The environmental performance of hydrogen production by steam-based gasification processes for fuel cell (FC) applications was evaluated using a Life Cycle Assessment (LCA) approach because the use of metal oxides as adsorbents or catalysts has a significant impact on the LCAs of FC applications. In this paper investigating systems for the removal of impurities from syngas, the process design of a Bio-H2 system was discussed in terms of the eco-burden of the impurity adsorbent. The HAS-Clay (a synthetic substance composed of hydroxyl aluminum silicate and clay) has particular potential as an adsorbent. This composite adsorbent can sequester H2S and/or HCl, though it is generally used in desiccant heat pumps to adsorb CO2 and H2O. By comparing two different removal systems, the role of HAS-Clay as an adsorbent was investigated via the eco-indexes of global warming potential (GWP) and abiotic depletion potential (ADP). Consequently, it was found that HAS-Clay had a direct or indirect capture capacity of H2S and HCl as well as CO2 and H2O. Compared to the conventional case in which a metal oxide is used as an adsorbent, a greater environmental benefit was obtained in the case of H2S removal. In this case, the GWPs of the two-step pressure swing adsorption (2-step PSA) +ZnO or Fe2O3 were 3.18 and 1.43 g-CO2/Nm3-Bio-H2 respectively compared to 19.4 g-CO2/Nm3-Bio-H2 for the conventional system. Furthermore, the ADPs of 2-step PSA+ZnO or Fe2O3 were 7.63×10-6 and 3.42×10-6 g-Sb eq./Nm3-Bio-H2, as opposed to 2.75×10-2 g-Sb eq./Nm3-Bio-H2 for the conventional system. On the other hand, in the case of HCl removal, a blend of HAS-Clay and CaCO3 cannot obtain any environmental benefit without either the regeneration of HAS-Clay or the substitution of clay (a natural resource). Our results may imply that HAS-Clay is an extremely important adsorbent in term of reducing the eco-burden.
A lignin solution in methanol was treated with in-liquid plasma at 27.12 MHz radio frequency to produce H2 and aromatic monomers. Gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS) analyses were performed to characterize the produced gases and degradation products contained in the solution. GC analysis identified H2, CO, CH4, C2H2, CO2, and C2H4 in the sample. GC-MS analysis identified several products, including benzene, toluene, and phenol. The quantity of each of these products was determined. These results indicated that the bonds around the benzene ring were broken in the plasma and reacted with OH radicals and CH3 radicals from methanol.
Biomethane could be upgraded from biogas to increase its heating value, avoid corrosion and eliminate toxicity. The simplest and most common technique for upgrading biogas is absorption process. In this study, two processes between water scrubbing and chemical scrubbing with diethanolamine (DEA) solution integrated with regeneration and recirculation are compared through Aspen Plus simulations. The aim of this study is to find the suitable operational condition in absorption process in order to increase the efficiency of the process in recovery methane and to decrease the energy consumption in the system. Our model was developed by including one additional absorber unit. Results show that the systems, both water scrubbing and chemical scrubbing, can achieve high purity of biomethane of >96 %v/v. In comparison between models for water scrubbing, our proposed system offers higher recovery methane of 4.68% of and 7,863.07 kW of energy of biomethane. In chemical scrubbing process, our system was able to decrease the pressure of absorber from 55.2 to 10 bar. Consequently, the recovery methane and energy of biomethane were increased while the energy consumption of system was decreased.
Based on elemental analyses, slop oil which is typical petroleum waste could be represented by kerosene according to the major content of hydrocarbons containing 8-15 of carbon atoms. It was found that co-pyrolysis of mixture of kerosene and ferrocene with a certain amount of ferrocene preloaded into a quartz tube reactor could result in formation of carbon nanotubes with uniform morphology and substantial yield. Based on thermogravimetric and SEM analyses, it was found that typical sample of CNTs synthesized with a designated weight ratio of ferrocene mixed with kerosene and preloaded ferrocene of 1:1 exhibited better thermal stability and more uniform morphology with an average diameter of less than 100 nm.
High-voltage pulse discharges were generated between underwater two metallic Tin (Sn) wires in order to synthesize nanoparticles. Nanoparticles were synthesized in pure water or aqueous gelatin solution. In pure water, Sn and SnO2 particles of approximately 5 nm in diameter were synthesized. However, synthetic particles in pure water had a problem of aggregation. The influence of gelatin solution on the particle size and dispersibility of the synthetic particles was investigated. In 10 mg/L gelatin aqueous solution, metallic Sn particles of approximately 40 to 400 nm in diameter were synthesized and were dispersing separately. From the peak width of X-ray diffraction (XRD) spectrum, the particle size was estimated using the Scherrer’s equation. As a result, the minimum size was approximately 20 nm at 2 mg/L of aqueous gelatin solution.
This research focuses on the preparation, characterization and catalytic properties of novel magnesium oxide in mesoporous MCM-22 Silica (MgO/MCM-22) for biodiesel production from jatropha oil. The catalysts were prepared by impregnation method and characterized. Then, the catalyst were tested for biodiesel production from jatropha oil where the reaction parameters were studied. The obtained results of the characterization showed that, the prepared catalyst has an amorphous structure with high Si/Al ratio which changes to a more of crystalline structure after successful incorporation of MgO. The result of the transesterification shows that, magnesium oxide (MgO) supported with silica is highly effective for the production of biodiesel where the high fatty acid methyl ester of 98% was achieved. Furthermore, the synthesized catalyst was able to be used up to three times with a slight reduction in catalytic activity. Hence, it can be concluded that the catalyst prepared from MgO/MCM-22 can serve as an outstanding alternative catalyst for biodiesel production.
This study is focused on the catalytic activity of monometallic and bimetallic Al-MCM-41 supported Ce and Zr heterogeneous catalysts prepared by impregnation and co-impregnation methods, respectively. Physicochemical properties of the catalysts determined, such as N2 adsorption isotherms and X-ray diffraction (XRD) studies show that the catalysts were mesoporous aluminosilicates with disordered hexagonal structure. The prepared catalysts were applied in simultaneous esterification and transesterification reactions of Jatropha oil for biodiesel production. The bimetallic catalyst was found to be more active than both the monometallic catalysts and the support. The bifunctional activity of the synthesized catalysts was observed at varied reaction conditions. Influence of the reaction conditions shows the highest conversion of biodiesel was obtained at methanol to oil ratio 6:1, reaction temperature 90 °C, reaction time 4 h and catalyst loading 5 wt%. The high performance of the bimetallic catalyst in the reaction process is attributed to optimum regulation of active sites by both Ce and Zr metals on the surface of the catalyst. Results from the GC-FID chromatograph shows the successful conversion of triglyceride to methyl esters.
HEMS attracts attention not only as a system for optimizing energy consumption in home, but also as a system for taking on demand side management (DSM) of electric power. In this study, we conducted a questionnaire survey on consumers’ intention to use HEMS, and analyzed factors influencing consumer’s introduction intention to HEMS. A descriptive analysis of the survey results allowed us to divide consumer energy saving behavior into eight distinctive types. Multivariate probit analysis showed that the type of consumers’ energy - saving behavior has relevance to demographic factors such as the age of the person, the situation of the family, and the time at home. Also it was found that the degrees of introduction intention to HEMS were greatly influenced by the type of energy saving behavior. Based on the results of this study, we can see how to segment consumers interested in HEMS and can propose HEMS promotion method to them.