷硅酸盐凝胶的质子电导率, 并且掺杂质量分数为0.97%时质子电导率达到最大值(σ130=2.38 S/m). 掺杂样品在相对湿度为40%条件下放置30 d后, 未发生H3PO4渗出现象, 其质子传导性能基本不变. 核磁共振谱结果表明, 掺杂ZrOCl2减少了磷硅酸盐凝胶结构中自由磷酸的形成, 提高了与四面体之间的化学结合力.  相似文献   

11.
A preparation of the superphosphate on the basis of a apatite concentrate and Mardin-Mazidagi phosphorite mixture was investigated. It was stated that the superphosphate obtained as a result of a substitution of the apatite concentrate by Mardin-Mazidagi phosphorite up to 45% met the requirements of State Standards.  相似文献   

12.
《Analytical letters》2012,45(8):701-734
Abstract

The use of packed-bed solid sorbent tubes was investigated for the collection and concentration of lead and lead compound aerosols utilizing a lead metal laboratory test atmosphere and lead containing automobile exhaust. Four different sorbents were tested: alumina (100–150 mesh), silica gel (80–200 mesh), Chromosorb 102 (60–80 mesh), and Tenax-GC (80–100 mesh). The following average collection efficiencies were observed for the first portion of each sorbent in the tube (200 mg of sorbent) when sampling automobile exhaust: 95.8 ± 5.7 % for alumina, 98.5 ± 3.2 % for silica gel, 98.0 ± 3.7 % for Chromosorb 102, and 99.2 ± 2.6 % for Tenax-GC. Using the lead metal test aerosol, the average efficiencies were 99.2 ± 1.0, 99.2 ± 1.1, 99.9 ± 0.1, and 100.0 ± 0.0 % for the alumina, silica gel, Chromosorb 102, and Tenax-GC, respectively. Consideration of percent collection efficiency, blank values, and elution efficiency of lead from the sorbent indicated that Tenax-GC provided the best results.  相似文献   

13.
Nondestructive photon activation analysis with 30 MeV bremsstrahlung was applied to determine trace element concentrations in the livers and spleens of five pigs. Samples were freeze-dried, pulverized and fractionated into four groups corresponding mesh size; smaller than 60 mesh, 60–100 mesh, 100–200 mesh and larger than 200 mesh. Up to 9 elements in each fraction were analyzed. The concentrations of Br, Fe, Mg, Mn, Mo, Na, Rb and Zn in each liver fractions were almost constant, as were concentrations of Mg and Rb in spleens.  相似文献   

14.
高镁磷尾矿中钙、镁、磷赋存状态研究   总被引:1,自引:0,他引:1  
选择了贵州省重要磷矿生产基地—瓮福磷矿浮选尾矿为代表,对其中钙、镁、磷的矿物学重要特征进行了比较系统的研究,获得了一些重要结论,从而为高镁磷尾矿的综合利用、白云石与胶磷矿的分离等提供理论依据,对实现磷尾矿资源的二次利用、指导开发者设计科学合理的矿石选冶工艺流程都有十分重要的意义。按照元素赋存形态分析的方法,选用了化学成分、化学物相、电子能谱、扫描电子显微镜、X射线粉晶衍射分析方法等多种手段系统、全面地测定了磷尾矿结构、形貌的重要特征,获得了钙、镁、磷赋存状态的重要结论,发现了尾矿及其原矿的异同性:磷尾矿中含量最高的组分及其含量分别是:氧化钙34.11%,氧化镁17.65%,五氧化二磷5.30%;镁主要以白云石的形式赋存,并有少量以磷酸盐、硅酸盐形式存在,其在各相占的比例分别为99.80%、0.10%、0.10%;磷主要以磷灰石的形式赋存(占97.08%),并有少量以铁氧化物(1.04%)、独居石(0.19%)、磷钇矿(1.83%)形式存在;钙主要以白云石的形式赋存(占96.95%),并有少量以方解石(1.11%)、磷酸盐(1.94%)形式存在。贵州瓮福地区高镁磷尾矿中的镁、磷、钙主要赋存形式分别为白云石、磷灰石、白云石。  相似文献   

15.
With a complex of physico-chemical methods for analysis it is proved that in the course of mechanochemical treatment of a Syrian phosphorite and ammonium sulphate mixture new phases have been formed. The thermal analysis proves an increase in the reaction properties of the ammonium sulphate and the Syrian phosphorite which is a prerequisite for the increase in the content of P2O5assimilated , in the activated phosphorite mixtures and the possibility to use them in the production of NP complex fertilizers.  相似文献   

16.
应用化学组分分析、X射线衍射分析、扫描电子显微镜及X射线能谱法等多种方法对贵州省瓮福地区磷尾矿中钙、镁及磷的赋存状态作了分析和研究。结果表明:①选自该矿区的磷尾矿为高镁(wMgO17.26%~17.65%),高钙(wCaO34.11%~34.56%),低磷(wP2O55.30%~5.69%)的固体矿物;②尾矿中镁主要以白云石形式存在,并有少量以磷酸盐和硅酸盐形式存在;钙主要也以白云石形式存在,加上少量以方解石和磷酸盐形式存在;磷主要以磷灰石形式存在,有少量存在于铁氧化物及独居石、磷钇矿中。  相似文献   

17.
We report a simple and environment friendly method to fabricate superhydrophobic metallic mesh surfaces for oil/water separation. The obtained mesh surface exhibits superhydrophobicity and superoleophilicity after it was dried in an oven at 200 °C for 10 min. A rough silver layer is formed on the mesh surface after immersion, and the spontaneous adsorption of airborne carbon contaminants on the silver surface lower the surface free energy of the mesh. No low‐surface‐energy reagents and/or volatile organic solvents are used. In addition, we demonstrate that by using the mesh box, oils can be separated and collected from the surface of water repeatedly, and that high separation efficiencies of larger than 92 % are retained for various oils. Moreover, the superhydrophobic mesh also possesses excellent corrosion resistance and thermal stability. Hence, these superhydrophobic meshes might be good candidates for the practical separation of oil from the surface of water.  相似文献   

18.
Harbour activities such as loading, unloading and transport of materials may be an important source of Atmospheric Particulate Matter (APM). Depending on the materials, the type of operation and the meteorological conditions, these activities may have an impact on the levels of APM around harbour areas. The aim of this work was to characterize the emissions of dust providing from operations associated with phosphorite handling in harbours. Phosphorite is a non-detrital sedimentary rock which contains high amounts of phosphate bearing minerals and is used for the production of phosphorous based fertilizers. When handled in harbours frequently cause visual and environment impacts due to its physical and chemical characteristics. The techniques Instrumental Neutron Activation Analysis and Particle Induced X-ray Emission were applied as sensitive analytical tools for the determination of heavy metals and rare earth elements in phosphorite and in the APM sampled in the harbour during the unloading operations. Results showed that manipulation of phosphorite during harbour operations resulted in high emissions of particles, principally from the coarse fraction. These emissions were enriched in rare earth elements and heavy metals and were very affected by the provenience of the phosphorite.  相似文献   

19.
Kragten J  Ozinga W 《Talanta》1985,32(1):27-30
With DTPA present in excess, small amounts of uranium (100-200 mug) can be reduced quantitatively to the quadrivalent state in a Jones reductor (5% amalgamated Zn powder, 50 mesh). The excess of DTPA is back-titrated photometrically with thorium, with Semi-Xylenol Orange as the indicator. The accuracy is +/- 0.2 mu g at the 200-mu g level. Metals forming complexes with DTPA at pH 2 interfere.  相似文献   

20.
氧化锌脱硫中氢和氧的双气氛效应及动力学研究   总被引:4,自引:0,他引:4  
用热重法研究了氧化锌脱硫中氢氧的气氛效应以及氢氧共同存在下氧化锌脱硫的微观动力学行为。实验温区为200 ℃~320 ℃,氧化锌粒度为100目~120目。研究结果表明,在0%~40%的体积浓度范围内,氢可促进脱硫反应进行;氧则由于会引起氧化锌表面析硫使得脱硫过程随其浓度的变化复杂化。氢氧双气氛下,氧化锌脱硫动力学行为可用改良收缩核模型进行描述,表面反应活化能和固体扩散活化能分别为14.96 kJ/mol和46.77 kJ/mol。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号