Potassium catalyzed hydrogasification of low-rank coal for synthetic natural gas production

Potassium catalyzed isothermal coal hydrogasification was investigated, as an alternative route for synthetic natural gas production. Potassium chemisorption occurred on oxygen sites in the coal structure and was strongly affected by the solution pH and followed the Cation Exchange Capability (CEC) which is also pH-dependent. A quadratic function described the relation between the solution pH and the fraction of the chemisorbed potassium, while; the cumulative distribution function of two Weibull probability density functions correlated the solution pH with the CEC that was linearly correlated with the fraction of the chemisorbed potassium. Coal hydrogasification is strongly affected by the increased alkalinity of the impregnating solution and increased methane yields were obtained while carbon conversion was slightly affected. This was attributed to the formation of profuse K+ substituted active sites that decompose under H2 attacks and trigger scission of the aromatic rings followed by K+ migration to neighboring complexes, thus, the hydrogasification reaction continuous to yield CH4, as codified in a three stage reaction mechanism. The relative specific hydrogasification rate was found to increase linearly with the CEC of the coal samples, suggesting that the oxygen functional groups, on which potassium is chemisorbed, act as “active sites” and are linked with the carbon’s reactivity

Effects of Arbuscular Mycorrhiza Fungi on Growth Characteristics of <i>Dactylis glomerata</i> L. under Drought Stress Conditions

Limited information is available regarding the selection of effective mycorrhizae and the exploitation of their beneficial effects on the enhancement of the forage production of Dactylis glomerata under the predicted warmer and drier conditions in the Mediterranean region. The objective of this study was to test the effects of Glomus intraradices, Glomus mosseae and their mix inoculation on growth characteristics and dry matter production of Dactylis glomerata in relation to full and limited irrigation. The experiment was conducted in Orestiada, Northeastern Greece. Limited irrigation significantly decreased yield and yield components of Dactylis glomerataover the full irrigation. Drought stressed plants had significantly higher root dry weight as a response for better survival under water deficit conditions. The Arbuscular mycorrhizal fungi (AMF) inoculated plants had significant higher shoot dry weight, tiller height and number of leaves in comparison to the non-inoculated plants. On the contrary, under drought stress conditions all AMF plants had lower root dry weights than control plants. Among the studied mycorrhizae species, Glomus intraradices performed better than Glomus mosseae and their mixture as it increased S/R ratio, tiller height and number of leaves

Effects of Arbuscular Mycorrhiza Fungi on Growth Characteristics of <i>Dactylis glomerata</i> L. under Drought Stress Conditions

Limited information is available regarding the selection of effective mycorrhizae and the exploitation of their beneficial effects on the enhancement of the forage production of Dactylis glomerata under the predicted warmer and drier conditions in the Mediterranean region. The objective of this study was to test the effects of Glomus intraradices, Glomus mosseae and their mix inoculation on growth characteristics and dry matter production of Dactylis glomerata in relation to full and limited irrigation. The experiment was conducted in Orestiada, Northeastern Greece. Limited irrigation significantly decreased yield and yield components of Dactylis glomerataover the full irrigation. Drought stressed plants had significantly higher root dry weight as a response for better survival under water deficit conditions. The Arbuscular mycorrhizal fungi (AMF) inoculated plants had significant higher shoot dry weight, tiller height and number of leaves in comparison to the non-inoculated plants. On the contrary, under drought stress conditions all AMF plants had lower root dry weights than control plants. Among the studied mycorrhizae species, Glomus intraradices performed better than Glomus mosseae and their mixture as it increased S/R ratio, tiller height and number of leaves