原料对自由落下床中生物质与煤共热解行为的影响

在500～700℃和生物质混合比0～100％(质量分数)条件下,利用自由落下床反应器考察原料对生物质与煤共热解行为的影响.所用煤原料为大雁褐煤(DY)和铁法烟煤(TF),而生物质原料为农业废弃物秸秆(LS)和木材加工余料白松木屑(SD).结果表明,即使在自由落下床中停留时间短的条件下,生物质与煤共热解的协同效应仍然发生...     

不同等级煤与油共炼的转化率差异及残渣分析

选取安徽褐煤、辽宁褐煤和贵州烟煤三种煤为原料,以油溶性环烷酸钼为催化剂,分别与马瑞常渣(MRAR)、克炼常渣(KAR)以及催化裂化油浆(FCCS)在高压釜内模拟悬浮床加氢共炼反应。结果表明,不同的油体系下,两种褐煤都能达到83%以上的转化率,而对于贵州烟煤,转化率最高的FCCS体系与最低的KAR体系分别为67.75%和50.31%,相差很大。采用FT-IR和SEM分析反应后固体残渣,计算了固体残渣中脂肪族和芳香族中各个基团的相对含量,并对比了不同体系反应后固体残渣的微观形貌。结果表明,KAR体系的固体残渣脂肪链较长,支链化程度高,取代度较低。转化率较高的褐煤反应后固体残渣结构松散,分散度高;转化率较低的烟煤固体残渣随着转化率降低,残渣颗粒逐渐变大,表面更加光滑,板结程度加深。     

神东煤液化残渣显微组分的特征与分类研究

在PSU处理能力为0.1t/d的小型连续液化装置上对神东煤进行了加氢液化试验，对其液化残渣进行了显微光学研究。结果表明，在液化过程中，原料煤中的壳质组和镜质组全部转化，惰质组部分转化，在残渣中可见未反应的惰质组，同时在残渣中出现中间相小球体和半焦等新生组分。矿物质大量富集，并基本保持煤中原有的形态特征。THF处理后残余惰质组反射率在2.0%~3.8%，略高于煤中高反射率惰质组反射率，煤中高反射率惰质组是残余惰质组的主要来源。     

煤直接液化残渣焦CO2气化反应的研究

比较了流化床条件下神华煤及其直接液化残渣焦在CO2气氛中的气化反应性，考察了添加液化催化剂、脱除矿物质以及脱除重质油对煤直接液化残渣气化反应的影响规律。结果表明，残渣焦的气化反应性比原煤焦好，残渣焦在1000℃和1100℃的气化反应性指数为0.135和0.290，而原煤焦的则为0.118和0.200。脱灰后残渣焦气化反应性低于脱灰后的煤焦，说明直接液化反应后剩余的难液化物质的气化反应性低于煤焦；未经脱灰处理的残渣焦气化反应性高于煤焦，反映了液化过程中富集的矿物质及铁系催化剂的催化气化活性。脱除残渣中的重质油会降低残渣焦的气化反应性。     

Composition of extraction products from alkylated high-sulphur coals

Products of reductive and non-reductive methylation of two high-sulphur coals (Mequinenza and Illinois No. 6) have been extracted by dichloromethane. It has been established that the efficiency of the transformation of coal to the products soluble in CH₂Cl₂ is higher for coals subjected to non-reductive methylation by the Liotta method than for those after reduction in the potassium/liquid ammonia system. The extracts and the extraction residues were subjected to elemental analysis, IR spectroscopy, and AP-TPR (Atmospheric Pressure-Temperature Programmed Reduction) measurements. It has been shown that the main species undergoing extraction by CH₂Cl₂ are aliphatic compounds or aromatic structures of low degree of condensation. The effect of the extraction on the sulphur groups in coal has been discussed.     

不同液化条件下生物质残渣的燃烧特性研究

对锯屑在不同液化条件（溶剂、气氛、温度、催化剂）下所得液化残渣在热天平上进行了燃烧特性研究,通过比较液化残渣燃烧的三个特征温度,着火点ti、燃烧峰温tp和燃烬温度tb,分析了液化条件对残渣燃烧特性的影响。同时通过热重曲线所得数据探讨了液化残渣燃烧过程的动力学,并计算了活化能和频率因子 。结果表明,不同溶剂下所得液化残渣的燃烧特性显著不同,以四氢萘为溶剂所得液化残渣具有较好的燃烧特性;不同气氛下所得残渣的燃烧特性没有明显的不同;350℃下所得液化残渣的燃烧特性要好于300℃下所得液化残渣的燃烧特性;由于催化剂的影响,加入1%Mo后降低了所得液化残渣的燃烧特性;液化残渣的燃烧反应符合两段一级反应动力学。     

阴离子表面活性剂存在下光系统II中酪氨酸残基的性能研究

通过荧光光谱和富立叶变换红外(FT-IR)光谱研究了阴离子型表面活性剂－十 二烷基硫酸钠（SDS）与光系统II（PSII）的相互作用。结果表明,PSII表现出酪 氨酸荧光的特性。在PSII蛋白质内部,存在着232 nm处的组分与酪氨酸之间以及这 两种氨基酸列基与叶绿素a之间的能量传递。SDS的存在会使这些能量传递以及 PSII中蛋白的骨架结构和酪氨酸残基的结构发生改变,而变化方式又明显受SDS在 溶液中聚集状态的影响。低于其临界胶束浓度(cmc)时,SDS会促进蛋白质中232 nm外的组分与酪氨酸之间的能量传递,并且使酪氨酸残基外于极性更小的环境; 而大于cmc时,SDS却产生相反的效应。但不同浓度的SDS均会抑制酪氨酸残基至叶 绿素a的能量传递。     

煤液化残渣中残留催化剂对其挥发分测定的影响

用热重分析仪对兖州加氢液化残渣（THF不溶物）的工业分析进行了测定，重点考察了液化催化剂其挥发收率测定的影响。比较了相同液化条件下残渣的挥发分收率，发现催化液化残渣的总挥发分（GB法测定的挥发分含量）比热液化的高。通过对TG／DTG谱图的分析，确定了失重峰的归属，同时定义110℃-700℃间的挥发分V700为有机军发分，该值与这两种残渣的H／C比遵循共同的线性关系，而与添加的液化催化剂无关，可作为表征液化残渣基本性质的参数之一。     

X-ray fluorescence raw intensities vs. concentration data for multivariate classification of hungarian coal

A set of coal samples was examined by routine methods of coal analysis (density, calorific value, sulfur content, etc.) and by trace element determinations on the coal ash. Both data sets gave satisfactory clustering of samples from similar geological zones. X-ray fluorescence spectra were evaluated in order to identify the significant data-reduction steps in the sequence raw spectra/net intensities/trace element concentrations that is commonly used in x-ray spectrometry. The deconvolution yielding net intensities from spectra was identified as the most significant step. This was explained by the decorrelation effect of geochemically dissimilar elements.     

Characterization and thermal analysis of agave bagasse and malt spent grain

A comprehensive study on agave bagasse (AB) and malt spent grains (MSG) was performed using thermal analysis (TG-DTA) to characterize their thermal behavior. The study also focused on to identify their constituents by the application of elemental, proximate, and chemical analyses. The calorific values were also tested. The Fourier transform infrared spectroscopy (FTIR) was used to determine the main constituents. SEM images showed that their morphology and X-ray diffraction patterns of these residues showed their characteristic structures. Thermal degradation of AB and MSG presented two mass loss steps: the first step can be attributed to the release of moisture, and the second one is related to the release of organic volatile compounds. Based on the chemical analyses, the determined quantity of volatile materials, ash, and fixed carbon for AB were 78.1, 7.4, and 14.5 %, respectively; whereas for MSG were 79.9, 6.3, and 13.8 %, respectively. Additionally, MSG had hemicelluloses in a higher extend compared to AB, but the former had a greater content of cellulose than MSG. The calorific value for AB and MSG achieved 16.35 and 19.06 kJ g^?1, respectively. The FTIR analysis showed characteristic bands of alkenes, esters, aromatics, ketones, and alcohols. EDS analyses for AB showed Ca, Cu, and Zn while for MSG metals such as Ca, Si, Cu, and Zn were found. X-ray diffraction patterns of these residues showed mostly cellulose, a common structure present in plants. This research helps to know the properties of these materials and to evaluate them as an energy source.     

偏最小二乘法结合傅里叶变换红外漫反射光谱快速测定煤质

发热量、挥发分和灰分等是衡量煤质的质量指标。通常,烟煤的发热量、挥发分和灰分是按行业标准方法[1]分别进行测定的,操作过程繁琐,速度慢,且费用高。随着化学计量学多元校正方法的发展与广泛应用,董庆年采用最小二乘法结合红外光谱成功测定了灰分[2];而应用偏最小二乘法[3](P     

An experimental analysis of coal aluminium mixture in coal fired furnace

Coal is an important fuel used in boiler furnaces. There are problems like unburnt coal and solid wastes like ash contain arsenic, selenium, chromium and cadmium while using it. In order to avoid all such difficulties, aluminium metal powder in various grain sizes mixed with pulverized coal and burned. aluminium metal powder is one of the pyrotechnics having higher calorific value and low ignition temperature. The thermal behavior of aluminium powder along with coal is recorded in DTA. The collected ashes were tested in Scanning Electron Microscope and X-Ray Diffraction meter. The SEM results show that coal ash is having granular and regular structure. All the particles have a size range from 5 to 8 μm. On the other hand, the aluminium coal mixture ash shows a fibrous matrix and the particles are irregular. In XRD graph, the peaks in the graph show orientation of atoms in particular plane and angle. The coal ash has a lot of peaks, but the maximum count value reaches only to 340.97. However the value of counts reaches a maximum of 1,539.06 for aluminium ash. This denotes high atom orientation in a single lattice plane.     

Co-pyrolysis of waste polymers with coal

Co-pyrolysis of coal with waste polymers in a stationary quartz reactor was performed. Mass balance of the process was evaluated and properties of products were characterized. The main product (solid carbonaceous residue) exhibits low ash and sulfur contents and, from the point of view of application, satisfactory surface properties. Therefore, the solid residue is suitable as a smokeless fuel or as an industrial sorbent. The by-products were tar and gas. The tar may be used as a source of chemicals or a low-sulfur heating oil, the gas was highly calorific, therefore it may serve as a heating gas for energetical purposes.     

煤直接液化残渣及其萃取产物的热重分析

利用热天平考察了神华和胜利两种典型中国煤直接液化残渣及其萃取产物的失重曲线。实验表明,神华残渣和胜利残渣的轻质组分含量相近,其失重率也相近,但轻质组分组成不同使得失重过程并不一致 。升温速率增加,热解最大失重速率增加,最大失重速率温度升高。以残渣各组分失重曲线拟合得到的残渣失重曲线可近似表示残渣的失重曲线。动力学分析表明,由实验数据拟合的活化能和指前因子计算得到的失重曲线,与实际实验得到的失重曲线较为一致。液化残渣在低温区失重率很高,而且这部分失重产物可以通过溶剂萃取的方式得到。     

原煤低温氧化预脱硫的实验研究

采用三种高硫煤，在固定床反应器中考察了原煤在空气、空气水蒸气和空气氮气气氛下低温氧化预脱硫过程的影响因素，包括煤种（总硫含量、形态硫分布和挥发分含量）和化学反应条件（温度、停留时间）。脱硫前后的样品中硫及硫形态、热值、工业分析和元素分析依据国际进行测定。实验结果表明硫及碳质的氧化在开始阶段以不同的速率析出，随后反应中差别减小；黄铁矿硫可得到高的脱除率；水蒸气适当比例的加入可以增加黄铁矿的脱除，同时降低碳的转化和热量的损失；而氮气的加入在降低碳和热量的损失外，降低了硫的脱除。     

Forest waste as a potential alternative energy source

Following a method based on the procedure given by Hubbardet al. [1] the calorific values of combustion in oxygen at 298.15 K were measured by static-bomb calorimetry for forest residues. This waste mainly coming from mount reforestation, construction of firebreaks, etc., constitutes an important risk to originate forest fire. From combustion experiments the mean calorific value of all species studied was found close to 19 000 kJ·kg^?1, similar to calorific values of Municipal Waste. It can be concluded that this forest residues can be used as an additional fuel to be added to Municipal Solid Waste in energy recovery plants. By doing this, energy, in this moment lost as abandoned residues, can be recovered. At the same time the elimination of this waste minimizes the risk of forest fires. Our results reasonably agree with literature values.     

The interaction of His337 with the Mn4Ca cluster of photosystem II

The most recent XRD studies of Photosystem II (PS II) reveal that the His337 residue is sufficiently close to the Mn(4)Ca core of the Water Oxidising Complex (WOC) to engage in H-bonding interactions with the μ(3)-oxo bridge connecting Mn(1), Mn(2) and Mn(3). Such interactions may account for the lengthening of the Mn-Mn distances observed in the most recent and highest resolution (1.9 ?) crystal structure of PS II compared to earlier, lower-resolution (2.9 ? or greater) XRD structures and EXAFS studies on functional PS II. Density functional theory is used to examine the influence on Mn-Mn distances of H-bonding interactions, mediated by the proximate His337 residue, which may lead to either partial or complete protonation of the μ(3)-oxo bridge on models of the WOC. Calculations were performed on a set of minimal-complexity models (in which WOC-ligating amino acid residues are represented as formate and imidazole ligands), and also on extended models in which a 13-peptide sequence (from His332 to Ala344) is treated explicitly. These calculations demonstrate that while the 2.9 ? structure is best described by models in which the μ(3)-oxo bridge is neither protonated nor involved in significant H-bonding, the 1.9 ? XRD structure is better reproduced by models in which the μ(3)-oxo bridge undergoes H-bonding interactions with the His337 residue leading to expansion of the 'close' Mn-Mn distances well known from EXAFS studies at ～ 2.7 ?. Furthermore, full μ(3)-oxo-bridge protonation remains a distinct possibility during the process of water oxidation, as evidenced by the lengthening of the Mn-Mn vectors observed in EXAFS studies of the higher oxidation states of PS II. In this context, the Mn-Mn distances calculated in the protonated μ(3)-oxo bridge structures, particularly for the peptide extended models, are in close agreement with the EXAFS data.     

Control of lysine reactivity in four-helix bundle proteins by site-selective pKa depression: expanding the versatility of proteins by postsynthetic functionalization

Five 42-residue polypeptides have been designed to fold into hairpin helix-loop-helix motifs that dimerize to form four-helix bundles, and to serve as protein scaffolds for the elucidation at the molecular level of the principles that control and fine-tune lysine and ornithine reactivities in a protein context. Site-selective control of Lys and Orn reactivity provides a mechanism for addressing directly individual residues and is a prerequisite for the site-selective functionalization of folded proteins. Several lysine and one ornithine residues were introduced on the surface and in the hydrophobic core of the folded motif. The reactivity of each residue was determined by measuring the degree of acylation of the trypsin cleaved fragments by HPLC and mass spectrometry. The most reactive residues were Orn34 and Lys19, both of which were located in d positions in the heptad repeat, and therefore in hydrophobic environments. Upon reaction of the helix-loop-helix dimer KA-I with one equivalent of mono-p-nitrophenyl fumarate, Orn34 was acylated approximately three times more efficiently than Lys19, whereas Lys10 (b position), Lys15 (g position), and Lys33 (c position) remained unmodified. In the sequence KA-I-A(15) Lys15 was replaced by an alanine residue and the selectivity of Orn34 over Lys19 increased to approximately a factor of six, probably because Lys15 had the capacity to reduce the pK(a) value of Lys19 and 85 % of site-selectively monoacylated product was obtained. The pH dependence of the acylation reaction was determined and showed that the pK(a) of the reactive residues were 9.3, more than a pK(a) unit below the magnitude of the corresponding residue in a solvent exposed position. Introducing Lys and Orn residues into a or d positions of the heptad repeat therefore serves as a mechanism of depressing their pK(a) to increase their reactivity site selectively. Extensive NMR and CD spectroscopic analyses showed that the sequences fold according to prediction.     

Identification of organically associated trace elements in wood and coal by inductively coupled plasma mass spectrometry

1-Methyl-2-pyrrolidinone (NMP) was used to extract samples of wood (forest residue) and coal; the extracts were analysed by inductively coupled plasma mass spectrometry (ICP-MS) using two different sample preparation methods, in order to identify trace elements associated with the organic part of the samples. A sample of fly ash was similarly extracted and analysed in order to assess the behaviour of the mineral matter contained within the wood and coal samples. 32% of the biomass was extracted at the higher temperature and 12% at room temperature while only 12% of the coal was extracted at the higher temperature and 3% at room temperature. Less than 2% of the ash dissolved at the higher temperature. Size exclusion chromatograms of the extracts indicated the presence of significant amounts of large molecular mass materials (>1000 mu) in the biomass and coal extracts but not in the ash extract. Trace element analyses were carried out using ICP-MS on the acid digests prepared by 'wet ashing' and microwave extraction. Sixteen elements (As, Ba, Be, Cd, Co, Cr, Cu, Ga, Mn, Mo, Ni, Pb, Sb, Se, V and Zn) were quantified, in the samples before extraction, in the extracts and in the residues. Concentrations of trace elements in the original biomass sample were lower than in the coal sample while the concentrations in the ash sample were the highest. The major trace elements in the NMP extracts were Ba, Cu, Mn and Zn from the forest residue; Ba, Cu, Mn, Pb and Zn from the coal; Cu and Zn from the ash. These elements are believed to be associated with the organic extracts from the forest residue and coal, and also from the ash. Be and Sb were not quantified in the extracts because they were present at too low concentrations; up to 40% of Mn was extracted from the biomass sample at 202 degrees C, while Se was totally extracted from the ash sample. For the forest residue, approximately 7% (at room temperature) and 45% (at 202 degrees C) of the total trace elements studied were in the extract; for the coal, approximately 8% (at room temperature) and 23% (at 202 degrees C) were in the extract. For the ash, only 1.4% of the trace elements were extracted at 202 degrees C, comprising 25% of Cd but less than 1% of Pb.     

低阶煤温和液化特征分析

利用管弹反应器考察了霍林郭勒褐煤在温和条件下的液化特征,探讨了温度、溶剂、压力、气氛、催化剂对液化产物分布的影响;分别利用程序升温热解技术和红外光谱分析了液化产物中己烷不溶物的气态烃逸出规律和结构特征;利用凝胶渗透色谱、同步荧光光谱和红外光谱分析了不同反应条件下产物沥青烯和前沥青烯的结构特征。结果表明,实验条件下霍林郭勒煤的起始热解液化温度在350℃左右;随温度的升高,液化转化率增大。较高温度时(450℃)缩聚反应加剧,液化转化率开始减小;溶剂对沥青烯类产物的生成极为重要,提高反应压力和添加催化剂主要促进油气的生成;温和条件下(350、400℃)对霍林郭勒煤的临氢处理,可获得热解反应性较原煤高的液化残渣(己烷不溶物);产物沥青烯和前沥青烯的分子量在液化温度为300和350℃时为最大;随反应温度升高,沥青烯和前沥青烯的芳烃结构特征增强,烷烃结构特征减弱。