GTU 3150501 Mass Transfer Operations I Summer 2024 Question Paper & PDF

Discuss the effect of temperature and pressure on diffusivity for gases and liquids. For a gaseous system, DAB = 0.202 cm²/s at 25 °C. Determine diffusivity (m²/s) of that system at 40 °C if pressure is halved and other parameters remain constant.

Ethanol vapor is diffusing through a layer of water vapor under equimolar counter diffusion at 35 ºC and 1 atm. pressure. The molal concentration of alcohol on the two sides of the gas film (water vapor) 0.3 mm thick are 80% and 10% respectively. Assuming the diffusivity of alcohol–water vapor to be 0.18 cm²/s,

Classify Gas-Liquid equipment in details and compare packed tower with tray tower. Also compare random and regular packings.

In a wetted wall column, Carbon dioxide is being absorbed from air by water flowing at 2 atm and 25 ºC. The MTC ky’ is to be 6.78*10⁻⁵ kmol/m²s mole fraction. Determine rate of absorption if partial pressure of carbon dioxide at interface is 0.2 atm and the air is pure. Also determine ky and kg.

For a multistage counter-current liquid extraction operation, carry out material balance and explain it.

If 1000 kg/h of a nicotine (C)-water (A) solution containing 1% nicotine is to be counter currently extracted with kerosene at 20°C to reduce the nicotine content to 0.1%, determine (a) the minimum kerosene rate and (b) the number of theoretical stages required if 1150 kg of kerosene is used per hour x (kg nicotine/ kg water) 0 0.001011 0.00246 0.00502 0.00751 0.00998 0.0204 y* (kg nicotine/ kg water) 0 0.000807 0.001961 0.00456 0.00686 0.00913 0.01870

Explain the effect of temperature on the ternary diagram for a system of three liquids with one pair partially soluble

Ammonia is diffusing through an inert air film 2 mm thick at a temperature of 20 ºC and a pressure of 1 atm. The concentration of ammonia is 10% by volume on one side of the film and zero on the other side. Determine the mass flux. Estimate the effect on the rate of diffusion if the pressure is increased to 10 atm. The diffusivity of NH3 in air at 20°C and 1 atm. is 0.185 cm²/s.

An air–NH3 mixture containing 20 mole % of NH3 is being treated with water in a packed tower to recover NH3. The inlet gas rate is 700 kg/hm². The water used is 1.5 times the minimum and enters the tower with 2% of NH3. Under these conditions, 90% of NH3 is absorbed from the feed. Determine Gs, inlet and outlet mole ratio of ammonia in gas stream and liquid stream. Also mention steps in detail to determine number stages graphically for a counter current absorber.