Investigation of mass transport and cell performance on μDMFC with different anode flow fields

The study systematically analyzes the performance of micro direct methanol fuel cell (μDMFC) with different flow fields. A two‐phase three‐dimensional model is developed to evaluate the mass transport accurately. The transport of methanol and air, the pressure distribution, the anode saturation, and the methanol crossover are numerically observed, the under‐rib convection is also investigated numerically. The flow fields with an active area of 0.64 cm² are fabricated on silicon wafers by micro electromechanical system technology. Performance of μDMFCs with different flow fields is sorted as: double‐serpentine flow field (DSFF) > single‐serpentine flow field (SSFF) > triple‐serpentine flow field (TSFF), and the dynamic test results indicate the cell with DSFF takes the shortest time to reach a stable power output when compared with other cells. Copyright © 2013 John Wiley & Sons, Ltd.     

Bio-oil extraction and physicochemical characterization of Caesalpinia pulcherrima plant seed oil

Dwarf Poinciana (Caesalpinia pulcherrima) seeds are studied for first time for the extraction of bio-oil. The dried and crushed seeds are optimized for maximum yield of bio-oil with a series of polar and nonpolar solvents and recovered by a simple distillation process. Methanol is found to yield the maximum bio-oil. The fatty acid analysis of bio-oil reveals the prevalence of linoleic acid (54.67%), followed by palmitic acid (16.9%), stearic acid (12.5%), and oleic acid (10.32%). Basic fuel properties like specific gravity, viscosity, refractive index, iodine value, saponification value, fire point, flash point, pour point, and calorific value are studied.     

Steam reforming of methanol over ruthenium impregnated ceria,alumina and ceria–alumina catalysts

The wet impregnation method was used to prepare different ruthenium promoted Ce–Al catalysts. These catalysts were used in the steam reforming of methanol reaction (SRM). The effects of the reaction temperature (200–400 C) and the catalyst composition were studied for optimization reasons. The steam to methanol molar ratio was kept constant (S/M = 2). The promotion of cerium/aluminum oxides with Ru enhanced their catalytic activity. The catalytic test results showed that the Ru/Ce combination was the most beneficial. The synergy between Ru and cerium oxide led to the formation of active sites with excellent redox properties. For high active phase content, the 5 RuCe catalyst exhibited the highest hydrogen production amount with no CO formation. This catalyst was kept under stream for 5 days at 400 C, and no significant deactivation was observed. Copyright © 2016 John Wiley & Sons, Ltd.     

原料中的NH_3含量对甲醇制丙烯催化剂性能的影响

在连续流动固定床微型反应器中,对甲醇制丙烯的ZSM-5分子筛催化剂的性能进行了评价,并采用XRD、吡啶吸附-FTIR和TG等方法对反应后的催化剂进行了表征,考察了原料中的NH3含量对催化剂性能的影响,同时考察了NH3含量与催化剂寿命和甲醇转化率的关系。实验结果表明,在催化剂装填量10 g、常压、480℃、甲醇重时空速1.0 h-1、水与甲醇的质量比0.69的反应条件下,NH3的存在对ZSM-5分子筛催化剂的晶型结构没有影响,但对酸性影响较大;随NH3含量的增加,尤其是当NH3含量大于0.010%(w)时,催化剂的积碳量显著降低,催化剂的寿命大幅缩短。     

Low cost compact onsite hydrogen generation

High cost and lack of convenient supply infrastructure for hydrogen is believed to the major hurdle to the commercialization of hydrogen energy. Low cost compact onsite hydrogen generator is developed to produce three purity levels of hydrogen for use with high temperature polymer electrolyte membrane (HTPEM) or low temperature polymer electrolyte membrane (LTPEM) fuel cell. The small modular reformer has process efficient higher or equal to large scale central production plant without the penalty of expensive distribution cost. The cost of hydrogen from primary reformate hydrogen to high purity hydrogen ranges from $3.16/kg to $5.84/kg and the corresponding power cost from FC system is $0.352 to $0.408/KWh. The hydrogen costs are much lower than one can obtain from an industrial gas company with central supply system and expensive cost in distribution. These direct power costs without depreciation cost are comparable or lower than the comparable size of diesel power cost.     

Conceptual design and statistical overview on the design of a passive DMFC single cell

A conceptual design and statistical overview about passive direct methanol fuel cells that have been fabricated from 2002 to 2013, is performed [1–70]. The major components of passive DMFCs such as: active area, type of Nafion, catalyst loading on the anode and cathode side, characteristics and designs of current collectors (CC), and also the optimum methanol concentration which resulted in the best performance are categorized and studied statistically and individually. Finally, the best combination for the design and fabrication of a reliable passive DMFC is recommended. Obtained results indicated that a MEA with 4 cm² active area, Nafion 117 and 4 mg/cm² Pt/Ru at the anode and 2 mg/cm² Pt black at the cathode (or 4 mg/cm² Pt/Ru at the anode – 4 mg/cm² Pt black at the cathode) as the catalyst loading, which is sandwiched between two stainless steel perforated current collectors that are coated by Pt (or Gold) could be a reliable design for a passive direct methanol single cell.     

Preparation and characterization of directional conducting and lower methanol permeable ultrathin membrane based on poly (vinyl alcohol) and imidazolium compounds

To produce directional conducting and lower methanol permeable ultrathin membrane for fuel cell, the imidazolium salt as both cross-linking agent and proton donor has been designed to build a directional proton conducting channel in a poly (vinyl alcohol)-based membrane. The methanol permeability of directional conducting membrane is very low, which is about twice smaller than that of Nafion₁₁₇. In addition, the membranes show a relatively high oxidative durability in H₂O₂ solutions, with only about 10% weight loss after the membrane being immersed in 3% H₂O₂ solution for 120 h. All the properties of prepared directional conducting membrane indicate their promising prospects in proton conducting membrane applications.     

新型合成气脱除羰基铁净化剂RA-201性能评价

研究了净化剂RA-201脱除合成气羰基铁的性能。结果显示,RA-201净化剂具有铁容量大(～20%)、不易发生副反应、稳定性好等优点。该净化剂能满足甲醇工业等的生产要求。     

百万吨甲醇三塔精馏的自动化控制

大唐内蒙古多伦煤化工年产168万t甲醇(46万t聚丙烯)是目前国内已投产的单套最大生产能力的装置。2011年6月21日15时58分大唐内蒙古多伦煤化工年产168万t甲醇合成装置投料开车成功产出粗甲醇,三塔甲醇精馏装置于2011年6月30日15时16分产出合格精甲醇产品,产品品质达到了GB338-2004优等品指标。经过生产操作实际情况,对百万吨甲醇三塔精馏的自动化控制应用进行了总结,为现代大型煤化工的自动化控制提供操作经验。