煤的微生物降解率与降解液吸光度的关系拟合

为了准确且便捷地得出煤样粒度较细时微生物对煤的降解率,分别采用绿孢链霉菌、恶臭假单胞菌和黄孢原毛平革菌对光氧化内蒙胜利褐煤进行微生物降解,测得了降解率(η)和降解液在450 nm处吸光度A_(450)(Y)的相关数据,进行线性拟合得到拟合方程,并采用光氧化云南昭通褐煤、光氧化山西浑源褐煤和光氧化内蒙元宝山褐煤对拟合方程进行了验证实验。结果表明,绿孢链霉菌、恶臭假单胞菌和黄孢原毛平革菌对光氧化内蒙胜利褐煤的η与降解液Y值之间的拟合方程分别为η=0.02466+0.07453Y,R~2=0.98392;η=0.02919+0.06412Y,R~2=0.99075;η=0.02336+0.08945Y,R~2=0.97836。3个拟合方程分别对3种不同光氧化褐煤的降解率预测值与实测值相比,相对误差较小,具有一定的普适性。     

黄孢原毛平革菌降解褐煤工艺条件的研究

选用对木质素具有降解能力的黄孢原毛平革菌（PC菌）对硝酸预处理义马褐煤进行生物降解转化实验。主要考察了煤样粒度A、菌液用量日、煤浆浓度C和降解时间D对降解转化率的影响,实验结果表明：各因素对褐煤转化率影响的主次依次为：煤样粒度〉菌液用量〉煤浆浓度〉降解时间。在选定的实验条件区间内,各因素的最优水平为：煤样粒度为一0．2mm;菌液用量为10mL;煤浆浓度为0．9g／50mL;降解时间为12d;即最优工艺参数组合为A1B2C2D3。     

微生物降解低阶煤的光氧化预处理工艺条件优化

利用旋转床光化学反应器光氧化预处理低阶煤(内蒙古胜利褐煤),再采用黄孢原毛平革菌降解光氧化煤,以降解煤液的A_(450)值为考核指标,采用正交实验优化光氧化预处理工艺条件。结果表明:煤样粒度、紫外灯功率和氧化时间对褐煤光氧化效果的影响极显著,马达转速对褐煤光氧化效果的影响较显著;最佳工艺条件为:煤样20 g、氧气流量200 mL·min~(-1)、通氧时间40 min、煤样粒度(-0.15+0.075) mm、紫外灯功率150 W、马达转速120 r·min~(-1)、氧化时间42 h。     

两种细菌降解新疆大南湖褐煤的最优工艺条件

利用8 mol/L的硝酸溶液对新疆大南湖褐煤原煤进行氧化预处理,采用冷湖游动微菌和格尔木马赛菌两种细菌对氧化煤进行降解实验,通过单因素和正交实验探索了培养方式、煤样粒度、接种量、煤浆质量浓度和降解时间对降解效果的影响,获得了冷湖游动微菌降解的最优工艺条件:摇床培养,煤样粒度为0.075 mm～0.125 mm,接种量为...     

多噬香鞘氨醇单胞菌降解陕西神府褐煤的工艺条件及产物研究

利用多噬香鞘氨醇单胞菌对陕西神府褐煤进行降解实验,通过单因素和正交实验确定了多噬香鞘氨醇单胞菌降解陕西神府褐煤的最佳工艺条件.煤样预处理采用10 mol/L硝酸氧化,煤样粒度为0.074 mm～0.125 mm,菌液量为8 mL/50 mL(培养基),降解时间为14 d,培养温度为35℃,培养方式为摇床培养,此时最大降...     

微生物法对煤进行改性的研究进展

介绍了几种对硬煤和褐煤进行微生物改性的方法、测试手段、改性效果和改性效果好的菌种，以及当前比较先进的菌种分离技术．通过微生物法对硬煤和褐煤进行改性，煤的溶解性有了一定的提高，其中有些方法用于降解煤样．可以分离出芳香化合物．用于改性煤样的担子纲类真菌对煤的改性效果较好．     

放线菌降解云南昭通褐煤工艺条件优化研究

对五株放线菌和硝酸氧化的云南昭通褐煤进行菌-煤匹配降解实验,筛选出降解优势菌绿孢链霉菌。在单因素实验的基础上,通过正交实验优化了绿孢链霉菌降解硝酸氧化昭通褐煤的工艺条件。结果表明,影响权重为:煤样粒度煤浆浓度接种量培养时间,最佳工艺条件为:煤样粒度-1 003+500μm,煤浆浓度0.200 0 g/20 m L,接种量1.8 m L/20 m L,培养时间20 d,转化率42.56%。红外分析表明,煤中的有机大分子已被绿孢链霉菌降解成小分子。滤液乙酸乙酯萃取物的GC-MS总离子色谱图证明了降解液中含有丰富的小分子有机物,且大多为脂肪烃、酯、醛、酮、胺及芳香族化合物等。     

放线菌降解云南昭通褐煤工艺条件优化研究

对五株放线菌和硝酸氧化的云南昭通褐煤进行菌-煤匹配降解实验,筛选出降解优势菌绿孢链霉菌。在单因素实验的基础上,通过正交实验优化了绿孢链霉菌降解硝酸氧化昭通褐煤的工艺条件。结果表明,影响权重为:煤样粒度>煤浆浓度>接种量>培养时间,最佳工艺条件为:煤样粒度-1 003+500μm,煤浆浓度0.200 0 g/20 m L,接种量1.8 m L/20 m L,培养时间20 d,转化率42.56%。红外分析表明,煤中的有机大分子已被绿孢链霉菌降解成小分子。滤液乙酸乙酯萃取物的GC-MS总离子色谱图证明了降解液中含有丰富的小分子有机物,且大多为脂肪烃、酯、醛、酮、胺及芳香族化合物等。     

山西临汾褐煤微生物降解工艺条件的优化

对6株细菌和硝酸氧化的山西临汾褐煤进行菌-煤匹配降解实验,筛选出降解优势菌恶臭假单胞菌.在单因素试验的基础上,通过正交试验优化了恶臭假单胞菌降解临汾褐煤的工艺条件,得出的影响权重为:煤样粒度煤浆质量浓度培养时间接种量.较优降解工艺条件为:煤样粒度75μm,煤浆质量浓度0.200 0g/10mL,培养时间14d,接种量1.0mL/10mL.此条件下的降解转化率达到46.81%.对降解后的煤残渣和降解产物进行红外检测,结果表明:煤残渣在氧化煤既有波数处的吸收大部分已消失或者变弱,说明煤中的有机大分子已被恶臭假单胞菌降解成小分子,包含在降解后的黑色油状滤液中.滤液分级萃取物的GC-MS总离子流色谱证明了降解液中含有丰富的小分子有机物,且大多为脂肪烃、酯、羧酸及芳香族化合物.     

褐煤深度脱水的实验研究

针对褐煤低温烟气干燥技术脱水幅度难以提高,发热量增加不多等问题,提出了低温干燥与深度脱水的联合工艺。研究了不同干燥温度、干燥时间和煤样粒度对褐煤深度脱水效果的影响,结果表明:褐煤深度脱水适宜的干燥温度为500～800℃,较为适宜的干燥时间为80 s左右,当粒度小于50 mm时,干燥产物发热量随粒度变化不大。最后提出了褐煤深度脱水最佳工艺条件和参数,即当预干燥煤的Mar约为18%,煤样粒度为-50 mm,干燥温度为700℃,干燥时间为80 s时,深度脱水产物的Mar为8%,Vdaf在46%左右,折算Qnet,ar约为21 kJ/g。褐煤深度脱水促进了褐煤发热量的进一步提高,实现了褐煤资源的增值,研究结果为褐煤低温干燥与深度脱水联合工艺技术方案的确定奠定了基础。     

褐煤半焦水蒸气活化法制备活性炭的工艺研究

通过对褐煤半焦水蒸气活化法制备活性炭原理的探讨及实验研究,分析了活化温度及时间、水蒸气流量等影响因素;用煤焦油做粘结剂制得的活性炭具有优越的物理和化学性能;在褐煤半焦粒度- 1 0 0目,活化温度70 0℃,活化时间4h ,水蒸气流量1 0 88 .89ml/min时,制得的活性炭碘吸附值达到了1 1 36. 39mg/g。     

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.     

Action of aerobic microorganisms on the macromolecular fraction of lignite

Microorganisms able to utilize untreated Morwell lignite and the fraction insoluble in tetrahydrofuran (THF) as their sole carbon and energy source were isolated by enrichment from coal exposures in Victoria. Most isolates can use a variety of long-chain aliphatic and single-ring aromatic compounds but not more complex aromatic substrates, indicating that their growth on whole lignite is due to use of the low-molecular-weight compounds constituting the mobile phase and bound aliphatic moieties which can be cleaved from the macromolecular coal matrix. Organisms able to utilize THF-insoluble lignite are less abundant than those able to use whole coal. Amongst these are isolates able to utilize diaryl compounds and anthraquinones, compounds with structures analogous to components of the macromolecular matrix of lignite. Two fungal isolates, CJ2 and CJ4, were found to alter the elution profile of alkali-solubilized Morwell lignite in size-exclusion chromatography. When incubated with these fungi in growth medium, the apparent molecular weight of the lignite increased by 10000. However, when polyvalent metal ions were removed, the apparent molecular weight was lower than that of uninoculated coal, indicating attack on the macromolecular matrix of the lignite.     

Solubilization of Neyveli lignite by oxidative degradation: A potential source of carbochemicals

The recent and possible future shortages of petroleum-derived hydrocarbons for use as starting materials for the synthesis of organic chemicals/products have stimulated renewed interest in the use of coal as raw material for chemical production. Oxidatively solubilized coal and or lignite (OSC) in alcohol is a potential substitute for value added carbo-chemicals of the future. Phenomenal increase in the solubility of lignite in organic solvent consequent on treatment with dilute nitric acid under mild conditions was considered to be an expedient pathway for its direct utilization. The primary requirements for the solubilization are generation of functional groups like free carboxyl groups and size degradation. For the desired product the reaction should also be guided in such a manner, so that the aromatic/hydroaromatic moieties of the coal/lignite are preserved. The present study aims at the selection of the required reaction parameters for the conversion of lignite to such a product. Characterization of the original lignite and the products have been done chemically and spectroscopically. FT-IR, ¹³C (solid state) and ¹H NMR spectra have shown that substances posses both aromatic and aliphatic characteristics. The dominant functional groups which contribute to the reactivity of the substances are phenolic and carboxylic acids.     

A comparison of the results obtained from grinding in a stirred media mill lignite coal samples treated with microwave and untreated samples

Various studies have been carried out on the effect of microwave-treatment on grinding different types of coal. However, the effect of microwave treatment on grinding coal samples −3.35 mm in size which can be considered to be fine is still under investigation. The purpose of this paper is to make contributions to these studies conducted. In the study, lignite coal samples with pyritic sulphur and 25% structural moisture were crushed below −3.35 mm particle size using jaw and cone crushers and then classified into three different mono size groups by Russel sieve. For a complete removal of the structural moisture from the lignite coal, a microwave application with 600 W needs approximately 35% more energy consumption than that with 850 W. The untreated coal samples and the ones treated with microwave at 850 W were ground for 5, 15, 30, 60, 120 s in a stirred media mill. The breakage rates of microwave-treated coal increased and accordingly the ground products of microwave-treated coal yielded finer particles than −106 μm as compared to untreated coals. The untreated and microwave-treated feed coals of −3350 μm and −1180 μm particle sizes were ground for 2 min in the stirred media mill. It was found that the increases in the rate of weight percentages for −106 μm particle size fraction after 2 min of grinding of untreated and microwave-treated feed coals of −3350 μm and −1180 μm were found to be 15.81% and 2.69%, respectively. Moreover, Hardgrove Index (HGI) test results of lignite coal showed that the HGI index value increased by approximately 23% after microwave treatment with 850 W.     

Effect of Drying Conditions on Moisture Re-Adsorption Performance of Dewatered Lignite

In order to improve the drying efficiency of lignite and restrain the moisture re-adsorption of dewatered coal, the drying characteristics of typical Chinese lignite, the re-adsorption performances of dewatered samples and the change in pore structure throughout the entire processes were investigated in this study. Lignite samples with four different particle size fractions were dried in a fixed-bed reactor in the temperature range 60–160°C. The re-adsorbing moisture behaviors of dewatered coal samples containing different water contents were investigated at temperatures of 20–40°C and humidities of 55–95%. The changes in the pore structure of raw coal and different dried samples were measured by mercury intrusion porosimetry (MIP) and the relations between their re-adsorption performance and change in pore structure were explored. The moisture removal yields of lignite increased with an increase in drying time and temperature and was close to 100% above 120°C and over 100% after holding 40 and 15 min at temperatures of 140 and 160°C due to the release of CO₂ from the decomposing carboxyl group in the coal matrix. The re-adsorbed moisture content in dewatered coal was influenced by drying temperature and coal particle size through varying pore structure. The temperature and relative humidity in the re-adsorbing process were the main factors that influenced the moisture re-adsorption capacity of dewatered lignite, in which the re-adsorbing temperature mainly operated by varying the bonding ability of water on the surface of dewatered coal, and the relative humidity was connected with the pore structure as well. The mesopore was the main factor that influenced the re-adsorption of dewatered coal and the re-adsorption of moisture in dewatered coal at 100°C was highest due to the narrow range of the pore radius and because the relative volume ratio of 5 to 50 nm mesopore (above 91%) was high. The water loss yield of lignite with smaller particle size was higher due to its larger pore volume and surface area, but its re-adsorption capacity was lower because of lower volume ratio of 5 to 50 nm mesopore volume in dewatered coal obtained from the smaller size lignite.     

胜利褐煤超临界醇解反应行为研究

对胜利褐煤在甲醇、碱体系中的超临界反应行为进行了研究,考察了反应温度、反应时间和碱的种类分别对胜利褐煤转化率、产物收率和分布规律的影响.结果表明,反应温度显著影响褐煤的转化率和产物收率,产物主要为四氢呋喃可溶组分(占67%～85%)和甲苯可溶组分(占8%～22%);300℃时,胜利褐煤在甲醇-NaOH体系中转化率和收率最高(99%左右);反应时间显著影响褐煤的转化率和产物收率,80 min后褐煤的转化率和产物收率分别为99%和100%;反应过程中四氢呋喃可溶组分可转化为甲苯可溶组分、正己烷可溶组分和水溶性组分;碱的种类对褐煤超临界醇解转化率和产物收率有显著影响.