焦炉上升管内壁结焦炭层的光谱学分析及结焦机理研究

以焦炉上升管内壁结焦炭层块为研究对象，采用X射线荧光光谱仪（XRF）、X射线衍射仪（XRD）、傅里叶红外光谱仪（FTIR）和激光共聚焦拉曼光谱仪（Raman）对结焦炭层的元素组成，以及各结焦炭层的矿物组成、组成结构和分子结构进行测试。分析从结焦炭层块外表面向内表面过渡的各结焦炭层的差异性，揭示焦炉上升管内壁结焦机理。结果表明焦炉上升管内粉尘中Fe，S和Cr极易催化荒煤气中蒽、萘等稠环芳烃化合物成炭，在焦炉上升管内壁形成炭颗粒沉积，为焦油凝结挂壁提供载体，在荒煤气温度降至结焦温度时易结焦积碳。结焦炭层均含有芳香层结构，随着结焦炭层从外表面向内表面过渡，各结焦炭层的面层间距(d₀₀₂)逐渐降低、层片直径(L_a)先降低后增加、层片堆砌高度(Lc)和芳香层数(N)先稳定后增加。结焦炭层石墨化过程是由结焦炭层内表面向外表面进行，主要包括其片层外缘的羧基和部分C-O结构的降解剥离，从而形成高度规整的共轭结构。结焦炭层块中C元素是以结晶碳与无定型碳的混合物形式存在。以上研究为解决焦炉上升管内壁结焦及腐蚀问题，提高换热器换热效率，有效回收焦炉荒煤气显热，降低焦化企业能耗提供实验基础和理论依据。     

Electrophoretically deposited sulfonated poly(styrene-co-divinylbenzene) on a screw for microextraction of cationic dyes from aqueous solutions

In the present work, a novel solid-phase microextraction on a screw (MES) was employed to extract cationic dyes (malachite green, methylene blue, and rhodamine B) from food samples and fish breeding pool water. The sulfonated poly(styrene-co-divinylbenzene) was electrophoretically deposited on the surface of the grooves of a screw. Then the screw was placed inside a silicon tube as a holder to create a channel to run a test solution through it. The extracted dyes on the coated screw were eluted by a suitable eluent. High-performance liquid chromatography with an ultraviolet/visible detector was utilized for the separation and analysis of the analytes. The effective parameters of the analyte extraction efficiency were optimized. Under optimum conditions, the limits of detection were 0.15 μg/L, and calibration curves were linear in the range of 0.50–250.00 μg/L, with coefficients of determination > 0.989 for all studied dyes. The relative standard deviations of intra and inter-day (n = 3) were in the range of 2.8%–7.0% and 7.0%–9.5%, respectively. The MES was applied as a simple and repeatable method with acceptable relative recoveries (82.0%–103.0%) for the determination of cationic dyes in grape nectar, ice pop, jelly powder, and fish breeding pool water.     

Radiometrische Bandwaage mit Rechnerschaltkreis zur Signalaufbereitung

Es wird eine radiometrische Bandwaage zur Koksaustragsmengen-Messung in BHT-Kokereien beschrieben. Voranstellend werden einige analytische Ausdrücke zur theoretischen Behandlung dieses Bandwaagentyps mitgeteilt. Die Waage zeichnet sich durch hohe Stabilität der Anzeige, durch die Möglichkeit des routinemäßigen Umsetzens von Meßstelle zu Meßstelle innerhalb kurzer Zeit und durch einen relativ kleinen Wägefehler (Meßunsicherheit ≦ 2,9%) aus. Die Signalaufbereitung innerhalb der Elektronik erfolgt durchgängig digital unter Verwendung eines Rechnerschaltkreises.     

不同活性焦载体对V2O5/AC催化剂脱硫活性的影响

活性焦载体的选择是制备高活性烟气脱硫催化剂的关键.以四种煤制活性焦(AC)为载体,制得了系列V2O5/AC催化剂.通过脱硫活性评价、催化氧化能力测试和孔结构分析表明,AC表面的高活性氧化位较少,担载V2O5使AC表面产生了新的高活性氧化位,其脱硫活性显著提高;V2O5在具有高比表面积和较大孔容的载体上分散性较好,能够形...     

助剂形态对Pt/γ-A12O3催化剂抗积炭性能的影响

采用CO和H2脉冲吸附、程序升温还原、NH3程序升温脱附及X射线衍射等手段对各金属氧化物改性的Pt/Al2O3催化剂进行了表征,研究了助剂形态对Pt/Al2O3催化剂在非临氢条件下催化环己烷脱氢反应性能的影响.结果表明,催化剂稳定性从高到低依次为Zr-Pt/Al2O3＞ Ca-Pt/Al2O3＞ Ce-Pt/Al2O3...     

A Solution‐Processed Air‐Stable Perylene Diimide Derivative for N‐type Organic Thin Film Transistors

For future all‐soluble organic thin film transistor (OTFT) applications, a new soluble n‐type air‐stable perylene diimide derivative semiconductor material with (trifluoromethyl)benzyl groups (TC–PDI–F) is synthesized. The film is formed by spin‐coating in air and optimized for OTFT fabrications. The transistor characteristics and air‐stability of the TC–PDI–F OTFTs is measured to investigate the feasibility of using solution‐processed TC–PDI–F for future OTFT applications. For all‐solution OTFT process applications, the transistor characteristics are demonstrated by using TC–PDI–F as an n‐type semiconductor material and liquid‐phase‐deposited SiO₂ (LPD–SiO₂) as a gate dielectric material. All processes (except material synthesis and electrode deposition) and electrical measurements are conducted in air.     

中温热解焦油重馏分悬浮床加氢裂化的研究

以中温热解煤焦油为原料,对其性质进行了分析,其中,350℃重质馏分中胶质含量30.88%,沥青质含量37.27%,四氢呋喃不溶物3.36%,属于常规固定床加氢裂化难以直接处理的馏分。合成了一种Mo系超分散催化剂,采用FT-IR、XPS、XRD、SEM和TEM等对催化剂进行了表征,催化剂中含有Mo=O和Mo-S特征结构,活性金属的硫化率为84.34%,在体系中具有优良的分散性,在反应体系内原位分解为超分散MoS_2颗粒;在0.25 t/d连续装置上进行了热解重油悬浮床加氢裂化实验研究,考察了反应条件对产物分布情况和结焦率的影响,得出适宜的反应条件为19 MPa,440℃,催化剂的添加量为300 mg/kg;此条件下石脑油收率24.47%,柴油馏分收率49.71%,结焦率1.32%。     

石灰岩对褐煤模拟地下气化残焦物化性质的影响

基于煤炭地下气化过程中石灰岩可能影响煤焦的组成和结构,借助煤炭地下气化模拟实验系统对不同石灰岩掺量(质量分数为0-30%)的褐煤进行水蒸气气化,并采用低温N_2吸附-脱附、XRD和FT-IR等分析手段研究石灰岩对褐煤模拟地下气化残焦的组成、比表面积及孔结构特征、微晶结构和表面官能团等物理化学性质的影响。结果表明,石灰岩对煤焦的元素组成有较大影响。石灰岩可促使煤焦中的微孔向中孔发育,增大煤焦的比表面积和孔容积;当石灰岩掺量从0增加到30%时,煤焦的比表面积增大21.91%,介孔率增加21.49个百分点。XRD分析表明,钙的存在破坏煤焦的芳香结构,使煤焦无序化程度增加,晶面间距(d_(002))增大,抑制煤焦的石墨化发展倾向。FT-IR分析表明,石灰岩存在下,煤焦的羟基官能团减少。     

Effect of Ni loadings on the activity and coke formation of MgO-modified Ni/Al2O3 nanocatalyst in dry reforming of methane

MgO-modified Ni/Al₂O₃ catalysts with different Ni loadings were prepared and employed in dry reforming of methane (DRM). The effect of Ni loadings on the activity and coke formation of Ni/MgO-Al₂O₃ catalysts were investigated. The synthesized catalysts were characterized by XRD, N₂ adsorption-desorption, SEM, TPO and TPR techniques. The obtained results showed that increasing nickel loading decreased the BET surface area and increased the catalytic activity and amount of deposited carbon. In addition, the effect of gas hourly space velocity (GHSV) and feed ratio were studied.     

Coking-resistant Ni-ZrO2/A1203 catalyst for CO methanation

Highly coke-resisting ZrO2-decorated Ni/A1203 catalysts for CO methanation were prepared by a two-step process. The support was first loaded with NiO by impregnating method and then modified with ZrO2 by deposition-precipitation method （IM-DP）. Nitrogen adsorption- desorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetdc analysis, H2 temperature- programmed reduction and desorption, NH3 temperature-programmed desorption, and zeta potential analysis were employed to characterize the samples. The results revealed that, compared with the catalysts with the same composition prepared by co-impregnation （CI） and sequential impregnation （SI） methods, the Ni/A1203 catalyst prepared by IM-DP showed much enhanced catalytic performance for syngas methanation under the condition of atmospheric pressure and a high weight hourly space velocity of 120000 mL.g-1 .h-1. In a 80 h life time test under the condition of 300-600 ~C and 3.0 MPa, this catalyst showed high stability and resistance to coking, and the amount of deposited carbon was only 0.4 wt%. On the contrary, the deposited carbon over the catalyst without ZrO2 reached 1.5 wt% after a 60 h life time test. The improved catalytic performance was attributed to the selective deposition of ZrO2 nanoparticles on the surface of NiO rather than A1203, which could he well controlled via changing the electrostatic interaction in the DP procedure. This unique structure could enhance the dissociation of CO2 and generate surface oxygen intermediates, thus preventing carbon deposition on the Ni particles in syngas methanation.