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1.
炼制高硫原油焦化装置的硫腐蚀原因及对策   总被引:6,自引:0,他引:6  
分析了加工高硫油后,焦化装置内设备和工艺管线的硫腐蚀原因。利用腐蚀原理,从而有针对性地提出了焦化装置的防腐对策。  相似文献   

2.
气化条件下,煤中含铁矿物被还原,气化渣中析出单质铁,影响熔渣的黏度.以铁含量较高的煤样为研究对象,借助XRD和穆斯堡尔谱分析煤中矿物尤其是含铁矿物的组成.利用高温管式炉模拟气化条件,制备不同温度不同气氛下的熔渣,采用穆斯堡尔谱定性和定量分析熔渣中的含铁物相,研究熔渣中含铁物相的生成与温度和气氛的关系,探讨单质铁的析出机...  相似文献   

3.
Marc Bläsing 《Fuel》2011,90(6):2326-2333
Alkali metal, sulphur, and chlorine species released during coal gasification are of concern, because they can lead to problems in colder parts of the plant. Therefore, hot gas cleaning technology is recently under development. This clean-up strategy requires a comprehensive knowledge of the release characteristics of inorganic compounds. The principal objective of this work was to provide details of the influence of pressure on the release of key chemical species, e.g. sodium, potassium, sulphur, and chlorine. Hence, a total of 19 different coals were investigated in lab-scale gasification experiments in an electrical heated pressurised furnace at absolute pressures of 2, 4, and 6 bar in an atmosphere of He/7.5v%O2 at 1325 °C. Hot gas analysis was carried out by molecular beam mass spectrometry. The quantitative results showed a decreasing release of 34H2S+, 36HCl+, 39K+/39NaO+, 58NaCl+, , and 74KCl+ with increasing pressure. The discussion was supported by thermodynamic calculations.  相似文献   

4.
    
The aim of this work is to understand the catalytic behaviour of Li and Cs promoted Mo2N for CO hydrogenation to hydrocarbons and oxygenates at the reaction conditions 275–325 °C, 7 MPa, and 30 000 h?1 GHSV. Molybdenum nitrides were synthesized via temperature programmed treatment of ammonium heptamolybdate (AHM) and alkali metal (AM) precursors under continuous gaseous ammonia flow. Unpromoted Mo2N and AM‐Mo2N catalysts were characterized using BET‐pore size, X‐ray diffraction, TPD‐mass of CO, HR‐TEM, and XPS techniques. Nominal loadings of 1, 5, and 10 wt% of Li and Cs were selected for these studies. At a 10 % CO conversion level, the total oxygenate selectivity of 28, 11, and 6.5 % was observed on 5Cs‐Mo2N, 5Li‐Mo2N, and unpromoted Mo2N, respectively. The decreased oxygenate selectivity for unpromoted Mo2N was mainly associated with CO dissociative hydrogenation on Moδ+ sites. On the other hand, improved molecular CO insertion into ?CxHy intermediate accelerates the total oxygenate formation on the Cs‐Mo‐N catalyst. However, during nitridation, crystal structure changes were observed in Li‐Mo‐N and the obtained oxygenates selectivity was attributed to the Li2MoO4 phases. At lower AM loadings, the active sites corresponding to oxygenates formation were inadequate, and at higher AM loadings, surface metallic molybdenum decreased the total oxygenate selectivity.
  相似文献   

5.
三氟碘甲烷合成和应用研究进展   总被引:1,自引:0,他引:1  
介绍了新型灭火剂和环保型制冷剂三氟碘甲烷的特性,叙述了合成路线及其应用研究进展,其中以活性炭负载碱金属或碱土金属盐为催化剂气相催化制备三氟碘甲烷法,具有工序简单、高效经济、环境污染小和易连续生产等优点,具有工业化前景.  相似文献   

6.
为缓解上安电厂2号锅炉完成低氮燃烧改造后下炉膛水冷壁出现的严重硫化物高温腐蚀问题,针对该厂2号W火焰锅炉燃烧方式的特点及设备状况,分析得出锅炉进行分级送风、煤粉浓淡分离、增加燃烬风等低氮燃烧改造,使得下炉膛区域由过氧燃烧转变为欠氧燃烧是引起高温腐蚀的主要原因,并提出从运行氧含量、燃烬风门开度、外二次风旋流强度、煤质和运行磨煤机组合等几个方面寻优的燃烧调整策略。结果表明,根据各项测试最优结果进行优化组合后满足O_2含量2%,CO含量0.2%条件的测点个数明显增加,下炉膛壁面还原性气氛明显减弱,高温腐蚀问题得到较大缓解,提高了机组运行的安全性,保证最优工况下选择性催化还原法(SCR)入口的NO_x浓度低于改造设计值的800 mg/m~3,表明调整策略同时兼顾了环保运行的要求。  相似文献   

7.
研究了中性碱土金属盐(NAEM)催化的碱性亚硫酸钠溶液中添加蒽醌和甲醇(ASAM)法制浆的机理,结果表明,NAEM+ASAM法蒸煮对木素具有良好的选择性,从而改善了碳水化合物的稳定性,成浆具有高的半纤维素保留率。  相似文献   

8.
    
Magnesium oxide (MgO) is favored for solid-state carbon dioxide (CO2) capture due to its high theoretical adsorption capacity, abundant reserves, low cost, and environmental friendliness. However, its practical application in industry is hindered by low CO2 adsorption capacity under moderate operating conditions. In this work, MgO was modified by a deposition method using LiNO3, NaNO3, KNO3, Na2CO3 and K2CO3 as additives.  相似文献   

9.
《Ceramics International》2023,49(1):625-634
Spinel-type Li4Ti5O12 (LTO) is known as a “zero-strain” material due to its negligible structural change during the charge/discharge process. However, high production cost and poor electrical conductivity limit the wide application of spinel-type LTO. Herein, a novel preparation process was developed to prepare a Li4Ti5O12/C–S composite using industrial H2TiO3 as the titanium source. In the calcination process under a carbon reducing atmosphere, SO42? adsorbed on industrial H2TiO3 not only promotes the carbonization of glucose on the surface of LTO but also introduces S heteroatoms into the carbon coating layer in the form of C–S bonds through a series of reactions with glucose, which significantly improves the overall conductivity and the Li+ diffusion coefficient of the material. Therefore, the synthesized Li4Ti5O12/C–S composite exhibits excellent rate performance and cycling stability, with a specific capacity of 135.88 mAh g?1 even at 10C and a capacity decay rate of only 0.011% per cycle after 1000 cycles at 5C. This study delivers a novel method for the industrial production of LTO with both cost and performance advantages.  相似文献   

10.
应用量子化学方法,从微观角度了解一氧化碳(CO)分子吸附在碱金属离子(Li+、Na+、K+、Rb+、Cs+)交换Y型分子筛上的机理,详细研究了吸附时红外光谱的变化情况。研究发现,CO分子能与碱金属离子交换Y型分子筛发生多分子吸附,且其吸附行为和结构相类似。CO发生单分子和双分子吸附后,其红外光谱均会发生蓝移。当CO双分子吸附时,其红外光谱会出现两个新的吸附带,且其振动频率比单分子吸附时有所降低。当CO在Li-Y、Na-Y分子筛上发生双分子吸附时,其振动频率与单分子吸附时有较大差别;而CO在K-Y、Rb-Y、Cs-Y分子筛上发生双分子吸附时,其吸附前后的振动频率变化较小,且两个CO分子的振动频率很接近。能量计算结果显示,CO分子吸附强度会随着离子半径的增加而减弱。  相似文献   

11.
添加剂对型煤固硫促进作用的研究   总被引:3,自引:1,他引:3  
研究了添加剂对型煤高温(1200℃)固硫效果的影响.实验发现:MgO对Ca(OH)2固硫反应有较强促进作用;在钙基固硫型煤中同时加入硅酸盐和Fe2O3,可大大提高固硫效果,其XRD图表明灰渣中形成了一些耐高温物质和 CaSO4复盐(Ca3Al6O12·CaSO4);并得出 MS型煤的Ca(OH)2和 MgO加入摩尔比和固硫率关系的回归方程.  相似文献   

12.
    
The ability to accurately identify fire patterns is the fundamental requirement for fire investigations. The corrosion layers of steel in fire scenes exhibit three distinct characteristics. First, due to steel's nonflammable nature, steel patterns can be preserved better at the fire site than patterns formed on other combustible materials; second, both the high temperature and the smoke during the fire affect the high-temperature oxidation process; and third, the corrosion layer of steels inevitably undergoes further evolution after the fire because of the subsequent room-temperature corrosion. This study focuses on investigating Q235 steel because of its extensive use in construction and vehicles. The pattern evolution processes of high-temperature oxidation at elevated temperatures in air, polyethylene (PE), and polyvinyl-chloride (PVC) combustion smoke and the corresponding subsequent corrosion at room temperature were systematically investigated from the perspective of macroscopic and microscopic morphology. The results showed that the smoke atmosphere played an important role in the formation of the corrosion layer of Q235 steel. Compared with samples oxidized in air, samples oxidized in PE combustion smoke exhibited a uniform and dense oxide layer on the surface, which inhibited the corrosion at room temperature further. The PVC combustion smoke accelerated the high-temperature oxidation of the sample, and its influence on the subsequent room-temperature oxidation process was closely correlated with the temperature of the high-temperature oxidation. The results of this study provide important references for understanding the formation of the corrosion layer of Q235 steel for fire investigations.  相似文献   

13.
糠醛渣的能源化利用是糠醛产业清洁生产和碳减排的有效途径。然而,现有的直接燃烧利用常面临着因糠醛渣高K引起的灰分烧结严重、高S导致的SOx排放量大和高水含量导致的燃烧效率低等难题。基于此,在管式炉中考察了单一气氛(N2、CO2、O2)和混合气氛(N2+H2O、CO2+H2O、O2+H2O)中糠醛渣灰在不同温度下的烧结特性,并对灰分颜色、收缩率、微观形貌、矿物质成分和K/S释放等特性进行系统分析。灰分热收缩行为显示,随温度升高,灰样收缩率增加;在单一气氛中添加水蒸气能促进灰分烧结。SEM分析发现,在灰分烧结前,其微观结构在低温下已出现熔融和结渣。XRD分析表明,灰分烧结与低熔点矿物生成紧密相关。单一气氛中,高温下N2促进钾长石生成;CO2抑制钾长石生成;O2促进钙铝黄长石和透辉石生成。在混合气氛中,水蒸气的出现促进多种低熔点钾铝硅酸盐生成,如钾长石和白榴石等。XRF分析显示,随温度升高,灰样中K的固留率(GK)和S的固留率(GS)降低;在考察的单一气氛中,高温时,N2GK最低;GS受气氛的影响较小。在考察的复合气氛中,高温时,GK受气氛影响较小;GS受气氛影响严重,特别地,O2+H2O气氛中GS最高,S逸散最少。为抑制糠醛渣灰分烧结和K/S元素逸散到气相中,糠醛渣在流化床燃烧过程中应控制运行温度(低于900℃)、降低气氛中N2的含量。  相似文献   

14.
金培 《江苏陶瓷》2011,(4):11-12
依据稳定烧成气氛理论的要点,进行了陶瓷烧成缺陷原因的分析,并指出在实际生产中其纠正措施在于强化工艺纪律管理。  相似文献   

15.
油田生产中硫酸盐还原菌的危害及其防治   总被引:1,自引:0,他引:1  
李林 《化工时刊》2010,24(9):59-62
归纳了硫酸盐还原菌在油田生产活动中的危害,并通过对硫酸盐还原菌代谢机制的研究,深入了解其代谢特点和金属腐蚀机制。在此基础上,全面总结了硫酸盐还原菌的防治方法,包括物理方法、化学方法和生物方法,并提出了硫酸盐还原菌的防治策略和未来发展方向。  相似文献   

16.
负载型固体碱催化合成三氟碘甲烷   总被引:1,自引:0,他引:1  
将碱金属、碱土金属盐负载在活性炭载体上制备的多种负载型固体碱作为催化剂,应用于五氟乙烷、氧气和碘合成标题化合物的实验表明,所制备的固体碱中钾盐催化活性高,选择性好,是理想的活性组分。  相似文献   

17.
Corrosion Mitigation of Mild Steel by New Rare Earth Cinnamate Compounds   总被引:1,自引:0,他引:1  
Corrosion rate measurements based on weight loss (i.e., mild steel immersed for seven days in 0.01 M NaCl) and linear polarization resistance (LPR) techniques have shown that even low concentrations (200 ppm) of cerium and lanthanum cinnamates are able to significantly inhibit corrosion. Of all the compounds investigated in this work Ce(4-methoxycinnamate)3· 2 H2O and La(4-methoxycinnamate)3· 2 H2O compounds exhibited the greatest inhibition and, in comparison with the component inhibitors, a synergy was clearly observed. The mechanism of corrosion inhibition was investigated using cyclic potentiodynamic polarization (CPP) measurements. The results suggest that La(4-nitrocinnamate)3· 2 H2O and Ce(4-methoxycinnamate)3· 2 H2O behave as mixed inhibitors and improve the resistance of steel against localized attack.  相似文献   

18.
碱渣废液是一种具有强烈刺激性和恶臭气味的危险废液;主要由石油炼化行业在油品精制过程中产生。其特点是难降解、毒性强且呈强碱性;同时含有高浓度的硫化物和有机物。为实现碱渣废液的资源化利用或达标排放;必须对其进行硫稳定化处理。基于此;以某石化厂产生的汽柴油碱渣废液为对象进行了系统研究。实验结果表明;该废液呈强碱性;S2-的质量浓度高达24.22 g/L;同时含有少量SO₄2-。此外;该废液还含有多种复杂的有机硫化合物;包括甲硫醇、二甲基二硫醚、甲基乙基二硫醚等。系统研究了中温低压湿式氧化技术对S2-的氧化效果;发现该技术可以实现S2-的完全氧化;最终产物为SO42-。具体研究结果表明;当湿式氧化温度升至60 ℃时;甲硫醇被氧化为二甲基二硫醚;并伴随剧烈放热。随着温度的进一步升高;以二甲基二硫醚为主的有机硫经深度氧化生成亚砜和砜类化合物;最终以可溶性SO42-的形式存在于废液中。通过中温低压湿式氧化处理;碱渣废液中的S2-和有机硫得到了完全氧化;硫元素最终以稳定性良好的SO42-形式存在于废液中。该工艺不仅有效去除了废液的刺激性气味;降低了其毒性;还为碱渣废液的资源化回收利用创造了有利条件;具有重要的环境保护意义。  相似文献   

19.
不溶性硫磺高温稳定性测定方法的研究   总被引:1,自引:2,他引:1  
介绍测定不溶性硫磺高温稳定性的两种方法(湿法和干法)并进行比较。湿法操作复杂,但物料受热均匀,结果较合理;干法操作简便,但少量物料温度不一致,分析结果偏低,但仍在可接受范围。两种方法都可满足工业应用的要求。  相似文献   

20.
为改善超滤膜结构和性能,将金属有机框架材料HKUST-1掺杂于聚醚酰亚胺(PEI)铸膜液中,制备了HKUST-1掺杂聚醚酰亚胺混合基质膜(HKUST-1/PEI)。通过FTIR、SEM、AFM和水接触角测定仪对HKUST-1/PEI的结构、形貌以及表面浸润性能进行了表征。结果表明,HKUST-1纳米材料掺杂质量分数为0.05%的混合基质膜具有较好的性能,在0.1 MPa运行压力下,其纯水通量能够达到1304 L/(m2·h),对质量浓度为1.0 g/L 牛血清白蛋白(BSA)的截留率在97%以上;在酸性(pH =2)、碱性(pH =12)溶液中浸泡24 h后,对BSA的截留率仅下降约2%(纯水通量基本保持不变),具有良好的耐酸碱性能;在80 ℃高温下膜的纯水渗透通量达到1587 L/(m2·h)且BSA截留率>95%,具有较强的耐高温性能;此外,其通量恢复率达到92%,膜的防污性能得到了极大的改善。  相似文献   

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