MTP反应器改造对产物分布的影响

主要对MTP微反评价装置反应器内径由Φ0.65cm变至Φ0.90cm,等温区长5cm,填装催化剂的量由0.5g变至1.0g、2.0g,管长由24cm变为31cm,考察MTP催化剂填装方法对MTP产物分布与催化剂寿命的影响.结果显示催化剂填装量1.0g,丙烯选择性最高,催化剂长周期运行寿命较长。     

催化精馏塔中催化剂填装技术的研究述评

按气、液、固三相间不同的接触方式,将催化精馏技术中的瓶颈问题之一的催化剂填装技术分为两大类作了系统的介绍,即气、液、固三相混合接触式和液、固与气、液分别接触式。阐明了各类填装方式的优缺点及其可能的应用领域,指出了催化剂填装技术未来多元化的发展趋势。     

生物学视角下酱香型白酒的研究进展

在传统的固态白酒的酿造过程其实就是微生物运作过程,在整个酿酒过程中,微生物对于白酒的品质以及风味都起着重要作用。本文通过生物学视角,分析我国当下白酒酿造技术最新进展,并从酒曲微生物、酒醅微生物、窑泥微生物三方面分析了我国未来白酒微生物研究主要方向以及分子水平的机制机理的基础理论,得出微生物对就只风味影响的重要性,为推动我国酱香型白酒朝着更好更健康的道路发展。     

渗流型催化填料的流体力学性能

提出了一种液、固与气、液分别接触式渗流型催化剂填装构件,并在直径为100mm的冷模实验装置中对该催化填料的流体力学性能进行研究,与传统捆扎包形式的催化填料相比,该渗流型催化填料具有压降低、液泛气速高等优点.     

调整硫酸生产转化三段催化剂量使尾气排放SO_2达到新国标

针对部分硫酸企业尾气SO_2排放达不到新国标,回顾硫酸生产转化工艺技术发展历程,分析发现全国许多厂一次转化的三段转化率低,催化剂填装量过少,使SO_2反应后移,是总转化率上不去的主因,也是排放尾气SO_2超标的关键。对企业进行技术改造,调整现行转化器催化剂填装量。改造后,总转化率在99.9%左右,尾气排放ρ(SO_2)在300 mg/m~3左右。     

蒸馏原理在衡水老白干酒生产中的应用

白酒生产的重要原理之一是蒸馏作用,只有通过蒸馏才能有效地从酒醅发酵液中分离、浓缩、提纯各种骨架成分和微量成分,再根据其馏出规律进行掐头去尾,将各种不同成分、不同比例的基酒进行勾兑,生产出高质量的饮用白酒。     

加热浓缩对1,10-菲罗啉分光光度法测定铁的影响分析

以国电荥阳煤电一体化有限公司的水汽为研究对象,分析了实验中加热浓缩时间对铁标准溶液、凝结水、饱和蒸汽、循环冷却水中铁离子含量的影响。实验表明,铁标准溶液的测定结果重现性好,准确度高,浓缩时间对标准溶液测定结果影响不大;凝结水随着加热时间的增加铁离子含量稍有增加;饱和蒸汽加热浓缩过程中,铁离子测定结果稍有减小;循环冷却水含铁量与加热浓缩时间关系密切,加热越久,含铁量增大明显;对于有机化合物较多的样品,需事先进行消解处理。     

白酒塑料包装中增塑剂的迁移行为

采用气相色谱-质谱法研究了市售白色塑料酒壶中邻苯二甲酸二(2-乙基己烷)酯(DEHP)、邻苯二甲酸二异壬酯(DINP)和邻苯二甲酸二丁酯(DBP)在不同浸泡时间和温度以及不同酒精度条件下向白酒中迁移量的变化规律。结果显示,相同条件下,DEHP的迁移量最大;3种邻苯二甲酸酯(PAEs)向白酒中的迁移量与酒精度数和浸泡时间均成正比;当浸泡温度高于常温时,PAEs的迁移量将随着温度的增加而增加。因此,市售白色塑料酒壶在贮藏高度数酒时,不宜在高温条件下长期贮藏,以免白酒中PAEs含量过高而对饮酒者造成不良的健康风险。     

海水盐度对海水沸腾传热及淡水产率的影响

对机械蒸汽压缩式(MVC)海水淡化中的沸腾传热与海水淡化性能进行理论分析。以竖直管式蒸发冷凝器建立具有不同盐度的海水核态沸腾传热模型,对海水的传热性能、热流密度、淡水产率以及海水淡化的能耗进行系统分析。为避免单位压缩功和淡水产率不能同时达到最优,设定单位压缩功不变。计算结果表明,海水盐度的增加对海水淡化的系统性能不利:海水盐度增加,沸腾换热系数αe、总传热系数、热流密度q和淡水产率m将有不同程度减小;增加沸腾压力和单位压缩功均有利于系统的传热性能,但单位压缩功的增大,增加了海水淡化的能耗。     

蒸汽品质的测定

<正> 蒸汽品质,包括饱和蒸汽和过热蒸汽是蒸汽锅炉汽水质量中的一个重要方面。蒸汽品质的好坏首先影响着使用直接蒸汽加热的物料体系,其次是给热力管道造成腐蚀或结垢堵塞,同时,蒸汽品质的好坏也可反应出锅炉运行工况的效果。因此,严格掌握蒸汽品质是汽水监测分析中的重要环节。影响蒸汽品质的主要因素是由于汽水共     

Optimization of the distillation process of Chinese liquor by comprehensive experimental investigation

Systematic experiments were carried out to optimize the distillation process of Chinese liquor through an industrial-scale distiller. Effect of the operation conditions on the yield and quality of the liquor, and variation of liquor components during distillation were investigated. The steam flowrate of 1.60 kg/min gives the best yield and quality, suggesting there exists an optimal flowrate for the distillation. The yield and quality of the liquor drops down obviously with the increase of bulk density, implying that the fermented grains should be loosely packed. Increasing the bed height from 600 to 1250 mm enhances the yield and quality, indicating that current distiller (commonly used bed height from 700 to 900 mm) has great potential of improvement. Adding small amount of edible alcohol in the steam boiler is proven to increase the liquor yield, but excess amount causes the quality degraded sharply. The liquor-vapor leaking is found to commonly occur at the initial stage of distillation process and dramatically decrease the yield and quality. A simple method is proposed to eliminate the leaking effectively. The gas chromatography analysis results show that the variation of flavor compounds during distillation is closely related to their dissolving properties in ethanol.     

蒸汽雾化式减温器探讨

通过蒸汽雾化式减温器的减温过程分析其质量和热量平衡,建立减温后的蒸汽流量和减温水流量公式,阐明影响减温水流量和减温后蒸汽温度的各种因素。针对蒸汽雾化式减温器的结构提出了减温水品质、雾化蒸汽压力、汽化长度、喷水调节阀、选型等使用要求。结合蒸汽雾化式减温器的优缺点,简要介绍了蒸汽雾化式减温器的应用现状。     

轧钢含油污泥湿式减压蒸馏处理工艺优化

使用湿式减压蒸馏法分离轧钢含油污泥的油分和残渣。采用二次通用旋转组合设计实验，研究了温度、真空度和水蒸气流量对分离效果的影响。结果表明，相比于简单蒸馏，湿式减压蒸馏能显著减轻对油分的破坏，提高油分回收率。在实验参数范围内，当蒸馏温度为321.4℃、真空度为90 kPa、水蒸气流量为1 ml·min⁻¹时，获得最大油分回收率（57.2%）。回收油分时，过高的温度和水蒸气分压会破坏油分，前者促进油分胶质组分向芳香烃和饱和烃转化，后者则会促进脂类水解，并与Fe₂O₃作用氧化重质油组分，促进胶质组分向芳香烃转化。而对于蒸馏残渣中难以分离的沥青质等大分子有机物，可通过提高温度和水蒸气流量，特别是可以提高温度，促使其分解炭化，以获得较低的残渣含油率，便于残渣中铁金属元素的回收利用。     

Steam system network synthesis with hot liquid reuse: II. Incorporating shaft work and optimum steam levels

In this first of a series of two papers, the effects of varying steam levels on the total steam flowrate are analyzed mathematically for the traditional parallel configuration as well as for the case of hot liquid reuse. It is demonstrated that in the case of parallel heat exchangers utilizing only latent heat, a minimum total steam flowrate is obtained by optimally selecting steam levels, but that in the case of hot liquid reuse, introducing multiple steam levels increases the minimum total steam flowrate attainable under those conditions. The flowrate attained utilizing hot liquid reuse, however, remains lower than when only utilizing latent heat. It is concluded that the lowest steam flowrate is attained using hot liquid reuse and only a single level of steam, but that the presence of additional steam levels resulting from turbines requires a more holistic approach to the synthesis of steam networks.     

Steam system network synthesis with hot liquid reuse: I. The mathematical model for steam level selection

In this first of a series of two papers, the effect of varying steam levels on the total steam flowrate within steam systems is analysed mathematically for the traditional parallel configuration as well as for the case of hot liquid reuse. It is demonstrated that in the case of parallel heat exchangers utilising only latent heat, a minimum total steam flowrate is obtained by optimally selecting steam levels, but that in the case of hot liquid reuse, introducing multiple steam levels increases the minimum total steam flowrate attainable under those conditions. The flowrate attained utilising hot liquid reuse, however, remains lower than when only utilising latent heat. It is concluded that the lowest steam flowrate is attained using hot liquid reuse and only a single level of steam, but that the presence of additional steam levels resulting from turbines requires a more holistic approach to the synthesis of steam networks.     

Economic trade-offs in acrylic acid reactor design

The acrylic acid process using air oxidation of propylene presents many interesting design trade-offs, particularly in the design of the reactor. The desired and undesired reactions are highly exothermic and very temperature dependent (large activation energies), so a large flowrate of inert water is also fed to the reactor to act as a thermal sink. Propylene conversion increases with temperature and reactor size, but acrylic acid yield decreases with increasing temperature. The heat of reaction is removed by generaing steam, and the steam pressure is an important design optimization variable since it sets low limits on reactor temperature. Using low-pressure steam gives high acrylic acid yield and lower carbon dioxide generation but requires large reactors. Larger air flowrates increase reactor oxygen concentrations, which reduce reactor volume but increase air compression costs.This paper explores the effects of the many design trade-offs on capital investment, energy cost and product selectivity.     

光氯化法制造邻氰基氯苄中试工艺研究

研究了邻氰基甲苯用光氯化法制备邻氰基氯苄的中试工艺。把160 kg的邻氰基甲苯投入到300 L的搪瓷反应釜中,把3只100 W白炽灯的光照引入到邻氰基甲苯液体中,在130~155℃下以9~10 kg/h速度通入干燥的氯气,通氯约40 kg停止反应,冷却氯化液,用离心机分离析出的晶体,母液再投入到反应釜中,重复上述操作,通氯质量分别为16 kg、11 kg和6 kg,把所得的邻氰基氯苄合并,用乙醇重结晶,干燥,共得到产物168 kg,总收率81.3%,w(邻氰基氯苄)=99.2%。     

福建无烟粉煤-纸浆黑液小型流化床水蒸汽催化气化表观动力学研究

在内径为26mm的实验室小型流化床反应器中进行福建尤溪无烟粉煤与纸浆黑液(BL)浸渍混合后的水蒸气催化气化实验.考察了4g/min水蒸汽流量下,不同催化剂加载浓度及不同温度对碳转化率的影响,并对催化气化表观动力学参数进行拟合与计算.研究结果表明:气化温度的升高和催化剂加载浓度的增大能显著提高碳转化率和产气速率,催化剂加载浓度从0%到8%的增加明显降低了催化气化反应的活化能,而从8%到10%的增加又令活化能有增加的趋势.在本实验条件下,BL作为催化剂的饱和加或浓度为8%.     

蒸氨塔氨汽导入硫铵酸洗塔的经验总结

蒸氨氨汽与煤气混合后进入酸洗塔 ,可提高硫铵产率 ,降低煤气管道腐蚀 ,具有较好的经济效益和环保效益。     

Comparison of alkali and steam (acid) pretreatments of lignocellulosic materials to increase enzymic susceptibility: Evaluation under optimised pretreatment conditions

The alkali pretreatment of sugar cane bagasse was optimised and compared with an optimised steam (acid) pretreatment. The optimised alkali pretreatment gave an overall sugar yield of 37.4 g sugars per 100 g bagasse accounting for 43.8% of the initial xylan and 64.5% of the glucan. Potential effluent problems were identified with the alkali treatment and several strategies were suggested to minimise them, with liquor recycling showing some promise. The optimised steam (acid) pretreatment gave an overall sugar yield of 55.7 g sugars per 100 g bagasse accounting for 76.5% of the xylan and 89.5% of the glucan. The superiority of the steam (acid) pretreatment over the alkali pretreatment depends on the ability to utilise the xylose produced.