Consider a spherical tank of air originally at atmospheric pressure (1.013*105 N/m2). Air is being supplied at a uniform velocity of 2 m/s through a tube of diameter 2 cm. The tanks diameter is 1m. The inlet pressure is maintained at 3*105 N/m2 and the temperature of the tank and inlet pipe is 300K. Determine the time required for the pressure in the tank to reach 2*105 N/m2.

Please make sure to display your thought process? It is important to be able how the answer was deduced.

A certain extruder for plastics was found to work best at a melt viscosity of 2 X 10⁴ Pa-s. The polymer of choice had this viscosity at 145 °C when its DP­_w was 700. This polymer has a Tg of 75 °C. Because of polymerization kinetics miscalculation by someone who did not take polymer science, today’s polymer has DP_w of 500. At what temperature should the extruder be run so that the viscosity will remain at optimum conditions? (Assume two carbon atoms per mer backbone)

Calculate the energy required to convert 100 kg of ice at 0 degrees C and 1 atm. to water vapor at 650 degrees C and 60 bar. The heat of fusion of ice is 333.6 J/g at 0 degrees C.

Suggested path: i) convert the ice from solid to liquid, ii) heat the liquid to the boiling point, iii) convert the saturated liquid to a saturated vapor, iv) heat the vapor to the final temperature, v) pressurize the gas to the final pressure. Other paths are equally effective.

1. What are the main differences between the production of oil, natural gas and coal?

2. Write a short description of Gas to refinery products (fuels) conversion technology using Natural gas, carbon dioxide and water?

Which form of biomass do you prefer and why?

Consider the materials used for a bicycle frame. Common materials are aluminum, titanium and steel. A) Explain what are the main considerations for material selection for this application. B) Mention the principal advantages and disadvantages of using the mentioned materials. C) How can advanced materials can be used in this application? Which advanced materials do you propose that can be used?

A natural gas containing 82 mol% CH4 and the balance C2H6 is burned with 25% excess air in a boiler furnace. The fuel gas enters the furnace at 298 K, and the air is preheated to 423 K. The heat capacities of the stack gas components may be assumed to have the following constant values:

CO2: Cp=50.0 J/(mol.K)

H2O(v): Cp=38.5 J/(mol.K)

O2: Cp=33.1 J/(mol.K)

N2: Cp=31.3 J/(mol.K)

Assuming complete combustion of the fuel, calculate the adiabatic flame temperature in K.

For the liquid-phase isomerization reaction, cyclohexane (C6H12) methyl-cyclopentane (CH3-C5H9), 100.0 g of cyclohexane and 0.0 g of methyl-cyclopentane are present. Determine the mass of all reactants and products at thermodynamic equilibrium at 25degreesC. (Kc = 0.143 @ 25oC).

Compressed natural gas is fed into a small underground pipeline having an inside diameter of 5.9 in. The gas enters at an initial temperature of 120oC and constant pressure of 132.3 psig. The metered volumetric flow rate at standard pressure of 14.7 psia and standard temperature of 25oC is 195.4 ft3/min. The ground temperature is constant at 15oC and serves as an “infinite sink” for heat transfer. a) Show that the mass flow rate is 0.0604 kg/sec, volumetric flow rate is 0.01 m3/s at 50oC and 10 atm, the total system pressure is 10 atm, and the gas density assuming ideal behavior is 6.04 kg/m3 at 50oC. You may assume other properties not dependent on pressure for methane at 50oC are k = 0.035 W/m K, Cp = 220 J/kg K and μ = 1.2x10-5 kg/m-sec. b). Develop an energy balance model to predict the steady state temperature profile of the natural gas in the pipe. c). Is the gas flow laminar or turbulent? d). What are the Prandtl, Nusselt, and Stanton numbers, and also the heat transfer coefficient of methane in the pipe?

Suagr syrup is concentrated from 10% solids to 40% solids at the rate of 100 kg/h using steam in a jacketed tube. The syrup enters the tube at 15 C and is evaporated under reduced pressure at 80 C. The steam is supplied at 115 C. Assuming boiling point remains constant. Other pertinent properties are

Specific Heat of syrup= 3.96 kJ/kg

Latent Heat of vaporization= 2309 kJ/kg

Latent heat of steam condensation= 2217 kJ/kg

Specific heat of water= 4.2 kJ/kg

Calculate the amount of steam needed per hour assuming 1) condensate exits at boiling point temperature ,and 2) condensate exits at steam temperature.

A stream of methane at 86.06 kg/hr is burned in a boiler to heat water. The boiler is fed 47.7 % excess air. Solve for air flow rate in kg/hr.

Note: Air can be treated to be 78 % N₂, 21 % O₂ and 1% Ar, where all percentages are in mole percents. The average molecular weight for air of this composition is 28.970 kg/kgmol

Q2.

Chlorine gas is the main disinfectant used at a particular WWTP for pathogen removal. A spill has occurred within the plant that is some 15 ft below ground level.

a)What symptoms would you expect persons in close proximity to the plant to experience?

b)What safety precautions would you recommend in the event of a chlorine gas leak given it’s properties?

c)Explain the concept of breakpoint chlorination paying close attention to free and combined residuals at each stage of the process? (Chemical Equations are needed.)

1.Which of the following best describes Maxwell's Demon?