排序方式: 共有74条查询结果,搜索用时 15 毫秒
21.
超临界CO2处理含氰废水初步研究 总被引:8,自引:0,他引:8
超临界CO2能萃取出含氰废水中的CN^-,萃取物在压力降低时释放出来,释放物用饱和FeCl2溶液吸收稳定。萃取的最佳条件是:压力为10MPa-15MPa,温度为30-50℃,时间为20min-30min。 相似文献
22.
超临界流体色谱分析有机污染物 总被引:5,自引:0,他引:5
概述了超临界流体色谱的进展,特点、原理及影响超临界流体色谱测定的主要因素。介绍了超临界流体色谱与其他测定仪器的联用技术。列举了该技术在分析环境样品中有机污染物的应用。如分析有机氯、有机磷和氨基酸酯及农药的残留组分,多环芳烃,芳香烃等化合物。 相似文献
23.
The kinetic analysis method using non-isothermal technique was proposed to determine the kinetic parameters for the transesterification reaction of waste pig fat in supercritical alcohols. To investigate the transesterification of waste pig fat, the waste pig fat to alcohol ratio (w/w) was varied from 1:1.5 to 1:2.5 between the temperatures 220 and 290 °C at an interval of 10 °C in a 25 mL batch reactor. The products were analyzed by gas chromatography mass spectrometry. To verify the effectiveness of the proposed kinetic analysis method, the experimental values were compared with the values calculated using the kinetic parameters obtained from this work. It was found that the proposed kinetic analysis method gave reliable kinetic parameters for the transesterification of waste pig fat in supercritical alcohols. Further, it was found that the apparent activation energy for supercritical ethanol was lower than the value for supercritical methanol. 相似文献
24.
On December 7, 2009, a 50-foot-tall high-pressure vessel ruptured in the Nihon Dempa Kogyo Crystal, Inc. facility in Belvidere, Illinois. Several projectiles rapidly traveled outward from the facility, killing a truck driver 650 feet away and injuring an employee in another building 435 feet away. This paper summarizes the lessons learned from this incident both on causal and consequential aspects. Stress corrosion cracking was identified as the failure mechanism by the U.S. Chemical Safety and Hazard Investigation Board. After analyzing the operating conditions and the aftermath, this incident has been identified as a Boiling Liquid Expanding Vapor Explosion (BLEVE) under a supercritical pressure. A consequence analysis of the incident is performed where overpressure and fragment distance are calculated, together with safety distance estimation. Additionally, other safety-related problems, such as safety culture, management inside the corporation, and communication between this facility and the government are discussed. 相似文献
25.
Eremurus spectabilis samples were liquefied in organic solvents (methanol, ethanol and acetone) with (sodium hydroxide and ferric chloride) and without catalyst in a cylindrical reactor at temperatures of 270, 290 and 310 °C under supercritical conditions. The effects of liquefaction parameters such as temperature, catalyst and solvent on product yields were investigated. The liquid products were extracted with diethyl ether and benzene using an extraction procedure. The product yields in supercritical methanol, ethanol and acetone were found to as 41.6%, 53.8% and 64.3% in the non-catalytic runs at 310 °C, respectively. The highest conversion was obtained in supercritical acetone in the presence of ferric chloride (10%) at same temperature in the catalytic runs. The produced liquids in acetone were analyzed and characterized by elemental, Fourier transform infrared spectroscopy (FT-IR), gas chromatography–mass spectrometry (GC–MS). The liquid products (bio-oils) obtained with acetone contained various types of components including aromatics, nitrogenated and oxygenated compounds. As the bio-oils obtained exhibit high heat values, E. spectabilis is presented as a potential feedstock candidate for production of bio-fuels or valuable chemicals. 相似文献
26.
27.
Supercritical water oxidation for the destruction of toxic organic wastewaters: A review 总被引:9,自引:0,他引:9
The destruction of toxic organic wastewaters from munitions demilitarization and complex industrial chemical clearly becomes an overwhelming problem if left to conventional treatment processes. Two options, incineration and supercritical water oxidation (SCWO), exist for the complete destruction of toxic organic wastewaters. Incinerator has associated problems such as very high cost and public resentment; on the other hand, SCWO has proved to be a very promising method for the treatment of many different wastewaters with extremely efficient organic waste destruction 99.99% with none of the emissions associated with incineration. In this review, the concepts of SCWO, result and present perspectives of application, and industrial status of SCWO are critically examined and discussed. 相似文献
28.
Lotaustralin from the root of Rhodiola rosea L was extracted using supercritical carbon dioxide with methanol as modifier. Response surface methodology using Box–Behnken experimental design was utilized to explore parameters for supercritical carbon dioxide extraction. The effects of various values of temperatures (50–70 °C), pressures (200--400 bar), and percentages of methanol modifier (80%–100%) on the extraction yields of lotaustralin were evaluated. Extract identification was performed using high-performance liquid chromatography. The experimental data obtained were fitted to second-order polynomial equations and assessed using analysis of variance. The highest yields predicted from the experiments were 2.05 g kg?1 lotaustralin at the optimal values, i.e. temperature 65 °C, pressure 316 bar, 88% methanol modifier at a flow rate of 0.4 mL min?1, and dynamic extraction time 90 min. 相似文献
29.
The standard idea for deep saline aquifer sequestration is to separate carbon dioxide from a process stream, compress it, and inject it underground. However, since carbon dioxide is less dense than water, even at the high pressures found in aquifers, it is buoyant and will move towards the surface unless trapped by an impermeable seal. Also, significant energy expenditure is required to separate and compress carbon dioxide, even though neat carbon dioxide is not a desired product. These issues may be addressed by combining the idea of fast dissolution at the surface with supercritical water oxidation (SCWO). By burning coal at high pressure in supercritical water drawn from an aquifer, and then sequestering the entire pre-equilibrated effluent, all carbon from the fuel is captured, as well as all non-mineral coal combustion products including sulfur and metals.A possible block diagram of an SCWO-based electric power plant is proposed, including processes to handle salts from the aquifer brine and minerals from coal. The plant is thermodynamically modeled, using an indirectly fired combined cycle to convert energy from hot combustion products to work. This model estimates the overall thermal efficiency that can be achieved, and reveals unanticipated interactions within the plant that have significant effects on efficiency. The assumptions and results of the model highlight design challenges for an actual system. 相似文献
30.
超临界水氧化处理含油废水的实验研究 总被引:12,自引:1,他引:11
在间歇式超临界水氧化反应装置上进行含油废水的超临界水氧化实验研究,反应温度390~430℃、压力24~28MPa、反应时间30~90s。研究表明:超临界水氧化法是一种高效、快速的有机废弃物处理技术;随反应时间增加、温度升高,废水COD去除率显著增大;以幂函数方程描述了氧化剂过量时含油废水超临界水氧化的反应动力学规律,氧化反应对废水的反应级数为1级,在26MPa时,反应活化能和频率因子分别为(5896.83±243.68)J/mol和(0.0652±0.0028)s-1,模型计算值与实验值的误差为±13%。 相似文献