淖毛湖煤慢速热解过程官能团相互作用

采用滴管炉,在短停留时间下,制备具有一定低温反应活性而消除主要低温交联位点的淖毛湖煤（NMHcoal）快速热解半焦（NRPchar）,再将NMHcoal和NRPchar混合进行慢速热解,研究官能团间的相互作用。热重分析结果表明,NMHcoal/NRPchar混合比为5∶5,温度为500℃热解时具有较强的负协同作用。固定床热解结果表明,NMHcoal热解生成的挥发物部分扩散至NRPchar中,?CH₃与芳碳自由基以及?O有更多的结合概率与时间,使焦油中含甲基的萘、酚类增多,半焦中烷基化邻氧芳碳结构与醚类结构增加。析出的酚类增多,使半焦中连氧芳碳结构减少。NRPchar中生成较多的多环芳烃前体,它们与酚类物质发生反应生成多环芳烃和CO,使共热解焦油中5、6环化合物含量增加,而另一部分滞留在半焦中使其比表面积降低。     

生物质焦表面形貌SEM研究

采用扫描电镜对生物质焦的表面形貌进行研究。扫描电镜实验结果表明,生物质在制焦后,表面粗糙度提高,比表面积增大,孔隙更加发达。焦样表面形貌的特征主要是由生物质种类决定的,在扫描电镜下,稻壳焦样表面有锯齿状不规则的突起,但是开口在表面的孔很少;树叶焦样表面有不规则的孔;玉米杆焦样有如同蜂窝状的表面结构,表面孔十分丰富;棉花杆焦样有着絮状的表面结构,表面孔也较明显。热解温度对焦样表面形貌的影响不大。     

煤炭中温活化碳共价键解聚机理

为研究煤粉不同气氛和温度活化后的热半焦在微观结构上的变化规律，采用拉曼光谱对煤焦碳架结构进行表征，采用X射线光电子能谱(XPS)检测C和O的表面官能团，固态核磁共振碳谱(¹³C-NMR)表征碳共价键。将3种测量方法互相验证，提高结果可靠性，从微观层面表征半焦的化学结构，分析煤粉中温活化反应中温度和气氛对煤焦化学结构和表面官能团演变的影响，并探讨中温活化机理。结果表明，60～900℃下CO₂和水蒸气对半焦活性均有显著增强作用，这可能是气体分子与煤焦分子结合形成羰基或羧基，在羰基或羧基分子影响下相连的碳键削弱断裂，从而破坏芳香环，产生新的活性位点，增强煤炭反应活性。经800℃下CO₂活化或900℃下水蒸气活化后的半焦，活性位点数量均增加2倍以上，同时羰基和羧基占比之和由18%分别增至32%和34%,而CO₂中温活化引起接氧脂碳由0.02增至0.11,水蒸气活化后桥碳比为0.01,相比N₂热解半焦桥碳比大幅降低。煤粉中温活化反应主要通过形成羰基或羧基破坏芳香结构形成更多活性位点，但二...     

Fe负载污泥生物炭催化热解聚丙烯及产物特性

针对塑料成分复杂、热解产油组分不稳定和品质控制难的问题，本文以市政污泥为原料制备Fe负载污泥基生物炭催化剂，以聚丙烯塑料(PP)催化热解促进焦油裂解与合成气生产的试验路线开展研究，分析了PP热解产物中焦油的去除效果、富H₂合成气关键组分以及催化热解过程对污泥基生物炭表面特性的影响。结果显示FeCl₃浸渍比为5%(质量分数，以Fe计)制备的污泥基生物炭可显著促进PP催化热解产氢，1g塑料氢气产率达17.39mmol，分别高于未经Fe负载污泥生物炭催化对照组268.43%以及纯PP热解对照组2046.91%。催化热解过程强化了焦油裂解，焦油裂解率达29.65%。焦油组分中醇类物质相对占比下降，烯烃类与卤代酯类物质相对占比上升。同时，催化热解后污泥基生物炭表面出现特殊的薄层状孔隙结构，比表面积增至225.90m²/g。XPS分析发现污泥基生物炭表面的碳氧官能团结合碳、晶格氧以及羧基氧相对比例上升，证明在此Fe浸渍比例下出现了更多的活性位点。     

碳氧官能团对煤焦低温还原NO的影响

在450℃对神木煤制半焦还原NO进行研究,采用Raman、FT-IR、XPS等分析方法探究了半焦脱硝影响因素与其表面碳氧官能团的关系。结果表明：热解制焦温度、烟气中氧气浓度以及负载金属对脱硝效果的影响都与半焦表面碳氧官能团有关,降低热解温度、增大氧气浓度、负载金属均有利于增加C—O官能团。采用XPS表征对金属负载半焦表面的碳氧官能团进行分析,发现热力学相对稳定的C—O官能团含量与脱硝指标之间存在明显的线性关系(R²>0.96)。研究进一步揭示了热力学稳定的C—O官能团在半焦脱硝过程的重要地位。     

水葫芦生物质炭的制备与染料吸附性能研究

以水葫芦为原料,采用限氧升温热解的方法制备了水葫芦生物质炭,研究热解温度对生物质炭理化结构与染料吸附性能的影响。结果表明,通过SEM、XRD、BET表征可以看出,在一定温度范围内,随温度升高生物质炭比表面积越大,孔隙结构越发达。当热解温度为500℃,生物质炭会有更多的含氧官能团以及较好的孔隙结构。随着热解温度的升高,生物质炭对染料吸附量先增加后有所降低,生物质炭对阳离子染料亚甲基蓝能达到更好的吸附效果,刚果红次之,甲基蓝的吸附效果一般。     

水葫芦生物质炭的制备与染料吸附性能研究

以水葫芦为原料,采用限氧升温热解的方法制备了水葫芦生物质炭,研究热解温度对生物质炭理化结构与染料吸附性能的影响。结果表明,通过SEM、XRD、BET表征可以看出,在一定温度范围内,随温度升高生物质炭比表面积越大,孔隙结构越发达。当热解温度为500℃,生物质炭会有更多的含氧官能团以及较好的孔隙结构。随着热解温度的升高,生物质炭对染料吸附量先增加后有所降低,生物质炭对阳离子染料亚甲基蓝能达到更好的吸附效果,刚果红次之,甲基蓝的吸附效果一般。     

生物质碳基电解水催化剂定向构筑研究进展

生物质碳具有廉价易得、环境友好以及物化结构可调控的优点,是负载过渡金属的良好基底,在电解水方面应用前景广阔。碳基底的比表面积、孔隙分布等物化结构直接影响了催化活性位点的利用以及电解液离子扩散,是发挥过渡金属电解水催化潜力、决定催化剂性能的关键。介绍了不同生物质的热解机理,对高温热解法、水热碳化法以及微波热解法等生物质碳常见制备方法进行了归纳,并比较不同制备方法优缺点。总结了物理法、化学法及模板法等生物质碳物化结构定向调控策略,探讨了不同调控策略对生物质碳比表面积、孔容、平均孔径等物理化学性质的影响。归纳了杂原子掺杂及金属活性组分负载等常见生物质碳基电解水催化剂构筑策略,并对其在析氧反应、析氢反应、双功能催化及杂化电解水等方面的研究现状进行总结,详细阐述了其在电解水方面取得的进展。最后对生物质碳基电解水催化剂在微介孔比例调控、导电性提升、亲水性提升以及催化剂成型处理等方面面临的挑战进行了展望。     

猪肝为原料制备氧还原电催化剂及其电催化性能

选用价格低廉的生物质猪肝为原料,采用两步热解法和碳负载法制备M-N/C型非贵金属催化剂,考察了热处理温度、混合气体比例及前驱体对催化剂结构和电催化性能的影响.结果表明,热处理温度为1000℃、氮气与氨气体积比为7:3的条件下,二次热解所得催化剂氧还原电催化性能最好.氨气中二次热解改变了催化剂的表面形貌和物相结构,有利于产生更高含量的吡啶型氮,增强了催化剂在碱性溶液中的氧还原电催化活性.黑珍珠2000(BP2000)虽然能显著提高一次热解催化剂的活性,但由于其在氨气中的反应活性不如热解猪肝所得碳材,在氨气二次热解中对催化剂活性反而有不利影响.     

生物质颗粒孔隙结构在热解过程中的变化

利用氮气等温吸附/脱附法（-196℃）和扫描电镜（SEM）等研究了热解过程中生物质颗粒孔隙结构的演化规律,并用分形维数来描述焦颗粒内部孔隙表面形态的复杂程度。结果表明,热解温度对生物质焦的孔结构和表面形态有显著影响。热解过程中孔网络结构在发生演变,孔的形状发生了一定变化,且孔径有先变小后变大的趋势。高温导致焦颗粒发生塑性变形,使得孔隙扩大和孔表面更加光滑。随着温度的升高,生物质焦的BET比表面积先增大后减小,500℃以前,孔容积的变化规律与比表面积相近。通过分形FHH方程回归得到的分形维数能较好地表征颗粒内部孔隙表面的分形特征。其分形特征与热解温度密切相关,分形维数的变化与BET比表面积有一定关联。     

谷壳气化过程中颗粒物理化学结构的演化

对生物质气化过程的研究通常着眼于对气相组分分析,而很少对颗粒相的演化进行探讨。本文通过氮气等温吸附/脱附法(-196℃)、压汞法(414 MPa)、真密度仪(He)等详细研究了在气化条件下谷壳的物理结构的演化,同时利用元素分析和傅里叶红外对颗粒化学结构进行分析。结果表明,在气化的不同阶段,颗粒内孔的结构发生改变。BET比表面积在反应开始时增加缓慢,当反应率达到0.6以后其增加速度明显加快。由压汞法测定得到的大孔（macropore）演化规律与微孔不太一致,在反应初期大孔所占比例较高,随气化进行,这一比例快速下降,但大孔的绝对数量还是在一直增加。通过比较真密度仪和压汞法测定的结果发现,颗粒真密度与视密度变化正好相反。元素分析结果表明,在气化过程中O、H、N、S的变化规律各不相同。而红外分析也表明随反应率增加,颗粒表面上的OH、CO、CH以及Ar—H等基团快速消失。     

Influence of pyrolysis conditions on the structure and gasification reactivity of biomass chars

The physical and chemical structure as well as gasification reactivities of chars generated from several biomass species (i.e. pinus radiata, eucalyptus maculata and sugar cane bagasse) were studied to gain insight into the role of heating rate and pressure on the gasification characteristics of biomass chars. Char samples were generated in a suite of reactors including a wire mesh reactor, a tubular reactor, and a drop tube furnace. Scanning electron microscopy analysis, X-ray diffractometry, digital cinematography and surface area analysis were employed to determine the impact of operating conditions on the char structure. The global gasification reactivities of char samples were also determined for a range of pressures between 1 and 20 bar using pressurised thermogravimetric analysis technique. Char reactivities were found to increase with increasing pyrolysis heating rates and decreasing pyrolysis pressure. It was found that under high heating rates the char particles underwent plastic deformation (i.e. melted) developing a structure different to that of the virgin biomass. Pressure was also found to influence the physical and chemical structures of char particles. The difference in the gasification reactivities of biomass chars at pressure was found to correlate well with the effect of pyrolysis pressure on the graphitisation process in the biomass char structure.     

煤焦吸附NO特性与红外光谱分析

对煤焦与NO 的化学吸附过程进行了分析,研究了颗粒粒径和温度对煤焦吸附NO特性的影响; 得到了吸附平衡和动态数据, 利用漫反射红外光谱来研究煤焦经过表面吸附化学反应后官能团结构变化的信息,从而揭示煤表面吸附过程中发生的化学变化。结果表明,煤焦经化学吸附后表面增加了—NO2和—NO官能团,NO气体分子在煤焦表面主要发生的是二位吸附;并且随着煤样平均粒径的减小和温度的升高,—NO2和—NO官能团吸收峰强度明显增强,表明粒径减小和温度升高有利于煤焦化学吸附NO气体。     

印尼油砂沥青组成及化学结构分析

利用FTIR和¹³C NMR对印尼油砂沥青中的脂肪烃结构、芳香烃结构、含氧官能团以及碳骨架进行研究,并就印尼油砂样品中较高的硫含量进行XPS分析。结果表明：4个印尼油砂样品沥青中脂肪碳含量均占到了70%左右,脂肪烃主要由亚甲基构成,甲基与次甲基次之,样品中有大量的烷基侧链。FTIR无法准确分辨芳香烃部分的苯环取代结构,通过¹³C NMR发现芳香烃中质子化芳碳的含量较高,桥头芳碳与侧枝芳碳为主要非质子化芳碳,由带质子化芳碳的比例大小可以推断样品芳香环上的取代度为2～4。样品含氧官能团部分以C－O形式存在于醇和醚中,部分以羧基形式存在。样品中硫主要为有机硫,芳香族硫化物含量最高,其次为脂肪族硫化物,存在一定比例亚砜。无机硫以黄铁矿硫与硫酸盐硫形式存在,由于油砂表面被有机质包裹,无机物裸露较少,XPS没有测得硫酸盐硫,黄铁矿硫的检测值也偏低。     

Volatilisation and catalytic effects of alkali and alkaline earth metallic species during the pyrolysis and gasification of Victorian brown coal. Part VII. Raman spectroscopic study on the changes in char structure during the catalytic gasification in air

FT-IR/Raman spectroscopies have been used to identify the structural features of Victorian brown coal chars during the gasification in air at 400 °C. The deconvolution of the Raman spectra has allowed us to identify the main structural sites in char where preferential reaction with O₂ takes place. The presence of Na and Ca catalysts is shown to alter the reaction pathways between char and O₂. In the absence of a catalyst, the O-containing functional groups formed in char during gasification were closely associated with the aromatic structure and thus tended to loosen the aromatic structure. The non-catalysed gasification was slow and took place on some specific (especially sp³-rich or sp²–sp³ mixture) sites distributed throughout the char. In the presence of a catalyst (Na or Ca), the O-containing functional groups were not closely associated with the main aromatic structure throughout the char. The catalytic gasification reactions were localised on the sites associated with the catalysts. The preferential removal of smaller aromatic ring systems and the persistence of cross-linking structures in the presence of a catalyst mean that the large aromatic ring systems were increasingly concentrated with little flexibility, affecting the dispersion of catalyst.     

富氧气氛下改性生物质焦脱汞的氧化机理

富氧燃烧作为新型燃烧方式可以有效减少CO₂排放,提高燃烧效率,与传统燃烧方式相比,烟气组分也产生较大的变化。玉米秸秆焦可以作为吸附剂在燃烧后阶段对汞进行脱除。本文采用1% NH₄Cl溶液浸渍的玉米秸秆焦为吸附剂,在富氧气氛下探究NO及O₂对汞氧化脱除机理。文中指出玉米秸秆焦经浸渍改性处理后,其表面孔隙结构更加丰富,比表面积以及总孔容积增大。同时,改性后表面官能团的数量大大增加,尤其是含氧的官能团,对汞的吸附起着重要作用。富氧气氛下NO与生物质焦表面的O₂和含氧基团反应生成具有氧化作用的NO₂,与零价汞反应促进汞的去除。NO和O₂共存时对零价汞的氧化有更明显的促进作用。O₂含量的增加也会促进生物质焦对汞的吸附,这主要是由于O₂的强氧化作用导致,与零价汞发生非均相氧化反应生成HgO。此外,含氧官能团化学键的断裂也为汞的氧化提供了氧自由基团。     

Evaluation of structural features of chars from pyrolysis of biomass of different particle sizes

The structural features of chars derived from pyrolysis of mallee wood of different particle sizes in a novel fluidized-bed/fixed-bed reactor have been investigated. Raman spectroscopy was used for structural evaluation of chars. Spectra were curve-fitted with 10 Gaussian bands representing typical structural features of the chars. The temperature had a significant influence on the evolution of char structure and thus the total Raman peak area between 800 and 1800 cm^− 1 is seen to decrease significantly with increasing pyrolysis temperature for all chars. On the other hand, the ratio I_D/I_{(Gr + Vl + Vr)} between the band intensities of condensed aromatic ring systems (> 6 rings) and amorphous char structures with small aromatic ring (3-5 rings) systems is seen to increase with increasing temperature. The particle size of biomass has a great role in char structure at fast heating rate (> 1000 °C/s) pyrolysis although it has no effect on char structure at slow heating rate pyrolysis (0.17 °C/s). However, in the bigger biomass particle, the structure of char prepared under fast heating rate pyrolysis is similar to that of the structure of char prepared under slow heating rate pyrolysis.     

处理芳烃油在胎面胶料中的应用研究

将5种处理芳烃油(TDAE)用于胎面胶料中,研究TDAE理化性质对胶料各项性能的影响。结果表明:5种TDAE的环保性能均能满足欧盟标准要求;TDAE中芳烃、环烷烃和链烷烃中碳原子所占比例对胶料的硫化特性、物理性能、抗湿滑性能和滚动阻力均有一定影响。     

Adhesion and corrosion resistance properties of coatings obtained from modified low-molecular-weight polystyrenes

In this study, as a continuation of our previous studies, chemical modification of low-molecular-weight polystyrenes (PSs) was carried out with various functional group modifiers: epichlorohydrin (ECH), maleic anhydride (MA) and acetic anhydride (AA), in a single stage using a cationic catalyst. It was determined that the amounts of the functional groups bound to the structure of the polymer depended on the molecular weight of the polymer used, and more functional groups were bound to the lower-molecular-weight PSs. It was found that the coating properties (adhesion properties and resistance to aggressive conditions) of the functional group containing PS to the metal surface depended on the structure and the amount of the functional groups bound to the aromatic ring of the polymer. In addition, it was observed that the PS modified with MA and ECH having carboxyl- and epoxy-groups in their aromatic rings had higher adhesion, as well as higher corrosion resistance properties. Various functional groups bound to the aromatic ring of the polystyrene and their amounts were determined by spectral and chemical analysis methods.     

Effects of micropore development on the physicochemical properties of KOH-activated carbons

Effects of micropore development through varying the KOH/char ratio on the porous, electrochemical, electronic, and adsorptive properties for corncob-derived activated carbons (ACs) prepared by means of the KOH activation method were systematically compared. The pore properties of ACs, including BET surface area, total pore volume, micropore volume ratio, bulk density, and product yield based on the raw material were investigated to gain an understanding for the influence of KOH dosage on the pore development. Element analysis and temperature-programming desorption (TPD) were used to obtain the information of chemical composition and surface oxygen functional groups on ACs in order to propose the reaction mechanism of KOH activation. Based on the pore development, KOH-activated carbons can be classified into two groups: a combination of physical activation and chemical KOH etching at low KOH/char ratios (0.5-2) as well as chemically uniform etching at high KOH/char ratios (≥3.0). From the adsorption study for five organics with molecular weights varying from 129 to 466 g/mol, the specific adsorption capacity of ACs for organics is independent of their specific surface area. The specific capacitance of ACs reached a maximum as the KOH/char ratio was equal to 3, attributed to a compromise between the specific surface area and electronic resistance of ACs.