Oxidation of fuel

A regenerative fuel cell system can also be a single electrochemical cell in which both the oxidation of fuels (i.e., production of electric power) and reduction of CO2 (to obtain fuels) can be carried out by simply reversing the mode of operation. 

In biological systems the oxidation of fuels by oxygen is a fundamental reaction by which energy is created, along with by-products such as water and carbon dioxide ... 

A flame is a thin region of rapid, self sustaining oxidation of fuel that is often accompanied by the release of large amounts of heat and light. Flames are what we most coninionly associate with combustion. One part of combustion science focuses on the different ways flames can be formed and the scientific and practical consequences of each. 

Composition of synthesis gas from steam reforming natural gas and partial oxidation of fuel oil ... 

The citric acid cycle is an integral part of the process by which much of the free energy liberated during the oxidation of fuels is made available. During oxidation of acetyl-CoA, coenzymes are reduced and subsequendy reoxidized in the respiratory chain, hnked to the formation of ATP (oxicktive phosphorylation see Figure 16-2 and also Chapter 12). This process is aerobic, requiring oxygen as the final oxidant of the reduced coenzymes. The enzymes of the citric acid cycle are lo-... 

The catalyst can decompose hydroperoxide homolytically, as well as heterolytically (see Chapters 10 and 17). Special experiments on the oxidation of fuel T-6 were performed in the presence of MoS2 with combined initiation by the initiator (DCP) and hydroperoxide formed in T-6 in the presence and absence of MoS2 [10]. It was found that the rate of the free radical generation and the rate of the hydroperoxide decay proceeds by the equations... 

There is specificity of the antioxidant action in the presence of heterogeneous catalyst. The kinetics of ionol retarding action on the oxidation of fuel T-6 catalyzed by the copper powder and homogeneous catalyst copper oleate was studied in Ref. [12]. Copper oleate appeared to be very active homogeneous catalyst it was found to catalyze the autoxidation of T-6 in such small concentration as 10 6 mol L-1 (T = 398 K). The kinetics of autoxidation catalyzed by copper salt obeys the parabolic law (see Chapter 4) ... 

The general requirements for an SOFC anode material include [1-3] good chemical and thermal stability during fuel cell fabrication and operation, high electronic conductivity under fuel cell operating conditions, excellent catalytic activity toward the oxidation of fuels, manageable mismatch in coefficient of thermal expansion (CTE) with adjacent cell components, sufficient mechanical strength and flexibility, ease of fabrication into desired microstructures (e.g., sufficient porosity and surface area), and low cost. Further, ionic conductivity would be beneficial to the extension of... 

Malinin, G. V. et al., Russ. Chem. Rev., 1975, 44, 392-397 Thermal decomposition of metal oxides was reviewed. Some oxides (cobalt(II, III) oxide, copper(II) oxide, lead(II, IV) oxide, uranium dioxide, triuranium octaoxide) liberate quite a high proportion of atomic oxygen, with a correspondingly higher potential for oxidation of fuels than molecular oxygen. 

Additionally, the incomplete oxidation of fuel generates weak organic acid anions. Furthermore, there is loss of base in the faeces each day which, in effect, leaves the body with an excess of protons to be excreted. In total, about 70 milliequivalents (mEq) of acid require excretion each day. Note mEq is used to quantify the acid load because this takes account of the valency of the ion 1 mmol of sulfate, S04, for example, is 2 mEq of negative charge, requiring 2 mEq of protons for neutralization, but for monovalent ions, such as protons or bicarbonate, 1 mEq= 1 mmol. ... 

The main function of mitochondria is the generation of adenosine triphosphate (ATP) from adenosine diphosphate (ADP) and phosphate, which is achieved by energy transfer from oxidation of fuels. Some cells (e.g. hepatocytes) contain several thousand mitochondria, whereas others, such as erythrocytes, lack them entirely. 

Figure 2.3 Changes in the heavy isotope content of oxygen and hydrogen in the urine with time after administration of The and 0 are diluted by the formation of H2O from oxidation of fuels and particularly that ingested in food and drink. The 0 in water is diluted from the production of CO2 via the oxidation of the fuels. The difference in the slopes indicates the rate of CO2 production. The label heavy isotope content is actually the isotopic enrichment. Physical activity, for example, increases fuel oxidation (i.e. respiration) and therefore greater dilution of...

Dual isotope technique The technique uses two heavy isotopes, oxygen ( 0) and deuterium ( H). Water that contains these isotopes is prepared. The subject drinks a glass of this water, as part of a normal meal. Once equilibrated with body water, which occurs quickly, the content of in the water falls due to the production of unlabelled water from the oxidation of fuels. Similarly, the 02 content in the water also falls but the rate is greater than that of since the 02 equilibrates not only with the oxygen atoms in water but also with those in carbon dioxide. An equihbrium between water and carbon dioxide is rapidly estabhshed due to the activity of the enzyme carbonate dehydratase. 

After administration of C-labeUed hydrogencarbonate, the CO2 rapidly equilibrates with the CO2 in the whole body. Since the urea produced in the hver is in isotopic equihbrium with the CO2 produced from the oxidation of fuels, changes in the radioactivity in urea in the urine can be used to measure the rate of CO2 production and hence the rate of fuel oxidation. An advantage of the technique is that it is accurate over relatively short periods (e.g. 24 hours). 

Kidney medulla From the metabolic point of view the kidney is virtually two organs, the cortex and the medulla. The cortex contains the glomeruli, through which the blood is filtered, the proximal tubules and part of the distal tubules, from which ions and molecules are reabsorbed. The cortex is well supplied with blood so that ATP is generated by the oxidation of fuels. The medulla is metabolically quite different. Here the ATP is required for the reabsorption of ions from the loop of Henle. Some ATP is generated by anaerobic glycolysis, since the supply of blood, and therefore of oxygen, to the medulla is much poorer than to the cortex. This reflects control of the uptake of water and Na+ ions into the blood by the counter current mechanism. This depends on a slow flow of the blood in the capillaries. 

Oxidation of Fuels and ATP Generation Physiological and Clinical Importance... 

CH 9 OXIDATION OF FUELS AND ATP GENERATION PHYSIOLOGICAL AND CLINICAL IMPORTANCE... 

Many other physiological processes are supported totally by the complete oxidation of fuels and cannot be supported by glycolysis alone, as calculations similar to the above would testify. Some of these processes are described in the next section. 

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