基于EPI的乙烯行业效率分析

为了有效评价乙烯行业的能效水平,寻找能效改进机会,针对乙烯装置数据特点,结合能源消耗中的活动影响、结构影响与强度影响等因素,提出基于能源绩效指标(EPI)的乙烯行业能源效率评价方法。在能效分析的基础上,结合数据包络分析(DEA)方法,将能效指标与产物收率综合进行分析评价。最后,给出了针对若干装置能源数据的分析评价实例,实验结果验证了该方法的准确性与有效性,为乙烯装置效率评价提供了新思路。     

固载化离子液体催化环氧乙烷和二氧化碳合成碳酸乙烯酯

用溴化1-羟乙基-3-乙烯基咪唑、甲基丙烯酸钠、丙烯酸羟乙酯、苯乙烯4种单体共聚合成了高分子离子液体催化剂,表征了其结构. 将该催化剂固载到分子筛上制成固体颗粒催化剂,催化环氧乙烷(EO)与CO2合成碳酸乙烯酯(EC)的反应,考察了反应时间、温度、压力、催化剂用量对EO转化率及生成EC选择性的影响. 结果表明,在反应时间4 h、温度403.15 K、压力2.5 MPa、催化剂与环氧乙烷质量比9%的条件下,EO转化率为95%, EC选择性为98%,催化剂在循环使用10次后,EO转化率无明显下降,EC选择性接近100%. 该反应为一级反应,动力学方程为r=-dCEO/dt=9.872×104e-52.00/(RT)CEO.     

碳酸乙烯酯合成的研究进展

介绍了碳酸乙烯酯的各种合成方法,对二氧化碳和环氧乙烷(EO)直接合成碳酸乙烯酯(EG)的研究现状及其反应中所使用的各种催化剂的活性做出综述,并且展望了该领域的研究前景.     

以碳酸乙烯酯为吸收剂吸收环氧乙烷的方法

研究了以碳酸乙烯酯和水配比液为吸收剂吸收环氧乙烷的方法,结果表明其吸收效果要好于以水为吸收剂的吸收效果。同时,增加吸收塔塔顶压力,降低吸收温度,提高液气质量比,可以提高吸收剂的吸收效果,有效降低尾气中EO的含量。     

乙烯冷能利用方案设计

某厂EO装置和CO2装置需运行冷冻机组为装置提供冷量。低温乙烯作为下游原料时,需用蒸汽加热气化,为充分利用乙烯冷能,达到节能降耗的目的,现对其工艺流程进行方案优化设计。本文设计两种方案,分别对这两种方案进行了分析和比较,在保证充分利用能源的情况下,方案一更具有操作可行性和稳定性。     

微波氧化脱除煤中有机硫

采用微波联合超声波分别对潞安煤、西山煤、云南煤和阳泉煤进行脱硫研究.考察了氧化剂配比、微波辐照时间、超声波联合微波等条件对煤中有机硫脱除效果的影响.实验结果表明,不同氧化剂配比有不同的脱有机硫效果.其中,V(HAc):V(H2O2)=1∶1时,脱硫效果最佳;微波辐照时间对脱硫率有明显的影响,随着微波辐照时间的延长,有机...     

锂硫电池硫/炭复合正极材料的研究进展

锂硫电池具有高比能量密度、原料丰富且对环境友好等优势,成为当前最具有吸引力的二次电池体系之一.然而循环寿命低制约着其商业化进程.本文主要综述了几十年来国内外学者在硫/炭复合正极材料方面的研究现状,并对未来新型正极材料的研究方向进行了展望.     

热泵在乙烯精馏工艺中的运用

常规精馏塔需从塔顶冷凝器取出热量,从塔釜再沸器加入热量,其消耗的能量为精馏塔的主要操作费用。热泵利用机械能或电能将低温位热能提高到高温位热能,在精馏中将塔顶气相加压冷凝后作为塔底再沸器的热源,特别是在乙烯装置乙烯精馏中运用热泵,将乙烯冷剂的循环和乙烯精馏结合为一体,利用乙烯冰机将开式热泵用在乙烯精馏中,可节约能耗,降低生产成本。     

复合离子交换树脂催化环氧乙烷水合制乙二醇的性能研究

采用悬浮聚合方法合成制备了以碳纳米管或石墨烯复合的强碱性离子交换树脂催化剂,表征发现纳米碳材料可以有效分散于复合型树脂的聚合物基体中,并且由于复合型树脂内添加的纳米碳材料与聚合物碳骨架之间存在较强的空间限制作用,复合树脂的热稳定性和抗溶胀性能均有一定提高,发生热分解起始温度提升近15℃,交换容量提高5倍以上。在小型固定床反应器中对合成的树脂催化剂进行一系列环氧乙烷催化水合反应性能的考评,对比结果发现,进料的水与环氧乙烷物质的量比为10的条件下,石墨烯复合型树脂催化剂的催化活性、选择性及稳定性最好,环氧乙烷转化率大于98%,稳定运行300 h保持乙二醇产品收率在95%以上。     

Capture of solar energy using elemental sulfur

Use of the equilibrium sulfur vapour system as the basis for a thermochemical solar energy conversion system is suggested. This chemical system is shown to be both thermodynamically and kinetically well suited, as well as possessing several other desirable features. A key advantage is provided by reliance on the proven mature Claus technology for materials handling and the heat recovery stage of the proposed scheme.     

乙烯装置能耗指标探讨

分析了目前国内使用的蒸汽裂解生产乙烯装置能耗计算指标存在的问题,提出了增加单位双烯能耗指标和单位高附加值产品能耗指标的建议。     

Study of unsteady-state catalytic oxidation of sulfur dioxide by periodic flow reversal

A systematic study of catalytic oxidation of sulfur dioxide in a fixed bed reactor operated in flow reversal mode was made. A heterogeneous transient model of the reactor was developed. The global rate equations and the heat transfer parameter correlation were obtained, based on a series of previous experiments. The experiments of unsteady-state oxidation of low concentration SO₂ were conducted in a bench-scale fixed bed reactor, packed with a domestic commercial catalyst. The model can successfully predict the transient concentration and temperature profiles when a correction factor is introduced to the global rate equations.     

碳一化合物合成乙二醇技术的研究进展

我国具有丰富的煤和天然气资源,以碳一化合物合成乙二醇(EG)具有广阔的发展空间和应用前景。本文综合国内外相关文献,对当今碳一化合物合成EG的技术进展进行了综合论述,并提出了其今后的发展方向。     

乙烯氧化制环氧乙烷银催化剂研究进展

综述了乙烯氧化制环氧乙烷银催化剂的重要研究进展。包括通过调整添加组分及配比、改进载体结构、控制载体中各种杂质含量等方法改进载体;通过各种共促进剂的使用、改进载体浸渍方法和催化剂活化过程,提高Ag-Re-Cs体系催化剂的性能;通过低浓度CO2进料、高温预处理、反应抑制剂控制、反应失控控制和使用微通道反应器等工艺方法改善催化剂的使用性能。     

塔段板效率可调的乙烯精馏塔稳态与动态模拟

提出一种板效率可调的乙烯精馏塔稳态与动态模拟方法,将精馏塔分为5段,利用流程模拟软件模拟各塔段板效率不同时,乙烯精馏塔的稳态与动态响应曲线。结果表明:板效率下降会导致乙烯精馏塔的分离效果降低,产品质量下降。而且该结果能够反映实际生产过程。     

节能技术在乙烯存储系统中的比较和应用

乙烯是石油化学工业中最重要的基础有机原料之一。通常乙烯采用低温常压存储,因此存储的能耗对乙烯储运的运行成本影响较大。本文通过对低温乙烯存储系统中不同的工艺能耗进行了分析和比较,发现节能技术的应用能回收乙烯冷量,有效的降低乙烯存储的能耗,为低温乙烯存储系统中的节能技术的应用提供参考。     

乙烯冷能利用的全液体空气分离装置

通过对全液体空分装置常规氮循环、利用乙烯冷能的两种流程组织形式进行分析比较和模拟计算,利用乙烯冷能的流程组织形式可达到节能降耗的目的。     

不同乙烯产品外送方案对乙烯装置能耗和经济性的影响

研究某百万吨级乙烯装置所采取的乙烯产品外送方案,发现乙烯产品外送方案对乙烯制冷压缩机、丙烯制冷压缩机的功率有着显著的影响.不同的乙烯产品外送方式对应乙烯装置不同的公用工程消耗、能耗、设备投资和操作运行费用.通过对比,得到了最优化的乙烯产品外送方案,实现乙烯装置的经济效益和市场竞争力的提高.     

Conversion of SO2 into elemental sulfur by using the RF plasma technique

This study demonstrates a new approach for converting SO₂ into elemental sulfur by adding CH₄ in a radio-frequency (RF) plasma reactor. With the applied power (P) of the RF reactor specified at 90 W and operating pressure set at 4000 N/m², it was found that as the CH₄/SO₂ ratio (R) was increased from 0.3 to 1.0, most sulfur-containing products were in the form of elemental sulfur. While R was increased from 1 to 2, the content of elemental sulfur was decreased significantly, but CS₂ was increased dramatically. While R was increased from 2 to 3, both elemental sulfur and CS₂ contents became quite comparable. Nevertheless, it was found that both H₂ and CO (that is, syngas) were the main nonsulfur-containing products under all testing conditions. These results indicate that the use of the RF plasma technique was not only beneficial to convert SO₂, but also was able to convert CH₄ into useful materials. For R = 0 (that is, no CH₄ was introduced), it was found that the SO₂ conversion (i.e., η) = 0.084, indicating that the RF plasma process was inadequate to convert pure SO₂ without adding CH₄ as a reducing agent. While R was increased to 2, it was found that η was improved significantly to 0.968 accompanied with η = 0.999. But as R was increased from 2 to 3, both η and η were slightly decreased. Both η and η also were sensitive to the applied power (P). As P was increased from 15 W to 90 W at R = 2, it was found that both η and η were increased dramatically from 0.247 and 0.320 to 0.968 and 0.999, respectively. But as P was increased from 90 W to 120 W, the increase on both η and η became very limited. Based on these, this study suggests that the operating condition of R = 2 and P = 90 W would be the most appropriate combination for SO₂ conversion. © 2004 American Institute of Chemical Engineers AIChE J, 50: 524–529, 2004     

Factors affecting the oxidation of elemental sulfur in soils

The use of elemental sulfur (S⁰) to alleviate widespread S deficiencies in agricultural soils is limited by the unpredictability of its oxidation to plant available sulfate. Here we review the biological, fertilizer and soil-related factors that control S⁰ oxidation. Sulfur oxidation in soil is mediated primarily by microorganisms, and thus it is the size, composition and activity of the microbial community which dictate oxidation rates. Because S⁰ oxidation is a biological process, it is strongly influenced by factors directly affecting microbial activity including soil temperature, water potential, and aeration. In many soils these factors represent the primary constraints to S⁰ oxidation. Oxidation is also influenced by the effective surface area of the S exposed to microbial activity. Thus oxidation is favored by reducing the particle size and abundant populations of heterotrophic bacteria and fungi capable of oxidizing S⁰, thus the availability of organic substrates from residue additions or root exudates may also affect S oxidation. Previous application of S⁰ may increase oxidation rates in many soils, presumably by stimulating S⁰ oxidizing populations. The large number of factors that govern S⁰ oxidation account for the variability in oxidation rates among soils, climatic regions, and agronomic practices. Many of these factors are subject to agronomic control, however, and it should be possible to devise S fertilizer strategies that exploit the slow release characteristics of S⁰ to meet crop demands efficiently in a variety of conditions.