Hydroliquefaction of Kentucky 914 coal using bottoms recycle

Kentucky $\text{9}\text{14}$ bituminous coal has been liquefied in a batch reactor using blends of distillates and SRC or SRC fractions as the solvent. The most effective solvents contained either mildly hydrogenated SRC or the cyclohexane-soluble oil fraction of SRC. Approximately 65 wt% of Kentucky $\text{9}\text{14}$ coal was converted to C₄-700K liquids using these solvents. This yield can be compared to a yield of ≈40 wt% C₄-728K produced in the SRC-II process from Kentucky $\text{9}\text{14}$ coal.     

前处理方法对准东煤中钠含量测定的影响

为研究前处理方法对准东煤中钠含量测定的影响,以新疆准东木垒煤和五彩湾煤为原料,对比分析了逐级萃取、直接消解、815℃高温灰化、575℃低温灰化4种前处理方法对煤中钠含量测定的影响。结果表明:2种煤样中水溶性钠均占各自总钠含量的70%以上,硅酸盐形式的钠元素均不足5%。4种前处理方法测定2种准东煤中钠含量的大小顺序均为:逐级萃取575℃低温灰化直接消解815℃高温灰化;煤样逐级萃取过程中并无钠损失,钠含量测定结果准确,但操作步骤多、耗时长;2种煤直接消解的钠元素含量为煤样逐级萃取的75%以上;815℃高温灰化时钠元素含量均不足煤样逐级萃取的60%;575℃低温灰化钠元素含量均在煤样逐级萃取的85%以上。因此575℃低温灰化是一种简单、快捷、较准确获得准东煤中钠含量的前处理方法。     

Hydroliquefaction of Victorian brown coal in a continuous reactor: 1. Effects of residence time,temperature and catalysts on conversion

Slurries of two, closely related, Victorian brown coal samples in tetralin (1:3) were reacted with hydrogen in a continuous reactor system both with and without the addition of iron and iron-tin-based catalysts. The conversion to liquid products was greater when the catalysts were ion-exchanged onto the coal rather than being added as powders and the previously observed trend of iron/tin giving greater conversion than iron was exhibited. Increased temperature and residence time increased the oil yield.     

Hydroliquefaction of Australian coals with recycled slurry oil in a 1 kg h−1 continuous reactor

Coals from major Australian fields considered as suitable hydroliquefaction feedstocks were hydrogenated in a 1 kg h^?1 continuous reactor unit at reaction conditions 415–435 °C and 21 MPa using a stirred flow reactor with retention time of about 2 h. The effect of coal rank and the catalytic effects of disposable iron-based (red mud plus sulphur) catalysts were studied. The system was operated continuously with process-derived recycle solvent for up to 236 h. The time for a single pass of recycle solvent was estimated to be 20 h. Distillate oil yields in the range 35–53% on daf coal were obtained under catalytic operation. The heavier product oils were shown to contain predominantly aromatics, hydroaromatics and phenolics. This indicates that fairly severe hydro-treatment would be required to produce specification diesel and aviation turbine fuels. Recycle solvent composition was observed to stabilize in 2–4 passes after making a process change. These data compare favourably with those obtained on the same coals in larger pilot plants showing that this unit is capable of producing useful yield data.     

铁炭还原法预处理难降解有机化工废水

石油化工工业废水含有较多的难降解的有毒有害物质,如硝基苯、苯胺等,属于难降解有机化工废水,不宜直接采用好氧或厌氧工艺处理,需要进行预处理,以提高其可生化性。因此,高效可行的预处理成为此类废水的达标处理关键。进行了铁炭微电解+调碱混凝工艺对难降解有机化工废水的预处理研究。结果表明,在进水pH 3.5,曝气反应时间为60 min条件下,硝基苯的去除率可达到73.2%,废水的BOD5/CODCr值可由0.13提高到0.299,为废水的后续生化处理提供了有效保障。     

Coal-oil mixture from a synthetic oil obtained by hydroliquefaction of a South African coal

A coal-oil mixture (COM) was prepared from a South African coal and a synthetic oil derived from the same coal by hydroliquefaction. The settling and rheological properties of this mixture were compared with those of a mixture of the same coal with fuel oil. The synthetic oil mixture showed greater settling stability, comparable with that of a commercial COM containing additives. The increased stability may be related to polar compounds present in the oil and on the coal surface.     

Equilibrium studies of the direct reduction of sulphur dioxide by coal

The direct reduction of sulphur dioxide to elemental sulphur using coal has been studied utilizing models that simulate thermodynamic equilibrium. Comparison has been made between the computer models and process results. The results of the analysis indicate a discrepancy which may be attributable to the manner in which samples are taken for analysis. The actual process may be in thermodynamic equilibrium.     

Textural changes in coal after reduction with lithium in ethylenediamine

Textural changes in six bituminous coals (from 16.3 to 31.4% VM daf), after reduction with lithium in ethylenediamine at 373 K, have been established according to N₂ isotherms at 78 K and C0₂ isotherms at 298 K. Changes in pore volume were determined from the real and apparent densities and from the volume filling of micropores. Macroscopic changes on the grain surfaces were determined by means of the scanning electron microscope. It appears from these experiments that an initial increase in total porosity is caused by the action of ethylenediamine alone, while the final changes, primarily in the meso- and macropores (similar to disturbances of the external grain surface), result from the reduction process. The location of the added ethylenediamine in the bulk of the reduced coal has also been considered.     

Preparation of SiC from acid‐leached coal gangue by carbothermal reduction

For the comprehensive utilization of coal gangue, acid‐leached coal gangue was used as silicon source and part of carbon source, low ash anthracite and degreasing cotton were added respectively as supplementary carbon source, SiC and SiC fiber were prepared by carbothermal reduction method accordingly. The results show that the main components in leached coal gangue are amorphous SiO₂ and carbon, which are suitable for the synthesis of SiC as raw materials. The synthesis temperature and holding time have important influence on the synthesis of SiC, and the optimum synthesis parameters for SiC are at 1550°C for 4 hours; under this condition, the yield of SiC is 78.27%, and the specific surface area is 6750 cm²/g. The results show that the resulting products are essentially composed of β‐SiC with a minor amount of α‐SiC. Besides, based on the carbon fiber transformation method, SiC fiber was prepared by using leached coal gangue and degreasing cotton as raw materials. Therefore, it can be concluded that leached coal gangue is a very effective and inexpensive source for preparing SiC, and more importantly, this work has important economic and social significance to realize waste recycling and control pollution.     

Nitric oxide reduction by char and carbon monoxide: Fundamental kinetics of nitric oxide reduction in fluidizedbed combustion of coal

The reduction of nitric oxide during combustion of coal char in a fluidized-bed combustor was examined with respect to two reactions : a char-catalysed reaction; and a char-consuming reaction, which control nitric oxide emissions. The relative importance of the two reactions was investigated by measuring detailed material balances for the reactions. The product distribution was explained in terms of three fundamental parallel reaction paths. Reaction rates were investigated with a fixed-bed flow reactor over the temperature range 883–1194 K, the same as the fluidized bed combustor.     

利用煤还原硫酸钾的研究

介绍了在高温下用煤作还原剂还原硫酸钾生成硫化钾的新方法。当ｍ（还原煤）：ｍ（硫酸钾）为０．３０：１、炉温为９２０℃、反应时间为１．２５ｈ时，转化率可高达８０％。     

催化还原技术处理水溶液中氯代有机物的实验研究

以四氯化碳和四氯乙烷为代表物,研究了水溶液中氯代烷烃的催化还原脱氯技术,使用的还原剂为废铁刨花并添加催化剂和极化材料．结果表明该方法能使氯代有机物在零价铁体系中有效地发生还原反应,能迅速脱氯为氯离子,降低氯代有机物的毒性。探讨了有机物浓度对反应速率的影响,并分析了还原脱氯速率和反应中间产物,四氯化碳的反应产物主要是二氯甲烷,而1,1,2,2-四氯乙烷的主要反应产物是二氯乙烯。氯代有机物直接得到电子而发生还原脱氯是其主要反应机理。     

Direct measurement of organic sulphur in coal

A method of direct determination of the organic sulphur content of coal has been developed using the transmission electron microscope. An electron beam is focussed on a thinned section of coal and X-rays emitted from the elements in the volume irradiated by the electrons are measured by X-ray emission spectroscopic methods. Both the characteristic K_α line of sulphur and the bremsstrahlung from the material in the irradiated volume are detected by a solid-state detector. An analytical method has been developed which uses these two measurements for a direct determination of the organic sulphur concentration. Minerals can easily be avoided since they are plainly seen by conventional electron microscope techniques. Several measurements of the organic sulphur concentration in coals have been made; they agree with the conventional chemical values reported for these coals. Of most importance, though, is the use of this technique to detect spatial variations of sulphur over small distances within the coal maceral.     

Study on NO heterogeneous reduction with coal in an entrained flow reactor

The effects of coal types with a wide range of volatile matter content including lignite, bituminous coal, and lean coal, as well as the effects of reaction temperature, coal particle size, the primary-zone stoichiometry (SR1) and reburning-zone stoichiometry (SR2), etc. on NO reduction efficiency were carried out systematically in an entrained flow reactor. The heterogeneous NO reduction mechanism was analyzed. The results indicate that the NO reduction efficiencies increase with decreasing SR2 and coal particle size, and with increasing reaction temperature. The char contributions to the total NO reduction efficiency increase with increasing proximate volatile matter, coal particle size, and with decreasing reaction temperature. The char contribution can be reached more than 40% when SR2 is larger than 1.06 or less than 0.92 for XLT lignite. The char contribution at the conditions of SR1 = 1.0 and SR1 = 1.2 is significantly larger than that at SR1 = 1.1 for coals with high-volatile matter at a fixed reburning fraction.     

褐煤制浆和配煤制浆技术

基于中国煤炭资源状况及褐煤难成浆的特点,提出采用配煤制浆的方法来提高制浆浓度。分析了国内外褐煤和配煤制浆技术的研究现状,同时介绍了国内褐煤制浆技术的发展。研究发现:现有的配煤技术多采用煤质较好的原煤和褐煤,应寻求更多的现有资源和褐煤配煤制浆来提高煤浆浓度,尤其是热值不低却未被充分利用的煤炭资源,如煤炭液化废渣、沥青等,以充分利用煤炭资源,保护环境。     

高硫无烟煤降灰脱硫可行性试验研究

重点分析了王河煤矿高硫无烟煤的煤质特征、可选性及降灰脱硫的可行性。研究表明:简单地利用现有的物理分选方法很难将该矿区高硫无烟煤精煤硫分降到1%以下,而且精煤理论产率很低;如果将精煤硫分控制在1.2%～1.3%,并采用配煤等技术,可使精煤产率达到一个相对合理的水平;可以从高硫煤洗矸中选出硫精矿,实现资源的综合利用;也可考虑发展煤化工项目。     

Carbonization of coals to produce anisotropic cokes.: 4. Improving co-carbonization behaviour of bituminous and subbituminous coals with pitch by pretreatment coals to remove cations

Several de-ashing pretreatments of selected coals have been examined to establish simple and effective procedures to improve, in terms of anisotropic development, the co-carbonization behaviour of the coals with pitches. Refluxing pretreatments of the coals in 1N HCI containing methanol and in boiling water containing EDTA-2Na (EDTA-2Na/coal = 7/100 byweight) improve the co-carbonization behaviour of Witbank, Miller, Taiheiyo and Wandoan coals, all of which, in their original, untreated form, are modified in terms of anisotropic development only very slightly in co-carbonizations with A240 petroleum pitch. Pretreatment of coals of very low rank appears to be ineffective in co-carbonizations with A240; however, co-carbonization with hydrogenated A240 shows that the pretreatments are effective. Analyses and FT-i.r. spectroscopy of mineral matter suggest that improved behaviour due to the pretreatment is related to the removal of divalent cations and to the modification of the oxygen functionality of the coals.     

烟煤地下气化对地下水潜在的有机污染

以水蒸气为气化剂,利用自建的煤炭地下气化模拟试验系统模拟了鹤壁烟煤在不同温度下的地下气化过程。将模拟地下气化产生的粗煤气用深层地下水进行洗涤,并使用GC-MS检测煤气洗涤水中的有机物,模拟研究了煤炭地下气化对地下水可能造成的有机污染。结果表明:鹤壁煤气化过程中煤气溶解到地下水中的有机组分有108种,以脂肪烃为主,其次是卤代烃和芳香烃,同时检测到洗涤水中含有少量的苯系物和酚。参照国际癌症研究署(IARC)公布的《致癌物分类列表》和国家《危险废物鉴别标准》,苯及其衍生物、苯酚、甲酚、二甲酚以及萘等是主要的有毒有机污染物。地下气化过程中溶解在地下水中的污染物种类和浓度与气化温度有关。     

低阶煤有机溶剂萃取的研究进展

鉴于煤有机溶剂萃取的迅速发展,以低温和高温热萃取作对比,对相应的萃取机理、影响因素及萃取物的应用等进行分析。结果表明:萃取温度在200℃以下的多为低温物理萃取,萃取率一般较低,所得萃取物多用于研究煤的分子结构;而温度在300~400℃的萃取多为高温溶剂萃取,所得萃取率较高,萃取过程中会伴随化学键的断裂及相应化学反应的发生,所得萃取物多用在研究配煤炼焦、劣质煤的气化液化、新型煤基材料等领域。     

煤炭循环经济对CO2减排的研究

基于碳循环分析,提出煤炭转化为高热值燃料的必要性,煤矿循环经济建设将为CO2减排提供多重选择;通过分析潞安集团在煤炭绿色开采、煤炭清洁高效利用、矿区生态建设方面取得的成绩,说明循环经济减排CO2的有效性;大型煤炭企业实现碳材料资源的深层次循环将为CO2减排及低碳经济模式建立做出突出贡献。