ELEMENTARY PRINCIPLES OF CHEM. PROCESS.
ELEMENTARY PRINCIPLES OF CHEM. PROCESS.
4th Edition
ISBN: 9781119249214
Author: FELDER
Publisher: INTER WILE
bartleby

Videos

Textbook Question
Book Icon
Chapter 9, Problem 9.67P

A coal contains 73.0 wt% C, 4.7% H (not including the hydrogen in the coal moisture), 3.7% S, 6.8% H2O, and 11.8% ash. The coal is burned at a rate of50,000 lbm/h in a power-plant boiler with air 50% in excess of that needed to oxidize all the carbon in the coal to CO2. The air and coal are both fed at 77°F and 1 atm. The solid residue from the furnace is analyzed and is found to contain 28.7 wt% C, 1.6% S, and the balance ash. The sulfur oxidized in the furnace is converted to SO2(g). Of the ash in the coal, 30% emerges in the solid residue and the balance is emitted with the stack gases as fly ash. The stack gas and solid residue emerge from the furnace at 600°F. The higher heating value of the coal is 18,000 Btu/lbm.

  1. Calculate the mass flow rates of all components in the stack gas and the volumetric flow rate of this gas. (Ignore the contribution of the fly ash in the latter calculation, and assume that the stack gas contains a negligible amount of CO.)
  2. Assume that the heat capacity of the solid furnace residue is 0.22 Btu/(lbm·°F), that of the stack gas is the heat capacity per unit mass of nitrogen, and 35% of the heat generated in the furnace is used to produce electricity. At what rate in MW is electricity produced?
  3. Calculate the ratio (heat transferred from the furnace )/(heating value of the fuel). Why is this ratio less than one?
  4. Suppose the air fed to the furnace were preheated rather than being fed at ambient temperature, but that every thing else (feed rates, outlet temperatures, and fractional coal conversion) were the same. What effect would this change have on the ratio calculated in Part (c)? Explain. Suggest an economical way in which this preheating might be accomplished.
  5. Exploratory Exercises—Research and Discover

  • At least three components of the stack gas from the power plant raise significant environmental concerns. Identify the components, explain why they are considered problems, and describe how the problems can be addressed in a modem coal-fired power plant.
  • Several minor constituents of coal were not mentioned in the problem statement, and yet they may be part of the stack gas. Identify one such species and, as in Part (e), explain why it is a problem and how the problem either is or could be addressed in a modem coal-fired power plant.
  • Blurred answer
    Students have asked these similar questions
    The vapor pressure of Toluene at 50°C in Pa? Find it on perry's chemical engineering handbook 9th or 8th edition
    Hydrogen (H₂) is considered a clean energy carrier. For its use as a fuel, hydrogen is stored at 5 bar insidea cylindrical tank made of nickel (Ni) with 7 cm inner diameter, 1.2 mm thickness, and the length of L. Thetank is maintained at 358 K. Unfortunately, a small amount of hydrogen diffuses out of the tank, slowlydepleting its contents. You may assume that the hydrogen pressure outside the tank is essentially zero andconvective resistance inside and outside of the cylinder is negligible.• Solubility of H2 in Ni at 358 K = 0.00901 kmol/m3·bar• DH2, Ni at 358 K = 1.2 x 10-12 m2/sCalculate the maximum length of the nickel tank wall to ensure that the hydrogen loss does not exceed0.01 kg per year.
    You just took out a cold soda can (at 1 oC) from the refrigerator. Calculate thetemperature of the soda can after the can is placed in a room (at 31 oC, h = 100 W/m2-K) for 60 mins (we all know that soda tastes much better when it is cold!). • k = 0.617 W/m-K, density = 996 kg/m3, Cp = 4178 J/Kg-K• Height = 10 cm & Diameter = 5 cmCalculate the temperature of the soda can surface at the middle point of the heightusing 2-D analysis.

    Additional Science Textbook Solutions

    Find more solutions based on key concepts
    Knowledge Booster
    Background pattern image
    Chemistry
    Learn more about
    Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
    Similar questions
    SEE MORE QUESTIONS
    Recommended textbooks for you
    Text book image
    Introduction to Chemical Engineering Thermodynami...
    Chemical Engineering
    ISBN:9781259696527
    Author:J.M. Smith Termodinamica en ingenieria quimica, Hendrick C Van Ness, Michael Abbott, Mark Swihart
    Publisher:McGraw-Hill Education
    Text book image
    Elementary Principles of Chemical Processes, Bind...
    Chemical Engineering
    ISBN:9781118431221
    Author:Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
    Publisher:WILEY
    Text book image
    Elements of Chemical Reaction Engineering (5th Ed...
    Chemical Engineering
    ISBN:9780133887518
    Author:H. Scott Fogler
    Publisher:Prentice Hall
    Text book image
    Process Dynamics and Control, 4e
    Chemical Engineering
    ISBN:9781119285915
    Author:Seborg
    Publisher:WILEY
    Text book image
    Industrial Plastics: Theory and Applications
    Chemical Engineering
    ISBN:9781285061238
    Author:Lokensgard, Erik
    Publisher:Delmar Cengage Learning
    Text book image
    Unit Operations of Chemical Engineering
    Chemical Engineering
    ISBN:9780072848236
    Author:Warren McCabe, Julian C. Smith, Peter Harriott
    Publisher:McGraw-Hill Companies, The
    Mod-01 Lec-23 Degrees of freedom analysis; Author: nptelhrd;https://www.youtube.com/watch?v=c4h85JjrkzQ;License: Standard YouTube License, CC-BY
    Introduction to Degrees of Freedom; Author: LearnChemE;https://www.youtube.com/watch?v=tW1ft4y5fQY;License: Standard Youtube License