Orsat analysis

Bulk physical property tests, such as density and heating value, as well as some compositional tests, such as the Orsat analysis and the mercuric nitrate method for the determination of unsaturation, are still used. However, the choice of a particular test is dictated by (1) the requirements of the legislation, (2) the properties of the gas under study, and (3) the selection by the analyst of a suitable suite of tests to meet the various requirements. For example, judgment by the analyst is necessary whether or not a test that is applied to liquefied petroleum gas is suitable for process gas or natural gas insofar as inference from the nonhydrocarbon constituents will be minimal. 

Moist hydrogen containing 4 mole percent water is burnt completely in a furnace with 32 % excess air. Calculate the Orsat analysis of the resulting flue gas. 

Note The Orsat analysis is on a moisture free basis. 

It has been suggested that the gas be disposed of by burning with an excess of air. The gaseous combustion products are then emitted to the air through a smokestack. The local air pollution regulations say that no stack gas is to analyze more than 2 percent SCfc by an Orsat analysis averaged over a 24-hr period. Calculate the minimum percent excess air that must be used to stay within this regulation. 

C A low-grade pyrites containing 32 percent S is mixed with 10 kg of pure sulfur per 100 kg of pyrites so the mixture will bum readily, forming a burner gas that analyzes (Orsat) SQ>, 13.4 percent O2. 2.7 percent and N2, 83.9 percent. No sulfur is left in the cinder. Calculate the percentage of the sulfur fired that burned to SO5. (The SO3 is not detected by the Orsat analysis.)... 

An Orsat analysis (a technique for stack analysis) yields the following dry basis composition ... 

Measured by oxygen disappearance in regenerator as determined from Orsat analysis and oxygen balance. 

The analyses of gases such as air, combustion products, and the like are usually on a dry basis—that is, water vapor is excluded from the analysis. Such an analysis, called an Orsat analysis, is explained in Sec. 2.3. If the gas acts as an ideal gas and its cornponents are each measured by volume, you know (or will learn in Sec. 3.1) that volume percent under ordinary conditions is the same as mole percent. For example, consider the composition of air, which is approximately... 

Define flue gas, stack gas, Orsat analysis, dry basis, wet basis, theoretical air (oxygen), required air (oxygen), and excess air (oxygen). 

Explain the difference between flue gas analysis and Orsat analysis wet basis and dry basis for a gas. 

Toluene, CtHs, is burned with 30% excess air. A bad burner causes 15% of the carbon to form soot (pure C) deposited on the walls of the furnace. What is the Orsat analysis of the gases leaving the furnace ... 

The utilization of coal to produce gaseous fuels for heating and generating power as a supplement to the dwindling supplies of natural gas is a major research and development activity in the United States at the present time. Barriers to q nthetic fuel production are more economic than technological, but there are still many technical problems to be resolved. In a test of pilot plant coal gasifier with a production rate of 25.8 mVhr, the output gas with a composition of 4.5% CO2, 26% CO, 13% H2, 0.5% CH4, and 56% N2 is burned with 10% excess air. Calculate the Orsat analysis of the combustion product. ... 

In many fermentations, the maximum amount of cell mass must be obtained. However, the amount of mass that can be made is ultimately limited by the cell volume. Cells occupy a finite volume and have a rigid shape so that they cannot be packed beyond a certain limit. There will always be some water remaining in the interstices between the adjacent cells, which represents the void volume that at best can be as low as 40% of the fermenter volume. Calculate the maximum cell mass on a ilry basis that can be obtained if the wet cell density is LI g/cm. Assume the 40% void volume applies. Note that cells themselves consist of about 75% water and 25% solids, and cell mass is reported as dry weight in the fermentation industry. Aviation gasoline is isooctane, CgHjs. If it is burned with 20% excess air and 30% of the carbon forms carbon monoxide, what is the Orsat analysis ... 

A fuel composed of ethane (C2H6) and methane (CH4) in unknown proportions is burned in a fufhace ith oxygen-enriched aiir (50T0 mdle"% 02)r Your Orsat analysis is 25% CO2, 60% Nj, and 15% O2. Find ... 

When both boilers are on the line, the flue gas shows (Orsat analysis) 10.0% CO2, 4.5% O2, and the remainder N2. What percentage of the total carbon burned comes from the oil (Hint Do not forget the H2O in the stack gas.)... 

Given that the Orsat analysis from a turbojet shows 12.2% CO2, 0.4% CO, and 6.2% O2, compute the net hydrogen/carbon ratio in the fuel (the fuel contains negligible sulfur and nitrogen). Also compute the cubic meters of air used at 27"C and 101.4 kPa/kg of fuel burned. 

A hydrocarbon fuel is burned with bone-dry air in a furnace. The stack gas is at 116 kPa and has a dew point of 47°C. The Orsat analysis of the gas shows 10 mol % carbon dioxide the balance consists of oxygen and nitrogen. What is the ratio of hydrogen to carbon in the hydrocarbon fuel ... 

Bulk physical property tests, such as density and heating value, as well as some compositional tests, such as the Orsat analysis and the mercuric nitrate method for the determination of unsaturation, are still used. 

Oxygen and hydrogen in chlorine will be determined by Orsat analysis or gas chromatography. Results of samples taken at intervals will be averaged. 

Orsat analysis A measurement of the oxygen, carbon dioxide, and carbon monoxide in a mixture of gases, usually from the exhaust of combustion processes such as boilers, furnaces, fired heaters, and combustion engines. Named after its inventor H. Orsat in 1873, it involves absorption of the gases onto materials contained in pipette tubes. The method has been largely replaced by other techniques. 

---