Determine the percentage of mass transfer resistance

Assignment Help Chemical Engineering
Reference no: EM131316940

Q1. Water is used to absorb the vapor of methanol at 300 K and 101.325 kPa. The concentration of methanol in both gas and liquid phases are very low, with the equilibrium relation following Henry's Law. The known parameters are:

solubility of methanol in water = 1.995 kmol/(m3 .kPa)
local mass transfer coefficient for gas film kG = 1.55E-5 kmol/(m2.s.kPa)
local mass transfer coefficient for liquid film kL = 2.08E-5kmol/(m2.s.kmol/m3)
(1) Please determine the overall mass transfer coefficient for gas phase, KG,

(2) And determine the percentage of mass transfer resistance in gas film out of the overall resistance.

(3) At steady operation in certain section of the absorption column, the partial pressure of methanol is 5 kPa and the liquid composition is 2.11 kmol/m3. Please determine the methanol absorption rate NA, [kmol/(m2.h)] . (2 points)

Q2. Water is used to absorb NH3 (mole fraction 0.1) from air at 1 atm in a counter current operation. The gas mixture at 313 K is fed to the bottom of the column at a flow rate of 0.556 m3/s and a velocity of 1.2 m/s. Water is introduced to the column from the top. Due to the enthalpy of dissolution, the temperature of the ammonium water is higher at the bottom of the column. The temperature and composition distribution in the liquid phase from top to bottom of the column, with corresponding gas phase equilibrium compositions are described by Table 1.

Table 1.

temperature of NH3 solution

composition of NH3 solution

gas phase composition

deg C

X, kmol (NH3) / kmol (H2O)

Y*, kmol (NH3) / kmol (air)

20

0

0

23.5

0.005

0.0056

26

0.01

0.01

29

0.015

0.018

31.5

0.02

0.027

34

0.025

0.04

36.5

0.03

0.054

39.5

0.035

0.074

42

0.04

0.097

44.5

0.045

0.125

47

0.05

0.156

(1) If the recovery of NH3 is 95%, assuming air is totally inert, please determine the theoretical minimum liquid flow rate Lmin, (kg/s)

(2) If the real liquid flow rate is 1.1 times of the theoretical minimum, and if the KGa is known to be 0.0556 kmol/(m3.s), please determine the diameter of the column, (m).

(3) Please determine the height of the packings (m), based on the above information.

Q3. Clean water is used to remove SO2 from air through a counter current scrubbing process to reach a 95% recovery, in which the flow rate of gas is 5000 std m3/h containing 10%(v/v) SO2. The equilibrium for the solute between gas and liquid is Y* = 26.7 X.

(1) Please determine the required liquid flow rate, assuming 1.5 fold of the theoretical minimum, (kmol/h).

(2) Please determine the number of theoretical plate.

(3) Using the number of plate determined from (2), if the recovery is to be increased from 95% to 98%, what will be the new water consumption (kmol/h)?

Page limit: 10 pages (maximum, excludes cover sheet)

Reference no: EM131316940

Questions Cloud

Prepare a cash budget for november through april : Assuming that the firm has a cash balance of $42,000 at the beginning of November and its desired minimum cash balance is $25,000, prepare a cash budget for November through April.
Evaluate and summarize quality management at process level : Evaluate and summarize overall quality management at the organization level. Evaluate and summarize quality management at the process level. Evaluate and describe quality management at the performer level.
Identify the roles of various stakeholders : Identify the selected health care service provider selected.Identify two additional services and products he or she provides.Identify the roles of various stakeholders and emerging roles within the health care service provider selected.Explain how th..
Book review of the five dysfunctions of a team : Book Review of The Five Dysfunctions of a Team OR The Dream Manager: Prepare a 25 page summary on the book double spaced paper to include: What did you learn about this book? What was if any impact on your thoughts as a current manager or a future m..
Determine the percentage of mass transfer resistance : ENSC3019 - Determine the percentage of mass transfer resistance in gas film out of the overall resistance - determine the height of the packings (m), based on the above information.
What are the key components of culture : Choose a social problem, and explain how the sociological imagination, as defined by C. Wright Mills, can be used to understand the causes and consequences of that problem. Be sure that you address and apply the components of the sociological imag..
Discuss legal aspects involved with contract closure : Discuss legal aspects involved with contract management and closure. Discuss the process to be used to handle any outstanding issues, claims, and disputes such as through an alternative dispute resolution (ADR).
How is the macro-trend personal lifestyle has affected : Macro-trends affect Healthcare. How is the macro-trend Personal Lifestyle and Behavior has affected the health communities in US?Using the above macro-trend (Personal lifestyle and behavior) identify 2 great jobs related to this macro-trend that ..
What methodology do they employ : What are the faculty main research questions and goals?What methodology do they employ?Does it seem appropriate for the research questions and goals? (Why or why not?)What evidence is presented? Do you find it convincing? (Why or why not?)

Reviews

Write a Review

 

Chemical Engineering Questions & Answers

  For making styrene from benzene and ethylene

Table: contains six-month average price data for styrene and its feedstock's ethylene and benzene for South Korea over the period Jan. 1999 to Dec. 2010. Calculate the gross margin

  What is the downstream temperature

Ten kmol per hour of air is throttled from upstream conditions of 298.15 K (25°C) and 10 bar to a downstream pressure of 1.2 bar. Assume air to be an ideal gas with Cp = (7/2)R.

  What is the flow rate of the gas stream

A gas stream contains 18.0mole% hexane and the remainder nitrogen, the stream flows to a condenser, where its temperature is reduced and some of the hexane is liquefied.

  Approximate percentages of the microconstituents

For parts (a), (c), (d), (f), and (h) of Problem 10.20, determine the approximate percentages of the microconstituents that form. (a) Rapidly cool to 250(C (480(F), hold for 103 s, then quench to room temperature.

  What is the composition of the final mixture

Compartment A contains 0.2 mol of pure methane at 50 °C, 1 bar. Compartment B contains 0.8 mol of a methane-ethane mixture at 100 °C, 1 bar with ymethane = 0.5. The partition is removed and the system reaches equilibrium.

  Which of the substance is soluble in water

On the basis of the general solubility rules given in Table 4.1, predict which of the following substances are likely to be soluble in water.

  Find the line current delivered by the source

Balanced wye-connected loads drawing 10 kW at 0.8 power factor lagging and 15 kW at 0.9 power factor leading are connected in parallel and supplied by a 60-Hz, 300-V, three-phase system. Find the line current delivered by the source.

  Determine the maximum value of the voltage induced in coil

determine the maximum value of the voltage induced in the coil.

  Find current through the capacitor

The voltage across a 4 mF capacitor is (t) = (200,000t 50,000)e-2000t µ(t) V. Find current through the capacitor

  Design a heat exchanger for the following dutyreduced crude

design a heat exchanger for the following dutyreduced crude oil leaving a distillation unit with a flow rate of 3166.04

  How are its profits affected when the yen depreciates

How are its profits affected when the yen depreciates against the dollar?

  How much heat is required to vaporize the steam

In an auto thermal reforming process, 1000 kmol/h of methane at 20 °C is compressed to 10 bar, mixed with 2500 kmol/h of saturated steam, and reacted with pure oxygen to give 98% conversion of the methane.

Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd