生物质溶剂液化及生物油品质提升技术综述

综述了生物质溶剂液化过程中原料、溶剂、催化剂、液固比、温度、反应气氛、压力、反应时间、停留时间、加热速率等因素对液化反应的影响。进一步分析了多种生物油提质改性的方法,主要有催化加氢、催化裂解、催化酯化、添加物质、乳化、重整制氢、萃取等,旨在为生物质液化条件的优化以及生物油的规模化应用提供依据。

离子液体与水混合溶剂应用于微晶纤维素溶剂液化研究

将离子液体氯化1-丁基-3-甲基咪唑([BMIM]Cl)、水、固体酸催化剂组成的混合溶剂应用于微晶纤维素的预处理过程中,并尝试把经过预处理的微晶纤维素应用于随后的溶剂液化的研究中,对经过混合溶剂处理后的微晶纤维素进行表征分析。通过测定纤维素的聚合度、官能团基变化、热重分析、结晶结构和表面结构等对微晶纤维素结构进行比较分析。通过对苯酚溶剂液化的基本表征、残渣物的结晶结构以及生成物相对分子质量的变化了解了混合溶剂对微晶纤维素的处理效果。结果表明,通过混合离子液体[BMIM]Cl和水并且添加固体酸催化剂形成新的混合溶剂体系对微晶纤维素进行预处理,发现溶剂在保留纤维素主要葡萄糖单元的同时能够有效地降低聚合度。聚合度从未处理时的190降到样品[B]Cl(10)的165和样品[B]Cl(10)+NR50的151。混合溶剂对非结晶或低结晶物质具有一定的溶解能力,并且对高结晶性纤维素部分的氢键结构起到破坏作用和造成整体结晶结构的歪曲。在随后的液化过程中,处理后的纤维素液化效率有所提高,在反应2 min时,固体酸加混合溶剂处理的微晶纤维素液化残渣率为19%,而未处理的液化残渣率29%。表明使用了混合溶剂添加固体酸的溶剂体系对加速液化的效果更佳,预处理对最终液化生成物的性质影响不大。

木质纤维素液化制备植物基多元醇研究进展

介绍了木质纤维素的组成及各组分的液化机理,综述了溶剂热液化催化剂的研究现状,催化效果及缺陷。木质纤维素结构复杂,纤维素具有高结晶度,不利于木质纤维素的液化,为提高液化效率,提出了对木质纤维素进行预处理的解决方法,包括物理预处理、生物预处理和化学预处理。

用n-d-M法计算煤直接液化溶剂油芳碳率的方法探讨

以核磁共振法为基准,通过大量样品和实验数据考察了用n-d-M法(SH/T0729)计算煤直接液化溶剂油fa值的准确性.结果表明:用n-d-M法计算溶剂油的芳碳率时,加氢前溶剂油的fa值与核磁共振法的结果误差较大,须进行修正;加氢处理后溶剂油的fa值与核磁共振法结果非常接近;可采用n-d-M法代替核磁共振法计算加氢后溶剂油的fa值,计算公式中建议采用70℃下溶剂油的密度和折光率.

全二维气相色谱-飞行时间质谱/氢火焰离子化检测器对煤直接液化循环溶剂的定性与定量分析

建立了全二维气相色谱-飞行时间质谱/氢火焰离子化检测器(GC×GC-TOF MS/FID)对煤直接液化循环溶剂(CDLRS)定性定量的分析方法。采用TOF MS和FID两种检测器同时采集数据,并结合谱库检索、标准物质保留值对照、谱图解析、标准质谱图对照、全二维谱图特征以及提取化合物分子离子等定性方法,将TOF MS检测数据定性,然后将定性的烃类化合物以z值分类法分为18类;应用Chroma TOF数据处理软件将TOF MS数据的定性分类结果应用到FID的检测数据中,对TOF MS和FID采集的数据色谱峰面积归一化处理,实现CDLRS的半定量分析。GC×GC/FID定量结果显示:煤直接液化循环溶剂中饱和烃和芳烃分别占45.805%、53.938%,其中饱和烃主要为二环烷烃及三环烷烃,含量依次为14.644%、18.021%;芳烃主要为一环烷苯和二环烷苯,含量依次为19.759%、16.528%。该方法为CDLRS的定性定量提供了一种有效的分析方法。

煤液化溶剂结构族组成计算方法的研究

测定了煤直接液化溶剂的^1H核磁共振波谱、元素组成和分子量、密度、折光度数据，分别利用B—L法、n—d—M法计算煤直接液化溶剂的平均结构参数，结果显示对于加氢前溶剂两种方法的计算结果存在较大误差，而对于加氢后溶剂两者的计算结果误差较小。笔者将适用于石油馏分的n—d—M法中各参数进行了修正，使之能够较好地适用于煤液化油结构参数的计算，对回归公式进行准确性检验。

竹材在溶剂中的催化液化技术研究进展

比较分析了不同种类液化介质条件下竹材的催化液化特性,包括液化产率、影响因素和液化产物的应用等。其中最常用的液化溶剂为苯酚和醇类,对竹材均具有很好的催化效果,而其他液化溶剂的催化液化工艺的实际应用技术还有待进一步优化。

催化裂化(FCC)油浆作煤直接液化溶剂的研究进展

现今,各国的相关学者针对于催化裂化(FCC)油浆作煤直接液化溶剂已经进行了大量的研究,并且相应地取得了一定的研究成果。但是对于催化裂化(FCC)油浆作煤直接液化溶剂的研究进展却没有一个定性的分析,无法知道现今的相关研究进度以及相关先进技术,在一定程度上对于催化裂化(FCC)油浆作煤直接液化溶剂的研究也造成了一定的影响。因此,本文作者在查阅大量研究文献后,采用逐步分析法针对催化裂化(FCC)油浆作煤直接液化溶剂的研究进展的问题进行了探讨。

BP网络预测H_2在煤液化油混合组分中的溶解度

为满足煤制油工业化过程中设计和操作需要,以H_2在神华煤液化油模型组分混合溶剂中实测溶解度为基础,考察利用人工神经网络法预测H_2在该系统中溶解度的能力。结果表明,神经网络的计算精度随着循环次数的增加而提高;对于不同种类的混合溶剂,随着隐藏层个数的增加,计算值与试验值之间的相对误差呈现逐渐减小的趋势,从减小计算量的角度考虑,选定为4个隐藏层;3-4-1网络结构对于H_2在不同混合溶剂中溶解度的计算值与试验值最大相对误差为4.48%,这表明该模型能够满足H_2在该系统中溶解度的预测需要。

生物质油制备及应用现状分析

综述了国内外生物质油制备技术,分析生物质油在我国的应用现状,并预测了其未来发展方向和趋势。现阶段主要采用热裂解液化技术、溶剂热液化技术以及微波热解技术制备生物质油。制备得到的生物质油可用来生产燃料油或提取化工产品、气化生成合成气、制备生物沥青、实现老化沥青再生利用、作为生物质固体燃料胶结剂以及与石油二次加工重质油混合炼制。最后对生物质油发展前景提出建议及展望,以期为实现生物质资源高效利用提供参考和借鉴。

木质素磺酸钠改性硬质聚氨酯泡沫材料的制备与性能研究

以聚乙二醇400(PEG 400)与丙三醇的混合液对木质素磺酸钠(SLS)进行液化改性,获得残渣率极低的溶剂液化产物,无需分离,直接与聚醚多元醇及相关助剂复配,并与二苯基二异氰酸酯(MDI)反应,制备木质素改性的硬质聚氨酯泡沫材料(PUF)。通过考察SLS和发泡剂用量及液化产物与多元醇的复配比等因素对改性泡沫材料表观密度与压缩强度的影响,优化了发泡配方,并对材料的微观形貌、结构及热稳定性进行了研究。研究结果表明,利用SLS溶剂液化产物改性的PUF材料与未改性的泡沫材料相比,压缩强度从481.05kPa最高可提高至880.60kPa,700℃的残炭率基本不变,但泡孔的均匀性下降。

固相萃取-全二维气相色谱-飞行时间质谱法分析表征煤直接液化循环溶剂中的氢化芳烃

建立了固相萃取-全二维气相色谱-飞行时间质谱(SPE-GC×GC-TOF MS)分析表征煤直接液化循环溶剂中的氢化芳烃的分析方法。固相萃取小柱将循环溶剂分离为饱和烃部分和芳烃部分,芳烃部分用GC×GC-TOF MS分析。结果表明:固相萃取方法可以有效的将循环溶剂中的饱和烃和芳烃分离,减少饱和烃组分对氢化芳烃定性的干扰;GC×GC-TOF MS法相比于传统的一维气相色谱-质谱具有较高的分离度,能提供数倍的峰容量。通过定性分析,共鉴定出417种氢化芳烃。该方法为煤直接液化循环溶剂中氢化芳烃的分析表征提供了一种有效的分析方法。

Solvatochromic Parameters and Preferential Solvation Behavior for Binary Mixtures of 1,3-Dialkylimidazolium Ionic Liquids with Water

Binary mixtures of 1,3-dialkylimidazolium based ionic liquids （ILs） and water were selected as solvent systems to investigate the solute-solvent and solvent-solvent interactions on the preferential solvation of solvatochromic indicators at 25 ℃. Empirical solvatochromic pa- rameters, dipolarity/polarizability （π^＊）, hydrogen-bond donor acidity （α）, hydrogen-bond acceptor basicity （β）, and Reichardt＇s polarity parameters （ET^N） were measured from the ultraviolet-visible spectral shifts of 4-nitroaniline, 4-nitroanisole, and Reichardt＇s dye. The solvent properties of the IL-water mixtures were found to be influenced by IL type and IL mole fraction （XIL）. All these studied systems showed the non-ideal behavior. The max- imum deviation to ideality for the solvatochromic parameters can be obtained in the XIL range from 0.i to 0.3. For most of the binary mixtures, the π^＊ values showed the synergistic effects instead of the ETN, α and β values. The observed synergy extent was dependent on the studied systems, such as the dye indicator and IL type. A preferential solvation model was utilized to gather information on the molecular interactions in the mixtures. The dye indicator was preferentially solvated on the following trend： IL〉IL-water complex〉water.

Co-intensification of cyanide leaching gold by mercury ions and oxidant

The effects of mercury ions on gold cyanidation were studied. The results show that under low cyanide concentration, gold cyanide process is controlled by CN- transfer, while at higher cyanide concentration, there forms passivation on gold surface. Therefore, chemical oxidation of gold in cyanide solution of higher concentration is controlled by surface reaction. Small quantity of additions of mercury ions bring about great increases in anodic gold dissolution rate, decreases the passivation and reduces the equilibrium activated energy. In addition, they also markedly change the effect pattern of cyanide concentration. Mercury ions show positive effects on cathodic reduction of oxygen and raise the rate of electrochemical step of the cathodic reduction of oxygen. Addition of a certain amount of hydrogen peroxide is confirmed to be an effective way for intensification of cathodic process on gold electrode. Active potential range and current peak on anodic dissolution are enlarged when being co-intensified with Hg^2＋ and hydrogen peroxide. Co-intensifying effect may be obtained and gold from gold concentrates. gold leaching rate is considerably increased on cyanide leaching of

Enhanced photocatalytic activity of TiO_2 nanoparticles using WS_2/g-C_3N_4 hybrid as co-catalyst

TiO2/WS2/g-C3N4composite photocatalysts were synthesized by a liquid-exfoliation-solvothermal method.In this process,the WS2/g-C3N4nano-sheets were prepared by liquid-exfoliation method from the bulk WS2and C3N4in the alcohol system,and then the TiO2nanoparticles(NPs)grew on the WS2/g-C3N4nano-sheets by in-situ synthesized technique.The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic degradation of methyl orange(MO).The results showed that the as-prepared samples exhibited higher photocatalytic activities as compared to the pure TiO2,g-C3N4and TiO2/g-C3N4composite.The enhanced photocatalytic activities of TiO2/WS2/g-C3N4photocatalysts could be attributed to the synergistic effect of heterostructure between TiO2NPs and WS2/g-C3N4nano-sheets,which could efficiently improve the separation of photogenerated electron/hole pairs and utilization efficiency of photons.The quenching tests of radicals indicated that?O2?had crucial effect on degradation of MO,which demonstrated that?O2?was the main active radical in photocatalytic reaction process.

Selection of Chelated Fe(Ⅲ)/Fe(Ⅱ) Catalytic Oxidation Agents for Desulfurization Based on Iron Complexation Method

Optimization of factors influencing the experiments on reactions involving 8 different chelating agents and soluble Fe(III)/Fe(II) salts was carried out to yield chelated iron complexes. A combination of optimized influencing factors has resulted in a Fe chelating capacity of the iron-based desulfurization solution to be equal to 6.83—13.56 g/L at a redox potential of 0.185—0.3. The desulfurization performance of Fe(III)/Fe(II) chelating agents was investigated on a simulated sulfur-containing industrial gas composed of H2 S and N2 in a cross-flow rotating packed bed. Test results have revealed that the proposed iron-based desulfurization solution showed a sulfur removal efficiency of over 99% along with a Fe chelating capacity exceeding 1.35 g/L. This desulfurization technology which has practical application prospect is currently in the phase of commercial scale-up study.

Study of the Liquid Phase Volume Expansion for CO_2/Organic Solvent Systems

The supercritical antisolvent （SAS） process has been developed in recent years for the tormation of nanoand micro-particles. It is necessary to study the liquid phase volume expansion （LPVE） and find the relationships between the operating conditions and the LPVE in order to develop a practical method for determining the operation conditions and selecting an organic solvent for SAS process. The PR equation of state with vdW-1 mixing rule is used to calculate the LPVE for CO2/toluene, CO2/acetone and CO2/ethyl acetate systems, and the results show that the LPVE for each CO2/organic solvent system decreases as the temperature increases. The relationship between the LPVE and the solubility of CO2 in the liquid phase for CO2/organic solvent systems is investigated, and the results show that the LPVE is determined directly by the solubility of CO2 in the liquid phase, xCO2, and can be related to xCO2 independently. No matter what system of CO2/organic solvent is and how different the temperature is, the LPVEs have little difference as long as the solubility of CO2 in the liquid phase, xCO2, keeps constant. The lower temperature is always favorable to the SAS process. The higher the solubility of CO2 in an organic solvent under certain operation condition, the more suitable it is to the SAS process.

Kinetics of Glucose Ethanolysis Catalyzed by Extremely Low Sulfuric Acid in Ethanol Medium

The kinetics for production of ethyl levulinate from glucose in ethanol medium was investigated. The experiments were performed in various temperatures （433-473 K） and initial glucose concentrations （0.056-0.168 mol·L-1） with extremely low sulfuric acid as the catalyst. The results show that higher temperature can improve the conversion of glucose to ethyl levulinate, with higher yield of ethyl levulinate （44.79%, by mole） obtained at 473 K for 210 min. The kinetics follows a simplified first-order kinetic model. For the main and side reactions, the values of activation energy are 122.64 and 70.97 kJ·mo1-1, and the reaction orders are 0.985 and 0.998, respectively.

Precipitation of antimony from the solution of sodium thioantimonite by air oxidation in the presence of catalytic agents

The behavior of antimony oxidation in the solution of sodium thioantimonite was studied in the presence of catalytic agents. The catalytic effects of the respective addition of cupric sulfate, sodium tartrate, potassium permanganate, phenol, 1,2 dihydroxybenzene and their combination on the oxidation of sodium thioantimonite were investigated. A pilot test was carried out. The results show that the respective use of sodium tartrate, cupric sulfate, potassium permanganate, phenol and 1,2 dihydroxybenzene have little catalytic effect on the oxidation of sodium thioantimonite. However there exists obvious catalytic oxidation by the combination of 0.25 g/L 1,2 dihydroxybenzene, 0.5 g/L potassium permanganate and 1.0 g/L phenol. Moreover, high blast intensity, the increase of temperature and NaOH concentration favor the oxidation of antimony. The oxidation process of antimony has such advantages as quick reaction and low operation costs. The results of the pilot test are consistent with those of laboratory experiments.

Distribution and transformation behaviors of heavy metals during liquefaction process of sewage sludge in ethanol-water mixed solvents

Liquefaction of sewage sludge(SS)in ethanol-water cosolvents is a promising process for the preparation of bio-oil/biochar products.Effect of the combined use of ethanol and water on the distribution/transformation behaviors of heavy metals(HMs)contained in raw SS is a key issue on the safety and cleanness of above liquefaction process,which is explored in this study.The results show that pure ethanol facilitates the migration of HMs into biochar products.Pure water yields lower percentages of HMs in mobile/bioavailable speciation.Compared with sole solvent treatment,ethanol-water cosolvent causes a random/average effect on the distribution/transformation behaviors of HMs.After liquefaction of SS in pure water,the contamination degree of HMs is mitigated from high level(25.8(contamination factor))in raw SS to considerable grade(13.4)in biochar and the ecological risk is mitigated from moderate risk(164.5(risk index))to low risk(78.8).Liquefaction of SS in pure ethanol makes no difference to the pollution characteristics of HMs.The combined use of ethanol and water presents similar immobilization effects on HMs to pure water treatment.The contamination factor and risk index of HMs in biochars obtained in ethanol-water cosolvent treatment are 13.1-14.6(considerable grade)and 79.3-101.0(low risk),respectively.In order to further control the pollution of HMs,it is preferentially suggested to improve the liquefaction process of SS in ethanol-water mixed solvents by introducing conventional lignocellulosic/algal biomass,also known as co-liquefaction treatment.