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1.
进行高含氮木质废弃物的加压气化试验,研究反应压强对于气化的影响。结果表明:在高压热重上,高压可抑制挥发分析出,提高700℃以上气化反应速度,使气化结束温度从1104降至1076℃;在加压气流床装置上,增大压强可明显提高合成气的品质,CO与H2浓度明显增大,气化碳转化率、产气率与低位热值均有提高;随着压强的增大,高含氮木质废弃物气化产气中HCN与NH3浓度出现下降趋势,从4606和2405 mg/m3分别降至393和622 mg/m3。  相似文献   

2.
桂莹 《可再生能源》2023,(4):434-441
为促进氨氢可再生能源发展,文章基于高阶离散格式、详细动力学模型对NH3及NH3/H2/N2燃料的自燃过程进行了直接数值模拟研究,获得了NH3部分裂解对均质、非预混条件下燃料着火延迟时间、关键反应路径、自燃火焰结构、火焰位移速度等动力学特性的作用机制。研究结果表明:NH3预裂解可有效降低均质及非预混条件下的着火延迟时间,且在低温工况中尤为明显;在NH3自燃过程中,NH3+OH<=>H2O+NH2是NH3消耗主导反应;在NH3/H2/N2自燃过程中,H-O反应体系的增强使得NH3+O<=>NH2+OH成为额外的NH3消耗路径,H+NH3<=>H2  相似文献   

3.
以杉木屑为原料,CO2为气化剂,熔融碳酸盐Li2CO3-Na2CO3-K2CO3(LNK)为热介质和催化剂进行气化制合成气(H2+CO)的研究,考察气化剂CO2流量、CO2通入方式、复合熔盐体系中添加的金属氧化物种类和Cr2O3含量等因素对气体产物组成分布及产率的影响。结果表明:CO2流量显著影响气化反应的平衡;以鼓泡法通入CO2时生物质的气化效果优于吹扫法的情况,CO2流量为99.8 L/h时气化效果较好,合成气含量和产率分别达到61.4%和350.2 mL/g生物质;添加的金属氧化物中Cr2O3对生物质气化过程的促进作用优于MgO和Fe2O3,随着Cr2O3含量的增大,合成气含量先增大后略微减小,在Cr2O3含量为10.0%时最高,为67.9%。  相似文献   

4.
提高糖蜜酒精废水的厌氧发酵效率,实现其资源化再利用,本文研究了添加一定量Fe2+ 对糖蜜酒精废水厌氧发酵处理过程的影响。结果表明:添加Fe2+后发酵液中SO42− 的去除率由77.12%提高至90.79%;COD去除率由57.34%提高至81.14%;累积沼气产量由386 mL•g−1 VS提高至475 mL•g−1 VS;产气周期由29天缩短为26天;其氧化还原电位(ORP)升高,pH值降低。  相似文献   

5.
基于吉布斯自由能最小化原理,采用HSC Chemistry 6.0软件,对污泥化学链气化过程中NOx前驱物(NH3和HCN)与Fe2O3载氧体的氧化还原行为进行了热力学模拟。基于污泥热解实验中NOx前驱物的含量,计算载氧体与污泥的摩尔比(OC/SS)对NH3、HCN以及NH3和HCN混合气氧化过程的影响。热力学模拟结果表明:Fe2O3能显著促进NOx前驱物的氧化和裂解,主要生成N2,几乎无NOx生成;当NH3、HCN以及混合气(NH3和HCN)分别作为还原剂时,其最优OC/SS分别为0.02、0.04和0.05;由于HCN还原性强于NH3,其氧化速率较快。基于Fe2O3/Al2O3混合物(FeAl)载氧体,实验对比了污泥化学链气化与污泥热解过程中NOx前驱物的释放特性,发现Fe2O3能显著降低烟气中NOx前驱物的产率,NH3和HCN产率分别下降32%和62%。实验结果与热力学模拟结果一致。  相似文献   

6.
以小麦秆与印尼褐煤为原料,制备具有尖晶石结构的CuFe2O4复合氧载体,在自制多功能反应器上,系统研究了CuFe2O4氧载体反应活性及小麦秆和印尼褐煤化学链共气化特性,重点关注小麦秆和煤不同掺混比、气化温度、氧载体过量系数和水蒸气输入量这4个关键运行参数的影响。结果表明:CuFe2O4复合氧载体中Cu-Fe的协同作用有助于晶格氧的有效传递和反应活性的提升,而小麦秆和印尼褐煤化学链共气化时碳转化率及冷煤气效率比单一燃料的大,促进了高品质合成气的形成;小麦秆和褐煤在与CuFe2O4化学链气化过程中的最优运行参数为共气化温度950℃、氧载体过量系数0.2、水蒸气通入体积流量0.125 mL/min、小麦秆-印尼褐煤掺混质量比1∶1,在此最优条件下,合成气产量高达1.262 m3/kg, H2与CO体积比为1.69,碳转化率为89.7%,合成气选择性为63.2%。  相似文献   

7.
本文提出以Fe2O3为载氧体、以CaO捕集CO2的生物质化学链气化系统,利用Aspen Plus软件对该系统进行了模拟,以合成气组成(干基)、合成气氢碳比、含碳产物的碳摩尔分布、冷气效率及收率等为系统性能评价指标,重点分析了燃料反应器温度(TFR)、载氧体Fe2O3与生物质碳摩尔比(Fe2O3/C)、水蒸气与生物质碳摩尔比(Steam/C)、CaO与生物质碳摩尔比(CaO/C)等系统参数对固体生物质化学链气化系统的影响。结果表明,在TFR = 825℃、Fe2O3/C = 0.5、Steam/C = 0.71和CaO/C = 0.26条件下,合成气制备系统性能较优,合成气中H2和CO2含量分别为55.2%和15.4%,氢碳比为1.93,冷气效率为78.2%,被CaCO3捕集的生物质碳为18.2%,收率(湿气基)为1.95 Nm3/kgbiomass,其中合成气中H2和CO收率为1.24 Nm3/kgbiomass。  相似文献   

8.
生物质气化技术已得到广泛的应用,但气化过程产生的焦油会影响设备稳定运行。为了大幅减少焦油的干扰,以梨木的热解炭为原料,在管式炉中进行水蒸气气化制取富氢燃气试验研究,探究了反应温度、K2CO3添加量及利用次数对气化特性的影响。结果表明:900℃时H2的产气量为2.19 L/g,合成气中H2含量超过58%;K2CO3添加量为10%时产气效果最佳,此时合成气中H2+CO含量达到了88.5%。当K2CO3催化剂在第三次利用时,仍有较好的催化效果。  相似文献   

9.
搭建生物质与废塑料共气化动力学模型,并用实验数据对其进行验证。选用6种生物质和聚丙烯作为共气化反应物,以水蒸气为气化剂,计算气化温度在300~1000℃之间、气化压强在0.1~0.8 MPa之间、聚丙烯和松木锯末质量比例在0.5~2.5之间,以及不同生物质类型等对生物质和聚丙烯共气化产气特性的影响。结果表明:松木锯末气化中添加聚丙烯后,最高产气量和最大产气速率增加,最高产气总流量提高21.46%,最高产气速率提高4.64%,H2和CO最高产量分别提高54.27%和79.51%;压强增加不利于提高共气化产气的H2和CO含量,有利于提高CH4含量;6种常见生物质和聚丙烯共气化产氢量大小顺序为:果皮>棉花秆≈玉米秸秆>杨树木屑>稻秆>条浒苔;聚丙烯掺混比率增加有利于提高H2、CO和CH4等组分产量。  相似文献   

10.
以聚环氧乙烷(PEO)为黏结剂,离子导电性的Li1.5Al0.5Ge1.5(PO4)3(LAGP)为主相,乙腈为溶剂,按照EO/Li,摩尔比为13,变化LiN(CF3SO2)2(LiTFSI)中Li+ 与LAGP中Li+ 的比例,通过溶液浇注法制备得到LAGP-PEO(LiTFSI)固体复合电解质。用X射线衍射、扫描电镜(SEM)和电化学阻抗(EIS)等方法对固体复合电解质的形貌、结构和电导率进行表征。结果表明,LAGP可与PEO(LiTFSI)部分络合并均匀分散于PEO(LITFSI)内,整个体系内存有三个主体相,即PEO(LiTFSI)的复合相、LAGP晶相以及PEO与两种锂盐的过渡相。通过阻抗谱图发现,当质量比w(LAGP)∶w(PEO)=6∶4时,LAGP-PEO(LiTFSI) 固体复合电解质具有最高的室温电导率,为2.68×10-5 S/cm,在333 K时,达到1.86×10-4 S/cm,接近LAGP的电导率水平。这说明固体复合电解质中加入LAGP即降低了PEO的结晶度,LAGP自身的电导率也有一定贡献。  相似文献   

11.
Sweet sorghum (Sorghum bicolor (L.) Moench) has been recognized as an alternative crop for energy purposes. In the central area of the Iberian Peninsula, its main growth period coincides with the dry season and irrigation is needed for reasonable sorghum productivity. Knowledge of irrigation-yield relationships is fundamental, since water is a scarce resource there. Our objectives in this work were to study the effect of water regime on the productivity and water use efficiency (WUE) in a sweet sorghum cultivar “Keller” grown in lysimeters in Madrid. Experiments were carried out during three crop cycles. Three irrigation regimes: H1, H2 and H3, corresponding to a water supply of 5.7, 11.4 and 17.1 dm3 m−2 day−1 were experimented with during the main growth period. Maximum aerial biomass production was 4.0 103g DM m−2 in the H3 regime. WUE was quite similar for every irrigation regime but varied between sorghum seasons. 4.6 g aerial biomass DM dm−3 was obtained as the average for a crop cycle length of approximately 130 days. The water regime did not clearly affect the sugar content in stalk sections. The mean value of sugar content in whole stalks was 41.4% w/w on a dry-weight basis. The ratio of ethanol production to evapotranspired crop water was estimated at 0.63 g dm−3 (mean value).  相似文献   

12.
二株假单胞菌降解生物质气化洗焦废水COD的特性研究   总被引:1,自引:0,他引:1  
为了使生物质气化中产生的洗焦废水得到循-环使用,首先用木屑、活性炭过滤预处理,滤液用菌种Pseudomonas SP1和Pseudomonas SP2进行进一步好氧降解。结果表明,COD浓度小于1800mg/L,采用两种菌降解颗粒活性炭过滤后的洗焦废水,均达到了理想的降解效果。SP1和SP2的COD去除率分别为73.2%和82.9%,SP2的降解效果明显好于SP1。当SP1和SP2等量混合降解颗粒活性炭过滤后的洗焦废水时,COD去除率达到98.1%。然后用生物膜反应器处理未经过滤预处理的生物质气化洗焦废水,经挂膜和增菌后,反应器可得到稳定和高效的运转,进水浓度1800mg/L,水滞留期保持在36h,洗焦废水的COD去除率为89%,苯、萘、酚、蒽、喹啉和异喹啉的去除率达到了理想的效果。  相似文献   

13.
利用Aspen Plus 软件建立干桦木屑在下吸式固定床气化炉中的气化模型,模拟值与文献实验值吻合良好。利用Aspen Plus的灵敏度分析模块模拟分别以水蒸气(H2O)和二氧化碳(CO2)为气化剂时气化剂/生物质碳比(GC值)对气化结果的影响,并结合H2O、CO2各自的特点研究其复合气化。结果表明,H2O气化时可获得富氢煤气,但其净CO2排放量较高;CO2气化时碳转化率及冷煤气效率较低,但净CO2排放量较低;H2O、CO2复合气化使碳转化率及冷煤气效率略有降低,但可有效减少气化系统中的净CO2排放量。  相似文献   

14.
In recent years, Fe-N-C catalyst is particularly attractive due to its high oxygen reduction reaction (ORR) activity and low cost for proton exchange membrane fuel cells (PEMFCs). However, the durability problems still pose challenge to the application of Fe-N-C catalyst. Although considerable work has been done to investigate the degradation mechanisms of Fe-N-C catalyst, most of them are simply focused on the active-site decay, the carbon oxidation, and the demetalation problems. In fact, the 2e pathway in the ORR process of Fe-N-C catalyst would result in the formation of H2O2, which is proved to be a key degradation source. In this paper, a new insight into the effect of potential on degradation of Fe-N-C catalyst was provided by quantifying the H2O2 intermediate. In this case, stability tests were conducted by the potential-static method in O2 saturated 0.1 mol/L HClO4. During the tests, H2O2 was quantified by rotating ring disk electrode (RRDE). The results show that compared with the loading voltage of 0.4 V, 0.8 V, and 1.0 V, the catalysts being kept at 0.6 V exhibit a highest H2O2 yield. It is found that it is the combined effect of electrochemical oxidation and chemical oxidation (by aggressive radicals like H2O2/radicals) that triggered the highest H2O2 release rate, with the latter as the major cause.  相似文献   

15.
This study examines the effect of hydrogen peroxide (H2O2) on the open-circuit voltage (OCV) of a proton exchange membrane fuel cell (PEMFC) and the reduction of H2O2 in the membrane using a ruthenium/carbon catalyst (Ru/C) at the anode. Each cathode and anode potential of the PEMFC in the presence of H2O2 is examined by constructing a half-cell using 1.0 M H2SO4 solution as an electrolyte and Ag/AgCl as the reference electrode. H2O2 is added to the H2SO4 solution and the half-cell potential is measured at each H2O2 concentration. The cathode potential is affected by the H2O2 concentration while the anode potential remains stable. A Ru catalyst is used to reduce the level of H2O2 formation through O2 cross-over at the interface of a membrane and the anode. The Ru catalyst is known to produce less H2O2 through oxygen reduction at the anode of PEMFC than a Pt catalyst. A Ru/C layer is placed between the Nafion® 112 membrane and anode catalyst layer and the cell voltage under open-circuit condition is measured. A single cell is constructed to compare the OCV of the Pt/C only anode with that of the Ru/C-layered anode. The level of hydrogen cross-over and the OCV are determined after operation at a current density of 1 A cm−2 for 10 h and stabilization at open-circuit for 1 h to obtain an equilibrium state in the cell. Although there is an increase in the OCV of the cell with the Ru/C layer at the anode, excessive addition of Ru/C has an adverse effect on cell performance.  相似文献   

16.
In this paper, the optimization of hydrogen (H2) production by ammonia borane (NH3BH3) over PdCoAg/AC was investigated using the response surface methodology. Besides, the electro-oxidation of NH3BH3 was determined and optimized using the same method to measure its potential use in the direct ammonium boran fuel cells. Moreover, the ternary alloyed catalyst was synthesized using the chemical reduction method. The synergistic effect between Pd, Co and Ag plays an important role in enhancement of NH3BH3 hydrolysis. In addition, the support effect could also efficiently improve the catalytic performance. Furthermore, the effects of NH3BH3 concentration (0.1–50 mmol/5 mL), catalyst amount (1–30 mg) and temperature (20°C–50°C) on the rate of H2 production and the effects of temperature (20°C–50°C), NH3BH3 concentration (0.05–1 mol/L) and catalyst amount (0.5–5 µL) on the electro-oxidation reaction of NH3BH3 were investigated using the central composite design experimental design. The implementation of the response surface methodology resulted in the formulation of four models out of which the quadratic model was adjudged to efficiently appropriate the experimental data. A further statistical analysis of the quadratic model demonstrated the significance of the model with a p-value far less than 0.05 for each model and coefficient of determination (R2) of 0.85 and 0.95 for H2 production rate and NH3BH3 electrroxidation peak current, respectively.  相似文献   

17.
Using variable temperature in situ 1H NMR spectroscopy on a mixture of LiNH2 + LiH that was mechanically activated using high-energy ball milling, the dehydrogenation of the LiNH2 + LiH to Li2NH + H2 was investigated. The analysis indicates NH3 release at a temperature as low as 30 °C and rapid reaction between NH3 and LiH at 150 °C. The transition from NH3 release to H2 appearance accompanied by disappearance of NH3 confirms unambiguously the two-step elementary reaction pathway proposed by other workers.  相似文献   

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