氧漂桉木氢氧化钠-蒽醌浆的臭氧漂白工艺研究

采用氢氧化钠-蒽醌法制备桉木化学浆,经氧脱木质素处理后,对其进行臭氧漂白工艺研究。探讨了臭氧漂白过程中,温度、臭氧浓度、保护剂类型及用量(相对于绝干浆质量)对纸浆漂白及成纸后纸张物理性能的影响,初步得到较优的漂白工艺参数。结果表明,当漂白温度10℃、臭氧浓度80 g/Nm^(3)、草酸用量1.0%时,纸浆白度可达72.8%,黏度678 mL/g,Kappa值4.18,成纸后纸张抗张指数78.9 N·m/g,耐破指数4.99 kPa·m^(2)/g,撕裂指数5.96 mN·m^(2)/g,耐折度38次。

微界面强化蒽醌法制双氧水的氧化工段的模拟计算研究

双氧水是一种应用广泛的绿色氧化剂,在许多领域有重要作用,但国内的双氧水生产技术能耗高,工艺技术水平亟待提升.目前,工业上主要使用蒽醌法生产双氧水,氧化工段采用的多塔氧化流程存在设备投资高、尾氧含量高、氧化效率偏低等问题.为了探究微界面反应对氢蒽醌氧化工段的强化效果,基于传统三塔氧化流程,构建微界面体系的构效调控数学模型,通过模拟计算研究气泡尺寸和操作条件等因素对氧化工段的传质和反应的强化效果.计算结果表明,在工况条件下(空气压力为0.4 MPa,操作温度为50℃,空气流量减少10%),当气泡Sauter平均直径由5.0 mm减小至0.50 mm时,氧化效率从93%增大到99%,尾氧含量从6%减少到1%;此外,在保证反应效果的前提下,可以降低4~6℃的反应温度.本研究成果为推进微界面强化蒽醌法制双氧水的氧化工段的工业应用提供了理论基础.

100kt/a蒽醌法过氧化氢装置稳产高产技改小结

针对100kt/a蒽醌法过氧化氢装置存在的诸多问题,通过工艺优化和设备改造,实现了装置的稳产高产,并指出系统仍存在的问题及挖潜的方向。

蒽醌法过氧化氢生产受限空间作业风险分析及安全管控措施

蒽醌法过氧化氢生产,因本身工艺设计特点,大多涉及进入氢化塔、白土床、配制釜等受限空间作业。进入以上受限空间作业,危险性大,容易发生闪爆、中毒和窒息等事故,严重影响企业的安全发展。本文对蒽醌法过氧化氢生产危险性较大的受限空间作业进行了风险分析,结合笔者现场安全管理经验,有针对性地提出了操作性较强的安全管控措施。通过本文分享预防受限空间作业事故发生的经验,以期提升蒽醌法过氧化氢生产企业受限空间作业安全管理水平。

蒽醌生产技术现状及发展

介绍了蒽醌的生产技术,比较了蒽醌的生产方法,分析了我国蒽醌生产的发展情况,对我国蒽醌市场未来的发展进行了探讨。

Advances in the production technology of hydrogen peroxide

This article mainly summarizes various aspects of hydrogen peroxide(H2O2)production through the anthraquinone route,including hydrogenation catalysts,working solution,regeneration technique,hydrogenation reactors,and environmental protection.The advances and breakthrough of SINOPEC in the production of H2O2 through the anthraquinone route is presented in this review,highlighting recent innovative technology on these aspects developed independently.The technical prospect and scientific challenges associated with the direct synthesis method from hydrogen and oxygen are also briefly discussed.

Electrooxidative Degradation of an Anthraquinone Dye with in-situ Electrogenerated Active Chlorine in a Divided Flow Cell

The purpose of this paper was to investigate the possibility of treating C. I. Reactive Blue 19 wastewater by electrochemical oxidation via electrogenerated active chlorine, using metallic oxide coatings （dimensional stable anode, DSA） as anode. The electrolysis for the simulated wastewater was conducted at a constant current. Absorbances at 592 nm and 255 nm were measured to follow the decolorization of the dye and the degradatin of its aromatic ring. After 4 h of electrolysis under the experimental conditions： current density of 15 A·m^-2, 0.2 mol·L^-1 NaCl, 0.1 mol·L^-1 Na2SO4, 0.1 mmol·L^-1 dye, initial pH=6.4 and T=30℃, 100% decolorization of the dye and about 45% degradation of its aromatic ring were achieved, while no obvious change of total organic carbon was observed. The experimental results suggest that the decolorization of the dye and degradation of its aromatic ring were directly affected by current density, temperature, concentrations of the dye and sodium chloride, while slightly affected by initial pH and sodium sulfate concentration; the decolorization of the dye and degradation of its aromatic ring followed pseudo-first-order kinetics; and indirect electrooxidation, using electrogenerated active chlorine, predominated in the electrochemical oxidation.

Multistage Extractive Reaction for Hydrogen Peroxide Production by Anthraquinone Process

The extractive reaction process of oxygen-working solution-water three-phase system for the production of hydrogen peroxide by the anthraquinone method was investigated in a sieve plate column of 50 mm in internal diameter. The oxidation reaction of anthrahydroquinone in the working solution with oxygen and the extraction of hydrogen peroxide from the working solution into aqueous phase occurred simultaneously in the countercurrent mode. The agitating effect caused by gaseous phase made the droplets of the dispersed phase become smaller, thus, increasing the liquid-liquid interfacial contact areas and resulting in the improvement of the mass transfer velocity. Results showed that the gas-agitation had a beneficial effect on the extraction of hydrogen peroxide from the working solution into the aqueous phase; the concentration of hydrogen peroxide in the raffinate decreased with the increase of the gaseous superficial velocities; and the concentration of H2O2 in the raffinate increased with the increase of the dispersed phase superficial velocity at the same superficial velocity of the gaseous phase. In the G-L-L extractive reaction process, with the increase of the gaseous superficial velocities, both the conversion of the anthrahydroquinone oxidation and the extraction efficiency of hydrogen peroxide first increased significantly, then increased gradually.

蒽醌法生产过氧化氢中污水处理的几种方法

本文介绍了蒽醌法过氧化氢生产中产生废水的三种常用处理方法。

Effects of porous oxide layer on performance of Pd-based monolithic catalysts for 2-ethylanthraquinone hydrogenation

Pd/oxide/cordierite monolithic catalysts(oxide = Al_2O_3, SiO_2 and SiO_2\\Al_2O_3) were prepared by the impregnation method. The results of ICP, XRD, SEM–EDX, XPS and N_2 adsorption–desorption measurements revealed that the Pd penetration depth increased with increasing the thickness of oxide layer, and the catalysts with Al_2O_3 layers had the larger pore size than those with SiO_2 and SiO_2\\Al_2O_3 layers. Catalytic hydrogenation of 2-ethylanthraquinone(eA Q), a key step of the H_2O_2 production by the anthraquinone process, over the various monolithic catalysts(60 °C, atmosphere pressure) showed that the monolithic catalyst with the moderate thickness of Al_2O_3 layer(about 6 μm) exhibited the highest conversion of e AQ(99.1%) and hydrogenation efficiency(10.0 g·L^(-1)). This could be ascribed to the suitable Pd penetration depth and the larger pore size, which provides a balance between the distribution of Pd and accessibility of active sites by the reactants.

蒽油的深加工

兖矿集团公司和济宁煤化公司采用闪蒸、结晶、蒸馏、氧化等技术生产氧化蒽醌,联产咔唑,副产脱晶蒽油和萘油。该工艺技术先进,自动化程度高,三废排放少,符合环保要求,所得产品质量好,收率高。其中蒽的收率大于70％,蒽醌纯度达99％以上,咔唑收率大于60％,纯度达95％-98％。产品在市场上都具有较强的竞争力。

Influencing Factors and Product Toxicity of Anthracene Oxidation by Fungal Laccase

The transformation profiles of polycyclic aromatic hydrocarbons （PAHs） by pure laccases from Trametes versicolor and Pycnoporus sanguineus, and the optimal reaction conditions （acetonitrile concentration, pH, temperature and incubation time） were determined. Anthracene was the most transformable PAH by both laccases, followed by benzo[a]pyrene, and benzo[a]anthracene. Laccase-mediator system （LMS） could not only improve the PAH oxidation but also extend the substrate types compared to laccase alone. 5e/0 or 10~ （v/v） of acetonitrile concentration, pH 4, temperature of 40 ~C, and incubation time of 24 h were most favorable for anthracene oxidation by laccase from T. versicolor or P. sanguineus. The gas chromatography-mass spectrometry analysis indicated that 9,10- anthraquinone was the main product of anthracene transformed by laccase from T. versicolor. Microtox test results showed that both anthracene and its laccase-transformation products were not acute toxic compounds, suggesting that laccase-treatment of anthracene would not increase the acute toxicity of contaminated site.

Greatly promoted oxygen reduction reaction activity of solid catalysts by regulating the stability of superoxide in metal-O_(2)batteries

Oxygen reduction reactions(ORRs)with one-or two-electron-transfer pathways are the essential process for aprotic metal-oxygen batteries,in which the stability of superoxide intermediates/products(O_(2)^(-),LiO_(2),NaO_(2),etc.)mainly dominates the ORR activity/stability and battery performance.However,little success in regulating the stability of the superoxides has been achieved due to their highly reactive characteristics.Herein,we identified and modulated the stability of superoxides by introducing anthraquinone derivatives as cocatalysts which functioned as superoxide trapper adsorbing the superoxides generated via surface-mediated ORR and then transferring them from the solid catalyst surface into electrolyte.Among the studied trappers,1,4-difluoroanthraquinone(DFAQ)with electron-withdrawing groups showed the highest adsorption towards superoxides and could efficiently stabilize LiO_(2)in electrolyte,which greatly promoted the surface-mediated ORR rate and stability.This highlighted the magnitude of adsorption between the trapper and LiO_(2)on the ORR activity/stability.Using an aprotic Li-O_(2)battery as a model metal-O_(2)battery,the overall performance of the cell with DFAQ was substantially improved in terms of cell capacity,rate capability and cyclic stability.These results represent a significant advance in the understanding of ORR mechanisms and promoting the performance of metal-O_(2)batteries.