HYSYS流程模拟技术在丁辛醇装置用能优化方面的应用

分析了大庆石化公司丁辛醇装置工艺流程中用能优化的潜力,即可增没换热器,实现温度较低的精EPA与温度较高的粗EPA的换热,充分利用内部循环热能,同时可节约冷却水和加热蒸汽用餐。介绍了利用HYSYS流程模拟技术．通过采用定义虚拟组分来计算增设换热器换热面积的计算方法。根据模拟计算结果,采用换热面积为35m^2的新增换热器,每年节约1．3MPa蒸汽1×10^4t、冷却水28×10^4t。     

Hydrogen production via sorption enhanced steam reforming of butanol: Thermodynamic analysis

Thermodynamic equilibrium for sorption enhanced steam reforming of butanol (SESRB) to hydrogen was investigated using Gibbs free energy minimization method. The optimal operation conditions for SESRB are at 800 K, the steam-to-butanol molar ratio of 10, the calcium oxide-to-butanol molar ratio of 8 and atmospheric pressure. Under the optimal conditions, complete conversion of butanol, 97.07% concentration of H₂ and 0.05% concentration of CO₂, and efficiency of 86.60% could be achieved and at which no coke tends to form. Under the same conditions in SRB, 58.18% concentration of H₂, 21.62% concentration of CO₂, and energy efficiency of 81.51% could be achieved. Butanol steam reforming with CO₂ adsorption has the higher H₂ content and efficiency, and lower CO₂ content than that without adsorption under the same reaction conditions. In addition, reaction conditions for coke-free and coke-formed regions are also discussed in butanol steam reforming with or without CO₂ separation.     

Oxidation of 1-butanol and a mixture of n-heptane/1-butanol in a motored engine

The oxidation of neat 1-butanol and a mixture of n-heptane and 1-butanol was studied in a modified CFR engine at an equivalence ratio of 0.25 and an intake temperature of 120 °C. The engine compression ratio was gradually increased from the lowest point to the point where significant high temperature heat release was observed. Heat release analyses showed that no noticeable low temperature heat release behavior was observed from the oxidation of neat 1-butanol while the n-heptane/1-butanol mixture exhibited pronounced cool flame behavior. Species concentration profiles were obtained via GC-MS and GC-FID/TCD. Quantitative analyses of the reaction products from the oxidation of neat 1-butanol indicate that 1-butanol is consumed mainly through H-atom abstraction. Among the H-atom abstraction reactions, it is observed that the H-atom abstraction from the α-carbon of 1-butanol is particularly favored. The investigation on the oxidation of the mixture of n-heptane/1-butanol showed that the oxidation of 1-butanol is facilitated at low temperatures through the radical pool generated from the oxidation of n-heptane.     

丁醇-二丁醚汽液相平衡的实验测定与关联

实验应用改进的Rose釜测定了丁醇一二丁醚在760mmHg下的恒压汽液相平衡,所测数据符合热力学一致性。利用测定数据关联出一套NRTL参数,研究了它们的恒沸点情况,获得的结果对于工程模拟较为可靠。     

氯丁烷-正丁醇体系等压汽液相平衡研究

采用泵式沸点仪测定了常压下氯丁烷—正丁醇二元体系在不同液相组成下的沸点,并用间接法由TPX推算了与之平衡的汽相组成。用最小二乘法求出了该系统的液相活度系数模型参数,由模型参数推算的泡点与实验值符合良好。     

Catalytic decomposition of alcohols over size-selected Pt nanoparticles supported on ZrO2: A study of activity, selectivity, and stability

This article discusses the performance of ZrO₂-supported size-selected Pt nanoparticles for the decomposition of methanol, ethanol, 2-propanol, and 2-butanol. The potential of each alcohol for the production of H₂ and other relevant products in the presence of a catalyst is studied in a packed-bed mass flow reactor operating at atmospheric pressure. All the alcohols studied show some decomposition activity below 200 °C which increased with increasing temperature. In all cases, high selectivity towards H₂ formation is observed. With the exception of methanol, all alcohol conversion reactions lead to catalyst deactivation at high temperatures (T > 250 °C for 2-propanol and 2-butanol, T > 325 °C for ethanol) due to carbon poisoning. However, long-term catalyst deactivation can be avoided by optimizing reaction conditions such as operating temperature.     

Improvement of mono and diacylglycerol production via enzymatic glycerolysis in tert‐butanol system

In this work we report experimental data regarding the glycerolysis of olive oil using Novozym 435 in tert‐butanol organic system aiming at the production of monoacylglycerols (MAG) and diacylglycerols (DAG). Experiments were performed in batch mode, recording the reaction kinetics and evaluating the effects of temperature, enzyme concentration, tert‐butanol:oil/glycerol volume ratio and using solvent to substrates ratio of 1:1 and 5:1 v/v. Experimental results showed that lipase‐catalyzed glycerolysis in tert‐butanol might be a potential route for the production of high contents of MAG and DAG. The results also showed that it is possible to maximize the production of MAG and/or DAG, depending on the glycerol to oil molar ratio employed in the reactional system. Higher contents of MAG (53 wt%) and DAG (50 wt%) were achieved using glycerol to oil molar ratio of 3:1/6:1 and 0.5:1.5, respectively, both in 8 h of reaction at 70°C, 600 rpm and enzyme concentration of 10 wt%.     

Effect of butanol on flotation separation of quartz from hematite with N-dodecyl ethylenediamine

In order to investigate the effect of butanol on quartz flotation when N-dodecyl ethylenediamine(ND)was used as collector, single mineral flotation and artificial mixed mineral(hematite and quartz were mixed at a mass ratio of 3:2) separation were conducted in the laboratory. Experimental results indicated that addition of butanol could improve the collecting performance of ND on quartz and enhance the floatability of quartz. Best flotation recovery of quartz was obtained when butanol was mixed with ND at a mass ratio of 1:1. Moreover, the molecular structure of alcohols had a significant effect on mineral recovery. Best separation efficiency could be obtained when tert-butanol was added as it had the largest cross-sectional area. Zeta potential measurements indicated that alcohols could strengthen electrostatic adsorption between quartz and collector. Molecular dynamic simulations revealed that co-adsorption of alcohols along with ND had taken place on the quartz surface, and ND/tert-butyl combinations were more easily absorbed on the quartz surface.     

Modulation of crude glycerol fermentation by Clostridium pasteurianum DSM 525 towards the production of butanol

High production yields and productivities are requisites for the development of an industrial butanol production process based on biodiesel-derived crude glycerol. However, impurities present in this substrate and/or the concentration of glycerol itself can affect the microbial metabolism. In this work, the effect of crude glycerol concentration on the production of butanol and 1,3-propanediol (1,3-PDO) by Clostridium pasteurianum DSM 525 is studied. Also, the effect of acetate and butyrate supplementation to the culture medium and the culture medium composition are evaluated. The results showed a marked effect of crude glycerol concentration on the product yield. The competitive nature of butanol and 1,3-PDO pathways has been evident, and a shift to the butanol pathway once using higher substrate concentrations (up to 35 g l⁻¹) was clearly observed. Butyrate supplementation to the culture medium resulted in a 45% higher butanol titre, a lower production of 1,3-PDO and it decreased the fermentation time. Acetate supplementation also increased the butanol titre but the fermentation was longer. Even though glycerol consumption could not be increased over 32 g l⁻¹, when the concentrations of NH₄Cl and FeCl₂ were simultaneously increased, the results obtained were similar to those observed when butyrate was supplemented to the culture medium; a 35% higher butanol yield at the expense of 1,3-PDO and a shorter fermentation. The results herein gathered suggest that there are other factors besides butanol inhibition and nutrient limitation that affect the glycerol consumption.     

Laminar burning velocities and flame instabilities of butanol isomers-air mixtures

Laminar burning velocities and flame instabilities of the butanol-air premixed flames and its isomers are investigated using the spherically expanding flame with central ignition at initial temperature of 428 K and initial pressures of 0.10 MPa, 0.25 MPa, 0.50 MPa and 0.75 MPa. Laminar burning velocities and sensitivity factor of n-butanol-air mixtures are computed using a newly developed kinetic mechanism. Unstretched laminar burning velocity, adiabatic temperature, Lewis number, Markstein length, critical flame radius and Peclet number are obtained over a wide range of equivalence ratios. Effect of molecular structure on laminar burning velocity of the isomers of butanol is analyzed from the aspect of CH bond dissociation energy. Study indicates that although adiabatic flame temperatures of the isomers of butanol are the same, laminar burning velocities give an obvious difference among the isomers of butanol. This indicates that molecular structure has a large influence on laminar burning velocities of the isomers of butanol. Branching (CH3) will decrease laminar burning velocity. Hydroxyl functional group (OH) attaching to the terminal carbon atoms gives higher laminar burning velocity compared to that attaching to the inner carbon atoms. Calculated dissociation bond energies show that terminal CH bonds have larger bond energies than that of inner CH bonds. n-Butanol, no branching and with hydroxyl functional group (OH) attaching to the terminal carbon atom, gives the largest laminar burning velocity. tert-Butanol, with highly branching and hydroxyl functional group (OH) attaching to the inner carbon atom, gives the lowest laminar burning velocity. Laminar burning velocities of iso-butanol and sec-butanol are between those of n-butanol and tert-butanol. The instant of transition to cellularity is experimentally determined for the isomers of butanol and subsequently interpreted on the basis of hydrodynamic and diffusion-thermal instabilities. Little effect on flame instability is observed for the isomers of butanol. Critical flame radii are the same for the isomers of butanol. Peclet number decreases with the increase in equivalence ratio.