A chemical engineering has been working with a local manufacturing firm. For several years the firm has been using chemical A as a solvent in their manufacturing process. Chemical A is carcinogenic, although studies supporting this claim have only recently been published. Without taking elaborate safety precautions, workers handling chemical A would be exposed to sufficient amounts to risk cancer. Moreover, the disease takes up to 20 years to manifest itself. The company has tried to implement safety procedures and controls, but workers routinely ignore them. The safety procedures slow down the manufacturing process, and the workers frequently cut corners to meet quotas. The chemical engineer knows of another chemical, B, which also serves as a catalyst in this manufacturing process but is not carcinogenic. Nevertheless, chemical B is considerably more expensive.

What should she do? Elaborate with details.

Give example about replacing dangerous solvent with a relatively safer one  

Benzaldehyde is produced from toluene in the catalytic reaction:

C6H5CH3 + O2 -> C6H5CHO + H2O (1)

C6H5CH3 + 9O2 -> 7CO2 + 4H2O (2)

Dry air and toluene vapor are mixed and fed to the reactor at 350F and 1 atm . Air is supplied in 100% excess. Of the toluene fed to the reactor, 13% reacts to form benzaldehyde and 0.5% reacts with O2 to produce CO2 and H2O. The product gases leave the reactor at 379F and 1 atm. Water is circulated through a jacket surrounding the reactor entering at 80F and leaving at 105F. Over a four hour period, 23.2 lbm of water is condensed from the product gases. Assume complete condensation. The heat capacity of both toluene and benzaldehyde vapors is 31 Btu/lb-moleF, and that of liquid benzaldehyde is 46 Btu/lb-moleF. The standard heat of formation of of benzaldehyde vapor is -17,200 Btu/lb-mole.

a. Calculate the volumetric flow rates (ft^3/hr) of the combined feed stream to the reactor and product gas.

b. Calculate the required rate of heat transfer from the reactor and the flow rate of cooling water (kg/min).

Consider non-dissociative adsorption. Assuming both adsorption and desorption are first-order processes, write down an expression for the coverage of an adsorbate as a function of time. The system is at a temperature T, there is only one component in the gas phase above the surface at pressure p and the saturation surface coverage is given by qmax. Assume adsorption is non-activated and that the sticking is direct. Hint: Start by writing d? (t) dt =? 0 d?(t) dt = r ads ? r des

Determine the percent error in the vapor volume from the real value (experimental data) for n-butane at 15 bar, 125^oC using the follow equations of state:

i) Ideal gas

ii) Van der Waals

iii) Peng Robinson.

A counter-flow double-pipe heat exchanger is to heat water from 20ºC to 80ºC at a rate of 1.2 kg/s. The heating is to be accomplished by geothermal water available at 160ºC at a mass flow rate of 2 kg/s. The inner tube is thin-walled, and has a diameter of 1.5 cm. If the overall heat transfer coefficient of the heat exchanger is 640 W/(m2.ºC), determine the length of the heat exchanger required to achieve the desired heating using the effectiveness-NTU method. Take the specific heat of geothermal water to be 4.31 kJ/(kg.ºC) and that of water to be 4.18 kJ/(kg.ºC).

1.A bomb calorimeter, or a constant volume calorimeter, is a device often used to determine the heat of combustion of fuels and the energy content of foods. In an experiment, a 0.3807 g sample of 1,6-hexanediol (C6H14O2) is burned completely in a bomb calorimeter. The calorimeter is surrounded by 1.139×103 g of water. During the combustion the temperature increases from 25.30 to 27.59 °C. The heat capacity of water is 4.184 J g-1°C-1. The heat capacity of the calorimeter was determined in a previous experiment to be 760.0 J/°C. Assuming that no energy is lost to the surroundings, calculate the molar heat of combustion of 1,6-hexanediol based on these data. C6H14O2(s) + (17/2) O2(g) 7 H2O(l) + 6 CO2(g) + Energy Molar Heat of Combustion = ? kJ/mol

Calculate the magnitude of the heat transfer (kJ) required to cool 65.0 liters of a liquid mixture containing 70.0 wt% acetone and 30.0% 2-methyl-1-pentanol (C6H14O) from 45.0°C to 20.0°C The specific gravity of 2-methyl-1-pentanol is about 0.826. The true heat capacity of 2-methyl-1-pentanol is about 248.0 J/(mol °C).

Estimate the required heat transfer using Kopp's rule to estimate the heat capacities of both acetone and 2-methyl-1-pentanol. ? kJ

Estimate the required heat transfer using the true heat capacities. ? kJ

A compressor compresses air flowing at 15 litre/s, 150 kPa, 20°C at the inlet to 500 kPa, 250°C at the outlet. During the compression, heat is lost at the rate of 1.5 kW. Determine the minimum input work for the compressor.

The density and percent crystallinity for two Nylon 6,6 materials are:

1.188 g/cm³ and 67.3%

1.152 g/cm³ and 43.7%

Compute the density of the totally crystalline and totally amorphous Nylon 6,6.

Discuss the advantages and disadvantages of disinfectants for pathogen removal from drinking water

environmental fate of medications medications can enter wastewater management systems either ... Question: Environmental fate of medications Medications can enter wastewater management systems either thro... (1 bookmark) Environmental fate of medications Medications can enter wastewater management systems either through human excretions or through improper disposal. Many medications are not effectively treated by current wastewater management processes and therefore are discharged by wastewater treatment plants. Antidepressants are some of the most commonly prescribed medications in the United States, and many antidepressants are not effectively managed by wastewater treatment plants. a. A wastewater treatment plant discharges to Boulder Creek in Colorado at a rate of 64 million L/day, and the stream flow, upstream of the wastewater discharge point, is 1110 L/s. If the concentration of the antidepressant venlafaxine (Effexor) measured in the creek water is 10 ng/L, what is the mass discharged per day from the wastewater treatment plant, assuming that there are no sources other than the wastewater treatment plant, and assuming that the drug rapidly equilibrates among sediment, fish, and water? What is the concentration of the medication in the wastewater treatment plant effluent?

environmental fate of medications medications can enter wastewater management systems either ... Question: Environmental fate of medications Medications can enter wastewater management systems either thro... (1 bookmark) Environmental fate of medications Medications can enter wastewater management systems either through human excretions or through improper disposal. Many medications are not effectively treated by current wastewater management processes and therefore are discharged by wastewater treatment plants. Antidepressants are some of the most commonly prescribed medications in the United States, and many antidepressants are not effectively managed by wastewater treatment plants. a. A wastewater treatment plant discharges to Boulder Creek in Colorado at a rate of 64 million L/day, and the stream flow, upstream of the wastewater discharge point, is 1110 L/s. If the concentration of the antidepressant venlafaxine (Effexor) measured in the creek water is 10 ng/L, what is the mass discharged per day from the wastewater treatment plant, assuming that there are no sources other than the wastewater treatment plant, and assuming that the drug rapidly equilibrates among sediment, fish, and water? What is the concentration of the medication in the wastewater treatment plant effluent?

Environmental fate of medications Medications can enter wastewater management systems either through human excretions or through improper disposal. Many medications are not effectively treated by current wastewater management processes and therefore are discharged by wastewater treatment plants. Antidepressants are some of the most commonly prescribed medications in the United States, and many antidepressants are not effectively managed by wastewater treatment plants. a. A wastewater treatment plant discharges to Boulder Creek in Colorado at a rate of 64 million L/day, and the stream flow, upstream of the wastewater discharge point, is 1110 L/s. If the concentration of the antidepressant venlafaxine (Effexor) measured in the creek water is 10 ng/L, what is the mass discharged per day from the wastewater treatment plant, assuming that there are no sources other than the wastewater treatment plant, and assuming that the drug rapidly equilibrates among sediment, fish, and water? What is the concentration of the medication in the wastewater treatment plant effluent? BCF = 40.27 KOC = 3.162 Organic sediment = 15 ppm Biota concentration = 5 g/100 m3 b. A man fishing near the outflow point of Boulder Creek eats 0.2 kg of fish from the creek. How much venlafaxine will he ingest? One dose of Effexor contains 75 mg of venlafaxine. What percentage of a dose will the fisherman ingest?

Velocity field for this system is:

V=[X^2-(y*z^1/2/t)]i-[z*y^3+(x^1/3*z^2/t^1/2)j+[-x^1/3*t^2/z*y^1/2]k

find the components of acceleration for the system.

Question 2. A family in Eastern Australia installs solar panels to run an air-source heat pump to heat their swimming pool. The panels produce a total of around 6 kW of electricity during the day. The heat pump draws 5 kW of electricity and delivers 23 kW of heating to the pool.

a) The pool contains 40,000 litres of water. When the heat pump is running, estimate the rate at which the temperature of the water in the pool rises, in kelvins per hour. How much would the pool heat up after 8 hours of running the heat pump? Assume a specific heat capacity for the water of 4.18 kJ kg–1 K–1. [4 marks] Answers: 0.5 K per hour, 4 K

b) If the cost of electricity in that part of Australia is 0.25 $ per kWh, how much has the family saved by using solar power instead of purchasing electricity to heat the pool directly for 8 hours? [2 marks] Answer: $46

c) The additional 1 kW of electricity generated by the solar panels is available to run the centrifugal pump that pumps the water from the swimming pool through the heat pump (a negligible amount of this energy ends up as heat energy in the water; most is lost to the atmosphere). Figure 2.1 shows the characteristic curves for the pump at different speeds. The pump sits below the pool, with pipework totalling 11 m of 25.4 mm internal diameter smooth plastic piping. There is a sharp-edged inlet (KL = 0.5) and exit back into the pool (KL = 1.0), with two 90° bends (KL = 0.85 each) in the pipework on both the suction and discharge sides (four 90° bends altogether).

i) Write down the extended form of Bernoulli’s equation, including terms to account for the head loss due to friction and the head contributed by the pump. [3 marks]

ii) In this system the head loss due to friction must be just balanced by the pressure head increase delivered by the pump. Show that the head loss due to friction can be expressed as a function of the volumetric flowrate of fluid through the pump, Q, as follows: 2 ?h f ? 20 00 00KQ [6 marks]

iii) For a flowrate of 120 litres min–1, use the Moody chart on page 3 to show that the Fanning friction factor is around 0.0044, and show that the head loss due to friction is 10 m. Assume the density of water is 1000 kg m–3 and the viscosity is 0.001 Pa s. [10 marks]

iv) From the characteristic curves shown in Figure 2.1, identify the pump speed in rpm required to deliver the desired flowrate of 120 litres min–1. Explain your reasoning. [2 marks] Answer: 2000 rpm

v) Calculate the power drawn by the pump to deliver 120 litres min–1, if the pump efficiency is 65%. [3 marks] Answer: 300 W