Your truck transports ethylene to customers at - 200°F and 1 atm pressure. How manylb's of ethylene will it take to fill up a customers 100 ft3 tank to a final pressure of 1000psia and a final temperature of 70°F? (Tc= 283.1 K, Pc= 50.5 atm)

ANSWER IS 1400 lb. Please show steps to get answer.

Hydrogen may be the fuel of the next generation. Why would hydrogen be used in a fuel cell to make electricity rather than in a combustion engine?

Classify desalination technologies according to “Separation method” and “Driving force”. Give examples.

Explain the phenomenon of concentration polarization in ED systems (i.e. depletion of ions….etc). What should be done to minimize fouling? and define current density, and CD/N ratio. How is CD/N ratio related to concentration polarization in ED systems?

Compare porous vs non-porous membranes with respect to water diffusion mechanism, pressure difference. Give examples on both types.

Define salt rejection, salt passage, and water recovery.

What is the difference between membrane fouling and membrane degradation? Classify membrane fouling (i.e. biofouling, organic, and inorganic) and suggest cleaning methods.

Define Electrodialysis (ED), draw a schematic diagram of the process, and determine the main characteristics of ion exchange membranes to be used. What are the process limitations in ED systems? then differentiate between dialysis and osmosis phenomena.

What is sludge volume index used for? Describe the term “bulky sludge” and identify the reason behind its formation.

List examples of major unit operations in preliminary, primary, secondary and tertiary treatment stages. What is the main objective of each treatment stage?

What are the main advantages and disadvantages of MBRs? Compare submerged (internal) versus external types of MBRs. and what are the important parameters to be considered in the design of ASP or MBRs?

The walls of an industrial freezer are constructed from a composite of three materials, an inner layer of plastic, a layer of insulation material, and an outer layer of stainless steel. Heat transfer occurs into the interior of the freezer from the external atmosphere.

a) Provide a sketch to illustrate the variation in temperature from the interior of the freezer compartment to the outer ambient air. In your sketch clearly identify the individual thermal resistances and identify the mode of heat transfer for each resistance. You may assume there are no contact resistances at the interfaces

b) Determine the rate of heat transfer (per unit area) through the walls of the freezer. State any assumptions that you make.

c) What thickness of insulation material is required such that the rate of heat transfer per unit area is reduced to 18 W/m2 ?

Data :
Temperature of freezer compartment, 253 K Ambient temperature, 27 °C
Internal heat transfer coefficient, 13 W/(m2 K) External heat transfer coefficient, 6 W/(m2 K)

Plastic material: Thickness, 5 mm Thermal conductivity,

Insulation material: Thickness, 100 mm Thermal conductivity,

Stainless steel: Thickness, 1.5 mm Thermal conductivity,

1 W/(m K)

0.07 W/(m K)

16.5 W/(m K)

What are the main advantages of incorporating membrane technology in biological treatment such as ASP? Draw a schematic diagram of activated sludge process (ASP) and membrane bioreactors (MBRs). Label all streams and provide a brief description for mixed liquor suspended solids (MLSS), return activated sludge, wastage sludge, hydraulic retention time, solid retention time, and F/M ratio.

A liquid is stored in a vessel at 102 bar (absolute) from where it is transferred (at 1.5 kg/s) into another vessel via a 5 cm steel pipe (friction factor = 0.025). The pressure above the liquid surface in the second vessel is maintained at 2000 Pa (gauge). The pipe length between the two vessels is 200 m. Total minor head losses due to fittings, valves as well as entry and exit losses amount to 4,000 equivalent length in pipe diameters. The liquid level in the first vessel is 25 m higher than the liquid level in the second vessel. The specific gravity of the liquid is 0.9 while its viscosity is 0.76 mPa s. In order to recover excess energy, a turbine is integrated into the pipeline. (i) Calculate the Reynolds number for this liquid flow. (ii) Describe the characteristics of this flow in the context of its flow regime (laminar or turbulent). (iii) Estimate the power that can be recovered using the turbine (assuming it is 80% efficient).

Q1.

Describe the operation of a biofusion bioreactor.

Q2.

Why KL_a of a bubble column reactor is more than that of airlift bioreactor.

Q3.

For mycellial pellet growth, how is adequate interrupted O₂ supply maintained in case of large pellets?

Q4.

Why is dynamic method for KL_a determination in O₂ concentration not allowed to drop below its critical level?

Q5.

Describe hollow fibre reactor for the monoclonal antibodies by animal cell culture.