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1.
以磷钨酸为催化剂,混合多元醇为液化剂,在高压反应釜中对玉米秸秆进行催化液化试验。通过单因素和正交试验设计,详细考察催化剂用量、液化剂与玉米秸秆质量比(液固比)、反应时间和反应温度对玉米秸秆液化效果的影响。试验结果表明,在聚乙二醇400和乙二醇质量比6∶1,液固比12∶1,催化剂用量3%,反应时间75 min,反应温度150℃的条件下进行液化,玉米秸秆液化率为86.84%。  相似文献   

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以磷钨杂多酸为催化剂,多羟基醇为液化剂,在高压反应釜中进行玉米秸秆的催化液化实验。实验结果表明:以聚乙二醇400(PEG400)和乙二醇(EG)的混合多元醇为液化剂优于单一多元醇的液化剂,且当聚乙二醇400(PEG400)与乙二醇(EG)的质量之比是6∶1时,玉米秸秆的液化效果最佳。反应时间、液化剂与反应物料之比(液固比)、反应温度、催化剂的用量对玉米秸秆的液化效果均产生一定的影响。在单因素实验的基础上,通过正交试验设计,确定玉米秸秆在磷钨杂多酸催化下的最优工艺条件。在反应时间60 min、液固比12∶1、反应温度160℃、催化剂的使用量是3%的条件下,玉米秸秆的液化率为84.84%。  相似文献   

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以混合多元醇(聚乙二醇,乙二醇,丙三醇=1∶1∶1)为液化剂、浓硫酸为催化剂、玉米秸秆为原料,将生物质秸秆液化得到产物聚醚多元醇。研究表明:玉米秸秆的最佳液化条件为反应温度160℃,液固比20∶1,浓硫酸用量为4%。在该条件下,其液化率为94.08%,液化产物的羟值914.43 mg KOH/g,酸值75.05 mg KOH/g,粘度是90 MPa·s。  相似文献   

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固体超强酸Cl-/Fe2O3的制备及催化液化生物质   总被引:5,自引:0,他引:5  
乐治平  张宏  洪立智 《化工进展》2007,26(2):246-248
通过水热合法制备了固体超强酸催化剂Cl—/Fe2O3,并将其应用于稻壳,毛竹和玉米秸秆等生物质的催化液化。考察了催化剂用量、反应温度、反应时间等对催化剂性能的影响,试验表明在300℃、反应时间3 h、催化剂的用量为原料质量分数的4%时,可以获得较好的液化效果。以玉米秸秆为原料的催化剂寿命试验结果还表明,催化剂可以多次重复使用。  相似文献   

5.
采用正交试验,考察了苯酚用量、催化剂用量、反应时间及反应温度对茭白废弃生物质液化效果的影响,并研究了该液化产物制备胶黏剂的影响因素。结果表明:茭白废弃生物质液化过程中,苯酚用量的影响最大,反应温度和反应时间次之,而催化剂用量的影响相对较弱,优化参数是苯酚用量为1∶5,催化剂用量为7%,反应时间为90 min,反应温度为140℃,在此优化条件下,液化率为95.83%。胶黏剂制备过程中,茭白液化物与甲醛的质量比为1∶1.8,高温缩聚反应温度为92℃较为合适。  相似文献   

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选用胜利褐煤和玉米秸秆为原料,在高压反应釜内,对其共液化反应性进行了研究。利用索氏抽提对液相产物进行了分离,系统地考察了反应温度、原料配比、初始氢压和反应时间对胜利煤和秸秆共液化的影响。研究结果表明:秸秆能够有效地促进胜利煤的转化,提高油产率。在反应温度420℃、初始氢压9MPa、秸秆/胜利煤质量配比=2/8和反应时间60min时,胜利煤和秸秆共液化的转化率和油产率分别为99.74%、65.30%。  相似文献   

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以玉米秸秆粉末为原料,浓磷酸为反应催化剂,混合多元醇以及碳酸乙烯酯为液化剂,180℃条件下,在高压反应釜中对玉米秸秆进行催化液化实验。考察了聚乙二醇复配乙二醇、聚乙二醇复配碳酸乙烯酯以及聚乙二醇复配甘油3种不同混合液化剂对液化率和液化产物特性的影响。采用气质联用仪(GC-MS)以及傅里叶红外光谱仪(FT-IR)对液化产物和液化残渣进行表征。实验结果表明,以聚乙二醇与乙二醇混合溶剂液化时液化率最高,为97.83%。GC-MS分析结果表明,液化产物成分复杂,主要包括醇类、有机酸类、醚类、酮类、酯类和糖类等化合物。FT-IR分析结果表明,以聚乙二醇与乙二醇混合溶剂为液化剂时秸秆液化效果最好。  相似文献   

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竹废料液化制备多羟基化合物研究   总被引:2,自引:0,他引:2  
在硫酸的催化作用下,竹废料在由聚醚多元醇和粗甘油组成的混合液化剂中可被液化成多羟基化合物.重点研究了液化温度、液化时间、催化剂用量、竹屑添加量等液化反应参数对竹废料液化反应的影响.研究结果表明,当液化温度为160℃、液化时间为120 min、催化剂用量为液化剂质量的3%、竹屑量占液化剂质量的30%时,液化率可达95%,所得液化产物的羟值205 mg(KOH)/g,黏度为890 mPa?s,可以用于半硬质聚氨酯泡沫的制造.同时通过红外光谱分析方法对竹屑液化的机理做了初步探讨.  相似文献   

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苯酚液化是生物质液化的重要手段,农作物秸秆是一种不均一的原料,而完全液化将其看作是 "单一"的原料,针对这一问题本研究采用选择性液化处理方式对小麦秸秆进行了苯酚液化,并对比了选择性液化与完全液化。结果表明:低温下适当的浓硫酸用量、较高的苯酚用量、适当的反应时间有利于保留纤维素而选择性液化半纤维素和木质素;与完全液化处理方式相比,选择性液化反应条件温和,保留了大量的纤维素,大大提高了原料利用价值。通过均匀试验和数据回归分析并实验验证得到选择性液化优化条件为:浓硫酸用量占总反应体系质量分数的 3.0%,反应温度 100℃,反应时间 30 min,苯酚与秸秆质量比 3:1,纤维素残留率达 70%,而液化产物结合酚质量分数可达 100%。  相似文献   

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以微晶纤维素为原料,通过炭化和磺化制备了一种磺化碳固体酸催化剂,利用红外光谱和扫描电镜等方法对其进行了表征。研究了该催化剂在亚/超临界乙醇-水溶剂中针对玉米秸秆的催化液化性能,考察了反应温度、催化剂用量、乙醇/水体积比等因素对生物油得率的影响。结果表明:在反应温度320℃、催化剂用量为原料质量分数的6%、乙醇/水体积比为1/1、反应时间3 h条件下,生物油得率可达52%。  相似文献   

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Despite its industrial importance, the subject of freeze-thaw (F/T) stability of latex coatings has not been studied extensively. There is also a lack of fundamental understanding about the process and the mechanisms through which a coating becomes destabilized. High pressure (2100 bar) freezing fixes the state of water-suspended particles of polymer binder and inorganic pigments without the growth of ice crystals during freezing that produce artifacts in direct imaging scanning electron microscopy (SEM) of fracture surfaces of frozen coatings. We show that by incorporating copolymerizable functional monomers, it is possible to achieve F/T stability in polymer latexes and in low-VOC paints, as judged by the microstructures revealed by the cryogenic SEM technique. Particle coalescence as well as pigment segregation in F/T unstable systems are visualized. In order to achieve F/T stability in paints, latex particles must not flocculate and should provide protection to inorganic pigment and extender particles. Because of the unique capabilities of the cryogenic SEM, we are able to separate the effects of freezing and thawing, and study the influence of the rate of freezing and thawing on F/T stability. Destabilization can be caused by either freezing or thawing. A slow freezing process is more detrimental to F/T stability than a fast freezing process; the latter actually preserves suspension stability during freezing. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004 in Chicago, IL. Tied for first place in The John A. Gordon Best Paper Competition.  相似文献   

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In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (−)-α-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with ethanol lures (release rate, about 0.6 g/day at 25–28°C) were attractive to ten species of ambrosia beetles (Ambrosiodmus tachygraphus, Anisandrus sayi, Dryoxylon onoharaensum, Monarthrum mali, Xyleborinus saxesenii, Xyleborus affinis, Xyleborus ferrugineus, Xylosandrus compactus, Xylosandrus crassiusculus, and Xylosandrus germanus) and two species of bark beetles (Cryptocarenus heveae and Hypothenemus sp.). Traps baited with (−)-α-pinene lures (release rate, 2–6 g/day at 25–28°C) were attractive to five bark beetle species (Dendroctonus terebrans, Hylastes porculus, Hylastes salebrosus, Hylastes tenuis, and Ips grandicollis) and one platypodid ambrosia beetle species (Myoplatypus flavicornis). Ethanol enhanced responses of some species (Xyleborus pubescens, H. porculus, H. salebrosus, H. tenuis, and Pityophthorus cariniceps) to traps baited with (−)-α-pinene in some locations. (−)-α-Pinene interrupted the response of some ambrosia beetle species to traps baited with ethanol, but only the response of D. onoharaensum was interrupted consistently at most locations. Of 23 species of ambrosia beetles captured in our field trials, nine were exotic and accounted for 70–97% of total catches of ambrosia beetles. Our results provide support for the continued use of separate traps baited with ethanol alone and ethanol with (−)-α-pinene to detect and monitor common bark and ambrosia beetles from the southeastern region of the US.  相似文献   

14.
A highly moisture-proof polysilsesquioxane coating was obtained from a new bis-silylated precursor, which was synthesized from 3-aminopropyltriethoxysilane (APTES) and m-xylylene diisocyanate (m-XDI) in tetrahydrofuran (THF) and verified by 1H MAS NMR. For direct comparison purposes, an SiO2 coating was also prepared by the Stöber method using tetraethoxysilane (TEOS) as the reactant. Interestingly, the coating obtained from the polysilsesquioxane sol exhibited a much higher moisture resistance capability than its counterpart, which was attributed to its more compact feature between nanoparticles as characterized by N2 absorption experiment and transmission electron microscopy (TEM). Furthermore, its high transparency of about 92% showed potential for application in the protection of optical crystals.  相似文献   

15.
Glycidyl carbamate chemistry combines the excellent properties of polyurethanes with the crosslinking chemistry of epoxy resins. Glycidyl carbamate functional oligomers were synthesized by the reaction of polyfunctional isocyanate oligomers and glycidol. The oligomers were formulated into coatings with several amine functional crosslinkers at varying stoichiometric ratios and cured at different temperatures. Properties such as solvent resistance, hardness, and impact resistance were dependent on the composition and cure conditions. Most coatings had an excellent combination of properties. Studies were carried out to determine the kinetics of the curing reaction of the glycidyl carbamate functional oligomers with multifunctional and model amines. Detailed kinetic analysis of the curing reactions was also undertaken. The results indicated that the glycidyl carbamate functional group is more reactive than a glycidyl ether group. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, on October 27–29, 2004, in Chicago, IL.  相似文献   

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Vismiones and ferruginins, representatives of a new class of lypophilic anthranoids from the genusVismia were found to inhibit feeding in larvae of species ofSpodoptera, Heliothis, and inLocusta migratoria.  相似文献   

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