International Journal of Global Warming (9 papers in press)

• The conversion of acetol during concentrating process from wood vinegar
  by Ze Wang, Weigang Lin, Wenli Song, Jianzhong Yao 
  Abstract: With declining petroleum resources and more environmental concerns, biomass was laid a great deal of attention for bio-fuel and chemicals these years. Acetol, as one of the component in biomass pyrolysis liquid, is a high value added compound for medicine synthesis. If acetol can be extracted from the renewable pyrolysis liquid, much environmental and economical benefit may be obtained, while the instability of acetol makes the concentrating difficult. To clarify what compounds were formed from acetol during distillation process, the components in different distillation systems were analyzed and the mechanisms of the conversions were speculated. It was found that acetol may undergo aldol self-condensation reactions and followed by a series of intromolecular dehydrations to form five-ring or six-ring compounds. The major five-ring compound may be 2-hydroxy-3-methyl-2-cyclopenten-1-one or 3-methyl-1,2-cyclopentanedione. The six-ring compound is deduced as 5-methyl-6H-pyran-3-one by IR spectrum, calculated heat of formation, and mass spectrum analysis. The compound of 2,5-hexanedione may also be formed from acetol by homolytic cleavage and following recombination processes.
  Keywords: Wood vinegar; Pyrolysis oil; Acetol; Concentrating; Conversion; Mechanism
   
• MATHEMATICAL MODELING OF BIOMETHANE PRODUCTION AND GROWTH OF METHANOGENIC BACTERIA IN BATCH REACTOR SYSTEM FED WITH ORGANIC MUNICIPAL SOLID WASTE
  by Liliana Alzate, Antonino Pérez, Hector Poggi, PJ Sebastian 
  Abstract: A mathematical model was developed and validated for an anaerobic digestion system of the organic fraction of municipal solid waste by using a lab-scale system of two packed bed reactors. The equations for the model were obtained by the mass balances of methanogenic bacteria in the transitory state of the affluent and effluent lixiviated currents as well as the interior characteristics of the leachate of the organic fraction of municipal waste in each packed reactor. The methane production rate was obtained by multiplying methanogenic activity by methanogenic biomass. A differential equation was fitted with experimental results in order to obtain the parameters of the equation which best describe methanogenic behavior in the reactors. These kinetic parameters were used with the modified logistic equation with the special case n=1. The results obtained by the model corresponded well to the experimental results.
  Keywords: Mathematical model, anaerobic digestion, solid waste, packed bed reactor, coupled systems.
   
• Influence of precursor on the catalytic activity of alumina for bioethanol dehydration in microchannel reactors
  by Xilian Ouyang, Shulian Li, Jun Yue, Fengjun Jiao, Guangwen Chen 
  Abstract: Alumina has been widely employed as a catalyst or a catalyst support. In this paper, the effect of precursor on the catalytic activity of alumina for ethanol dehydration in a microchannel reactor was studied. Five catalysts were prepared by using precursors with different ratios of AlOOH (pesudo boehmite) and Al(OH)3 (bayerite). The physicochemical properties of the catalysts were characterized by X-ray diffraction and Temperature Programmed Desorption. The influence of reaction parameters, such as reaction temperature and space velocity, has been investigated experimentally. The results show that the catalyst prepared from precursor with AlOOH 46.3 mol% has the highest ethanol conversion of 98.69 % and ethylene selectivity of 96.97 %. Ethylene yield of 18.28 g/(gcath) can be achieved, implying that the ethanol catalytic dehydration process can be intensified using microchannel reactor.
  Keywords: activated alumina; pseudo boehmite; bayerite; bioethanol dehydration; microchannel reactor
   
• Effects of Some Micro-Level Exergetic Parameters of a PEMFC on the Environment and Sustainability
  by Adnan Midilli 
  Abstract: This paper deals with the effects of some micro-level exergetic parameters of a (Polymer Electrolyte Membrane Fuel Cell) PEMFC on macro-level environmental pollution and sustainability. For this pupose, exergetic, environmental and sustainability parameters of a PEMFC is investigated based upon its operating and technical aspects. In order to ensure the exergetic sustainability in terms of PEMFC use in residential and industrial applications, the cell should have higher exergetic efficiency, lower exergetic destruction ratio, lower environmental impact coefficient, higher environmental benign coefficient and higher exergetic sustainability ratio. Consequently, it will be quite important to take into consideration these indicators in developing energy and environmental policies for the residential and industrial applications using PEMFC power systems. Such parameters are expected to help to understand the linkage between micro fuel cell parameters and global aspects in terms of environmental impact and sustainable development and hence make PEMFCs more efficient, more environmentally benign and more sustainable. In this regard, the parameters developed here will serve as key indicators for the energy policy makers dealing with new exergetic dimensions of the environment and sustainability.
  Keywords: Exergy; environment; pollution; sustainability; PEM fuel cell.
   
• Statistical evaluation of the early-stage development of jatropha energy plantations in Northeastern Mexico
  by Alejandra Gallo, Rocio Gosch, Javier Amezcua, Eleazar Reyes, Oliver Probst 
  Abstract: A systematic evaluation of agricultural factors affecting the adaptation of the tropical oil plant Jatropha curcas L. to the semi-arid subtropical climate in Northeastern Mexico has been conducted. Six test arrays have been established using different plant density and topology, the effect of which on plant growth and fruit development has been evaluated. Common plagues such as fungi and plant viruses have been detected at the test plot, with one fungus showing a generalized presence at all test arrays. A multiple regression analysis shows that total fruit production can be well predicted by the area per plant and the total presence of fungi. Four herbicides have been evaluated and compared to the action of plastic foil used to block weeds from sunlight. One of herbicides was found to completely impair the development of the jatropha plant, while the herbicide of choice allows for an unaffected plant growth.
  Keywords: Jatropha curcas, Statistical evaluation, Energy plantation, Biodiesel
   
• Gas Permeation Properties of 6FDA-2,4-DAT/mPDA Copolyimides
  by Lina Wang, Yiming Cao 
  Abstract: A series novel fluorinated copolyimides were synthesized with various diamine compositions by chemical imidization in a two-pot procedure. The gas permeation behavior of 2,2’-bis(3,4’-dicarboxyphenyl) hexafluoropropane dianhydride(6FDA)- 2,4-diamine toluene(DAT) /1,3-phenylenediamine(mPDA) polyimides was investigated. The gas permeabilities coefficients decreased with increasing mPDA content; however, the permselectivity of gas pairs such as H2/N2, O2/N2 and CO2/CH4 was enhanced with the incorporation of mPDA moiety. The permeability coefficients of H2, O2, N2, CO2 and CH4 were found to decrease with the increasing order of kinetic diameters of the penetrants gases. Moreover, all of the copolyimides studied in this work exhibited performance near, lying on or above the existing upper bound trade-off line between permselectivity and permeability.
  Keywords: 6FDA ; copolyimide; permeability; gas separation
   
• Water disinfection by solar radiation in a green house effect device
  by Edgar Valenzuela, Peggy Alvarez, Delfeena Eapen, Diana Brito, Karla Camas, Gabriel Diaz, Karla Diaz, Francisco Espinosa, Carlos Vazquez 
  Abstract: The water-borne diseases are major concerns in developing countries since they are the main cause of sickness and death among the population in rural communities. The traditional methods such as chlorination and the use of wood fire to boil water have been rejected by population; as a consequence, most of the people who live in marginalized communities consumes water that has not been disinfected, leading to a high incidence of diseases such as dysentery and gastroenteritis. Considering that the pasteurization of water can be achieved at 65°C, the solar water heaters are considered as an effective, low cost and sustainable solution for water disinfection in rural areas. In this work, a solar water heater of greenhouse effect was built and characterized. Once the contamination of the water sources by coliform bacteria was confirmed, the samples were treated in the solar device and then analyzed to validate the complete elimination of pathogenic microorganisms.
  Keywords: Greenhouse water heater; Water pasteurization; Coliform bacteria.
   
• Multitemporal Monitoring of Water Resources Degradation at Al-Azraq Oasis, Jordan Using Remote Sensing and GIS Techniques
  by Mohammed Matouq, Monzer Krishan 
  Abstract: In this study, the historical topographic maps and satellite images of Al-Azraq Oasis of Jordan were collected from1953 to 2005. These images of the Oasis Lake are demonstrated for the first time. The calculated water surface area gave a clear procedure of environmental degradation at this Oasis which is due to water abstraction. The satellite land image for 2005 is considered to be the most significant one. It has been noticed that the water surface area for the Lake has declined to a level of accumulative declination 80.9%. This is considered to be the highest level of degradation since 1953. The results reveal that the degradation was mainly due to water abstraction for drinking purposes and irrigation of the newly established farms which were established after 1980 close to the Oasis The water degradation in the lake was fitted by linear regression and the best fitting for the calculated surface area for the water from GIS can be presented by a second order polynomial equation.
  Keywords: Al-Azraq Oasis, Jordan, GIS, remote sensing, water resources management, environmental hydrology, arid zones, global warming
   
• Environmental Change and Migration in Sub-Saharan Africa
  by Ulrike Grote, Koko Warner 
  Abstract: Environmental changes are especially pronounced in Sub-Saharan Africa (SSA). At the same time, SSA accounts for a large number of migrants. This paper analyzes the links between environmental change and migration in SSA. It provides latest figures and information related to environmental changes and migration flows; and refers to evidence from different branches of the literature - environmental sciences, migration research as well as development economics. The results show that migration is a complex process but with environmental factors playing an increasingly important role in driving migration in SSA. A focus on the four countries Ghana, Mozambique, Niger, and Senegal offers some evidence on the links from different regions in SSA.
  Keywords: Sub-Saharan Africa, migration, environmental degradation, natural disasters, vulnerability