氟化钾/镍铝复合氧化物的制备及催化合成生物柴油

采用共沉淀、煅烧及研磨的方法制备氟化钾/镍铝复合氧化物,并利用正交实验考察制备条件对氟化钾/镍铝复合氧化物催化合成生物柴油活性的影响,得到优化后的制备条件:镍/铝摩尔比为2、煅烧温度为550℃、煅烧时间为2 h、氟化钾/镍铝复合氧化物质量比为1。以优化条件下制得的氟化钾/镍铝复合氧化物为催化剂,催化蓖麻油与甲醇的酯交换反应,结果蓖麻油转化率为98.9%。采用TG-DTA,FTIR,BET,XRD技术对镍铝水滑石、镍铝复合氧化物及氟化钾/镍铝复合氧化物催化剂进行了表征,结果表明:镍铝水滑石在30~220℃,220~380℃及500~520℃3个温区有3个失重台阶;氟化钾/镍铝复合氧化物催化剂BET表面积为34.42 m2/g,BJH累积孔容为0.128 cm3/g,BJH平均孔半径为5.46 nm;氟化钾/镍铝复合氧化物催化剂由Ni O晶体和K3Al F6晶体构成。     

低温辐射绝热材料的研究——轻质镁铝绝热材料

低温辐射绝热材料的研究——轻质镁铝绝热材料石远志谢永明重庆北碚长江节能研究所南京新合集团保温材料厂重庆北碚长江节能研究所从传热理论研究入手，成功研制出低温辐射绝热材料——轻质镁铝绝热材料。在南京新合集团保温材料厂、洛阳同庆节能材料厂等批量生产，在国家...     

中低铝氧化物陶瓷低温烧结研究和烧结助剂的制备

基于氧化物陶瓷低温烧结理论,针对中低铝陶瓷(Al2O318%～75%,SiO225%～82%)采用廉价添加物配制了一种低温烧结助剂,烧结助剂包括助熔剂和活化剂两部分.此烧结助剂节能效果显著,改良产品的主要性能均达到或优于原产品.并应用XRD与SEM等研究手段,对原产品和添加烧结助剂产品的微观结构进行对比分析,发现此烧结助剂对改善产品强度,韧性,微观结构,提高化学稳定性与热稳定性均起到较好效果.     

乙酸镁对木屑催化热解特性的影响

通过自制的固定床热解实验台,以吸附浸渍的方式将不同浓度的乙酸镁与木屑均匀混合,在温度为600℃条件下以快速热解的方式探究乙酸镁对热解产物特性的影响,分析实验结果得出:在木屑热解过程中,随着乙酸镁添加量的增大,热解焦炭与热解合成气的收益率提高,热解生物油收益率有一定程度的下降;乙酸镁使热解后产生的生物油成分变得简单,随着乙酸镁添加量的增大,生物油成分中乙酸的相对含量有明显的提高;乙酸镁的添加会导致热解焦炭的比表面积和总孔容降低,乙酸镁高温分解产生氧化镁,TEM图片显示热解后有部分的氧化镁纳米颗粒会附着在碳片上,阻塞了一些孔隙结构;对于热解合成气,乙酸镁的添加会提高H_2与CO_2的含量,降低CO的含量,CH_4的含量几乎不受影响。     

镁铝尖晶石质耐火材料的开发与应用

阐述了镁铝尖晶石质耐火材料的性能及合成,论述了镁铝尖晶石质耐火材料的应用及发展趋势。     

生物质直接催化液化的研究

采用离子交换法制备Mn,Ni金属改性分子筛催化剂,用扫描电镜(SEM)和X射线衍射(XRD)对催化剂的性质进行表征,并将此催化剂应用在大豆秸秆直接液化反应中。通过对无催化剂和不同催化剂作用下得到的液体燃油的元素分析和GC-MS分析,结果表明,改性分子筛催化剂对生物质的直接液化有明显的催化作用,尤其是Mn/ZSM-5。以Mn/ZSM-5分子筛为催化剂能将生物油的产率从10.65%提高到14.61%,增加芳烃和烷烃的相对含量至12.78%和22.31%,将生物油的氧含量降低至6.28%,而生物油的热值则提高到43.56 MJ/kg。此法为通过催化剂调控生物油的组成和相对含量提升生物燃油的品质提供了研究基础。     

生物质催化热解的TG-FTIR研究

借助综合热分析仪和傅立叶红外联用技术(TG-FTIR),考察了HUSY、REY和HZSM-53种分子筛以及重油催化裂化催化剂MLC和馏分油催化裂解催化剂CIP对生物质催化热解的活性和选择性。研究结果表明,分子筛对生物质热解产物的脱氧活性顺序为:REY≈HUSY>HZSM-5,生成高辛烷值烃类的选择性顺序为:REY>HUSY≈HZSM-5;MLC催化剂和CIP催化剂都表现出较高的选择活性,前者的脱氧活性略高于后者;择形分子筛HZSM-5的引入对调整催化剂酸强度、提高催化转化选择性和抑制焦炭生成产生一定作用。     

基于生物质气的固体氧化物燃料电池-燃气轮机混合动力系统的性能分析

以生物质气为燃料,建立了固体氧化物燃料电池-燃气轮机混合动力系统的仿真模型.利用所建立的模型进行仿真,根据燃料电池特性参数和压气机、透平特性曲线,分析了燃料质量流量、空气质量流量等参数对混合动力系统性能的影响.结果表明:基于生物质气的固体氧化物燃料电池-燃气轮机混合动力系统的发电效率最高可达61.55%,但在这种情况下系统的寿命和可靠性急剧下降;在设计点工况下,系统的发电效率可达55.31%.燃料质量流量不变,空气质量流量可以在0.084 0~0.179 9kg/s内调节,系统效率变化范围为61.55%~51.43%;空气质量流量不变,为防止压气机发生喘振,燃料质量流量变化范围为0.062 3~0.084 6kg/s,功率变化范围为124.9~187.3kW.     

生物质炭催化裂解焦油的实验研究

通过实验方法研究了生物质炭对生物质热解焦油的催化特性。通过分析焦油裂解率在催化剂及其重量、蒸汽加入量和加入方式、氮气流量等条件下的变化可知:在蒸汽条件下,生物质炭对焦油有显著的催化裂解效果,最高焦油转化率可达96.1%。通过对实验条件下裂解产物、裂解气体积分数的分析可知,生物质炭和蒸汽可以促进热解产物里面的可凝结相转化为不可凝结的气体,并且导致气体组分体积分数的变化。裂解气中氢气产量增加较快,最高可达裂解气体积的50.2%。     

生物质炭催化裂解焦油的性能研究

采用管式反应器研究了生物质炭作为焦油裂解催化剂的性能,选用白云石和石英砂作对比试验。通过对焦油转换率、裂解产物、裂解气气体组分和动力学参数的分析对比可知:在所选用的3种材料中,生物质炭作为催化剂的焦油转化率最高,裂解产物中气体所占比重最大,且可燃气体的组分较高,反应动力学参数最小。生物质炭的催化性能显著高于石英砂,稍好于白云石,是一种高效的焦油裂解催化剂。     

A DFT study on production of hydrogen from biomass-derived formic acid catalyzed by Pt–TiO2

Production and storage of hydrogen from biomass component by using efficient catalysts, it can finely maintain the future energy of the world and reduce human dependence on fossil fuels. Hydrogen production mechanism via formic acid decomposition on the TiO₂ anatase (101) and Pt–TiO₂ surfaces in the solvent (water) and gaseous conditions performed by density functional theory (DFT) calculation. Regarding to the proposed routes, decomposition reaction of formic acid on TiO₂ surface incline to be followed by second route in the water which is acceptable in terms of energy. Decomposition reaction of formic acid on Pt–TiO₂ surface prefers to do it via first route (rotation around CO bond of formic acid) in solvent conditions. Furthermore, adsorption energy and geometric changes of formic acid on TiO₂ anatase (101) and Pt–TiO₂ surface in gaseous and solvent conditions were clearly studied.     

Study on preparation and electrochemical properties of biomass-derived spherical activated carbon

以生物质风化煤系腐殖酸（LHA）为炭质前驱体,通过溶剂蒸发和KOH活化方法制备了球形活性炭。使用扫描电子显微镜（SEM）、N2物理吸脱附仪等手段对球形活性炭形貌和孔道结构进行了表征;还将活性炭组装成扣式电容器,进行了充放电容量、循环伏安特性和交流阻抗行为等电化学性能测试。结果表明：所制备的球形活性炭具有良好的球形度,通过少量碱活化后球形活性炭BET表面积为2034 m2/g、总孔容为1.24 cm3/g、平均孔径为2.38 nm。同时,以球形活性炭作为电极材料应用于水系超级电容器后显示了优异的电化学性能,比电容可达到319 F/g,在进行10000次充放电后,比电容保持率为98.9%。此外,球形活性炭相比于颗粒活性炭具有更好的导电性,也展现了更加优异的倍率性能和循环性能。因此说明LHA基球形活性炭是一种有潜在优势的超级电容器材料。     

氢氧化钾催化木屑热解特性影响研究

为了考察钾盐催化剂对生物质热解特性的影响,实验以木屑为原料,采用浸渍方法加入不同质量KOH,干燥和粉碎后进行热重和热解实验。实验中使用热重分析仪对样品进行热重实验,采用Starink法进行动力学分析,使用自行搭建的固定床热解炉研究热解温度和KOH添加量对木屑热解的影响。热重结果表明,加入KOH后热解温度降低,改变了木屑热解路径,降低了热解失重速率。动力学分析结果表明,加入KOH后使木屑主要热解区间表观活化能降低。热解实验结果表明,加入KOH后,木屑热解产物中热解油产率降低,热解合成气和半焦产率增加。热解产物经分析发现,加入KOH后,热解合成气中氢气含量显著增加,热解油品质有所改善,低KOH添加量对半焦孔隙结构影响较小,高KOH添加量使半焦的孔隙更加发达。     

Study on the thermal decomposition of NaBH4 catalyzed by ZrCl4

The catalytic effect of zirconium tetrachloride (ZrCl₄) on the thermal dehydrogenation of NaBH₄ has been studied. The ZrCl₄ reduced to ZrCl₂ and metallic zirconium which exhibit the high catalytic activity during thermal dehydrogenation. The activation energy corresponding to dehydrogenation of NaBH₄ is remarkably reduced to 180 kJ/mol in the presence of a catalyst as compared to pure-NaBH₄ which was found to be 275 kJ/mol under the similar experimental conditions. The reduced activation energy leads to decreased onset dehydrogenation temperature (<300 °C). A substantial amount of sodium remained at the end of the dehydrogenation of catalyzed sample. The low-temperature dehydrogenation of catalyzed NaBH₄ could be useful to manage the evaporation of sodium metal.     

Study on the gasification of wastepaper/carbon dioxide catalyzed by molten carbonate salts

This study focuses on waste paper gasification in carbon dioxide atmosphere with molten alkali carbonates including potassium, sodium, lithium carbonate or their intermixtures as catalyst. The molten catalysts is capable of facilitating a desired reaction (C+CO₂→2CO), which was hardly feasible even at a high temperature of 973 K if catalyst absences. It is that the catalysts which provides a gas–liquid interface between carbon and carbon dioxide, replacing original gas–solid, then allows the two reactants contact each other effectively. Further experimental results demonstrate that the intermixture carbonates exhibit strongly enhancement on catalytic activity than any carbonate salts in the form of single. The reaction rate depends on temperature evaluating manners, a rapid heating processes is favorable to the aimed reaction. With respect to recycling of carbon dioxide, the process provides a conversion in 30%.     

A review of cleaning technologies for biomass-derived syngas

Syngas from gasification of carbonaceous feedstocks is used for power production and synthesis of fuels and commodity chemicals. Impurities in gasification feedstocks, especially sulfur, nitrogen, chlorine, and ash, often find their way into syngas and can interfere with downstream applications. Incomplete gasification can also produce undesirable products in the raw syngas in the form of tar and particulate char. This paper reviews the technologies for removing contaminants from raw syngas. These technologies are classified according to the gas temperature exiting the cleanup device: hot (T > 300 °C), cold (T < ∼100 °C), and warm gas cleaning regimes. Cold gas cleanup uses relatively mature techniques that are highly effective although they often generate waste water streams and may suffer from energy inefficiencies. The majority of these techniques are based on using wet scrubbers. Hot gas cleaning technologies are attractive because they avoid cooling and reheating the gas stream. Many of these are still under development given the technical difficulties caused by extreme environments. Warm gas cleaning technologies include traditional particulate removal devices along with new approaches for removing tar and chlorine.     

Optimization of mechanical pre-treatment of Laminariaceae spp. biomass-derived biogas

Macroalgae have not met their full potential to date as biomass for the production of energy. One reason is the high cost associated with the pretreatment which breaks the biomass's crystalline structure and better exposes the fermentable sugars to anaerobes. In the attempt to overcome this technological barrier, the performance of a Hollander beater mechanical pretreatment is assessed in this paper. This pretreatment has been applied to a batch of Laminariaceae biomass and inoculated with sludge from a wastewater treatment plant. The derived biogas and methane yields were used as the responses of a complex system in order to identify the optimal system input variables by using the response surface methodology (RSM). The system's inputs considered are the mechanical pretreatment time (5–15 min range), the machine's chopping gap (76–836 μm) and the mesophilic to thermophilic range of temperatures (30–50 °C). The mechanical pretreatment was carried out with the purpose of enhancing the biodegradability of the macroalgal feedstock by increasing the specific surface area available during the anaerobic co-digestion. The pretreatment effects on the two considered responses are estimated, discussed and optimized using the tools provided by the statistical software Design-Expert v.8. The best biogas yield of treated macroalgae was found at 50 °C after 10 min of treatment, providing 52% extra biogas and 53% extra methane yield when compared to untreated samples at the same temperature conditions. The highest biogas rate achieved by treating the biomass was 685 cc gTS⁻¹, which is 430 cc gTS⁻¹ in terms of CH₄ yield.     

A review of biomass-derived fuel processors for fuel cell systems

Fuel cell coupled with biomass-derived fuel processor can convert renewable energy into a useful form in an environmental-friendly and CO₂-neutral manner. It is considered as one of the most promising energy supply systems in the future. Biomass-derived fuels, such as ethanol, methanol, biodiesel, glycerol, and biogas, can be fed to a fuel processor as a raw fuel for reforming by autothermal reforming, steam reforming, partial oxidation, or other reforming methods. Catalysts play an important role in the fuel processor to convert biomass fuels with high hydrogen selectivity. The processor configuration is another crucial factor determining the application and the performance of a biomass fuel processing system. The newly developed monolithic reactor, micro-reactor, and internal reforming technologies have demonstrated that they are robust in converting a wide range of biomass fuels with high efficiency. This paper provides a review of the biomass-derived fuel processing technologies from various perspectives including the feedstock, reforming mechanisms, catalysts, and processor configurations. The research challenges and future development of biomass fuel processor are also discussed.     

Thermodynamics of water decomposition catalyzed by zeolites

Decomposition of water by thermal cycling of zeolites is shown to be thermodynamically feasible at temperatures of less than 500°C. The effects of temperature and pressure are shown to be comparable at these temperatures, with from 40 to 90 entropy units from each needed to drive the reaction.     

Hydrogen evolution catalyzed by viable and non-viable cells on biocathodes

The presence of microorganisms on cathodes has been shown to enhance the hydrogen evolution reaction (HER), but a requirement for viable cells has not been sufficiently examined. HER was examined using live or killed biocathodes of exoelectrogenic (Geobacter sulfurreducens) and non-exoelectrogenic (Escherichia coli) bacteria, and a hydrogenotrophic methanogen (Methanosarcina barkeri). Electrodes at a set potential of −0.6 V (versus a standard hydrogen electrode) containing G. sulfurreducens biofilms or killed controls produced hydrogen at a similar rates (118 ± 15 nmold⁻¹ mL⁻¹) over 5 months. Electrodes containing cell extracts produced hydrogen at approximately half this rate (56 ± 6 nmold⁻¹ mL⁻¹). Biocathodes fed lactate produced only 14 ± 2 nmol/d-mL. Electrodes inoculated with M. barkeri produced hydrogen at a rate (120 ± 18 nmold⁻¹ mL⁻¹) similar to the G. sulfurreducens, but no methane was recovered after the initial inoculation cycle. Non-exoelectrogenic E. coli cells and extracts produced hydrogen at a slower rate (13 ± 1 and 4 ± 1 nmold⁻¹ mL⁻¹, over 3 cycles). Electrodes exposed to viable cells that were examined after 5 months had increased levels of in nitrogen, sulfur, iron, nickel, cobalt, and peptides (possibly remnants of hydrogenases and other oxidoreductases) relative to uninoculated controls, and no intact cells. These results show that enhanced HER can result from cell debris and that living cells are not required.