Characterization of aggregate behaviors of torrefied biomass as a function of reaction severity

Several studies have shown that torrefaction can improve various characteristics of biomass, including grindability, flowability, and energy density, at least at the microscopic level. Furthermore, the improvements are often represented as a monotonic function of the torrefaction severity. However, the existing literature is less clear on whether or not these improvements persist at the aggregate level. This paper demonstrates that, at the aggregate level, using differently torrefied biomass in an experimental cookstove as a case study, the relationship between the improvements and torrefaction severity tells a much more complex story than a simple, monotonic correlation. Notably, by defining and measuring various cookstove performance characteristics ranging from stove temperature, effective heat output, and emission profiles, and how these characteristics vary with the severity of torrefied fuel, we conclude that, contrary to the conventional wisdom, more severe torrefaction in many cases does not always lead to more improved fuel characteristics

Radar Interferometry for Monitoring Crustal Deformation. Geodetic Applications in Greece

The chapatti and breadmaking quality of nine (eight Indian and one Australian) wheat (Triticum aestivum L.) cultivars was compared. The extension of a chapatti strip measured with a Kieffer dough extensibility rig correlated with chapatti scores for overall quality (r = 0.84), pliability (r = 0.91), hand feel (r = 0.72), chapatti eating quality (r = 0.68), and taste (r = 0.80). Overall chapatti quality also correlated with the resistance to extension of a chapatti strip (r = 0.68) when tested for uniaxial extension with a texture analyzer. The texture analyzer provided objectivity in the scoring of chapatti quality. The high-molecular-weight glutenin subunit protein composition assessed by sodium dodecyl sulfate polyacrylamide gel electrophoresis did not correlate with the overall chapatti score. A negative correlation was found between chapatti and bread scores (r = 0.77). The different requirements for chapatti and bread quality complicate the breeding of new wheat varieties and the exchange of germplasm between regions producing wheat for chapatti and those supplying bread producers

<i>In vitro </i>multiple shoot regeneration and plant production in <i>Alysicarpus rugosus</i> DC. var. <i>heyneanus </i>Baker

916-920A protocol for in vitro multiple shoot regeneration and plant production through seedling (shoot tip) culture was established for Alysicarpus rngosus DC. var. heyneanus Baker. Maximum number of adventitious shoots (14.4) per shoot tip explant were initiated after two subcultures on MS solid medium supplemented with IAA (2.85 μM) plus BAP (2.22 μM) after 4 weeks. Shoot elongation (3.0-3.5 cm) was achieved on MS medium without any hormones. Stunted shoots elongated on half MS medium without growth hormones. Rooting occurred in MS medium containing IAA (1.14-2.85μM) alone or in combination with IBA (0.89-2.46μM) and or NAA (1.07-2.69μM). Maximum rooting was established in MS medium supplemented with IAA (2.85μM). The plants were acclimatized successfully with 55% survival in pot containing cocoa peat and sand (1:1). After a month, hardened plants were transferred to pots with manure, garden soil and sand (1:2:1) for further growth and finally planted in field

<i>De novo </i>shoot regeneration from root cultures of<i> Garcinia indica </i>Choiss<i></i>

482-486Roots of plantlets of Garcinia indica when cultured for long time on half strength MS medium supplemented with BAP (0.44-2.22 µM) showed production of de novo shoots. Roots attached to mother plant showed more number of shoots, while excised root segments produced lesser shoots. Shoots (0.5-0.8 cm) were transferred to elongation medium consisting of Woody Plant Medium (WPM) supplemented with BAP (4.44-22.69 µM), IAA (5.71 µM) and kinetin (4.65 µM). It was observed that shoot length increased to1-2 cm. WPM medium supplemented with NAA (2.69-10.74 µM) and IBA (4.90 µM) induced rooting within 20-25 days. Using the present protocol, 20-25 plantlets could be regenerated from single root explant within 3 to 4 months. The protocol has potential for large scale production of elite plants

CO2 gasification of char from lignocellulosic garden waste: Experimental and kinetic study

In this study, the dry leaves litter from jackfruit, raintree, mango and eucalyptus trees, lignin, and cellulose were characterized, pyrolysed, and evaluated for their char reactivity towards CO2 gasification using TGA. The differences in char reactivity were attributed to the difference in char morphology and the varying inorganic contents. The mineral analysis of biomass ash showed the presence of alkali minerals some of which could act as catalysts. The adverse effect of high silica content was also evident through the experimental results. The kinetic parameters for gasification reaction were determined using three different reaction models. A modified random pore model was investigated to account for the influence of inorganic content. The effect of external catalyst on CO2 gasification was also studied by adding potassium carbonate to biomass char and pellets. The results obtained from this study can be conveniently used in the design of a gasifier for lignocellulosic garden waste

Exergy efficiency improvement in hydrogen production process by recovery of chemical energy versus thermal energy

Exergy analysis is recently being employed as one of the preferred methods to improve the design performance of a system and to achieve overall sustainability. Exergy is mainly composed of physical or thermo-mechanical and chemical components and a single stream can possess one or more forms of exergy. Where there is exergy lost in unused chemical streams or wasted energy, the recovery of exergy would reduce losses and increase the second law efficiency of the process. In many chemical process plants such as hydrogen (H-2), ammonia, nitric acid, etc., there is a potential to recover waste or excess heat by process heat exchange or by generating utilities. For a process like steam-methane (CH4) reforming (SMR), exergy efficiency can be improved by recovering the available excess heat partially or fully in the form of chemical energy or thermal energy. This paper presents the generalised system analysis to show that the recovery of exergy in the form of chemical energy is better than in thermal energy form due to fewer losses and higher efficiency. The concept is illustrated with the example of a simple combustion system with excess heat in which saving fuel proves to be more exergy efficient than generating utility. The approach is applied to an industrial case study of H-2-producing SMR plant with two modified cases of steam generation and recycling portion of unconverted CH4 as feed. In the case study, heat exchanger network is treated as a separate process component and a simple methodology is proposed to calculate the exergy losses for the same. The results of the case study prove that the recovery of chemical energy is more efficient than that of thermal energy from an exergy perspective

Cost-benefit analysis of different hydrogen production technologies using AHP and Fuzzy AHP

In this paper, cost-benefit analysis is performed to compare eight different hydrogen production technologies using the classical analytic hierarchy process (AHP) and the Fuzzy AHP. The technologies considered are steam methane reforming, coal gasification, partial oxidation of hydrocarbons, biomass gasification, photovoltaic-based electrolysis, wind-based electrolysis, hydro-based electrolysis, and water splitting by chemical looping. For each of the hydrogen production technologies, five criteria are used for evaluation: greenhouse gas emissions, raw material and utilities consumption, energy efficiency, scalability, as well as waste disposal and atmospheric emissions. The results obtained for benefits category using AHP and Fuzzy AHP are plotted against the normalized equivalent annual costs of each technology. It is concluded that the fossil fuel based processes appear to have less beneficial qualities including greater environmental impacts, but are more cost-effective. On the other hand, the renewable based processes appear to have more benefits as well as being more expensive for hydrogen production. However, the cost-benefit analysis results imply that the process of water splitting by chemical looping among the renewable approaches is the most promising new technology. Copyright (C) 2014, Hydrogen Energy Publications, LLC. Published by Elsevier Ltd. All rights reserved

An alternative process for nitric oxide and hydrogen production using metal oxides

A new process employing metal oxide is proposed for the production of nitric oxide and hydrogen which are precursors to the production of nitric acid. There have only been a few studies reporting the oxidation of ammonia by metal oxides, but the ammonia-metal oxide reactions for the simultaneous production of NO and H-2 have not yet been reported. The reaction of ammonia with different metal oxides is investigated in detail, including thermodynamic feasibility calculations. The salient feature of the proposed reaction is the production of H-2 in addition to NO. Experiments are performed for the most feasible metal oxides in a semi batch reactor. These experiments confirm the feasibility of the ammonia-metal oxide reaction for cupric oxide (CuO), ferric oxide (Fe2O3) and cobalt oxide (Co3O4) at 825 degrees C, 830 degrees C and 530 degrees C, respectively. The maximum yields of NO are around 90% for each metal oxide. The effect of varying the different parameters such as temperature, ammonia concentration, and particle size on the yield of nitric oxide is reported for the case of CuO and a reaction mechanism is proposed to explain these results. These results are used to develop two different chemical looping based processes for NO and H-2 production depending on the mode of regeneration of metal oxides. Crown Copyright (C) 2016 Published by Elsevier B.V. on behalf of Institution of Chemical Engineers. All rights reserved