煤热解技术研究与开发进展

介绍了国内外3种类型的煤热解技术,其中:气体热载体工艺包括美国的COED工艺、LFC工艺、日本的粉煤快速热解工艺、ECOPRO工艺、我国的MRF工艺和内构件移动床热解工艺等;固体热载体工艺包括美国的Toscoal工艺、德国的LR工艺、前苏联的ETCH-175工艺和大连理工大学开发的DG工艺等;无热载体工艺即神雾科技集团股份有限公司开发的无热载体蓄热式旋转床热解工艺。主要从工艺流程、技术特点、工业化应用等方面,对这些工艺进行了分析,并指出了煤热解技术的发展趋势。     

华亭FMTP项目废水处理工艺选择

为选定华亭FMTP项目配套污水处理工艺,实现投产后污水处理的达标排放,分析了污水预处理工艺、A2/O工艺、SBR工艺、MBBR工艺和BAF工艺的原理及各工艺的优缺点,结合华亭FMTP项目的实际情况和废水指标,预处理工艺选择混凝沉淀和气浮工艺,废水处理工艺选择了SBR和MBBR两级串联的处理工艺。     

联醇工艺中脱硫工艺技术的发展

论述和对比了联醇工艺中原料气脱硫所采用的栲胶脱硫工艺、ADA脱硫工艺、PDS脱硫工艺、氧化锌脱硫工艺、氧化铁脱硫工艺、活性炭脱硫工艺、铁钼加氢转化法脱硫工艺、有机硫水解脱硫工艺的技术原理和工艺特点;提出了将湿法脱硫与干法脱硫工艺进行合理组合,并结合有机硫水解装置的脱硫工艺选择理念;总结了“3次脱硫2次转化”脱硫工艺在联醇生产中的重要作用.     

用湿法磷酸制工业磷酸二氢铵工艺综述

综述用湿法磷酸制工业磷酸二氢铵的几种工艺,包括传统化学法工艺、改进化学法工艺、化学净化与溶剂萃取联合除杂质工艺、湿法磷酸净化工艺、化学净化与溶剂萃取相结合工艺、萃取盐酸法工艺,介绍各工艺的生产流程,分析各工艺优缺点。建议厂家根据实际情况选择合适的工艺。     

20亿m~3/a煤制天然气项目净化工艺的选择

以新疆伊犁新天煤化工有限责任公司20亿m3/a煤制天然气项目净化工艺方案的选择为例,介绍了NHD工艺和低温甲醇洗工艺的技术特点;对比分析了低温甲醇洗工艺之鲁奇工艺、林德工艺和大连理工大学工艺的技术特点。结果表明:①大型煤化工项目净化工艺宜首选低温甲醇洗工艺;②从投资、能耗、环保等方面综合考虑,林德工艺在低温甲醇洗工艺中具有一定的优势。     

国内外异丁烷脱氢制异丁烯工艺的技术进展

综述了国内外异丁烷脱氢制备异丁烯工艺的研究进展,包括FBD-4工艺、Oleflex工艺、Catofin工艺、Star工艺、Linde工艺和ADHO工艺等,提出了未来发展的建议。     

烷基化油生产技术的进展

介绍直接烷基化技术的FBA工艺、Alkylene工艺、Eurofuel工艺、ExSact工艺等固体酸烷基化工艺以及改进的液体酸烷基化技术和间接烷基化技术的InAlk工艺、CDIsoether工艺、NExOCTANE工艺、Alkylate 100SM工艺以及叠合–醚化技术的研究进展。提出了在我国发展烷基化油生产技术的建议。     

Fenton氧化法处理难降解工业废水的工艺研究进展

介绍了Fenton氧化法的基本反应原理,综述了传统Fenton氧化工艺、微电解-Fenton氧化工艺、Fenton流化床氧化工艺、UV-Fenton氧化工艺、电Fenton氧化工艺的主要工艺形式及其在难降解工业废水中的应用,并总结各种Fenton氧化工艺的特点及工艺选择原则。     

树脂基复合材料成型工艺的发展

随着复合材料工业的迅速发展,传统的复合材料成型工艺日臻完善,新的成型方法不断涌现。本文通过梳理接触低压成型工艺、拉挤成型工艺、模压成型工艺、缠绕成型工艺、铺放成型工艺、RTM成型工艺这几种先进树脂基复合材料成型工艺的发展历程,分析发展过程中的关键技术,来研究先进复合材料成型工艺的演变,从而探讨未来树脂基复合材料成型工艺的发展方向。     

太阳能级多晶硅生产工艺研究现状

介绍了改良西门子工艺、强化FBR联合碳化物工艺、混合工艺、新硅烷工艺和卤化硅的热分解或歧化工艺，并分析了每种工艺的流程及特点。     

通用级沥青纤维的不熔化

以新疆乙烯焦油为原料,制备改性沥青,通过熔融纺丝、不熔化、炭化等工艺制备沥青基炭纤维。利用TG、DSC、SEM等手段,对石油沥青纤维在空气中的不熔化处理进行了研究,并研究不熔化条件对炭纤维微观结构及拉伸强度的影响,分析皮芯结构的形成,以及不熔化过程中张力对纤维拉伸强度的影响。     

Carbonization properties of partially hydrogenated aromatic compounds—II: Factors influencing the coke yield in the carbonization of hydrogenated pyrene

Factors influencing the coke yield in the carbonization of hydrogenated pyrenes were investigated from the view of reactivities of their hydrogens. The amount of hydrogen located at 4 ppm in their proton NMR spectrum was found to be intimately related to the coke yield of hydrogenated pyrenes. Oxidative pretreatment at 150°C significantly increased the coke yield. The structural changes of hydrogenated pyrenes by oxidative pretreatment were investigated by means of GPC, IR and NMR. The scheme of oligomerization as the first step of carbonization is discussed in connection with the reactivities of hydrogens in hydrogenated pyrenes.     

Development of carbon nanofibers from aligned electrospun polyacrylonitrile nanofiber bundles and characterization of their microstructural, electrical, and mechanical properties

Carbon nanofibers with diameters of 200-300 nm were developed through stabilization and carbonization of aligned electrospun polyacrylonitrile (PAN) nanofiber bundles. Prior to the oxidative stabilization in air, the electrospun PAN nanofiber bundle was tightly wrapped onto a glass rod, so that tension existed during the stabilization. We also investigated several carbonization procedures by varying final carbonization temperatures in the range from 1000 to 2200 °C. The study revealed that: (1) with increase of the final carbonization temperature, the carbon nanofibers became more graphitic and structurally ordered; (2) the carbon nanofiber bundles possessed anisotropic electrical conductivities, and the differences between the parallel and perpendicular directions to the bundle axes were over 20 times; and (3) the tensile strengths and Young's moduli of the prepared carbon nanofiber bundles were in the ranges of 300-600 MPa and 40-60 GPa, respectively.     

高性能沥青基碳纤维制造——氧化碳化石墨化

本文论述了用于制造高性能碳纤维的中介相沥青初生纤维的氧化稳定化、碳化与石墨化过程及其对最终碳纤维力学性能与电导性能的影响;讨论了氧化碳化与石墨化温度、升温速率、中介相沥青原料种类与氧化稳定化程度、石墨化程度、抗张强度与模量、电阻率、纤维结构的关系;指出了五种加速氧化稳定化进程的有效措施。     

Gel-spun carbon nanotubes/polyacrylonitrile composite fibers. Part III: Effect of stabilization conditions on carbon fiber properties

The oxidative stabilization process of gel-spun carbon nanotube (CNT)/polyacrylonitrile (PAN) composite fibers have been studied and optimized. Optimum stabilization time depends on both the applied tension and temperature. Various characterization methods including thermal shrinkage, dynamic mechanical analysis, infrared spectroscopy, and wide angle X-ray diffraction are used to monitor the chemical and structural evolution during stabilization and carbonization. The relationship between the stabilization conditions of CNT/PAN composite fiber and the tensile properties of the resulting carbon fibers were investigated. By optimizing stabilization conditions, CNT/PAN based carbon fibers with a tensile strength of 4 GPa and a tensile modulus of 286 GPa were obtained using batch carbonization processing at 1100 °C.     

Effect of thermal preoxidation and the addition of ammonium molybdate on the thermal conversion of cellulose and cellulose compositions

As found by thermogravimetric and differential thermal analysis and gas chromatography, the thermal oxidative pretreatment of cellulose and cellulose compositions with high-molecular-weight polycondensed aromatic systems of natural origin resulted in a shift of peaks due to intense thermal degradation to the region of lower temperatures and changes in the yields of carbon residues and in the quantitative composition of the main gaseous products of pyrolysis. In the presence of ammonium molybdate, which is a catalyst for cellulose oxidation and carbonization, the effect of the thermal oxidative treatment was even more enhanced. This was reflected in an increase in the low-temperature shifts of intense degradation processes and a considerable increase in the yields of carbon residues of cellulose and cellulose compositions.     

Evaluating multi-step oxidative stabilization behavior of coal tar pitch-based fiber

Oxidative stabilization is an important step for isotropic pitch-based carbon fiber preparation; coal tar pitch-based fiber is treated by multi-step oxidative stabilization under various conditions to investigate the oxidative stabilization mechanism. The chemical structure changes of isotropic pitch-based fiber during the oxidative stabilization and carbonization stage are systematically characterized by In-situ diffuse reflectance infrared Fourier transform, elemental analysis, mass spectroscopy, X-ray photoelectron spectroscopy, nuclear magnetic resonance, scanning electron microscope with an energy dispersive X-ray spectrometer. These results show that the oxygen distribution gradient in oxidative stabilized fiber radial direction become homogeneously with the increasing of oxidation temperature and time under multi-step oxidative stabilization. The resultant carbon fiber shows tensile strength of 942 ± 42 MPa and Young's modulus of 42.8 ± 3.1 GPa due to appropriate oxygen content, homogeneous oxygen distribution, more cross-link bond (C-O-C) content, higher aromaticity and lower weight loss introduced in multi-step oxidative stabilized pitch fiber. The multi-step oxidative stabilization provides synergy effect between reaction rate and the oxygen diffusion rate as well as eliminates the oxygen concentration gradient, it provides an time-saving and energy-effective method for the oxidative stabilization of isotropic pitch-based carbon material (pitch fiber, pitch microsphere, etc.) and improve the resultant carbon material performance.     

On the chemistry of the oxidative stabilization and carbonization of carbonaceous mesophase

Two mesophase samples, one derived from a coal-tar pitch (M-A) and the other from a naphthalene-based pitch (M-B), were stabilized with air in a temperature range of 200-300 °C and then carbonized to 1000 °C. Elemental analysis and FTIR spectroscopy were used to monitor the changes produced by oxygen in the chemical composition of the mesophase samples at different stages of stabilization (from 200 to 300 °C) and after carbonization of the stabilized samples (from 300 to 1000 °C). The results show that oxidative stabilization is a dehydrogenative process, where the hydrogen removed is predominantly aliphatic and the oxygen uptake is mainly in the form of C-O-C and CO groups. The more aliphatic character of M-B accelerates the stabilization process with respect to M-A. M-B shows a higher weight gain and also a greater variety of oxygen-containing functional groups. As a result, the plasticity of M-B is more affected by changes in the stabilization temperature than that of M-A. Thus, the stabilization process is easier to control in the case of M-A. On carbonization, oxygen and hydrogen are removed from the stabilized samples and the carbons generated exhibit an increase in interlayer spacing and a decrease in crystallite size as the carbonization temperature increases.     

Influence of matrix and interface on the mechanical properties of unidirectional carbon/carbon composites

The mechanical properties and microstructure of unidirectional carbon/carbon (UD C/C) were investigated. The strength of one type of UD C/C, produced with an intermediate modulus fibre treated to four different levels of an oxidative surface treatment, was determined after each step of the production cycle (of loose, impregnated and carbonized impregnated fibre bundles). The impregnated bundle had a strength 1.9–4.3 times the strength of the loose bundle, whereas after carbonization the strength of the bundle dropped below the strength of the loose bundle. It is suggested that this is mainly caused by the formation of defects in the fibres due to the shrinkage process during carbonization. These defects are larger if a good fibre/matrix bond strength in the green material exists. The possibility that the low strength of carbon/carbon could be caused by stress-concentration effects was excluded with the aid of TEM investigations. They showed that the carbon matrix mainly consisted of vitreous carbon, the modulus of which (E = 35 GPa) does not become effective due to micro- and macrocracks.     

低变质煤富氧低温干馏试验研究

用富氧代替空气与煤气燃烧提供热源,利用燃烧废气与低温干馏过程产生的干馏煤气混合形成高温循环气,对煤进行富氧干馏。试验结果表明,在不改变现行低温干馏炉结构的情况下,富氧干馏完全可行,可大幅提高煤气的有效成分,降低氮含量,煤气热值是空气助燃干馏的2倍以上,煤气放散量减少约3/4。