木糖生产残渣制取乙酰丙酸及活性炭

用玉米芯制木糖后的废渣经加酸加热水解制取乙酰丙酸,收率为 １６．４％ ,产品纯度可达 ９０％ 。其残渣经硫酸炭化制得了木素活性炭,收率为 ８３％ ,脱色性能优于国家标准（ Ｇ Ｂ／ Ｔ １２４９６．２－ ９０）。本研究为以玉米芯为原料生产木糖的企业提供了一条综合利用、变废为宝的有效途径。     

生物质制备乙酰丙酸研究进展

乙酰丙酸被认为是一种介于生物质化学和石油化工之间的关键中间体。本文中综述了近几年利用生物质制备乙酰丙酸的方法及研究进展,介绍了乙酰丙酸形成机理及催化体系,并对生物质制备乙酰丙酸的研究前景进行展望,为下一步工作提供思路和参考。最后,展望了生物质制备乙酰丙酸的发展趋势。     

几种微波化学合成聚天冬氨酸体系的比较

研究了采用微波辐射化学合成聚天冬氨酸的方法。通过比较几种体系的产品收率,^1H NMR谱图,阻垢性能,原料成本和原子经济性,确定用作水处理剂为目的,最佳的微波化学合成体系为马来酐和氨水反应体系。     

新型绿色平台化合物乙酰丙酸的生产及应用研究进展

综述了乙酰丙酸及其重要衍生物的生产方法及应用的最新进展。总结回顾了乙酰丙酸的生产和应用,对相关领域今后的研究发展方向提出了建议。     

Adsorption of Levulinic Acid from Aqueous Solution onto Basic Polymeric Adsorbent: Experimental and Modeling Studies

Adsorption of levulinic acid onto a basic polymeric adsorbent was experimentally measured and numerical analyzed by batch and column methods. The adsorption equilibrium was correlated by a highly favorable Toth isotherm. Experimental adsorption rates in batch adsorber were fitted by the pore diffusion model and parallel pore/surface diffusion model. The resultant isotherm equation and diffusion coefficients were incorporated into the general rate model to predict the experimental breakthrough data. The film resistance and the axial dispersion in the column were estimated by Wilson-Geankoplis equation and Chung-Wen equation, respectively. Simulation elucidated that the parallel diffusion model successfully described the breakthrough behaviors and gave a better prediction than the pore diffusion model.     

微波助离子液体中松木屑稀酸水解性能的初步研究

研究以松木屑为原料,稀硫酸为催化剂,在[Bmim]Br离子液体介质中,用微波辐射加热促进纤维素的水解;探索微波的辐射功率、辐射时间、辐射温度以及离子液体加入量等因素对还原糖收率的影响。结果表明：在微波功率为600 W,微波时间为70 min,微波温度为85℃,离子液体[Bmim]Br的加入量为10 mL时,还原糖收率较高;与传统加热方法相比较,采用微波辐射加热能够显著提高还原糖收率。     

10-羟基癸酸绿色合成工艺的研究

研究了10-羟基癸酸的微波辅助合成绿色工艺.探讨蓖麻油为主要原料,一锅法合成10-羟基癸酸的微波辐射时间、反应温度和反应物配比等因素对产品收率的影响.试验结果表明,绿色合成工艺的优化反应条件为:m(蓖麻油):m(氢氧化钠):m(仲辛醇)=1:1.25:1.5,反应温度:167℃,反应时间:120 min.对比传统加热工艺,绿色合成工艺的温度降低,合成时间缩短2/3,收率达到77.41%.绿色合成产物经tR、MS分析表征为10-羟基癸酸.     

微波辐射树脂催化合成L-氨基酸酯

在微波辐射下,强酸性阳离子交换树脂为催化剂,一步酯化合成了8种空间位阻较高的L-氨基酸异丙酯和异丁酯,并用1HNMR和IR对其结构进行了表征。研究结果表明,微波辐射大大加速了酯化反应,所得8种酯的酯化收率在47%~67%。微波辐射反应所需时间大幅缩短,仅为常规加热时间的1/48~1/72,且反应物极性越大,反应时间缩短越明显。同时,对微波辐射功率、辐射时间及加热方式对酯化反应的影响进行了研究。     

微波辐射法合成及改性聚乳酸研究进展

聚乳酸作为新兴生物材料,因具有优良生物及力学性能,已在农业、食品包装、医疗卫生等领域得到了广泛应用,但聚乳酸及其共聚物的生产工艺复杂,耗时长,能耗高,污染重,限制了聚乳酸材料的推广应用。文章综述了微波辐射技术在聚乳酸合成及改性中的应用研究进展。     

微波辐照二氯乙酸甲酯制备乙醛酸

利用微波辐照二氯乙酸甲酯制备乙醛酸,研究了微波功率、辐照时间对乙醛酸产率的影响,并与常规热反应进行了比较。研究结果表明,微波辐照所得乙醛酸的产率与常规加热法相近,但反应速率显著提高。当乙醛酸产率达到68%左右,常规热反应需要48h,利用400W微波辐照8h就可完成。在相同反应时间下,乙醛酸的产率随微波功率增大而增加。     

微波辐射二甲苯磺酸催化合成乙酸异戊酯的研究

介绍了一种在微波辐射条件下,以废弃溶剂中二甲苯磺化得二甲苯磺酸为催化剂,合成乙酸异戊酯的方法;探讨了不同反应条件对乙酸异戊酯酯化率的影响,实验结果表明:当微波辐射功率为400 W,催化剂用量为0.9 g(异戊醇的反应摩尔数为0.1 mol),异戊醇与乙酸摩尔比为1︰2.0,反应时间为10 min,乙酸异戊酯的酯化率可达95.7%。     

微波照射对氨基苯磺酸催化合成环己酮乙二醇缩酮

在微波辐射下,以对氨基苯磺酸为催化剂,环己烷为带水剂,合成了环己酮乙二醇缩酮。考察了催化剂的用量、反应时间、酮醇物质的量比、带水剂的用量及微波功率等诸多因素对产品收率的影响。实验表明,固定环己酮0.2mol,在n(环己酮):n(乙二醇)=1:1.5,催化剂用量为反应物料总质量分数的4%,12mL环己烷为带水剂,反应温度135℃,微波功率为500W和反应时间为30min的优化条件下,环己酮乙二醇缩酮的产率可达80.2%。     

微波辅助合成5-硝基水杨酸的研究

以醋酸和醋酸酐的混和液为溶剂、浓硝酸为硝化剂,在冰浴中微波辐射下一步法直接合成5-硝基水杨酸,粗产率可达88．3％。经50％乙醇重结晶得到淡黄色粉状固体,产率为82．6％,产物结构经IR,1H NMR表征并得到确认。     

减四线馏分油微波辐射脱酸精制

用微波辐射法对大庆减四线馏分油进行了脱酸精制。得到了精制过程中的适宜实验条件:V(复合溶剂)∶V(油)=0 23∶1 00、压力为0 12MPa、恒压辐射时间为5min、微波功率为375W、静置时间为25min时,可将馏分油的酸值由0 31mgKOH/g降至0 0231mgKOH/g,达到Q/SHR001-95规定的润滑油质量标准(小于0 05mgKOH/g),馏分油回收率达到99 4%。精制过程节省时间、耗电量小、清洁高效。     

Ru@hyperbranched Polymer for Hydrogenation of Levulinic Acid to Gamma-Valerolactone: The Role of the Catalyst Support

Hydrogenation of levulinic acid (LA) obtained from cellulose biomass is a promising path for production of γ-valerolactone (GVL)—a component of biofuel. In this work, we developed Ru nanoparticle containing nanocomposites based on hyperbranched pyridylphenylene polymer, serving as multiligand and stabilizing matrix. The functionalization of the nanocomposite with sulfuric acid significantly enhances the activity of the catalyst in the selective hydrogenation of LA to GVL and allows the reaction to proceed under mild reaction conditions (100 °C, 2 MPa of H₂) in water and low catalyst loading (0.016 mol.%) with a quantitative yield of GVL and selectivity up to 100%. The catalysts were successfully reused four times without a significant loss of activity. A comprehensive physicochemical characterization of the catalysts allowed us to assess structure-property relationships and to uncover an important role of the polymeric support in the efficient GVL synthesis.     

微波辅射树脂催化合成L-氨基酸酯的研究

在微波辐射下,强酸性阳离子交换树脂为催化剂,一步酯化合成了8种空间位阻较高的L-氨基酸异丙酯和异丁酯,并用1HNMR和IR对其结构进行了表征。研究结果表明,微波辐射大大加速了酯化反应,所得8种酯的酯化收率均在50~70%之间。微波辐射反应所需时间大幅缩短,仅为常规加热时间的1/48~1/72,且反应物极性越大,反应时间缩短越明显。同时,就微波辐射功率、辐射时间及加热方式对酯化反应的影响进行了研究。     

松木粉制备高比表面积炭基固体酸催化剂

以一种廉价的农林废弃物——松木粉为原料,首先经过炭化和活化处理,制备活性炭,再通过苯磺酸重氮盐还原法处理活性炭引入磺酸基团（—SO3H）,从而制备出具有高比表面积的炭基固体酸催化剂（AC-SO3H）。其比表面积达到1364 m2/g,磺酸基密度为1.36 mmol/g。以乙酸的酯化反应考察了炭基固体酸催化剂的催化活性,并与Amberlyst-15、Nafion NR50以及Nafion SAC-13等几种固体酸催化剂进行了比较。实验结果表明,炭基固体酸催化剂的催化活性仅略低于Amberlyst-15,高于Nafion NR50和Nafion SAC-13,炭基固体酸催化剂的成本也远远低于Nafion NR50和NafionSAC-13。研究结果表明,以松木粉为原料,通过炭化、活化和磺化处理能够得到性能优异且成本低廉的炭基固体酸催化剂。     

松木粉制备高比表面积炭基固体酸催化剂

以一种廉价的农林废弃物——松木粉为原料,首先经过炭化和活化处理,制备活性炭,再通过苯磺酸重氮盐还原法处理活性炭引入磺酸基团(—SO₃H),从而制备出具有高比表面积的炭基固体酸催化剂(AC-SO₃H)。其比表面积达到 1364 m²/g,磺酸基密度为 1.36 mmol/g。以乙酸的酯化反应考察了炭基固体酸催化剂的催化活性,并与Amberlyst-15、Nafion NR50以及Nafion SAC-13等几种固体酸催化剂进行了比较。实验结果表明,炭基固体酸催化剂的催化活性仅略低于Amberlyst-15,高于Nafion NR50和Nafion SAC-13,炭基固体酸催化剂的成本也远远低于Nafion NR50和Nafion SAC-13。研究结果表明,以松木粉为原料,通过炭化、活化和磺化处理能够得到性能优异且成本低廉的炭基固体酸催化剂。     

两相水合熔盐体系中杂交狼尾草水解制备糠醛和乙酰丙酸

以杂交狼尾草为原料,先经甲苯-乙醇抽提,在硫酸浓度为0.05 mol/L的酸性溴化锂溶液中,加入邻苯二甲酸二乙酯为有机相,形成溴化锂水合熔盐-邻苯二甲酸二乙酯两相体系,将原料置于两相体系中水解反应制备糠醛和乙酰丙酸.考察了温度、酸浓度、反应时间、有机相体积等工艺条件对糠醛和乙酰丙酸得率的影响.实验结果表明:以硫酸浓度0...     

Modeling of Combined Microwave and Convective Drying of Wood: Prediction of Mechanical Behavior via Internal Gas Pressure

The impact of microwave drying on the quality of dried wood remains unclear. Particular attention should be paid in order to optimize the combined microwave and convective drying process. In this study, a comprehensive internal heat and mass transfer model was developed and numerically implemented in order to simulate and understand the physical phenomena occurring inside Jack pine wood during a combined microwave and convective drying process. The model was validated on the basis of the average moisture content curves for drying scenarios at various microwave power levels. According to the simulations results, an increase in microwave power significantly decreases the drying time of Jack pine wood and increases its internal gas pressure, which increases the risk of cracking. However, compared to purely conventional convective drying, combined microwave and convective drying at medium microwave power and air temperature significantly reduces the drying time and maintains the internal gas pressure at reasonable values. At these conditions, the risk of cracking will be diminished. This last result was checked via experimental measurements of the sample strength dried at different microwave power levels. From this study, we can consider that for Jack pine wood, combined microwave and convective drying is a more efficient technology compared to classical convective drying.