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1.
福建无烟粉煤催化气化   总被引:21,自引:5,他引:16  
报导了福建无烟粉煤在碱性催化剂作用下的催化气化工作进展,在小型Φ18mm固定床与Φ20mm流化床中,进行了水蒸气气化、混合气(空气/水蒸气)气化,采用复合1催化剂添加量8%,850~900℃及流化床条件下,即可获得产气率V>3m3/kg煤(无催化剂时,V<1.6m3/kg煤)及煤气热值QLVH>9MJ/m3(水蒸气气化)与>6MJ/m3(混合气气化)的结果,并与无烟煤气化的工业装置进行了比较,这为无烟粉煤有效转化的工业化试验提供了最重要的依据  相似文献   

2.
工业废液碱对福建无烟煤水蒸气催化气化的实验室研究   总被引:13,自引:7,他引:13  
在Φ28mm的反应管中,采用工业废液碱用于福建无烟煤固定床水蒸气气化实验。结果表明,该废液碱对福建无烟煤气化有很强的催化活性。在添加3%-12%废液碱的情况下,碳转化率均比无催化剂时增加2.55倍-3.93倍,明显大于添加以Na2CO3为催化剂的碳转化率。同时该废液碱对煤气组成,产气量和煤气热值均有明显提高。在催化气化的同时加入适量的脱碱剂可极大地降低灰渣中的含碱量。  相似文献   

3.
福建无烟粉煤流化床混合气催化气化表观动力学的研究   总被引:17,自引:9,他引:8  
在一模试流化床中,首次报道了福建劣质无烟粉煤(挥发分〈5%)采用工业副产碱盐为主制备的复合催化剂进行混合气催化气化的结果,指出这一复合催化剂适宜的添加饱和度为10%;表观动力学实验表明在该添加饱和度下,使反应表观活化能由无催化剂时的Ea=76.03kJ/mol降为Ea=45.83kJ/mol(几乎降低了40%),并且在气化温度850℃条件下,其表观反应速率常数比无催化剂时提高2.7倍;在气化温度850-900℃,催化剂浓度10%的适宜操作范围,可获得产气率V=3.77-3.58m^3/kg(1kg煤),煤气热值QLHV=5.31=6.03MJ/m^3与冷煤气效率η=79.72=85.73%的良好结果,这对劣质无烟粉煤催化气化生产燃料气与化工副产碱盐制取廉价催化的工业化实践具有重要的应用价值与可操作的现实意义。  相似文献   

4.
在实验室小型流化床反应器中研究了福建龙岩无烟粉煤纸浆黑液富氧催化气化的特性,考察了纸浆黑液催化剂添加量不同时氧体积分数变化对碳转化率、产气率、煤气组成与热值的影响。结果表明,纸浆黑液催化和富氧气体燃烧的双重作用明显地提高了煤的碳转化率和煤气有效组成;纸浆黑液中钠碱对煤焦气化的催化与对煤灰分中SiO2和Al2O3等氧化物的熔制反应同时发生并存在着竞争;纸浆黑液中钠碱对高温碳与气化剂之间多种反应表现出不同程度的促进。龙岩无烟粉煤在纸浆黑液富氧催化气化时适宜操作条件是氧的体积分数40%和蒸汽/富氧比为1.4kg/m3~2.0kg/m3。碳转化率94%、煤产气率为3.62m3/kg、煤气热值为7.33mJ/m3。  相似文献   

5.
高灰煤小型流化床混合气催化气化研究   总被引:4,自引:4,他引:0  
在内径28mm流化床中,对阳泉高灰煤在碱性催化剂(固碱和黏胶废碱液)作用下进行了混合气(空气/水蒸气)催化气化研究,两种碱性催化剂的适宜添加量均为6%。不加催化剂,气化温度830℃~900℃与900℃~920℃下,气化反应的表观反应级数n分别约为2/3与1/3;有催化剂(3%固碱)时,表观反应级数有两个明显的温度段,在830℃~860℃,催化气化的表观反应级数n=1;在860℃~920℃,催化气化的表观反应级数为n=1/3。  相似文献   

6.
城市生活垃圾气化过程中气化剂和温度的影响   总被引:1,自引:0,他引:1  
在间歇式固定床气化反应炉(φ40×750)中,考察了不同气化剂和反应温度对经预处理后的城市生活垃圾焦气化反应的影响。试验发现,当温度为900℃,用空气混合蒸汽为气化剂时,所得燃气热值为4.15MJ/m~3,气化强度为105kg/m~2·h,以空气为气化剂时,热值稍低,只有3.06MJ/m~3,气化强度仅为94kg/m~2·h;单纯用蒸汽气化时燃气热值最高可达8.89MJ/m~3。另外,气化剂量对气化反应有影响。在相同气化剂时,提高反应温度能强化气化过程,热值、产气量均有所提高。如以空气混合蒸汽为气化剂时,燃气热值和气化强度从850℃的3.22MJ/m~3和131kg/m~2·h提高到950℃的5.19MJ/m~3和166kg/m~2·h。  相似文献   

7.
生物质在流化床中的空气-水蒸气气化研究   总被引:22,自引:6,他引:22  
以流化床为反应器,对生物质的空气-水蒸气气化特性进行了研究。考察了一些主要参变量,如温度 (700 ℃~900 ℃)、水蒸气/生物质比(0~4.04)、空气当量比(0.19~0.27)以及生物质粒度(0.2 mm~0.9 mm)等对气化结果的影响。在实验研究的条件范围内,生物质产气率在1.43 m3/kg~2.57 m3/kg范围内变化,产气的低热值在6 741 kJ/m3~9 143 kJ/m3范围内变化。实验结果表明:较高的气化温度有利于氢的产生;但气化温度过高会使气体热值下降;与常规的空气气化相比,水蒸气的加入使生物质气化产气率显著提高,但水蒸气加入量过多使气化温度下降,产气率和产气热值降低;生物质颗粒粒度的大小对产气组分的分布和产气率均有影响,较小颗粒的生物质会产生较多的CH4、CO和较少的CO2。  相似文献   

8.
以碳酸钠为催化剂,在加压下用热天平等温热重法研究了四种高变质程度无烟煤(挥发分Vad=2.69%~4.35%)二氧化碳催化气化反应动力学,考察了0.101MPa~3MPa对二氧化碳催化气化反应的影响。结果表明,压力大于2.0MPa,增大压力不再加快反应速率。在2.0MPa、750℃~950℃测定实验无烟煤的转化率与时间的关系,用缩芯模型进行较好地拟合。按反应速率常数判定煤样活性大小顺序为:永安丰筛煤>永安加筛煤>永定煤>上京煤,活化能为: 157.21kJ/mol~185.89kJ/mol,要比相同煤种常压二氧化碳催化气化时具有更大的反应速率常数、 活化能和指前因子。 850℃及较低压力 0.101MPa~2.0MPa下,给出永安加筛煤气化动力学方程中的压力修正指数为0.34744,与文献报道一致。  相似文献   

9.
制备出NiSAPO-34及NiSAPO-34/HZSM-5催化剂,考察了其对二甲醚催化转化制备低碳烯烃的性能.利用Cu/Zn/Al/HZSM-55u筛选出的2%NiSAPO—34/HZSM-5催化剂进行生物质气经由二甲醚两步法制备低碳烯烃的实验,结果表明在SAPO-34上添2H2%的Ni不改变其结构,但降低了酸中心数量,并生成了较强的酸中心.添加少量具有稳定酸中心的HZSM-5,该催化剂的活性提高到3h以上,反应进行2h获得了最高的低碳烯烃选择性为90.8%.当把该催化剂应用到两步催化转化过程的第二个反应器中,其高催化活性可达5h以上.当以低氢碳比生物质气(H2/CO/CO2/N2/CH4=41.5/26.9/14.2/14.6/2.89)作为原料时,经两步转化,低碳烯烃的收率达到84.6g/m^3syngas.  相似文献   

10.
流化床反应器中生物质的催化裂解气化研究   总被引:30,自引:8,他引:22  
利用木材加工废弃的白木屑在自行开发的流化床生物质气化系统上进行了非传统气化新方法实验研究,制备了多种镍基催化剂并对不同催化剂的裂解气化性能进行了评价。结果表明,共沉淀镍铝催化剂性能最佳,镍铝比在0.5-1.0之间催化剂活性,稳定性最好,该催化剂连续使用200min活性无显著降低,失活催化剂可采用在650℃-700℃的混合气N2:CO2:O2:H2O(40:50:5:5)中焙烧的方法有效再生。  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.
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   

14.
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   

15.
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   

16.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

17.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

18.
Siqi Li  Xingpeng Chen  Jiaxi Xu 《Tetrahedron》2018,74(14):1613-1620
Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular SN2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.  相似文献   

19.
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   

20.
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   

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