Carbon Storage and Carbon Dioxide Emission as Influenced by Long-term Conservation Tillage and Nitrogen Fertilization in Corn-Soybean Rotation

Although agriculture is a victim of environmental risk due to global warming, but ironically it also contributes toglobal greenhouse gas (GHG) emission. The objective of this experiment was to determine the influence of long-termconservation tillage and N fertilization on soil carbon storage and CO2 emission in corn-soybean rotation system. Afactorial experiment was arranged in a randomized completely block design with four replications. The first factorwas tillage systems namely intensive tillage (IT), minimum tillage (MT) and no-tillage (NT). While the second factorwas N fertilization with rate of 0, 100 and 200 kg N ha-1 applied for corn, and 0, 25, and 50 kg N ha-1 for soybeanproduction. Samples of soil organic carbon (SOC) after 23 year of cropping were taken at depths of 0-5 cm, 5-10cm and 10-20 cm, while CO2 emission measurements were taken in corn season (2009) and soybean season (2010).Analysis of variance and means test (HSD 0.05) were analyzed using the Statistical Analysis System package. At 0-5 cm depth, SOC under NT combined with 200 kg N ha-1 fertilization was 46.1% higher than that of NT with no Nfertilization, while at depth of 5-10 cm SOC under MT was 26.2% higher than NT and 13.9% higher than IT.Throughout the corn and soybean seasons, CO2-C emissions from IT were higher than those of MT and NT, whileCO2-C emissions from 200 kg N ha-1 rate were higher than those of 0 kg N ha-1 and 100 kg N ha-1 rates. With any Nrate treatments, MT and NT could reduce CO2-C emission to 65.2 %-67.6% and to 75.4%-87.6% as much of IT,respectively. While in soybean season, MT and NT could reduce CO2-C emission to 17.6%-46.7% and 42.0%-74.3% as much of IT, respectively. Prior to generative soybean growth, N fertilization with rate of 50 kg N ha-1could reduce CO2-C emission to 32.2%-37.2% as much of 0 and 25 kg N ha-1 rates

TAP investigations of the CO2 reforming of CH4 over Pt/ZrO2

The adsorption and reaction characteristics of methane, carbon dioxide, carbon monoxide, and hydrogen have been investigated over a ZrO2support and a Pt/ZrO2catalyst by using a temporal analysis of products reactor system. It was observed that on Pt/ZrO2both methane and carbon dioxide dissociate independently of one another. The dissociation of carbon dioxide acts as an oxygen supplier, while the decomposition products of methane scavenge the oxygen from the catalyst. When an abundance of oxygen is present, pulsing of methane leads to the production of carbon dioxide. It is concluded that both the selectivity with which methane produces carbon monoxide or carbon dioxide and the carbon dioxide conversion is determined by the same reaction: COads+Oads CO2,ads

Carbon Dioxide Production in Animal Houses: A literature review

This article deals with carbon dioxide production from farm animals; more specifically, it addresses the possibilities of using the measured carbon dioxide concentration in animal houses as basis for estimation of ventilation flow (as the ventilation flow is a key parameter of aerial emissions from animal houses). The investigations include measurements in respiration chambers and in animal houses, mainly for growing pigs and broilers. Over the last decade a fixed carbon dioxide production of 185 litres per hour per heat production unit, hpu (i.e. 1000 W of the total animal heat production at 20 oC) has often been used. The article shows that the carbon dioxide production per hpu increases with increasing respiration quotient. As the respiration quotient increases with body mass for growing animals, the carbon dioxide production per heat production unit also increases with increased body mass. The carbon dioxide production is e.g. less than 185 litres per hour per hpu for weaners and broilers and higher for growing finishing pigs and cows. The analyses show that the measured carbon dioxide production is higher in full scale animal houses than measured in respiration chambers, due to differences in manure handling. In respiration chambers there is none or very limited carbon dioxide contribution from manure; unlike in animal houses, where a certain carbon dioxide contribution from manure handling may be foreseen. Therefore, it is necessary to make a correction of data from respiration chambers, when used in full scale animal buildings as basis for estimation of ventilation flow. Based on the data reviewed in this study, we recommend adding 10% carbon dioxide production to the laboratory based carbon dioxide production for animal houses with slatted or solid floors, provided that indoor manure cellars are emptied regularly in a four weeks interval. Due to a high and variable carbon dioxide production in deep straw litter houses and houses with indoor storage of manure longer than four weeks, we do not recommend to calculate the ventilation flow based on the carbon dioxide concentration for these houses

Journal Staff

Water and supercritical carbon dioxide have different wetting angles to a glass surface, where water has a lower angle. In a microfluidic channel, the lower wetting angle draws the water to surround the supercritical carbon dioxide and the supercritical carbon dioxide therefore easily form droplets or segments if the flow rate is low. In this study, the flow of supercritical carbon dioxide and water has been studied in a microfluidic system with a double Y-channel. The micro channels have been built in borofloat glass to withstand high mechanical and chemical forces, still enabling in situ characterization. The aim has been to analyze flow changes in the water and supercritical carbon dioxide in structured channels with and without surface modification.             The result shows that the flow regime of supercritical carbon dioxide and water can be controlled by changing flow rates, adding walls, or coating a channel as well as any combination of these three. If adding a large enough wall in a channel, the flow will be segmented only in half the channel at moderate flow rates from both sources, and parallel if the flow rate of supercritical carbon dioxide is high enough. A non-polar coating of half a channel will make the supercritical carbon dioxide flow along the coated side and supercritical carbon dioxide can by that way be forced to only take one of the outlets. However, still water exit at both outlets

Review of the Carbon Dioxide Splitting Patent Literature

Increasing concentrations of carbon dioxide in the atmosphere have stimulated significant global research and development efforts regarding the reduction in emissions from all point and non-point sources. In addition to technologies that do not use carbon feedstocks or which capture and "permanently" store carbon dioxide (i.e., sequestration), there is considerable worldwide interest for dissociating waste stream carbon dioxide molecules into their constituent carbon and oxygen atoms ("CO2 splitting") as a final "end-of-pipe" treatment option. This document presents a review of on-point issued and applied for patents in the field of carbon dioxide splitting. The findings suggest patents in this area appear to be subject to a higher standard because of the global importance of the carbon dioxide issue. Authorities may be hesitant, on policy grounds, to issue broad-ranging patents for carbon dioxide splitting in order to prevent a worldwide reluctance towards adopting feasible treatment methods because of the high patent licensing costs that may accrue

Spacecraft oxygen recovery system

Recovery system is comprised of three integrated subsystems: electrochemical carbon dioxide concentrator which removes carbon dioxide from atmosphere, Sabatier reactor in which carbon dioxide is reduced with hydrogen to form methane and water, and static-feed water electrolysis cell to recover oxygen from water

Carbon dioxide concentration indicator

Device will provide visual indication of concentration of carbon dioxide. It consists of small amounts of absorbent material contained in semipermeable membrane and device to detect color changes. Material will absorb quantity of carbon dioxide proportional to carbon dioxide concentration in atmosphere. Amount of absorption is indicated by color change

Wellbeing of Alcohol-preferring Rats Euthanized with Carbon Dioxide at Very Low and Low Volume Displacement Rates

The 2013 AVMA Guidelines on Euthanasia recommend the use of very-low or low flow rates of 100% carbon dioxide to euthanize small rodents. Although inhalation of high concentrations of carbon dioxide are generally recognized as painful in humans, whether the use of these low-flow methods of euthanasia increase potential distress for rats is unclear. This study compared physiologic and behavioral markers of animal wellbeing for rats euthanized by using 10% volume displacement per minute (VD/min), 30% VD/min, and 70% VD/min of 100% carbon dioxide. Rats were recorded during euthanasia for subsequent behavioral scoring, and blood samples were taken after euthanasia for assessment of blood glucose and serum corticosterone levels. In this study, rats euthanized with 10% or 30% VD/min of 100% carbon dioxide demonstrated increases in various behaviors, such as rearing and standing, concurrent with increases in serum corticosterone. Rats euthanized with 70% VD/min of 100% carbon dioxide did not exhibit these changes. The results suggest that a euthanasia method of 70% VD/min of 100% carbon dioxide may minimize potential pain and distress and thus be more humane for rats, as compared with very-low- and low-flow methods of carbon dioxide euthanasia

Carbon Dioxide in Exoplanetary Atmospheres: Rarely Dominant Compared to Carbon Monoxide and Water in Hot, Hydrogen-dominated Atmospheres

We present a comprehensive study of the abundance of carbon dioxide in exoplanetary atmospheres in hot, hydrogen-dominated atmospheres. We construct novel analytical models of systems in chemical equilibrium that include carbon monoxide, carbon dioxide, water, methane and acetylene and relate the equilibrium constants of the chemical reactions to temperature and pressure via the tabulated Gibbs free energies. We prove that such chemical systems may be described by a quintic equation for the mixing ratio of methane. By examining the abundances of these molecules across a broad range of temperatures (spanning equilibrium temperatures from 600 to 2500 K), pressures (via temperature-pressure profiles that explore albedo and opacity variations) and carbon-to-oxygen ratios, we conclude that carbon dioxide is subdominant compared to carbon monoxide and water. Atmospheric mixing does not alter this conclusion if carbon dioxide is subdominant everywhere in the atmosphere. Carbon dioxide and carbon monoxide may attain comparable abundances if the metallicity is greatly enhanced, but this property is negated by temperatures above 1000 K. For hydrogen-dominated atmospheres, our generic result has the implication that retrieval studies may wish to set the subdominance of carbon dioxide as a prior of the calculation and not let its abundance completely roam free as a fitting parameter, because it directly affects the inferred value of the carbon-to-oxygen ratio and may produce unphysical conclusions. We discuss the relevance of these implications for the hot Jupiter WASP-12b and suggest that some of the previous results are chemically impossible. The relative abundance of carbon dioxide to acetylene is potentially a sensitive diagnostic of the carbon-to-oxygen ratio.Comment: Accepted by ApJ. 12 pages, 8 figures, 2 table

Carbon Dioxide Splitting: A Summary of the Peer-Reviewed Scientific Literature

Increasing concentrations of carbon dioxide (CO2) in the atmosphere have stimulated significant global research and development efforts regarding the reduction in CO2 emissions from all point and non-point sources. In addition to technologies that do not use carbon feedstocks or which capture and "permanently" store CO2 (i.e., sequestration), there is considerable worldwide interest among the academic, industrial, and government communities regarding methods for dissociating waste stream carbon dioxide molecules into their constituent carbon and oxygen ("CO2 splitting") atoms as a final "end-of-pipe" treatment option. The splitting of carbon dioxide has also been actively discussed and researched in the space exploration and extraterrestrial colonization programs for several decades. This document summarizes the peer-reviewed open source scientific literature regarding carbon dioxide splitting