Carbon dioxide emission rates

Vs =superficial gas velocity B = number of stirrers j = baffle width di = impeller diameter RQ = respiratory quotient CER = carbon dioxide emission rate QUR = oxygen uptake rate pCQg = partial pressure of carbon dioxide pQg = partial pressure of oxygen i = air feed ... 

The carbon dioxide emitted by human respiration was estimated as follows. The population was assumed to be 5.64 billion (Table 1.3). The normal rate of respiration of an adult male is 13 to 18 breaths/min (Zoethout, 1948) it increases on muscular exertion. In females, the rate is 2 to 4 breaths/ min greater. The rate is 40 to 70 at birth at 15 years of age, it is about 20. Sleep decreases the rate by up to 25%. For this estimate, the average human respiration rate was assumed to be 15 breaths/min. Expired air is about 4.00 mol % carbon dioxide (Zoethout, 1948). Inspired air contains about 0.03 mol % carbon dioxide it was ignored for this estimate since it is only 0.75% of that in the expired air. The average volume of air per breath is about 0.5 L (Zoethout, 1948). At standard pressure and temperature conditions, the expired air is assumed to have a density of 1.873 X 10 t/L. The calculation of global carbon dioxide emissions from human respiration is then... 

We have designed and implemented a reactive divided wall distillation column for the production of ethyl acetate from acetic acid and ethanol. Important aspects derived from steady state simulation were considered for instance, a side tank was implemented in order to split the liquid to both sides of the wall and a moving wall inside the column that allows to fix the split of the vapor stream. The dynamic simulations indicate that it is possible to control the composition of the top and bottoms products or two temperatures by manipulating the reflux rate and the heat duty supplied to the reboiler, respectively. The implementation of the reactive divided wall distillation columns takes into account important aspects like process intensification, minimum energy consumption and reduction in Carbon Dioxide emission to the atmosphere. 

By the middle of the 21st century, global energy consumption will more than double from the present rate. To meet this demand under potential worldwide limits on carbon dioxide emissions, cost-effective solar energy must be developed.8... 

Every hour, up to 6.2 t of waste are incinerated. The combustion of one ton of waste yields, on average, 16 000 MJ. The carbon dioxide emission amounts to only half of the hourly emission rate of a commercial airplane. 

In the work of WRAP (Final Report, 2012 Dynamics), eco-efficiency across the supply chain of textile and clothing product consumption in the UK over one year is analyzed, consisting only of the production, distribution, and retailing phases. It is seen that in the baseline scenario a 4.1% reduction on current carbon dioxide emission is possible and if the highest possible reduction scenario occurs, the rate of reduction is estimated as 24.5%. Detailed information about the estimation of reduction in sector-based supply chain carbon dioxide emission in the UK can be found in the report. 

While production of most bioplastics results in reduced carbon dioxide emissions compared to traditional alternatives, there are some real concerns that the creation of a global bioeconomy could contribute to an accelerated rate of deforestation if not managed effectively. There are associated concerns over the impact on water supply and soil erosion and bioplastics represent a 42% reduction in carbon footprint. On the other hand, bioplastic can be made from agricultural byproducts and also from used plastic bottles and other containers using microorganisms. 

Roen et al. (2004) examined the effect of platinum on carbon dioxide emissions three synthesized in-house MEAs (carbon, 10 wt%and 39 wt%platinum supported on carbon catalysts) were potential cycled between 0 and 1 V (vs RHE) at 65 °C (100% RH, hydrogen/air or oxygen as reactants) and their carbon dioxide emissions were measured by mass spectrometry. The presence of Pt enhanced carbon corrosion rate since Pt catalyzes CO2 formation at low potentials (-0.55-0.65 V vs RHE) (Willsau and Heitbaum, 1984) and increases CO2 emission rates at 1V (vs SHE) (Roen et al., 2004). It was also reported that the carbon corrosion rate is enhanced as the range of potential cycling is increasing (higher anodic and lower cathodic potentials) due to the formation of defects (Stevens et al., 2005) on carbon support by chemical oxidation in low potentials and the presence of a harsh electro-oxidation envirorunent at high potentials (Maass et al., 2008). 

Illustration 4.2 Net Rate of Global Carbon Dioxide Emissions... 

The release of carbon dioxide into the atmosphere and its attendant effect on climate change have been widely publicized in recent years. A warning call came in the late 1980s and early 1990s when it was established that carbon dioxide concentrations in the air, then at a level of 370 ppm, were growing at a rate of 2 ppm per year. What we wish to do here is use this information to calculate the net rate of global carbon dioxide emissions (i.e., the amount in excess of what is consumed by plant life or taken up by water basins). 

Climate change constitutes one of the principal challenges of the twenty-first century, and one of the major dimensions of this challenge is technological. Net human carbon dioxide emissions to the ocean-atmosphere must eventually decline to zero for its concentration to be stabilized. This follows from the fact that long-term, steady-state concentrations are determined by cumulative emissions, not by the emissions rate. As such, CO2 is fundamentally different from other greenhouse gases. This feature of the climate problem has several important, near-term implications for the character of efficient policy development. 

Example 7 Radiation in Gases Flue gas containing 6 percent carbon dioxide and 11 percent water vapor by volume (wet basis) flows through the convection bank of an oil tube stiU consisting of rows of 0.102-m (4-in) tubes on 0.203-m (8-in) centers, nine 7.62-m (25-ft) tubes in a row, the rows staggered to put the tubes on equilateral triangular centers. The flue gas enters at 871°C (1144 K, 1600°F) and leaves at 538°C (811 K, 1000°F). The oil flows in a countercurrent direction to the gas and rises from 316 to 427°C (600 to 800°F). Tube surface emissivity is 0.8. What is the average heat-input rate, due to gas radiation alone, per square meter of external tube area ... 

The instrumental analyzer procedure, EPA Method 3A, is commonly used for the determination of oxygen and carbon dioxide concentrations in emissions from stationary sources. An integrated continuous gas sample is extracted from the test location and a portion of the sample is conveyed to one or more instrumental analyzers for determination of O9 and CO9 gas concentrations (see Fig. 25-30). The sample gas is conditioned prior to introduction to the gas analyzer by removing particulate matter and moisture. Sampling is conducted at a constant rate for the entire test run. Performance specifications and test procedures are provided in the method to ensure reliable data. 

The remaining. SO percent or less ot supply must have an average emission rate below the system average for fossil-fuel-emitted sulfur dioxide, nitrogen oxide, and carbon dioxide. 

Lan and Mottola [14] have presented two continuous-flow-sensing strategies for the determination of C02 in gas mixtures using a special reaction cell. Both approaches are based on the effect of the complex of Co(II) with phthalocyanine as a rate modifier of the CL emission generated by luminol in the absence of an added oxidant agent, which is enhanced by the presence of C02 in the system. This enhancement allows the fast and simple determination of carbon dioxide at ppm levels (v/v) in atmospheric air and in human breath. In the first case, a continuous monitoring system was applied however, because the flow of expired gas is not constant, a discrete sample introduction approach was used in the analysis of C02 in breath. 

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