流光电晕放电净化粗燃气焦油及粉尘研究进展

研究焦油及粉尘的高效净化方法对推动生物质气化技术的发展具有重要意义。流光电晕放电过程产生的O、H、OH等活性自由基可有效裂解燃气中的焦油类有机物分子,在直流基压上叠加窄脉冲电压则可实现粉尘的荷电及高效气-固分离,是一种较有应用前景的粗燃气净化方法。笔者对流光电晕放电净化粗燃气焦油及粉尘的技术进展进行了综述,分析了该过程的裂解焦油/除尘机理、研究现状及关键科学问题,并提出了一种基于电旋风等离子体反应器的焦油及粉尘同时净化方法。最后针对生物质气化粗燃气净化过程中的瓶颈问题,简要归纳了其研究重点。     

合成气预混火焰的热声振荡

使用天然气、氢气与氮气的合成气作为燃料,在模型燃烧室中对合成气的燃烧稳定性进行实验研究,利用动态压力传感器和ICCD相同步测量技术实现对压力和火焰面的测量.实验中保持氮气体积分数恒定在20%,通过改变天然气与氢气的体积比,对不同当量比和热值下的合成气燃烧稳定性进行研究,并对热声耦合振荡模态及其变化规律进行了分析,得到了合成气燃烧热声耦合的稳定范围,实验中发现,随着氢气体积分数的增加,发生热声耦合振荡的范围逐渐增大,然而振荡强度和天然气燃烧相比有所降低,声压级降低2～3,dB.     

Charged soc metal-organic framework for high-efficacy H2 adsorption and syngas purification: Atomistic simulation study

H₂ adsorption and syngas purification in charged soc metal-organic framework are investigated using atomistic simulations. As experimentally observed, the extraframework NO₃⁻ ions are entrapped in carcerand-like capsule with negligible mobility. At low pressure, H₂ adsorption occurs concurrently at multiple sites near the exposed indium atoms and organic components. The capsule is accessible at high pressure through the surrounding channels by restricted windows. Adsorption sites identified are remarkably consistent with inelastic neutron scattering measurements. The isotherm and isosteric heat of H₂ adsorption predicted match well with experimental data. As loading rises, the isosteric heat remains nearly constant, revealing the homogeneity of adsorption sites. CO₂/H₂ selectivity in syngas adsorption is up to 600 and substantially higher than other nanoporous materials. With a trace of H₂O, the selectivity increases slightly at low pressure due to promoted adsorption of CO₂ by H₂O bound proximally to the exposed indium atoms, but decreases at high pressure as a consequence of competitive adsorption of H₂O over CO₂. © 2009 American Institute of Chemical Engineers AIChE J, 2009     

Chloride Adsorbates Enhance the Photocarrier Separation and Promote the Bio-Syngas Evolution

Photocarrier separation and migration to the surface are vital for photocatalysis. However, the mobility of the surface holes and electrons makes them easily recombine before participating in the surface reaction, which constrains the photocatalytic efficiency. Targeting this problem, herein, it is reported that chloride adsorbates enhance the photocarrier separation and promote the bio-syngas evolution. Chloride, adsorbed on the surface of CdS (CdS-Cl), can increase the internal electric field and enhance the charge separation and migration to the surface. Moreover, compared with pristine CdS where holes are mobile and distributed on all the surface atoms, CdS Cl can reduce the hole mobility via delocalization on specific sites and thus prolong the photocarrier lifetime. This contributes to an 11-fold enhanced photocatalytic syngas evolution from glycerol. This study reports the pivotal effect of surface adsorbates on photocarrier separation and offers a convenient strategy to prohibit surface holes and electrons recombination for solar energy utilization.Chloride absorbates on CdS contribute to enhanced photocatalytic syngas evolution from glycerol by increasing the internal electric field.     

Design of experiments and analysis of dual fluidized bed gasifier for syngas production: Cold flow studies

Biomass gasification is a thermo-chemical process widely accepted as a future technology for syngas production. Numerous types of gasification systems have been proposed and studied in the past. Recent developments have shown that Dual Fluidized Bed (DFB) gasifier are commercially more attractive for production of the hydrogen-rich syngas as compared to others. DFB gasification system is very complex in construction and operation. Hence, a detailed understanding of hydrodynamics in such systems is essential for optimum design and scale-up. Hydrodynamics of DFB gasifier mainly depends on the Solid Circulation Rate (SCR). SCR is governed by riser velocity, gasifier velocity, and loop seal velocities. In present work, Central Composite Rotatable Design (CCRD) based Response Surface Method (RSM) was employed to determine the effect of riser velocity, gasifier velocity, recycle chamber velocity, supply chamber velocity, and vertical supply chamber velocity and their interaction on the SCR. Adequacy of regression model developed from RSM was confirmed using ANOVA analysis. The value of coefficient of determination (R²) of the model was 0.9729, which confirms model represents the experimental results satisfactorily. Riser and recycle chamber velocity were found to be most significant parameters, plays an important role in SCR in DFB gasifier.     

典型水煤浆制气装置大检修及开车情况介绍 隋兴彬

中国石化齐鲁分公司煤制气装置在2013年春季进行了首次全面大检修,介绍检修的主要项目．检修过程发现和解决问题对策,通过精心准备操作,实现了“事故为零、排放为零、开车1次成功”的检修目标。     

Management of waste lubricant oil (WLO): WLO-to-energy through gasification process

Possibility of synthesis gas (syngas) production from waste lubricant oil (WLO) through gasification process has been investigated. The objective of this work is to develop a comprehensive model to simulate WLO gasification using Aspen Plus simulator. The model was based on Gibbs free energy minimization and validated against the published data. Increase in ER results in CO, H₂, and CH₄ reduction and CO₂ enhancement due to partial oxidation of H₂ and CO. Since the standard chemical exergy and lower caloric value of H₂ is lower than that of CO and both of values are not considerable for CO₂, with increasing SFR (steam-to-fuel ratio) from 0.25 to 1.25, EE (exergy efficiency) and GE (gasification efficiency) were decreased.     

Effect of PH3 poisoning on a Ni-YSZ anode-supported solid oxide fuel cell under various operating conditions

The Ni-YSZ anode-supported solid oxide fuel cell (SOFC) can generate electrical power by using coal-derived syngas as the fuel. However, trace contamination of phosphine (PH₃) in the syngas can cause irreversible degradation in cell performance. A series of tests at 10 ppm PH₃ in the fuel gas was carried out under a variety of operating conditions, viz, with/without electrochemical reaction in syngas and with/without H₂O in H₂ fuel at 750 °C, 800 °C and 850 °C. The poisoning effects were evaluated by both electrochemical methods and chemical analyses. The post-mortem analyses of the SOFC anode were performed by means of XRD, SEM/EDS, and XPS. The results show that the degradation rate is larger at the higher cell working temperature using syngas with PH₃ in a 200 h test though PH₃ is more reactive with Ni in the anode at lower working temperature and produces a secondary nickel phosphide (Ni_xP_y) phase. The dominant compositions of Ni_xP_y on the cell anode are Ni₅P₂ with the presence of H₂O, and Ni₁₂P₅ without the presence of H₂O. The production of Ni_xP_y can be generated on the cell anode using syngas or dry H₂ fuel with 10 ppm PH₃ contaminant. Further, the appearance of Ni_xP_y phases is independent of the electrochemical reactions in the cell.     

Effect of H2S on the performance of La0.7Ce0.2FeO3 perovskite catalyst for high temperature water–gas shift reaction

The effect of H₂S on the performance of La_0.7Ce_0.2FeO₃ perovskite catalyst was investigated for the production of hydrogen from simulated coal-derived syngas via the water–gas shift reaction at 600 °C and 1 atm. The results show that the catalyst activity decreases with increasing concentrations of H₂S up to 1100 ppm, but the negative effect of H₂S on its activity is reversible. However, even at the high H₂S concentrations catalyst activity is still greater than that measured with sour shift catalyst. Overall, the results indicate that La_0.7Ce_0.2FeO₃ perovskite catalyst has a high degree of H₂S tolerance, particularly in the low H₂S concentration regime.