Oxygen-carbon Dioxide Mixture Research Articles

Carbon intensity of in-situ oil sands operations with direct contact steam generation lower than that of once-through steam generation

The oil sands resource in Western Canada are a considerable energy asset for Canada, but the energy and emissions intensities of producing this petroleum resource are substantially worse than that of conventional petroleum resources. With requirements for carbon-intensity reduction, new, less emissive recovery processes must be developed to enable continued production and cash flow from this important resource. The largest source of carbon emissions on in-situ in oil sands recovery processes, such as Steam-Assisted Gravity Drainage (SAGD), is steam generation, where natural gas is combusted. An alternative to conventional steam generation is Direct Contact Steam Generation (DCSG), where steam is generated in the combustion flame, and with rich oxygen combustion, the steam plus carbon dioxide mixture is injected into the reservoir. We explore the carbon intensity of DCSG and compare it to existing once-through steam generation using life cycle analysis. The results reveal considerable environmental benefits with nearly 30% emission reduction when applying a DCSG in SAGD instead of an OTSG. The results suggest that oil sands operators could improve their emissions intensity significantly if they adopted DCSGs in their operations.

Stable Artificial Solid Electrolyte Interphases for Lithium Batteries

A rechargeable lithium metal battery (LMB), which uses metallic lithium as the anode, is among the most promising technologies for next generation electrochemical energy storage devices due to its high energy density, particularly when Li is paired with energetic conversion cathodes such as sulfur, oxygen/air, and oxygen–carbon dioxide mixtures. Practical LMBs in any of these designs remain elusive due to multiple problems, including parasitic reactions of Li metal with liquid electrolytes, unstable/dendritic electrodeposition at the anode during cell recharge, and chemical reaction of dissolved cathode conversion products with the Li anode. The solid electrolyte interphase (SEI) formed between lithium metal and liquid electrolytes plays a critical role in all of these processes. We report on the chemistry and interfacial properties of artificial SEI films created by in situ reaction of a strong Lewis acid AlI3, Li metal, and aprotic liquid electrolytes. The study takes advantage of the strong surface aff...

Experimental study of the effect of water injection on the cycle performance of an internal-combustion Rankine cycle engine

The internal-combustion Rankine cycle engine uses pure oxygen instead of air as the oxidant during the combustion process so as to preclude the creation of nitrogen oxide emissions. Carbon dioxide can be recovered from the water vapour–carbon dioxide exhaust gas mixture through condensation at a relatively low cost and, thus, an ultra-low-emission working cycle is achieved. In this paper the working process of the internal-combustion Rankine cycle was studied on the basis of bench tests on a prototype engine. An oxygen–carbon dioxide mixture was utilized to simulate exhaust gas recirculation in order to control the combustion process, and water was injected near top dead centre to determine the impact on the reaction rate and the cycle performance. The results demonstrated that water injected at a temperature of 120 °C can modulate the reaction rate and expand the area of the pressure–volume diagram through vaporization. Furthermore, combustion phasing is retarded without reducing the maximum cylinder pressure. The indicated work under the test conditions is increased by 7.8%. However, when the water-injection temperature is 20 °C, the cycle performance is reduced.

Direct conversion of solid hydrocarbons in a molten carbonate fuel cell

Electrical characteristics of a molten carbonate fuel cell allowing direct electrochemical oxidation of dispersed hydrocarbons have been examined. As the fuel, graphite, anthracite, and cannel coal samples were used. Data illustrating the effect of electrolyte temperature, fuel type and dispersion, and also reactant gas mixture composition on the performance characteristics of the fuel cell, were obtained. Correlation between the specific characteristics of the fuel cell and the hydrogen content of fuel material was established. The maximum current-density values were achieved with hydrogen-rich cannel coal. For dispersed fuel samples, interparticle contact losses were found to have influence on the cell-generated voltage. The maximum cell opencircuit voltage was reached with stoichiometric oxygen-carbon dioxide mixture blown into the cathode. Yet, the largest current-density values were obtained when carbon dioxide lean mixtures were used. Even at zero carbon dioxide concentration the range of cathode polarizations was less than that observed with stoichiometric mixture. The processes proceeding in the cathode and anode packs of the fuel cell are believed to be interrelated processes. In a model fuel cell fueled with dispersed coal, current densities up to 140 mA/cm2 and specific powers up to 70 mW/cm2 were achieved.

Hyperoxia-induced Tissue Hypoxia

Hyperoxia-induced Tissue Hypoxia

An experimental study on the conditions of safe oxidation of toluene with oxygen—carbon dioxide mixtures

The flammability limits of saturated vapours of toluene in oxygen—carbon dioxide mixtures have been measured up to 180°C and 10 atm using a direct The flammability data have been presented in a pressure versus temperature diagram. The convenience of this form of diagram to determine the conditions

Electron attachment in oxygen—carbon dioxide mixtures: D A Price and J L Moruzz,Proc of 11 th Internat Conf on Phenom in Ioniz Gases, Prague 1973, 49

Electron attachment in oxygen—carbon dioxide mixtures: D A Price and J L Moruzz,Proc of 11 th Internat Conf on Phenom in Ioniz Gases, Prague 1973, 49

A kinetic approach to the study of absorption of solutes by isolated perfused small intestine.

1. A new technique has been developed for making serial measurements of water and solute absorption from the lumen of isolated small intestine.2. The isolated intestine is perfused in a single pass with a segmented flow of slugs of liquid separated by bubbles of oxygen-carbon dioxide mixture. Simultaneous collections are made of effluent from the lumen and of the fluid which is transported across the mucosa. This latter fluid appears to be a fair sample of the tissue fluid.3. Conditions in the lumen can be changed within less than 5 min. The effects of two or more treatments applied to the same segment of intestine can be determined and the time course of a change in luminal conditions.4. The rate of appearance of solutes on the serosal side depends on the rate of water absorption, and changes exponentially towards a steady state. The rate constant is a function of tissue fluid volume.5. In the steady state the concentration of glucose in the tissue fluid is 71 mM when the luminal concentration is 28 mM, and is 45 mM when the luminal concentration is 8.3 mM.6. For solutes such as glucose for which reflux from tissue fluid to lumen is small relative to flux from lumen to tissue fluid, the time of attainment of a steady state in secretion is usually 50-60 min.7. For solutes such as sodium for which the reflux is relatively high, the steady state may be reached in 15-20 min.8. The K(m) for glucose absorption (14-19 mM) is much lower than is found with unsegmented flow perfusion.9. These findings emphasize problems in interpreting results from other types of intestinal preparation.10. The rate of glucose absorption from the lumen falls only gradually when the luminal sodium concentration is reduced abruptly. In contrast the rate of glucose absorption falls suddenly when the luminal glucose concentration is reduced abruptly. This suggests that glucose absorption is not directly dependent on luminal sodium ions.

The upper limit of flammability of hydrogen in air, oxygen, and oxygen-inert mixtures at elevated pressures

The upper limit of flammability of hydrogen in air, oxygen, oxygen-helium, oxygen-neon, oxygen-argon and oxygen-carbon dioxide mixtures was measured at room temperature and pressures between 0.97 and 29 atm in two cylindrical bombs with volumes of 1.5 and 5.2 liters. The limit in ternary mixtures was determined in 20%, 40%, 60% and 80% helium, 20% neon and argon and 10% carbon dioxide concentrations. The maximum safe percentage of oxygen in a hydrogen-oxygen-helium mixture was calculated for pressures between 0.97 and 29 atm.

Determination of Oxygen and Carbon Dioxide in Medicinal Gas Mixtures by Gas-Solid Chromatography

Abstract A gas-solid chromatographic method is presented for the analysis of oxygen, oxygenhelium, and oxygen-carbon dioxide mixtures. The method utilizes a 16’ Porapak Q chromatographic column, hydrogen carrier gas, and a thermal conductivity detection system. It is applicable to the analysis of nitrogen, helium, argon, carbon monoxide, and nitrous oxide. Dry Ice conditions are required for the oxygen analysis; carbon dioxide is determined at ambient temperatures. Details for the assembly of a suitable chromatograph and a procedure for sampling gas cylinders are presented. Samples of medicinal gases were analyzed by the proposed method and by the Orsat absorption method. The results by both methods were in good agreement.

Silastic oxygenator and perfusion system for canine liver and kidney preservation

A silicone rubber oxygenator and perfusion circuit was developed for the prolonged preservation and metabolic study of intact hypothermic mammalian liver and kidney. With this perfusion system, the canine kidney may be studied up to 4 days and the canine liver up to 20 hrs. The low capacity membrane oxygenator consists of multiple strands of thin walled silicone rubber tubing in parallel through which the perfusate flows. An oxygen-carbon dioxide mixture is blown over the tubing surface. Oxygen transfer capacity of the oxygenator is about 2.5 ml per min at 10 °C. The perfusion system is reusable and autoclavable, and its size can be scaled up for larger organs or scaled down for rat organs.

Comparison of high-pressure oxygen-carbon dioxide mixtures in treatment of Clostridium perfringens infection in mice

Comparison of high-pressure oxygen-carbon dioxide mixtures in treatment of Clostridium perfringens infection in mice

Comparison of high-pressure oxygen and oxygen-carbon dioxide mixtures in treatment of Clostridium perfringens infection in mice

Comparison of high-pressure oxygen and oxygen-carbon dioxide mixtures in treatment of Clostridium perfringens infection in mice

Uptake of cholesterol and cholesterol esters by inverted sacs of rat intestine.

Conditions for the use of inverted sacs of rat small intestine for the study of the mechanism of cholesterol absorption are described. Incubation of inverted sacs in albumin-stabilized emulsions of free cholesterol or cholesterol esters, under oxygen-carbon dioxide mixture, led to the disappearance of cholesterol from the external medium and accumulation of free or ester cholesterol in the sacs. Both forms of cholesterol were taken up against a concentration gradient without demonstrable chemical change. The uptake of free cholesterol was quite constant from the lower duodenum to the upper ileum and was independent of the pH of the external medium. Additions of oleic acid, sodium taurocholate or pancreatic extract depressed the uptake of free cholesterol. Comparable but more variable effects were found in respect to cholesterol ester uptake. Addition of pancreatic extract to the external medium increased the proportion of ester in the total cholesterol taken up by the sacs. This was due, in part, to synthesis of cholesterol esters in the mucosa.

Influence of Mode of Immunization on the Relationship between the Development of Tissue Titers and the Release of Hemolysins in Vitro

Summary The capacity of surviving tissues to release hemolysins in vitro has been investigated, using tissues from rats immunized by intravenous or intraperitoneal injection of sheep erythrocytes. In addition, an attempt has been made to correlate the results obtained with the development of hemolysin titers in serum and tissue. In rats immunized by the administration of a single intravenous dose of antigen, the peak in antibody titer of serum and saline extracts of most tissues occurred within 5 days. At this time, minced splenic tissue from these rats showed a rapid release of hemolysins in vitro. This in vitro phenomenon was inhibited by substitution of a nitrogen atmosphere for the oxygen-carbon dioxide mixture otherwise used. The results obtained by extension of the usual 3-hour incubation period to 12 hours suggested an actual production of antibody in vitro. Lymphoid tissue (mesenteric lymph nodes or thymus) obtained from similar animals appeared inactive under these conditions. Tissue extracts prepared from rats immunized by periodic intraperitoneal injection of antigen attained maximal hemolysin levels which were in general similar to those observed in tissues from the intravenous group. These titers were apparently maintained throughout the period of antigen injection. Surviving splenic tissue from these animals showed no evidence of antibody production in vitro, whereas lymphoid tissue exhibited a high capacity for the selective release of hemolysins. The data suggest that lymphoid tissue and spleen may vary in relative importance in the production and release of antibody in vivo, depending on the mode of immunization employed.

Therapy of Asphyxia in Newborn Infants by Administration of Oxygen-Carbon Dioxide Mixture to Mother.

Therapy of Asphyxia in Newborn Infants by Administration of Oxygen-Carbon Dioxide Mixture to Mother.

Effect of Inhalation of High Oxygen Concentrations, With and Without Carbon Dioxide, on the Electrocardiogram

SummaryInhalation of 100% oxygen has been shown to result in the elevation of the T wave in the electrocardiogram in 20 of 26 cardiac cases, and in 2 of a group of 8 normal and miscellaneous cases. When 97 or 96% oxygen with 3 or 4% carbon dioxide was tested, similar electrocardiographic changes were observed although the degree of change was frequently less marked; thus, in 7 of 20 cardiac cases the T wave was distinctly more elevated after inhalation of 100% oxygen than after the oxygen-carbon dioxide mixture. The significance of these observations is discussed. It seems likely that inhalation of 100% oxygen shortens the recovery period of cardiac muscle.

XIX.—Apparatus to facilitate the Use of an Oxygen-Carbon Dioxide Mixture in the Treatment of Carbon Monoxide Poisoning

Breathing, in normal conditions, is regulated by the concentration of carbon dioxide in the blood; the “respiratory centre” of the brain, which directs the movements of the lungs, controls matters with a highly delicate degree of regulation so as to maintain that concentration at a fixed level. When, through hard exertion or through the influence of carbon monoxide poisoning, the organism becomes seriously affected by want of oxygen, that deficiency itself begins to influence the respiratory centre and to stimulate breathing. During the course of poisoning by carbon monoxide, then, the lung-ventilation increases; the increase accelerates the rate of saturation of the blood by the gas, which in turn reacts in intensifying the oxygen-shortage. A consequence of the hyperpnœa which thus progressively develops is the washing out of much of the carbon dioxide in the blood.