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1.
介绍了用于整体煤气化联合循环(IGCC)热煤气和增压流化床燃烧联合循环(PFBC-CC)高温烟气除尘的移动颗粒层试验台。调试阶段进行了一系列的条件试验。改进后的常温下进行了试验,结果表明在高压下能够实现颗粒层过滤和气力循环清灰的一体化稳定运动。研究发现移动颗粒层过滤时,气流之间的压力平衡是一个关键因素,运行中必须严格控制过滤气体和输送气体的压力。移动颗粒层过滤器和循环清灰系统的结构对过滤性能有较大的影响。  相似文献   

2.
流化床条件下煤的一次爆裂特性的实验研究   总被引:16,自引:2,他引:14  
流化床锅炉中煤的爆裂特性对锅炉运行的炉内传热、碳转化率和细微颗粒的排放等许多方面有重要影响。本文在一台小型常压流化床反应器中研究了了种烟煤的一次爆裂烟煤的。对此烟煤不同宏观煤岩类型(亮煤和暗煤)的一次爆裂特性进行了比较研究。实验发现颗粒的一次爆裂率和爆裂程度很大程度上取决于颗粒粒径以及煤颗粒的组成,亮煤具有与暗煤不同的一次爆裂特性,同一粒径的煤颗粒爆裂后形成具有一定特点的粒径分布。针对不同煤岩类型  相似文献   

3.
增压O2/CO2燃烧是一种可高效分离回收CO2的新兴燃烧技术,其燃烧机理与常压空气、常压O2/CO2燃烧存在较大差异。在加压热重分析仪上研究了增压条件下总压、氧浓度、气氛及粒径等反应参数对美国烟煤和淮北无烟煤燃烧特性的影响,确定了煤的着火温度,并对其进行燃烧动力学分析。结果表明,增压O2/CO2气氛下,随着压力或氧浓度的增加,DTG曲线向低温区移动,煤样整体燃烧速率加快。压力提升、氧浓度增加及煤粉细化均可改善O2/CO2气氛下煤样的着火特性。常压O2/CO2气氛下煤粉燃烧基本属于一级反应;增压O2/CO2气氛下,低温区属于0.5级反应,而高温区属于1.5级反应。  相似文献   

4.
循环流化床锅炉氮氧化物的生成与分解模型   总被引:1,自引:0,他引:1  
在国内外研究基础上,依据循环流化床锅炉炉内氮氧化物(NO和N2O)的生成与分解特性,建立了一个以化学反应动力学为基础的炉内NO和N2O的生成和分解模型,模型有机地结合在已有的循环流化床锅炉总体数学模型之中。模型对一台75t/h循环流化床锅炉炉内氮氧化物的生成和分解特性的模拟预测结果与工业试验结果吻合良好。模型的预测和工业试验表明循环流化床锅炉的氮氧化物(NO和N2O)的排放受锅炉运行参数如温度、一二次风比例等的影响,可以通过调整锅炉运行参数来控制锅炉氮氧化物的排放。  相似文献   

5.
通过对气固流化床颗粒作用壁面产生的声波信号的多尺度小波包分析, 发现各尺度能量分率随气速变化存在着规律性的演化行为, 建立了颗粒流化的能量分配理论, 包括能量一次分配理论和能量再分配理论. 并基于该能量分配理论, 提出了基于声信号分析的起始流化速度和初始湍动速度的判断准则. 在内径为150 mm的气固流化床冷模装置中, 以平均粒径为0.51, 0.64, 0.76, 1.02, 1.24 mm的5种高密度聚乙烯颗粒和平均粒径为0.365 mm的双峰聚乙烯颗粒为例, 分别以基于声信号分析的流化速度判断准则获得了颗粒起始流化速度和初始湍动速度, 与经典的压差法测得的起始流化速度和工业上经验性的初始湍动速度相比, 平均相对误差分别为5.18%和6.78%, 说明运用声信号的多尺度分析来获取气固流化床的流化特性参数是可行的.  相似文献   

6.
从合成气制取液体燃料的浆态床FT合成/固定床2SM-5改质的反应系统由Ⅰ段鼓泡浆液反应器(内径40mm,高450Omm)和Ⅱ段固定床ZSM-5反应器(内径40mm,高900mm)组成,在温度250~280℃(Ⅰ段),300~340℃(Ⅱ段),压力1.5~2.5MPa,空速2.0NL/gFe·h(Ⅰ段),500~1000h ̄-1(Ⅱ段),H_2CO比0.5~1.5和气速1~2cm/s范围内,考察了工艺参数对反应性能的影响,1000h以上的寿命试验的平均结果为:合成气单程转化率65.1%,产率100g/Nm ̄3(Co+H_2),总烃生产达350g/Fe。使用富CO合成气时,达110g/Nm ̄3(CO+H_2)。实测的FT合成反应热为2938;5kJ/Nm ̄3(CO+H_2)。长期运转试验表明,工艺流程合理,设备操作和温度控制可靠。采用的浆液循环回路方法可初步分离蜡中的催化剂。  相似文献   

7.
致密皮层非对称气体分离膜的制备   总被引:4,自引:0,他引:4  
以湿相转化法制备出分离性能优良的致密皮层非对称气体分离膜;建立了醋酸纤维素 丙酮 甲醇三组分制膜体系,所制得的致密皮层醋酸纤维素非对称气体分离膜,在室温、05MPa进气压力下,该膜对CO2/CH4的分离系数30,CO2透气速率可达18×10-8cm3(STP)/cm2·s·Pa;扫描电镜图显示该膜表层致密、超薄(约200nm)、支持层疏松,为理想结构的非对称气体分离膜.  相似文献   

8.
通过CFD双欧拉模型模拟了灰熔聚流化床气化炉内气体、固体颗粒于不同气体分布器、灰分离器结构下的流动行为,阐明了不同中心射流气速下的气体、固体流动循环状况;环管内气流分布与扩管张角的关系以及对颗粒运动的影响。研究结果为认识和改善气化炉煤灰的结渣、团聚、分离等过程提供了一定的理论基础。  相似文献   

9.
口服聚酯聚醚疫苗蛋白微球的制备研究   总被引:10,自引:0,他引:10  
采用本体聚合法合成不同聚醚含量的聚酯聚醚嵌段共聚物聚 DL 乳酸 聚乙二醇(Poly DL lactide b polyethyleneglycol,PELA).PELA及PLA包裹人血清白蛋白(HSA)微球采用溶剂挥发法双乳液体系(W1/O/W2)制备.微球球形规整,粒径集中在05~50μm.用CBB法检测微球中蛋白含量,蛋白包裹量达25%,包裹效率近80%.从双乳液体系中界面张力角度考察了聚合物囊材的性质、稳定剂的种类及W1/O的稳定性等对微球粒径及蛋白包裹量的影响.微球体外释放结果表明PELA蛋白微球的突释现象不明显,释放速度较为恒定.  相似文献   

10.
通过双流体模型对射流流化床煤气化炉进行了CFD(Computational Fluid Dynamics,计算流体力学)模拟。模拟着重分析了流化床气化炉气固流动的特性和传质、传热过程。结果表明,流化床中气固两相的传热、传质过程与气体和颗粒的运动特性密切相关。  相似文献   

11.
用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.  相似文献   

12.
Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.  相似文献   

13.
In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.  相似文献   

14.
The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.  相似文献   

15.
The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.  相似文献   

16.
KMnO4-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.  相似文献   

17.
The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.  相似文献   

18.
A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.  相似文献   

19.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
Regiospecific and direct imidation of the methyl C(sp3)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.  相似文献   

20.
A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.  相似文献   

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