基于等转化率法的煤焦-CO_2气化动力学研究

为获得可靠的煤焦-CO_2气化反应动力学参数,采用Flunm-Wall-Ozawa(FWO)等转化率法进行煤焦-CO_2气化动力学研究。在3个不同升温速率下进行了煤焦-CO_2气化热重试验,计算不同碳转化率下的反应活化能,用主曲线法分析了气化机理模型,并采用拟合法对等转化率法的结果进行验证。结果表明,气化主反应区不同碳转化率下(α为0.2~0.8)活化能的变化较小,为(228.25±5.22)k J/mol。煤焦-CO_2气化反应为均相模型,该模型标准曲线与试验曲线重合度较好,并符合目前常用的煤气化动力学模型。拟合法计算的活化能仅与等转化率法相差0.74 k J/mol,说明等转化率法研究煤焦-CO_2动力学可行。     

酸催化酯化法制备生物柴油动力学研究

以油酸和甲醇为原料,采用浓硫酸、固体酸SO42-/TiO2-SiO2或油酸的自催化作用进行催化,研究了油酸和甲醇酯化合成生物柴油过程的催化反应动力学.通过测定不同反应温度、不同催化剂浓度和不同甲醇/油酸摩尔比条件下油酸的转化率,回归得到了酯化反应动力学参数.研究结果表明,酯化反应及其逆反应均为二级反应.不同催化反应下的正逆反应活化能分别为33.8和13.9 kJ·mol-1(浓硫酸催化)、37.1和18.5 kJ·mol-1(SO42-/TiO2-SiO2催化)或49.1和31.1 kJ·mol-1(油酸自催化作用).以上述过程中得到的反应动力学方程分别计算了油酸的转化值,与实验值吻合很好.由上述结果可知,浓硫酸具有最高催化活性,要在相同反应时间内得到相同油酸转化率时需要的反应温度最低.油酸自催化反应速率慢,在相同的反应时间内,高温反应时才可使油酸的转化率与浓硫酸低温催化作用下的油酸转化率相同.SO42-/TiO2-SiO2催化活性介于浓硫酸与油酸自催化之间,由于具有稳定好、分离简单和无腐蚀等优点,也适合作为酯化反应的催化剂.     

温度和时间对神东煤直接液化转化率和收率的影响

采用高压反应釜,研究了反应温度和反应时间对神东煤直接液化性能的影响。结果表明,在不同的反应时间下,煤转化率大体上随着反应温度的升高而增加,其中当反应时间较短时,煤转化率增加的幅度较大;当反应时间较长时,煤转化率增加的幅度较小。在不同的反应时间下,随着反应温度的升高,大体上油收率逐渐增大,沥青质收率逐渐减小,水收率变化不明显,气收率逐渐增大。在不同的反应温度下,随着反应时间的延长,煤转化率和油收率都先是快速增大,然后缓慢增大,在反应温度太高时,随反应时间继续延长,煤转化率增加到最大值后基本不变甚至略有减小,油收率增加到最大值后开始减小。当反应温度为460℃,反应时间为90 min时,煤转化率和油收率达到最大值,分别为90.7%和61.8%。     

温度和时间对神东煤直接液化转化率和收率的影响

采用高压反应釜,研究了反应温度和反应时间对神东煤直接液化性能的影响。结果表明,在不同的反应时间下,煤转化率大体上随着反应温度的升高而增加,其中当反应时间较短时,煤转化率增加的幅度较大;当反应时间较长时,煤转化率增加的幅度较小。在不同的反应时间下,随着反应温度的升高,大体上油收率逐渐增大,沥青质收率逐渐减小,水收率变化不明显,气收率逐渐增大。在不同的反应温度下,随着反应时间的延长,煤转化率和油收率都先是快速增大,然后缓慢增大,在反应温度太高时,随反应时间继续延长,煤转化率增加到最大值后基本不变甚至略有减小,油收率增加到最大值后开始减小。当反应温度为460℃,反应时间为90 min时,煤转化率和油收率达到最大值,分别为90.7%和61.8%。     

阳离子交换树脂催化合成异丁酸正丁酯

以异丁酸和正丁醇为原料,阳离子交换树脂(NKC-9)为催化剂,合成了异丁酸正丁酯。考察了醇酸摩尔比、催化剂用量、反应时间等因素对反应的影响,并测定了动力学数据。通过实验得到了较佳制备工艺条件:n(正丁醇)∶n(异丁酸)=1.4∶1,NKC-9催化剂用量为异丁酸和正丁醇总质量的4%,反应温度≤125℃,反应时间2.0h,在该条件下,异丁酸的转化率达97.6%,催化剂重复使用5次后,异丁酸的转化率为96.4%。并建立了该酯化反应的表观动力学模型。     

用沉降天平法对苯乙烯聚合全程转化率的动力学研究

本文采用沉降天平法对ＢＰＯ引发苯乙烯聚合的全程转化率作了连续自动测定。采用溴化法对其进行了标定。发现采用此法能准确连续地测定苯乙烯的聚合动力学曲线。实验研究了不同ＢＰＯ用量及反应温度对聚合动力学曲线的影响，提出了苯乙烯聚合的动力学模型。     

半水法磷酸生产工艺研究

针对半水法磷酸工艺在高浓度磷酸条件下研究了磷矿粒度、反应温度和反应时间对P2O5转化率的影响,并在不同硫酸浓度条件下测定了反应活性表达式,最后对采用多种游离硫酸浓度条件下的半水流程进行了长周期运行,获得了较优的操作条件,当结晶槽中ρ（SO3游离）为40～50 g/L时P2O5转化率可以达到94.45％.     

十二烷基三甲基氯化铵的催化合成研究

采用高压釜反应器,以十二烷基二甲基叔胺（以下简称“12叔胺”）和一氯甲烷为原料,研究了12叔胺和一氯甲烷的最佳摩尔比。并在不同反应温度和反应时间条件下,以碳酸钠、硼氢化钠和氢氧化钠等为催化剂,对比合成十二烷基三甲基氯化铵（以下简称“1231”）的叔胺转化率和产品色泽。得到了叔胺转化率和产品色泽与反应时间和反应温度的关系曲线。结果表明：当原料摩尔比n(一氯甲烷)︰n(12叔胺)=1.02︰1时,以碳酸钠为催化剂,反应温度为80℃,反应时间为4 h,得到产品的色泽和和叔胺转化率最佳,色泽小于20 Hazen,叔胺转化率达99.5%,游离胺相对阳离子活性物的质量分数小于0.3%。     

异丁酸正丁酯的催化合成及反应动力学

以异丁酸和正丁醇为原料,阳离子交换树脂(NKC-9)为催化剂,合成了异丁酸正丁酯。考察了醇酸摩尔比、催化剂用量、反应时间等因素对反应过程的影响,并测定了动力学数据。通过实验得到了较佳制备工艺条件： n(正丁醇):n(异丁酸)＝1.4：1,NKC-9催化剂用量为异丁酸和正丁醇总质量的4%,反应温度≤125℃,反应时间2.0h,在该条件下异丁酸的转化率达到97.6%,催化剂重复使用5次后,异丁酸的转化率为96.4%。建立了该酯化反应的表观动力学模型,得到的反应速率方程。     

傅立叶变换红外光谱法研究马来酸酐与聚乙二醇酯化反应

利用傅立叶变换红外光谱法跟踪监测马来酸酐与聚乙二醇的酯化反应,根据酯化产物在不同反应时间上的特征红外吸收峰面积的变化半定量的作出酯化反应动力学曲线,并考察了催化剂、反应温度等对酯化反应动力学曲线的影响,找出获得单酯产物的最佳反应条件。     

SEDIMENTATION OF BINARY MIXTURES OF PARTICLES OF UNEQUAL DENSITIES AND OF DIFFERENT SIZES

A model is developed for the sedimentation from a suspension of two particle species of unequal densities and of different sizes. The composition and the thickness of various layers in the sediments are predicted using graphical and analytical methods. The model predictions were in excellent agreement with experimental results, when the particle size ratio was ≥ 108. When size ratio of the particles was 2.60 and 4.31 the agreement occurred in about 50 percent of the cases.     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

COMPARISON OF METHODS OF ANALYSIS OF GYPSUM1

The different analytical methods proposed for the evaluation of gypsum have been subjected to an experimental test. A combination method, consisting of a fusion with KHCO₃ and determination of CaO by KMnO₄ titration, the SO₃ by Andrews method of titration of BaCrO₄ has been found to give very reliable results with the least consumption of time.     

氢气纯度分析方法准确性的探讨

ONACCURACYOFANALYSISOFOFHYDROGEN1前言我公司目前应用的氢气纯度分析方法有两种,一种是爆炸反应法,另一种是焦性没食子酸吸收法。几年来,人们对两种分析方法的准确性曾有过褒贬不一的评论。这里我们也谈谈自己粗浅的观点。2爆炸法测定氢气纯度一定量的氢气样品与适量的空气之均匀混合物因反应后生成液体水而引起气体体积减少,减少的体积等于参加反应气体体积之和。其中l／3为氧气,2／3为氢气。根据氢气取样量和反应前后混气体体积之差,以及氢气在反应中的体积比例关系,可计算出样品的氢气纯度。计算公式式中：A一混…     

HEASUREHENT OF INSTANTANEOUS RATES OF LOSS OF VOIATILE COMPOUNDS DURING DRYING OF DROPS

A novel technique serves to monitor instantaneous rates of loss of a volatile solute from a suspended drop during drying. A highly sensitive electron capture detector is used to monitor concentrations of SF6 released into a flowing gas stream from a suspended, drying drop. Simultaneously, the appearance and morphological development of the drop are monitored with a video camera. This provides the wherewithal of relating instantaneous rates of loss of the volatile solute to particular events during the development of particle morphology.

Initial experiments have been carried out with drops of aqueous solutions of glucose, sucrose, maltodextrin and coffee extract. The results clearly display the onset of the volatiles-retentive selective diffusion phenomenon. There is also substantial loss of the volatile component later in the drying process, when the drops undergo repeated ex ansion, bursting and cratering due to the formation of internaf bubbles. These experiments appear to be the first quantitative demonstration of major losses accompanying changes in drop morphology.     

用两个形状指数表征粉煤灰颗粒形貌的研究

引用两个形状指数表征颗粒形状的概念,即先将颗粒形状近似为椭圆,再将椭圆图像分离:以圆为基准的颗粒宏观形状指数δ;以光滑椭圆为基准的颗粒轮廓凹凸度,即微观形状指数ζ。分析和发展了近似椭圆模型。并运用图像分析仪对粉煤灰、水泥样品进行实验。结果表明,粉煤灰颗粒的两个形状指数δ和ζ都大于水泥颗粒。证明粉煤灰颗粒的球形度、表面光滑度优于水泥,而且,随着粒径增大,δ和ζ呈下降趋势,表明磨制颗粒越粗。(?)粒形状越不规则。文中还运用近似椭圆模型再现了颗粒的模拟图像。     

典型煤碳燃烧特性研究和数值模拟

本文以三种典型煤的碳燃烧为研究对象，分别采用简单一维沉降燃烧方式和等温加热燃烧方式，实验研究了煤在快速加热条件下，其碳的初期和中，后期燃烧过程。以实验为基础，建立了煤的碳燃烧模型，变工况数值模拟了煤的碳燃烧过程，揭示了煤不同条件下的单颗粒碳燃烧特性。     

ANALYSIS OF RECENT MEASUREMENTS OF THE VISCOSITY OF GLASSES

Viscosity of Simple Soda-Silicate 500° to 1400°C Comparison of the results given by English with those of Washburn, Shelton and Libman, indicates a discrepancy in the absolute values of log₁₀ viscosity amounting to 0.6, those of Washburn et al., being relatively too high. If correction for this is made, the isothermal curves of log₁₀ viscosity as a function of soda content are smooth up to 50% Na₂O, showing no inflection. The observations as a function of temperature T are all represented within accidental error by an equation of the type where all three constants vary regularly with the composition. Change of Viscosity of Glass (6SiO₂, 2Na₂O) due to Molecular Substitution of CaO, MgO and Al₂O₃ for Na₂O The effect is clearly brought out by plotting (from the results of English) the change of log₁₀η due to the substitution as a function of temperature. The curves each show a sharp bend at a temperature between 840° and 1050°C, which is designated the aggregation temperature T_a. If we divide these curves by the corresponding percentage substituted, we get curves for each oxide which are straight and parallel below the aggregation temperatures, the slopes (increase of change of log₁₀η per 100°C) being −0.056 (CaO), −0.055 (MgO), −0.018 (A1₂O₃) per per cent oxide substituted. For substitution of 1/2 molecule the slopes are −0.325 (CaO), −0.23 (MgO) and −0.18 (Al₂O₃) per 100°. At the aggregation temperature the change of log₁₀η per per cent is a minimum, 0.03 to 0.06 for CaO, 0.12 for MgO, 0.07 for Al₂O₃. Evidence of Aggregation in Glasses, from viscosity Measurements The sharp bends in the plots of change of log₁₀η due to substitution of an oxide for Na₂O, suggest the beginning of molecular aggregation at these temperatures. These aggregation temperatures are close to the devitrification temperatures, but the effect on the viscosity curves cannot be due to actual devitrification since it does not change with time. Taking the aggregation temperatures as equal to devitrification temperatures, additional isotherms are roughly sketched into the equilibrium triangle of the system Na₂O-CaO-SiO₂. Change of Viscosity of Glass (4SiO₂, 2Na₂O) due to of Substitution of B₂O₃ for SiO₂ The change of log₁₀η (from the results of English) is plotted as a function of temperature, and also the change of log₁₀η per per cent B₂O₃. The curves are more complex than for the substitution for Na₂O.     

环氧树脂羟基值测定方法的研究

利用乙酸酐、吡啶和浓硫酸混合的乙酰化试剂测定环氧树脂中羟基值含量的方法具有操作简便、滴定终点明显和分析结果误差小等优点。     

制备板状玻璃炭工艺中固化曲线的确定

固化处理是在玻璃炭制备工艺中很关键的阶段．在差热分析和热失重分析的基础上．建立了玻璃炭（GC）固化升温曲线，并与等速升温法作了比较．