Stream compositions, gas

Experimental Apparatus. Our experimental apparatus is shown in Fig. la. Constant composition gas streams of CO, N2 and O2 were obtained by three separate sonic orifice meters. The flow through the sonic orifice meters is affected only by the upstream pressure and is independent of the. fluctuations downstream as long as the ratio between the upstream and downstream pressures is greater than 2. Exposure of the reactant streams to stainless steel was minimized by using only Teflon tubing after the switching valve junction. The switching valve directed a desired gas mixture flow to the reactor while another gas mixture flow was... 

Catalyst Gas stream composition Gas stream temperature ( C) Pressure Space velocity vol/hr/vol Application Reference... 

Two different types of dynamic test have been devised to exploit this possibility. The first and more easily interpretable, used by Gibilaro et al [62] and by Dogu and Smith [63], employs a cell geometrically similar to the Wicke-Kallenbach apparatus, with a flow of carrier gas past each face of the porous septum. A sharp pulse of tracer is injected into the carrier stream on one side, and the response of the gas stream composition on the other side is then monitored as a function of time. Interpretation is based on the first two moments of the measured response curve, and Gibilaro et al refer explicitly to a model of the medium with a blmodal pore... 

Gas purification processes fall into three categories the removal of gaseous impurities, the removal of particulate impurities, and ultrafine cleaning. The extra expense of the last process is only justified by the nature of the subsequent operations or the need to produce a pure gas stream. Because there are many variables in gas treating, several factors must be considered (/) the types and concentrations of contaminants in the gas (2) the degree of contaminant removal desired (J) the selectivity of acid gas removal required (4) the temperature, pressure, volume, and composition of the gas to be processed (5) the carbon dioxide-to-hydrogen sulfide ratio in the gas and (6) the desirabiUty of sulfur recovery on account of process economics or environmental issues. 

Small amounts of sulfuric acid mist or aerosol are always formed in sulfuric acid plants whenever gas streams are cooled, or SO and H2O react, below the sulfuric acid dew point. The dew point varies with gas composition and pressure but typically is 80—170°C. Higher and lower dew point temperatures are possible depending on the SO concentration and moisture content of the gas. Such mists are objectionable because of both corrosion in the process and stack emissions. 

The curve in Figure 21 represents SO2 equiUbrium conversions vs temperature for the initial SO2 and O2 gas concentrations. Each initial SO2 gas concentration has its own characteristic equiUbrium curve. For a given gas composition, the adiabatic temperature rise lines can approach the equiUbrium curve but never cross it. The equiUbrium curve limits conversion in a single absorption plant to slightly over 98% using a conventional catalyst. The double absorption process removes this limitation by removing the SO from the gas stream, thereby altering the equiUbrium curve. 

The coarse calciae cooler operates at 300°C, while the waste-heat boiler cools the gas to 350°C. The tubes ia the boilers have a chain-shaking arrangement operated by paeumatic hammers. Steam productioa is 0.78 kg/kg of dry coaceatrate. The only trouble with dust reported is ia the connection betweea the reactor and waste-heat boiler. It is necessary to cool the gas stream quickly to avoid sulfation, but even so the carry-over calciae coataias oa the order of four times more sulfate than the coarse overflow. In this plant, the composite calciae is 0.1% sulfide and 2.2% sulfate sulfur. 

Gas-stream characteristics (e.g., vohrme flow rate, tempera-trrre, pressrrre, hrrmidity, composition, viscosity, density, reactivity, combrrstibUity, corrosivity, and toxicity)... 

Very sensitive to fluctuations in gas-stream conditions (in particular, flows, temperature, particulate and gas composition, and particulate loadings)... 

In most processes involving the absorption of a gaseous pollutant from an effluent gas stream, the gas stream is the processed fluid hence, its inlet condition (flow rate, composition, and temperature) are usually known. The temperature and composition of the inlet liq-... 

Raw Gas Composition The suitabihty of the raw gas stream must first be determined. The raw gas stream must contain the following in order to ensure both reasonable removal efficiencies and microorganism hfe expectancy ... 

The test gas must be of uniform and known composition. This generally requires on-line gas analysis if flammable mixtures are not supplied from a suitable reservoir. If concentration gradients are created in the surrounding air, errors can be introduced by releasing the test gas stream from a perforated probe doubling as an electrode. The maximum effective energy of a... 

Engineering factors include (a) contaminant characteristics such as physical and chemical properties - concentration, particulate shape, size distribution, chemical reactivity, corrosivity, abrasiveness, and toxicity (b) gas stream characteristics such as volume flow rate, dust loading, temperature, pressure, humidity, composition, viscosity, density, reactivity, combustibility, corrosivity, and toxicity and (c) design and performance characteristics of the control system such as pressure drop, reliability, dependability, compliance with utility and maintenance requirements, and temperature limitations, as well as size, weight, and fractional efficiency curves for particulates and mass transfer or contaminant destruction capability for gases or vapors. 

Newby and his colleagues provided some calculations of the performance of this partial oxidation cycle. They show that a major parameter in the performance of the PO cycle is the PO turbine inlet pressure, and listed calculations for three values of this pressure 45 bar, 60 and 100 bar. Their results for the composition of the gas streams round the plant (from the 60 bar calculation, which gave 49.3% for 335 MW) are given in Table 8.2. 

The gas stream shown in Table 8-10 is fed to an isothermal absorber operating at 90°F and 75 psia. 90% of the n-butane is to be removed by contact with a lean oil stream consisting of 98.7 mol% non-volatile oil and the light components shown in Column 2 of Table 8-10. Estimate the composition of the product streams and the required number of theoretical stages if an inlet rate of 1.8 times the minimum is used. 

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