The entrained-flow gasifier for fine slag can be applied for large-scale industrial use of gasification fine slag. The gas-solid two-phase flow characteristics of a 10000 Nm3/h fine slag entrained-flow gasifier were studied using a cold flow experiment system and a PDA (Phase Doppler Anemometry) measurement system to improve the gasifier's gasification performance. The flow field in the gasifier was compared in detail with various burner bias angles. The results reveal that when the burner is arranged biased in the same direction, there is an obvious central tangent circle in the velocity field of the horizontal section where the burner is positioned. When the burner's bias angle is 2°, the tangential area is the smallest, the upward movement of particles is the greatest, the particle updraft rate is up to 0.47, and the turbulence intensity is more than when the bias angle is 4° or 6°. When the bias angle is 2° in the vertical section of the upper gasifier, the downward-moving particle velocity is the largest, the downward-moving particle concentration is the greatest, the airflow swirl intensity is the smallest, and the swirl is the weakest, which is not conducive to the formation of slag layer on the membrane wall. When the bias angle is 6° in the vertical section of the lower gasifier, the tangential velocity of the airflow is the greatest, the swirl intensity is the highest, and the axial velocity is greater than the axial velocity of 4° and 2°. The particles' residence time in the gasifier gets shorter, which hinders the complete reaction of the fine slag.
与煤共气化是实现煤直接液化残渣萃余物(ER)资源化利用,提升煤直接液化工程整体经济性的重要途径.气化过程灰渣的流动性是影响气化操作条件的重要参数,利用灰熔点仪、高温旋转黏度计、XRD及SEM等测试手段考察了 ER与煤共气化的灰渣熔融特性、黏温特性及晶体特性,并结合壳牌气化装置入炉煤配比和操作条件,从灰化学角度确定ER的最佳掺混比例及气化操作窗口.结果表明:ER属于高灰、高铁、高钙、高硫物质,且其灰成分偏碱性,随煤中ER添加量增大,掺混后的灰分、铁含量和硅铝比逐渐增大.当萃余物质量分数超8％,全液相温度T1iq降低,但萃余物添加量超20％时,熔渣类型从玻璃渣转变为结晶渣.XRD与SEM分析结果表明钙长石的析出造成熔渣类型改变,钙长石的析出主要是因为萃余物的添加使熔渣黏度降低,熔渣中团簇的扩散能力增强,有利于结晶行为.结合Shell气化炉的操作条件及对煤灰中铁含量的要求,当萃余物添加量为10％时,共气化熔渣适合气化炉排渣,对应的排渣窗口为1 335～1 557℃.该研究结果为ER与煤共气化提供指导,提高煤直接液化流程的经济性.
The preparation method of large-area molten carbonate fuel cell matrix and electrode was developed, and the assembly and test operation method of 10 kW level molten carbonate fuel cell stack was proposed in view of the difficulties in the preparation and matching characteristics of the key materials during the development of large-area molten carbonate fuel cell and its large power stack. A 10 kW class MCFC stack with 120 cells and an effective area of 0.2 m~2 for each cell was assembled and operated. During the constant voltage discharge test, the maximum output power reaches 16.51 kW and the current density is above 95 mA/cm~2. Through multiple experimental studies and analysis, an effective online evaluation method for the baking effect of MCFC electrolyte matrix is obtained, which makes the matrix, electrode and molten salt electrolyte in the molten carbonate fuel cell body matched well, and has important guiding significance for improving the success rate and the long cycle operation life of MCFC stack assembly. Meanwhile, the study of MCFC stack body and performance test methods will provide effective theoretical and experimental guidance for the subsequent development of larger power molten carbonate fuel cell power generation system, and have important significance in the commercial demonstration and promotion of MCFC.
To master the pollutant emission characteristics of a 350 MW supercritical CFB boiler under mixed combustion of multi-element low-calorific value coal including coal slime and coal gangue, taking a 350 MW supercritical CFB boiler of a power plant as the research object, and based on the measured data of on-site operation, the formation and emission characteristics of SO 2 , NO x and dust in flue gas were studied against the boiler load rate between 30% and 99%. Additionally, the key operated parameters including boiler operating load, average bed temperature, excess air coefficient and fluidizing air rate on its generation and emission level were investigated. The test results reveal that the flue gas pollutant emissions of the CFB unit can meet the emission standards within the load range of 30%-99% at total discharge outlet. The emission concentration of SO 2 , NO x basically decreases first and then increases rapidly with the decrease of boiler load. The concentration of dust emission decreases with the decrease of boiler load, and the dust emission concentration decreases with the reduction of boiler load. Among the key operating parameters studied, the boiler bed temperature plays a leading role in the emission level of SO 2 , NO x . The emission concentration of SO 2 and NO x is higher with the lower average bed temperature and the larger excess air coefficient, and the emission concentration is basically positively correlated with the excess air coefficient and fluidization air rate. Considering comprehensively, it is recommended that the average bed temperature of the boiler should be properly controlled above 800 ℃, and the excess air coefficient should be stabilized less than 1.3. The way of flue gas recirculation can be used to reduce the oxygen concentration of the flue gas under low load on the basis of the maintaining the normal fluidization of the material.
Aiming at the high temperature corrosion problem of the water wall of a 350 MW low nitrogen boiler in a power plant, the simulation study was carried out to adjust the air distribution and increasing near-wall air. The relationship between the concentration of reducing gases CO, H 2 S and NO x in the furnace was simulated when the burn-out air rate was 38%, 33% and 27% respectively, and the effect of increasing the wall air on the concentration of reducing gases near the water wall was simulated. The results show that the burn-out air rate is reduced from 38% to 33%, which can reduce the concentration of reducing gases CO and H 2 S in the furnace by 20% without significantly increasing the amount of NO x , and slow down the high-temperature corrosion of the water wall. Reducing the burn-out air rate from 38% to 27% can increase the oxygen concentration in the main combustion zone, reduce the production of CO and H 2 S, and slow down the high-temperature corrosion of the water wall, but the NO x concentration will increase significantly. The high-temperature corrosion area in the furnace is mainly located between the UAP nozzle of the compact burnout air and the SOFA3 nozzle of the intermediate burnout air. The near-wall air can be added on both sides of the UAP nozzle of the compact burnout air. The simulation results show that the concentration of CO and H 2 S near the water wall can be reduced by increasing the near-wall wind with the same rotation direction as the main flow, and there is the small effect on the flow field. Due to the high concentration of CO near the water wall, the flow of near-wall air on both sides is larger, which has better effect on reducing CO near the water wall. The coverage area of near-wall air on both sides is larger for high-temperature corrosion area, while the concentration of H 2 S near the water wall is lower. There is no obvious difference between the single-side near-wall air and the double-side near-wall air in reducing the H 2 S of the water wall, but the double-side near-wall air will disturb the distribution of the flow field, which is not conducive to pulverized coal combustion.
我国能源资源禀赋和煤气化产业的发展使煤气化渣排放量已达6 000万t/a.大量的煤气化渣堆存不符合能源清洁低碳高效利用的理念.对煤气化渣进行消纳处理过程中,由于含水量高、含碳量高,限制了规模化利用途径,因此需转换传统思路,向高值化方向进行性能开发是一种趋势.重点综述了煤气化渣在高值化方面的研究进展,概述了煤气化渣的来源及物理化学性质,总结了国内外煤气化渣在催化剂框架、聚合物补强、多孔材料、农业堆肥等高值化方面的研究现状,提出了高值化利用存在的局限性问题,展望了未来的发展方向.煤气化渣高值化利用是固废性能开发的主要形式,可降低生产成本,减少环境污染,并且煤气化渣的特性显示煤气化渣是错位的资源,适度开发其在高值化方面的应用,可实现煤气化渣变废为宝.
为响应"十九大"绿色环保精神,满足循环流化床机组超低排放需求,建立准确的NOx排放浓度机理控制模型对于设计循环流化床机组脱硝自动控制方法具有重大意义.从循环流化床锅炉燃烧机理切入,建立即燃碳模型,并将燃料氮分为挥发分氮与即燃碳氮2部分构建NOx炉内自生成模型;考虑CO和即燃碳对NOx的还原作用推导NOx自还原模型;构建选择性非催化还原脱硝模型,综合以上模型建立了适应深度调峰的循环流化床NOx排放模型.探究了机组深度调峰下运行参数与NOx排放浓度的关系以及与选择性非催化还原脱硝效率的影响因素.仿真验证试验表明建立的循环流化床NOx模型取得了较好仿真效果,稳态工况的模型计算值平均预测时间为114 s,与实测值的平均相对误差为2.50%;深度调峰下的模型计算值平均预测时间为126 s,与实测值的平均相对误差为5.42%.模型计算量较实测量提前2～3 min,具有一定预测效果.NOx排放浓度模型可为今后循环流化床机组适应深度调峰、快速变负荷以及超低排放研究提供参考.
在碳达峰、碳中和目标背景下,我国正加快构建新能源占比逐渐提高的新型电力系统,目前煤电正是消纳可再生能源大规模并网的最经济调节电源.循环流化床锅炉机组因自身天然优势在煤电深度灵活调峰中担任重要角色,但其独特的结构和运行方式导致变负荷速率偏低,消纳高比例新能源并网的能力亟待提高.分析了制约循环流化床锅炉变负荷速率的影响因素,包括气固两相流动的惯性、炉侧水侧传热的惯性、固体颗粒燃烧的惯性、水动力安全性、机炉动态匹配问题等,并解释了产生惯性的物理机制.归纳了提高循环流化床机组快速变负荷能力的关键技术,通过加快流动参数、提高传热系数、减小炉侧热容、增强炉侧水侧间的传热、强化燃烧反应、优化控制策略等方法,考虑工业尺寸锅炉的可行性,提出了一套综合优化技术方案,即"智能吞吐"系统的设想.在1台135 MW循环流化床锅炉上进行验证,结果表明,锅炉平均变负荷变化率可提升16%,最大负荷变化率短时间内可持续达到4%/min左右.在此基础上,对宽负荷灵活运行的循环流化床锅炉机组的设计思路进行展望,用数据驱动热力系统动态模型,融合创新技术的热力系统多时空匹配运行技术,构建"三自一体"的先进协同控制系统,并参考成熟的煤粉炉蓄能利用技术,为将来实际工业应用提供理论指导.
制备工艺是决定水煤浆浆体性能的重要因素,影响其储运和使用.综述了近年来水煤浆制备工艺的最新研究进展,包括不同种类水煤浆的制备工艺及制备环节中药剂制度、粒度级配方式的使用,按制浆原料的不同将水煤浆分为传统水煤浆和环保水煤浆,其中传统水煤浆是指制浆原料以煤基成分为主,如精煤水煤浆、低阶煤水煤浆和煤泥水煤浆,环保水煤浆则是在制浆原料上掺配了如生物质、工业废液和固体废弃物等,既可充分利用废弃物热值,又能降低处置成本,是资源化综合利用废弃物的新途径.分析对比了常规锅炉、循环流化床锅炉以及气化炉等应用场景对水煤浆的性能要求,其中常规锅炉要求水煤浆的黏度低、粒度细,制备工艺上通常采用单段磨矿工艺,循环流化床锅炉因其独特的悬浮流化燃烧方式,对水煤浆粒度和黏度的要求不高,可通过不排渣的运行方式,减少大密度床料的消耗,提高对制浆原煤的灰分含量以及灰熔融温度的包容性,气化对水煤浆的性能要求比燃烧更高,其中气化炉要求水煤浆的浆体浓度高、反应活性好,且为保证较好的雾化效果,气化水煤浆要求水煤浆颗粒的细粒度、低浆体黏度;对水煤浆制备技术的发展趋势进行了展望,提出探索低阶煤改性提质方法、超细颗粒对浆体特性的影响、拓展可掺配制浆废弃物种类等技术方向.
随着畜禽养殖业的规模化、集约化发展,畜禽粪便大量、集中产生,由于我国畜牧业与农业结合不紧密,且畜禽粪便中含过量重金属和抗生素,导致畜禽粪便的回田利用难度大.畜禽粪便经水热处理后制备生物燃料,可实现其能源化、无害化利用.以产量最大的猪粪为代表,总结了其组分及理化性质,讨论了传统处理方式的缺陷,对水热处理后猪粪残渣的产率、燃烧特性及脱水性能进行分析概述,最后探讨了水热残渣作生物燃料的发展前景.猪粪中含有半纤维素、纤维素、木质素、蛋白质及脂类等成分,且富含氮、磷、钾等植物生长所需的营养元素,合理处理后可实现资源化利用.好氧堆肥及厌氧发酵技术难以高效降解猪粪中的抗生素,且猪粪中高浓度的重金属也会对堆肥及发酵过程产生不利影响.水热处理是一种很极具前景的处理畜禽粪便等高含水率生物质的技术.通过水热处理可将猪粪转化为与褐煤相当的水热残渣及稀释后可用于灌溉的水热残液,且能有效固化重金属及降解抗生素.水热处理过程中有机物的降解和溶解使猪粪水热残渣的产率随水热温度升高呈下降趋势.在范式图中,猪粪水热残渣可达到褐煤区域,且其挥发分及高位热值也能达到褐煤水准.大量结合水在水热处理过程中被转化为自由水,改善了猪粪水热残渣的脱水及干燥性能.此外,碱金属在水热处理过程中易溶解进水热残液,降低了水热残渣燃烧时的结渣风险.水热处理可将重金属富集在水热残渣中,并降低其浸出率及生态毒性.猪粪水热残渣良好的燃烧特性及可研磨性使其具备与煤共燃的潜力,但需对煤粉炉进行适当改造并控制合理的过量空气系数等参数.猪粪与农林废弃物的共水热处理可降低水热残渣的灰分含量,提高固定碳含量及高位热值.畜禽粪便水热处理工艺的经济性问题是限制其工业化应用的主要原因,通过优化工艺设计等手段,有助于水热处理技术在畜禽粪便处理问题上的实际应用.
Purification section of syngas from coal is located after water gas shift to remove hydrogen sulfide, carbon dioxide as the main gas impurities and obtain high purity hydrogen. At present, the mature purification processes include wet method represented by low temperature methanol scrubbing and liquid nitrogen scrubbing, and dry method represented by pressure swing adsorption decarburization. The operating temperature of the elevated temperature pressure swing adsorption technology proposed is consistent with the temperature of the incoming shift gas. Self-made hydrophobic nitrogen-rich activated carbon adsorbent was deployed to achieve desulfurization and carburization by increasing the traditional pressure swing adsorption operating temperature to 170-220 ℃ and high humidity environment. Two new PSA steps, high pressure steam rinse and low pressure nitrogen purge, were adopted to improve H 2 recovery to above 99%. The elevated temperature pressure swing adsorption H 2 /CO 2 separation demonstration with a processing capacity of 5 000 m~3/h（standard condition）was built and operated using coal based shift gas from Quanji Plant as the feedstock for the pilot plant. The purity of hydrogen reaches the hydrogen fuel level（including N 2 ） through two-stage ETPSA, and the pilot plant has been running for more than 2 800 hours in total. In addition, the energy consumption of the pilot plant was calculated based on the utilities expenses. When taking power consumption into consideration, the operation cost of H 2 purification for the pilot test can be significantly reduced by about 35% compared with the power consumption of H 2 purification by low temperature methanol scrubbing at Fengxi Plant. This technology breaks through the limitation of temperature of conventional adsorption and purification for solid adsorbents, and realizes directional removal of impurities in hydrogen by using adsorbents with preferred selective adsorption performance at elevated temperature, which confirms a new process route for efficient and high-quality hydrogen purification.
Fuel flexibility is one of the most significant advantages of Solid Oxide Fuel Cell（SOFC）. However, when using hydrocarbons as fuel, the degradation of cell performance caused by anode carbon deposition is one of the most important reasons affecting the long-term stable operation of SOFC. To investigate the mechanism of the influence of anode carbon deposition on cell performance, a one-dimensional transient elementary reaction kinetic model of an SOFC fueled with syngas（H 2 ,CO,H 2 O,CO 2 ,CH 4 ） was developed. This model incorporates the coupling effect of heterogeneous elementary chemical and electrochemical reactions, the electrode microstructure evolution, the charge and mass transport processes and the detailed evolution reaction of surface adsorbed carbon. The accuracy of the model was verified using the electrochemical impedance spectra at different moments in the reference experiment, and the mechanism of carbon deposition at SOFC anode was proposed based on the model. Under high temperature（＞1 000 K） conditions, carbon is coverd on the Ni surface and Ni/YSZ/gas three-phase interface in the form of thin-film carbon, blocking the nonhomogeneous phase reaction and charge transfer reaction. At lower temperatures（＜1 000 K）, film carbon evolves into solid carbon, which grows inside the porous anode, blocking the anode pores and impeding gas diffusion. The constructed model can reflect this mechanism. Finally, the SOFC performance degradation due to carbon accumulation in different fuel components was investigated using the model. Study show that reducing the CH 4 content in the fuel can effectively reduce the performance degradation rate of SOFCs and improve its operational performance.
为积极应对全球气候变化,我国提出2030年前达到碳达峰、2060年实现碳中和的双碳目标.我国能源结构决定了煤炭是我国主体消费能源且短期内不会发生变化.为实现双碳目标,煤炭行业需从技术与理论2方面进行创新.为此,围绕煤炭地下气化思路,综述了煤炭深部流态化生产的3种方式:气化、热解以及生物溶解.其中,主要综述了煤炭地下气化技术,包括国内外部分典型煤炭地下气化项目的发展历程、气化工艺及气化稳定性影响因素,并简要分析煤炭地下气化技术仍有待进一步形成工业化生产的原因.同时,将石油行业中的多级压裂水平井同井缝间注采技术引入煤炭深部流态化开采,该技术通过注入气化剂和增加加热装置实现煤炭地下深部流态化开采.基于水平井同井缝间注采技术,探讨了一种新井型在煤炭地下气化、地下热解和地下生物溶解开采中的应用前景及适用范围.相比传统地下气化工艺,水平井同井缝间注采技术具有节约开采成本、提高经济效益、增大气化反应面积和提高波及范围等优势,此外,还可利用新能源技术发电加热,在一定程度上减少碳排放,推动双碳目标实现.最后,结合深部煤炭流态化发展现状,分析当前存在的问题,为我国未来深部煤炭地下气化工业发展提出了建议.
基于石墨烯与类石墨烯炭材料结构和性能差异,其有不同的潜在应用,恰当的表征手段对分析石墨烯与类石墨烯炭材料的性能及指导应用研究具有重要意义.以标注为单层石墨烯(G1)、少层石墨烯(G2)、多层石墨烯(G3)、工业级多层石墨烯(G4)的 4 种材料为研究对象,利用拉曼(Raman)光谱、扫描电镜(SEM)、透射电镜(TEM)、原子力显微镜(AFM)、X射线衍射(XRD)、氮气吸附仪等对样品的理化特性进行了综合表征,从结构分析到形貌分析,再通过晶型分析与比表面积分析验证,探讨了石墨烯与类石墨烯炭材料的表征手段、数据分析以及各表征结果之间相互关系.结果表明,G1层数相对较低,缺陷密度较大(D峰与G峰强度比ID/IG =0.88),经TEM、AFM形貌测定层数与XRD计算数据相互验证,实际层数为 10～20 层,比表面积为 564.03 m2/g,拉曼光谱与XRD晶型测定确定了其典型的石墨烯特征,属于石墨烯范畴;而G2～G4 的层数达100 层以上,比表面积为30～50 m2/g,ID/IG=0.07～0.18,结合结构与形貌的结果综合判断其属于类石墨烯炭材料,该研究为石墨烯及类石墨烯炭材料的判定途径及方法提供了参考和指导.
絮凝装置通过其内部流场影响絮凝过程和效果.根据涡旋絮凝动力学理论设计了旋流-扰流连续絮凝沉降一体化装置并用于煤泥水的絮凝沉降试验.首先通过沉降管絮凝沉降试验确定合适的药剂添加条件:聚合氯化铝质量浓度5 mg/L,聚丙烯酰胺质量浓度2 mg/L.在该药剂制度下,以底流浓度和溢流浊度为指标,考察了在内外径分别为 50 和 100 mm的环形流道内,底边长 10 mm的等腰三角形扰流板的高度、组数和安装角度对煤泥水絮凝沉降效果的影响.结果表明,扰流板高度和组数对絮凝沉降效果影响显著:试验范围内,5 组扰流板条件下,扰流板高度15 mm时最好,溢流浊度为142 NTU,比无扰流板时下降54 NTU;扰流板组数在 0～5 时,3 组效果最好,溢流浊度降至 112 NTU;在3 组15 mm扰流板条件下,改变扰流板角度对絮凝沉降效果影响较小,浊度在107～125 NTU,其中30°最理想.分析认为扰流板高度通过控制其引导的涡流特征尺度和能量耗散影响颗粒碰撞与破碎,而扰流板组数主要影响混凝区的长度,进而改变颗粒有效混凝时间.
燃煤电厂烟气碳捕集系统的产品处理装置包括压缩、干燥和液化装置,其选型方案决定产品气质量.基于某1 000 MW等级火力发电厂的50 万t/a规模烟气二氧化碳湿法捕集项目,针对湿法吸收工艺CO2气体含水率高、气量较大但压缩压力不高的特性,结合电厂发电、供热运行限制,对CO2气体压缩系统压缩、液化及冷却工序所需CO2压缩机、冷冻液化机等设备选型开展比型分析,并对化工系统设备应用于电力生产单位的适应性进行研究.结果表明,燃煤电厂烟气CO2捕集装置设备选型与石油化工单位CO2捕集装置设备选型差异极大.与化工单位的负荷追求稳定相比,现代火电厂调峰运行负荷波动性极强,火电厂CCUS项目采纳电厂排烟为原料,使用电厂余热蒸汽,占用厂用电份额,与电厂主系统共用循环水、闭式水、压缩空气等生产资料,导致火电厂CCUS项目所需烟气量、动力蒸汽参数、烟气CO2浓度、冷却水源等处于波动状态,换热装置、压缩机等选型的设计边界条件与化工单位不同;一般情况下,燃煤电厂与化工企业所处区位不同,化工企业多为上下游企业同处一个化工区,火电厂周围一般不毗邻CO2消纳单位,火电厂CCUS装置的产品气质量标准、气体封装及运输设备需结合区域及市场定位与化工单位相区别;与化工单位相比,燃煤电厂CCUS项目具有动力源成本较低等优势,电厂项目更多应考虑减少吸收剂损耗等成本,不必一味追求降低能耗成本.
我国煤炭资源相对丰富,但炼焦煤资源所占比仅 18.9%,气煤和 1/3 焦煤在炼焦煤查明资源储量中约占47%,而优质炼焦煤占比不到10%.许多钢铁企业为了生产更高品质的焦炭而配入过多优质炼焦煤,这为优质炼焦煤资源和高品质焦炭的持续供应带来极大困难.基于快速加热的预处理技术在拓展和节约使用优质炼焦煤资源,保证炼焦高产、优产,降低成本和提高焦炭品质等方面意义重大.综述了利用预热处理改善炼焦煤性质的研究,重点讨论了快速预热改善炼焦煤黏结性的影响规律.研究表明,炼焦煤在进行预热处理时,煤种、预热终温及升温速度等因素均会显著影响焦煤炭化过程中的结构演化.在热处理过程中,随热处理温度升高,煤的芳香结构不断发展,石墨化程度加深.快速预热一方面抑制了煤的热分解,另一方面使煤的大分子结构松弛,导致煤分子在热塑性阶段移动性增强,从而提高了煤黏结性.最后总结了快速预热技术在机理研究以及工业应用等方面存在不足.
高效利用太阳光是新能源领域的重要研究方向,而光催化是一种利用太阳光在常温常压条件下实现降解污染物、还原二氧化碳等一系列困难反应的技术,具有廉价、环保、可持续等优点.在非均相光催化反应中,为防止固相的光催化剂在液相或气相反应环境中团聚或损失,需适宜的负载材料以保护和固定光催化剂.碳气凝胶由于兼具碳材料的导电性、化学惰性及气凝胶材料的高比表面积等特点,与光催化反应需求相适配,在光催化领域得到广泛研究.生物质基碳气凝胶以生物质材料作为前驱体,相比常规碳气凝胶具有环保、成本低廉、原料来源广泛等优势.总结了生物质基碳气凝胶的特点,并在此基础上讨论生物质基碳气凝胶作为一种新型碳气凝胶的发展现状.最后,通过已有研究证明了其作为光催化剂负载材料的可行性与优势,并对未来生物质基碳气凝胶的研究方向提出建议.目前的生物质基碳气凝胶已开始在吸附重金属、油水分离、柔性电容器、电磁波吸收等多领域发展.而在光催化领域,关于生物质基碳气凝胶负载光催化剂的方法尚处于初期,研究主要集中在生物质原料的选择、光催化剂的负载方法等方面.其中,以纤维素气凝胶制备碳气凝胶和以多孔性植物为前驱体制备碳气凝胶是2 个主要研究方向.纤维素气凝胶与其他生物质如蛋白质、淀粉等提取物相比,具有原料来源广泛、含碳量高、更易构造出复杂凝胶网络等优势;而以多孔性植物为前驱体制备碳气凝胶的过程更快捷、简单,且生物质材料的天然复杂结构能成为碳气凝胶的天然模板,其中蕴含的多种P、S等元素也可为后续碳气凝胶的不同开发方向提供天然杂原子支持.截至目前,生物质基负载光催化剂的实际效果已得到验证.未来,生物质基负载光催化剂的研究可在现有成果的基础上,分析不同生物质前驱体的元素组成以及三维孔隙结构对负载的影响,并结合其他得以验证的光催化改性及负载方法.也可尝试充分发挥生物质的特点,如针对性地培育植物作为碳气凝胶的前驱体,以获得更好的碳气凝胶模板.最终,可进一步提高生物质基碳气凝胶负载光催化剂的催化能力、负载能力,并为廉价、环保的光催化系统提供新的解决思路.
为降低工业有机废弃物糠醛渣气化合成气中焦油含量,一方面通过在糠醛渣气化过程添加高能量密度的煤和有机固废糠醛渣进行共气化,提高气化温度,实现气化焦油的热裂解,提高碳转化率;另一方面通过添加CaO催化裂解焦油,实现糠醛渣原料气化产气的净化,提高糠醛渣原料的元素利用率.通过考察CaO的添加对共热解阶段及共气化阶段产品的影响规律,得到糠醛渣气化产气净化的基础数据.结果表明,CaO作为焦油裂解催化剂可在糠醛渣热解阶段提高热解反应速率,促进原料向轻质油和气体分子转化;糠醛渣/煤共气化过程,与不添加CaO相比,机械混合法添加的CaO可使共气化焦油脱除率达17.42%,而浸渍法添加的CaO可使焦油脱除率达69.41%,同时提高焦油轻质化程度;升温和提高CaO的添加比例均可使共气化产气中焦油浓度下降并提高气体产率;此外,通过采用X射线衍射光谱(XRD)和扫描电子显微镜(SEM)对气化后的固体残渣进行分析,由于CaO的助熔作用,1 000℃时,共气化会出现灰团聚现象.
低阶煤泥浮选过程中,由于其表面疏水性差,烃类油捕收剂能否顺利吸附在其表面,对最终的浮选效果具有重要影响.为强化烃类油捕收剂在低阶煤表面的吸附,采用理论计算、分子模拟和试验分析方法研究了高剪切调浆对低阶煤泥浮选的影响规律和强化机理.通过吸附量测试和理论计算研究了正十二烷油滴在煤颗粒表面的吸附规律;借助分子动力学模拟方法构建了正十二烷-水-低阶煤模拟体系,探索了正十二烷与煤表面的初始距离对最终吸附结果的影响;通过开展高剪切调浆浮选试验研究了叶轮转速对浮选精煤产率和灰分的影响规律.结果表明,高剪切调浆可显著提高捕收剂正十二烷在低阶煤表面的吸附量,当叶轮转速超2 000 r/min时,吸附量增幅逐渐降低,最终吸附量趋于稳定;正十二烷油滴与煤颗粒之间存在一个能垒,越过能垒后,总势能迅速降低;初始状态下正十二烷油滴与低阶煤表面的距离对最终模拟平衡结果有重要影响,初始距离较近时,油滴可在煤表面吸附并铺展,而初始距离较远时,则无法吸附;高剪切调浆可显著改善低阶煤的浮选效果,调浆叶轮转速为2 000r时,浮选精煤产率增加了近13%,而灰分基本保持不变.
