生物质热裂解和化学液化制燃料油技术现状及展望

综述了目前国内、外生物质转化为燃料油的研究状况.重点介绍了生物质热裂解液化、化学液化、生物质与煤共液化所采用的工艺路线和技术现状及制备的液化产物的性质.并详细介绍了对液化产物精制成燃料油所采用的技术路线.指出了目前生物质制备燃料油的技术难点和发展方向.     

GC-MS法测定缬草残渣中的化学组分

分别使用95％乙醇和四氯化碳作为提取溶剂,在78℃左右,对已提取过挥发油的缬草残渣中化学成分进行提取,借用气相色谱-质谱联用方法(GC-MS)对提取浸膏中化学组分进行分析.结果显示:以乙醇作为提取溶剂条件下,共鉴定出38中化学组分,数据出峰相对总质量分数为81.7％;以四氯化碳为提取溶剂条件下,共鉴定出44种化学组分,...     

煤直接液化残渣热态连续进料炼焦试验研究

通过试验分析,探索了煤直接液化残渣采用热态、小批量连续进料炼焦工艺的可行性。为综合加工利用液化残渣,实现残渣焦化与煤液化工艺的良好衔接,提供了科学可行的技术依据。     

煤加氢液化残渣利用研究进展

综述了液化残渣的组分性质及加氢裂解中原料的交互影响;系统总结了当前国内外关于煤加氢液化残渣的利用研究进展,主要包括气化、热解、制备碳材料以及改性沥青等,并对应用过程中存在的问题进行了探讨。液化残渣的高效合理利用,不仅能减轻环保压力,还能提升煤液化工艺过程的经济效益。     

煤加氢液化残渣利用研究进展

综述了液化残渣的组分性质及加氢裂解中原料的交互影响;系统总结了当前国内外关于煤加氢液化残渣的利用研究进展,主要包括气化、热解、制备碳材料以及改性沥青等,并对应用过程中存在的问题进行了探讨。液化残渣的高效合理利用,不仅能减轻环保压力,还能提升煤液化工艺过程的经济效益。     

神华煤液化残渣的液化特性研究

液化残渣有着许多不同于未液化煤的特性,研究液化残渣的特性对整个煤炭液化工艺过程以及对液化厂的经济性和环境保护都具有极大的现实意义。通过高压釜液化神华煤液化残渣,从液化恒温反应时间、温度和氢初压对神华煤液化残渣的液化特性影响进行了研究,为煤液化残渣的液化机理研究奠定基础。     

煤直接液化残渣的性质及利用现状

为了高效地利用煤直接液化残渣,从液化残渣的组成、结构特性、热解特性、溶解特性4个方面论述了液化残渣的物理化学性质的研究现状。研究发现:残渣在组成和结构特性上都保留了原煤的部分特性。在对直接液化残渣热解特性的研究中,论述了各种不同研究手段,例如热重分析仪、实验室移动床、小型焦炉、高压釜等对液化残渣的热解过程的研究进展及热解机理的解析现状。在对液化残渣的溶解性进行研究时,讨论了残渣溶解性研究的意义及其在各种溶剂中表现出的不同特征。最后论述了煤直接液化残渣的利用研究现状、分析了其潜在的高附加值利用方式、发展前景和存在的问题。     

神华煤液化蒸馏残渣加氢液化动力学研究

液化残渣有着许多不同于未液化煤的特性,研究液化残渣的特性对整个煤炭液化工艺过程以及对液化厂的经济性和对环境的保护都具有极大的现实意义。通过液化神华煤液化蒸馏残渣,对残渣液化动力学进行了初步探讨,为煤液化残渣的液化机理研究奠定基础。     

煤液化残渣灰分的测定

煤炭液化过程中的残渣是煤液化的主要产物这一,残渣中的灰分是计算煤炭液化过程中转化率的重要参数。目前,国内外测定残渣中的灰都是先经过正己烷、甲苯和四氢呋喃的一系列萃取,萃取后的不溶物,经真空干燥后测定其灰含量。这种方法分析时间长,不利于及时指导煤炭液化工艺条件的设定。本文通过残渣进马弗炉灼烧之前经电炉加热和未经加热的灰含量数据进行了比较。建立了一种简单快速测定残渣中灰含量的方法。     

煤液化残渣利用的研究进展

论述了国内外煤液化残渣的加氢及热解性能以及不同液化残渣不同反应条件其加氢动力学的研究现状,并介绍了煤液化残渣的加氢液化、气化、干馏(热解、焦化)以及燃烧等方面的研究进展及取得的成果,在总结国内外研究成果的基础上,提出了今后煤液化残渣的利用的研究方向。     

Characterization of liquefied wood residues from different liquefaction conditions

The amount of wood residue is used as a measurement of the extent of wood liquefaction. Characterization of the residue from wood liquefaction provides a new approach to understand some fundamental aspects of the liquefaction reaction. Residues were characterized by wet chemical analyses, Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), and scanning electron microscopy (SEM). The Klason lignin content of the residues decreased, while the holocellulose and α‐cellulose contents increased as the phenol to wood ratio (P/W) increased. A peak at 1735 cm^?1, which was attributed to the ester carbonyl group in xylan, disappeared in the FTIR spectra of the residues from liquefied wood under a sealed reaction system, indicating significantly different effects of atmospheric versus sealed liquefaction. The crystallinity index of the residues was higher than that of the untreated wood particles and slightly increased with an increase in the P/W ratio. The SEM images of the residues showed that the fiber bundles were reduced to small‐sized bundles or even single fibers as the P/W ratio increased from 1/1 to 3/1, which indicated that the lignin in the middle lamella had been dissolved prior to the cellulose during liquefaction. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007     

TG study on pyrolysis of biomass and its three components under syngas

Pyrolysis of sawdust and its three components (cellulose, hemicellulose and lignin) were performed in a thermogravimetric analyzer (TGA92) under syngas and hydrogen. The effect of different heating rates (5, 10, 15 and 20 °C/min) on the pyrolysis of these samples were examined. The pyrolysis tests of the synthesized samples (a mixture of the three components with different ratios) were also done under syngas. The distributed activation energy model (DAEM) was used to study the pyrolysis kinetics. It is found that syngas could replace hydrogen in hydropyrolysis process of biomass. Among the three components, hemicellulose would be the easiest one to be pyrolyzed and then would be cellulose, while lignin would be the most difficult one. Heating rate could not only affect the temperature at which the highest weight loss rate reached, but also affect the maximum value of weight loss rate. Both lignin and hemicellulose used in the experiments could affect the pyrolysis characteristic of cellulose while they could not affect each other obviously in the pyrolysis process. Values of k₀ (frequency factor) change very greatly with different E (activation energy) values. The E values of sawdust range from 161.9 to 202.3 kJ/mol, which is within the range of activation energy values for cellulose, hemicellulose and lignin.     

Preparation of semirigid polyurethane foam with liquefied bamboo residues

Bamboo residues were liquefied by using a solvent mixture consisting of polyethylene glycol 400 and crude glycerol (4/1, w/w) with 98% sulfuric acid as catalyst at 160°C for 120 min. The liquefied bamboo had hydroxyl values from 178 to 200 mg KOH/g and viscosities from 507 to 2201 mPa S. The obtained bamboo‐based polyols were reacted with various amounts of polyaryl polymethylene isocyanate (PAPI), using distilled water as blowing agent, silicone as surfactant, and triethylenediamine and dibutyltine dilaurate as cocatalyst to produce semirigid polyurethane (PU) foams. The [NCO]/[OH] ratio was found to be an important factor to control the mechanical properties of PU foams. At a fixed [NCO]/[OH] ratio, both density and compressive strength of PU foams decreased with the increase of bamboo content. The microstructure of PU foams indicates that [NCO]/[OH] ratios are important for cell formation and chemical reactions. The uniformity and cell structure of the foams are comparable to their corresponding compressive strengths. Moreover, the thermogravimetry analysis showed that all the semirigid PU foams had approximately the same degradation temperature of about 250 to 440°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Kinetic modelling of the pyrolysis of biomass and biomass components

The kinetics of the pyrolysis of lignocellulosic materials was studied with a view of providing simple kinetic models for engineering purposes. Experimental data obtained by means of thermal analysis techniques suggest that the pyrolysis of fine particles (below 1 mm) can be considered to be controlled by pyrolysis kinetics. The rate of pyrolysis of one biomass type can be represented by the sum of the corresponding rates of the main biomass components (cellulose, lignin, hemicellulose). The kinetics of each of these components was simulated by a kinetic scheme capable of predicting the pyrolysis rate and the final weight-loss for a wide range of pyrolysis parameters including various heating conditions.     

Recent advances in the catalytic pyrolysis of biomass

Biomass is considered as a renewable and alternative resource for the production of fuels and chemicals, since it is the only carbon and hydrogen containing resource that we can find in the world except for fossil resources, capable of being converted to hydrocarbons. The pyrolytic liquefaction of biomass is a promising way to convert biomass to useful products. This paper briefly surveys the present status of the direct catalytic pyrolysis for the liquefaction of biomass. The direct use of catalysts could decrease the pyrolysis temperature, increase the conversion of biomass and the yield of bio-oil, and change the distribution of the pyrolytic liquid products then improve the quality of the bio-oil obtained. The fact that biomass is in solid state present great challenges for its conversion and for the effective use of catalysts due to the bad heat transfer characteristics and bad mass transfer properties. These barriers appeal for the development of a new catalyst and new catalytic process as well as the integration of both. Process design and process intensification are of significant importance in the catalytic conversion of biomass.     

Characterization and catalytic gasification of the aqueous by-product from vacuum pyrolysis of biomass

Spruce wood residues were treated in a vacuum pyrolysis Process Development Unit with a throughput capacity of 28 kg/h. Two aqueous phase condensate samples with COD concentration varying between 190 and 255 g/L were produced and sequentially extracted with dichloromethane and ethylacetate solvents. The soluble organic matter was composed of acidic, phenolic, alcoholic and ketonic compounds. The insoluble fraction was sequentially distilled at 100 and 110°C under atmospheric pressure. Mainly water was recovered in the first distillate, while the second distillate contained 30.4% formic and acetic acids, 69.4% water and 0.2% residual organic compounds. The distillation residue was rich in oxygen and was essentially insoluble in any organic solvent. The two aqueous phase pyroligneous samples were treated in Bat-telle's Thermochemical Environmental Energy System (TEESr?), a registered service mark of Onsite*Ofsite, Inc. of Duarte, California, U.S.A. The results of the tests showed that similar results were obtained with either feedstock. In batch tests a COD reduction of 99% was achieved. The product gas composition was typically about 49% methane, 5% hydrogen, 1 % ethane and 45% carbon dioxide. Tests in a continuous stirred-tank reactor produced reproducible data which can be used for process scale-up. Catalyst lifetime was identified as needing further improvement. The preliminary results demonstrated the technical feasibility of the catalytic gasification process as a useful step in the recovery of energy from the secondary condensate stream and the cleanup of the by-product water from vacuum pyrolysis of wood.     

Carbon foam production from bio-based polyols of liquefied spruce tree sawdust: Effects of biomass/solvent mass ratio and pyrolytic oil addition

One of the next-generation structural materials is carbon foam. Porous materials have become an intriguing alternative material to traditional ones in many utilizations based on their light weight and incomparable properties. Coal or fossil oils are conventionally used to produce pitch, phenolic resin, and polyurethane as carbon foam precursor. Biomass liquefaction is a developing technique to convert biomass resources into the industrial chemicals. In this study, spruce tree sawdust was liquefied under mild conditions with different solvent type (phenol or phenol + bio-oil mixture). The unique aspect of this work is the synthesis of bio-polyol when pyrolytic oil is used as an alternative to phenol in the solvolysis reaction and its evaluation in carbon foam production with multilayer graphene sheets. Therewithal, the ratios of biomass to solvent were 1/3 as well as 1/5, and the comparison of product characteristics is another originality of the study. Slow pyrolysis of spruce tree sawdust was performed under static atmosphere and bio-oil was characterized with elemental analysis and various chromatographic and spectroscopic techniques. The effect of mass ratio of biomass/solvent on the characteristics of porous resin foams synthesized from liquefaction product. Obtained resin foams were carbonized at 400 °C, and then activated at 800 °C under nitrogen atmosphere. Structure evaluation of resin foams, carbonized foams, and activated carbon foams from liquefied spruce tree sawdust was investigated by using elemental analysis, x-ray diffraction, nitrogen adsorption/desorption isotherms, scanning electron microscopy, true/bulk density, and compressive strength tests. Although the surface area values decreased when bio-oil was added as a solvent, it was determined that the compression strengths of the produced carbon foams (up to 1.080 MPa) were higher than that of conventional phenolic foams. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47185.     

基于不同三组分模型解析生物质热解过程

三组分模型（three pseudocomponent model）通常被用来表征生物质热解过程。传统三组分模型中单个模型的反应级数被限定为1或3。在本研究过程中，利用非线性最小二乘法，在不限定反应级数的前提下回归三组分模型动力学参数（活化能、指前因子、反应级数）。通过研究发现，纤维素（cellulose）分解反应级数接近1，与前人结果相一致。木质素（lignin）分解级数与生物质种类有关，接近于1或3。半纤维素（hemicellulose）的分解过程最复杂，其反应级数在1.5～4之间变化。以Ozawa方法计算得到的活化能作为相对标准，对3种三组分模型进行比较，发现反应级数未确定时的模型比其他两种模型更精确地表征生物质热解过程。     

Heating value of biomass and biomass pyrolysis products

Studies conducted on the heating value of various types of biomass components and their pyrolysis products such as char, liquids and gases are presented. Heating values of chars are comparable with those of lignite and coke; heating values of liquids are comparable with those of oxygenated fuels such as methanol and ethanol, which are much lower than those of petroleum fuels. Heating values of gases are comparable with those of producer gas or coal gas and are much lower than that of natural gas. It is also found that the heating values of products are functions of the initial composition of biomass; correlations are developed to express these. Also, correlations are developed which explain the influence of ash elements on heating values of the pyrolysis products and on percentage distribution of energy in the products.