乙醇脱水吸附剂吸附-脱附性能的研究

研究了乙醇脱水吸附剂对水和乙醇的气相吸附性能.在φ50 mm×700 mm的吸附柱中测定了乙醇脱水吸附剂吸附乙醇溶液中水的穿透曲线,考察了进料流速、进料浓度和床层高度对吸附穿透曲线的影响.采用热空气对吸附剂进行再生,测定了再生后吸附剂的穿透曲线,找出了最佳再生条件.用环境扫描电镜和热重-差示扫描量热分析仪对吸附剂的性质进行了表征.结果表明:吸附剂对水的吸附比乙醇强烈地多,可以选择性吸附水分,达到脱水目的.吸附剂吸水的最大吸附量可达20%,再生后的吸附剂对水仍有很好的吸附能力,体现了该吸附剂具有较高的工业应用价值.     

2022年国内纯苯市场分析及预测

结合2022年的数据,对我国纯苯的生产建设、市场、价格、进出口等情况进行了分析和预测;预计,未来几年我国纯苯下游消费量仍将较大,进口纯苯仍是重要补充,2023年纯苯进口量或将继续保持高位。     

改进纯苯塔生产操作的经验

１存在问题我厂的精苯装置是以粗苯和轻苯为原料，装置的处理能力为１万t／a，由两苯塔、初馏塔、吹苯塔、纯苯塔、甲苯塔和二甲苯塔组成，采用全连续精馏工艺生产纯苯、甲苯和二甲苯产品。几年来，精苯装置的运行情况良好，产品质量稳定，只是纯苯塔的运行情况不很稳定，特别是该塔在开工时的调整周期长，一般需经３０h左右调整才能生产出合格的产品，操作条件稍有变化，立即影响纯苯的质量，甚至出现不合格品，成为整个装置的生产瓶颈。２标定纯苯塔我厂的纯苯塔为３５层浮阀塔，直径１m，塔板间距４５０mm，每层塔板上安装７０个浮阀。为…     

声空化对渗透脱水影响的实验研究

将声空化应用于苹果和梨的渗透脱水，研究了物料脱水率和干物质增加率随溶液浓度、空化强度、物料厚度及作用时间段的变化趋势。研究发现，声空化对物料渗透脱水过程中的脱水率影响显著；干物质虽有所增加，但增幅不大。同时简要阐述了声空化强化渗透脱水过程中质量传递的物理机制。     

利用膨胀制冷技术脱水脱烃的实验研究

此研究在长庆榆林气田根据膨胀制冷原理,结合其气田低温分离的特点,进行了天然气脱水脱烃的实验研究。长庆榆林气田目前多采用针阀节流的方式达到降压降温的目的,利用低温分离工艺进行天然气脱水、脱烃处理。对于井口压力低的井,采用针阀节流要达到低温分离目的所需的压降较大,达不到外输压力要求。在这种情况下,此研究使用膨胀制冷管开展实验研究,利用系统已有的背压条件取得相应的温度降,促进了气体中的游离水、重烃类的凝析。     

苯深度脱硫钌吸附剂失活及其原因分析

从吸附剂中活性组分钌的烧结、流失、氧化、中毒四个方面分析苯吸附脱硫钌吸附剂的失活原因,总结吸附剂的失活机制。以运行后的苯吸附脱硫钌吸附剂和新鲜吸附剂为研究对象,应用氮气吸附-脱附、X射线衍射、X射线荧光、透射电镜等手段对新鲜吸附剂及运行后吸附剂进行表征。结果表明,活性组分钌未出现明显流失,同时晶粒没有出现团聚,吸附剂表面孔结构变化、Fe和Cl中毒是其硫容降低的主要原因。吸附剂再生后,硫容约恢复到初始硫容的90%。     

吹苯塔和纯苯塔汽相串联的生产经验

我厂的精苯装置于1991年投产,采用连续吹苯后半连续精馏工艺.已洗混合分在吹苯塔中连续吹苯,吹出苯经冷凝冷却和油水分离流入贮槽,用泵连续送入纯苯塔提取纯苯,再用半连续间歇釜式精馏从纯苯残油中提取甲苯和二甲苯等产品.1997年改用导热油供热,2000年采用微机自动化集中控制.     

2011年中国纯苯市场分析

对2011年中国纯苯的生产、贸易、消费及价格等市场情况进行分析。     

采用吸附法对焦化纯苯进行脱硫精制的研究

介绍了采用粒状活性炭脱除焦化纯苯中CS2的研究结果。通过静态吸附试验确定了不同温度下的平衡吸附量;通过动态吸附试验考察了进料流速及活性炭床层高度等因素对吸附效率的影响。结果表明,低温对吸附有利,进料流速越小、床层越高,穿透时间越长以及在吸附前对活性炭进行N2吹扫活化,可明显提高吸附效果。采用活性炭吸附法可使焦化纯苯CS2含量降至3×10-6以下,可达到石油苯CS2的质量要求。     

Experimental study on principles of isothermal dehydration of anthracite

Isothermal dehydration experiments were performed and studied on anthracite. A mathematical model is established for anthracite dehydration to improve the efficient utilization of high-moisture anthracite exploited by water addition technology. Three kinds of high-moisture anthracite with different particle size were treated by isothermal drying methods. Experimental results show that there are two clear stage differentiations in the derivative thermogravimetric curve of the anthracite drying process, namely X_c1 and X_c2. The dehydration process can be divided into the rapid deceleration phase (X?<?X_c1), the steady linear dehydration phase (X_c1?<?X?<?X_c2), and the deceleration phase (X?>?X_c2). The drying mechanisms of the three dehydration stages are different. When X?>?X_c2, the evaporation of the free water and bound water in the large pore of the anthracite is influenced by the capillary force of the curved liquid surface. When X_c1?<?X?<?X_c2, the main driving force of water migration is the pressure gradient. When X?<?X_c1, the detached water partly comes from the internal micropores of the anthracite and the rest is connected with the functional groups of the anthracite surface. A high drying temperature contributes to increasing the drying rate of the drying process, thereby improving the effects of anthracite dehydration.     

褐煤热压脱水实验研究

为提高褐煤脱水率,以锡林郭勒褐煤为研究对象,采用高温反应釜进行了褐煤热压脱水实验,考察了温度、压力和保压时间对褐煤脱水率的影响,并利用静态氮吸附仪对热压脱水前后煤样的孔隙结构进行测定。结果表明:温度250℃、压力3 MPa、保压60 min时褐煤脱水率最大可达到93.67%。在热力协同作用下,加压可使褐煤实现"攥拳式"脱水,压缩褐煤碳骨架的同时,挤出内水,改变褐煤孔隙结构及分布。热压脱水后,褐煤比表面积、总孔体积、平均孔径分别降低了0.70192 m2/g、0.00405 cm3/g和1.38593 nm,煤样孔径分布明显改变,微孔比例增加5.57%,中孔比例增加4.97%,大孔比例减小10.54%。实验证明以气体加压方式进行褐煤热压脱水可行。     

Experimental study of the application of edible coatings in pumpkin sticks submitted to osmotic dehydration

Osmotic dehydration (OD) improves the organoleptic characteristics of products; nevertheless, depending on the product, the incorporation of great amounts of solute can be undesirable to consumers. The application of hydrogel coatings would overcome this, acting as a barrier to solute entering the product. An alginate–calcium chloride barrier system (A-CC) was tested with or without pretreatment of Ca²⁺ as a firmness agent applied to pumpkin sticks. Products were dehydrated in sucrose and glucose solutions (40 and 60% w/w). Different parameters were estimated such as soluble solids uptake, water content, and weight reduction; in addition, texture and microstructural changes were studied. The A-CC configuration complies with the barrier function to solids uptake from the dehydrating solution in case of 60% of sucrose, allowing water exit from the vegetal matrix. The pretreatment with Ca²⁺ contributed to the retention of product firmness. Integrity, adhesiveness, and thickness of the A-CC system during the OD process were evaluated by environmental scanning electron microscopy (ESEM). In this case, the coating thickness reduction was according to the product weight reduction, indicating that the coated product was dehydrated as an integrated system.     

模拟移动床改进进料模式实验研究

常规的模拟移动床色谱II区流出液与原料液在线混合进入III区,会导致进料浓度的降低,从而影响模拟移动床的生产效率。而新的进料模式,将II、III区断开,定期收集II区流出液,在II区流出液中溶解一定量的原料,使其浓度与初始进料浓度相等,然后在下一个周期中作为原料进到III区。以α-生育酚的制备为研究对象,对模拟移动床新型进料模式和传统进料模式进行对比,结果表明,新型进料模式比传统进料模式生产效率提高了53.04%,溶剂消耗减少了35%。同时,在新型进料模式下α-生育酚在SMB系统内部的最高浓度提高了77.24%,而非α-生育酚在SMB系统内部的最高浓度提高了67.31%。在改进进料模式下,α-生育酚的生产能力得到了提高。     

磷石膏脱水反应动力学研究

利用Netzsch STA 409PC型TG-DSC同步热分析仪,在升温速率分别为2.5,5.0,10,20℃/min的条件下对磷石膏脱水进行测试,研究其动力学和反应机理。结果表明,磷石膏脱水分为2步进行,产物分别是CaSO4.0.5H2O和CaSO4。2步脱水都遵循Avrami-Erofeev方程,脱水速率受晶核的形成及生长控制,活化能分别为97.67 kJ/mol和92.63 kJ/mol。利用得到的动力学方程对磷石膏在不同温度下的脱水过程进行模拟计算,结合工业上采用磷石膏制备建筑石膏的工艺和控制问题进行了讨论和分析。     

Experimental study on the laminar flame speed of hydrogen/carbon monoxide/air mixtures

Carbon monoxide and hydrogen are two important components in the syngas. In this study, the laminar flame speed of hydrogen/carbon monoxide fuel mixtures is measured over a large range of fuel compositions (0-100% volume fraction for hydrogen in the mixture) by using a Bunsen burner. The reaction zone area is used to calculate the laminar flame speed. The equivalence ratio covers from lean conditions to rich conditions. The experimental results show that by using the Bunsen flame, the laminar flame speed calculated with the reaction zone area is reliable. Based on the experimental results, empirical equations are derived which can be readily employed to calculate the laminar flame speeds of hydrogen, carbon monoxide, and hydrogen/carbon monoxide mixtures.     

Osmotic dehydration of blueberries pretreated with pulsed electric fields: Effects on dehydration kinetics,and microbiological and nutritional qualities

Fresh blueberries were treated by pulsed electric fields (PEF) at 2?kV/cm before osmotic dehydration in 70% cane sugar syrup. The changes in water loss, solids gain, populations of native microorganisms, antioxidant activity, contents of anthocyanins, predominant phenolic acids and flavonols, and total phenolics in blueberries were investigated after PEF pretreatment and during osmotic dehydration at 40°C. Compared with non-PEF-pretreated blueberry samples, PEF pretreatment reduced the osmotic dehydration time of blueberry samples from 120 to 48?h at target moisture content (3.0?g/g initial dry matter). No significant differences (p?>?0.05) in total phenolics, antioxidant activity, anthocyanins, and predominant phenolic acids and flavonols were observed between the PEF-pretreated and non-PEF-pretreated blueberry samples. The PEF-pretreated blueberry samples had lower microbial populations than those which were not subjected to PEF pretreatment. Regardless of pretreatment, decreases in anthocyanins, predominant phenolic acids and flavonols, total phenolics, and antioxidant activity in blueberries were observed during the osmotic dehydration process. The results demonstrate that PEF pretreatment significantly reduced the dehydration time and enhanced the microbiological quality of blueberries without affecting their nutritional quality.     

邻二甲苯制取苯酐工艺流程模拟

利用Aspen软件对邻二甲苯制取4万如苯酐工艺流程进行了模拟,并对模拟结果进行了分析。轻组分塔T201中顺酐、苯甲酸、苯酞都在塔顶被除去,其中塔顶组成：苯酐25．74％,顺酐39．11％,苯甲酸25．37％,苯酞9．78％。产品塔T202塔顶除含有极少量苯甲酸、苯酞外,其余均为苯酐,塔底为重组分,满足分离要求。在实际生产中,轻组分中苯酐含量约为50％,因此生产操作中可以加大回流比,优化操作。     

生物乙醇催化脱水制乙烯的动力学研究

采用质量分数3%金属镧改性的HZSM-5分子筛催化剂,考察在较低的反应温度（200～300） ℃、固定床反应器内质量空速、催化剂粒径、反应温度以及反应物分压对乙醇转化率、产物收率和生成速率的影响,确定了乙醇脱水反应的动力学控制区域：质量空速≥20 h^-1,催化剂粒径≤0.7 mm。在此基础上,建立了生物乙醇催化脱水的动力学模型,拟合值和实验值吻合较好。     

造纸黑泥脱水研究

利用银鸽集团的其它废料研究了黑泥的脱水,并初步阐述了脱除机理。结果表明,黑泥的脱水效果比较明显,与空白样相比,可以有效降低黑泥水分5%,同时不影响发酵后肥料的品质。该方法不但减少了其它废料造成的环境污染,同时能达到节能减排的效果,大大提高了经济效益。