ELEMENTARY PRINCIPLES OF CHEMICAL PROCESSES 3rd Edition

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ELEMENTARY PRINCIPLES OF CHEMICAL PROCESSES3rd
Edition

• Richard M. Felder
• Ronald W. Rousseau

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CHAPTER 2

• INTRODUCTION TO ENGINEERING CALCULATIONS

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UNITS AND DIMENSIONS

• All measured property has a value and a unit
• A dimension is a property that can be measured,
  or calculated by multiplying or dividing other
  dimensions.
• Measurable units are specific values of
  dimensions that have been defined by convention,
  custom, or law.

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• Numerical values of two quantities may be added
  or subtracted only if the units are the same
• Numerical values and their corresponding units
  may always be combined by multiplication or
  division

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SYSTEMS OF UNITS

• Base Units
• Multiple Units
• Derived Units
• SI system
• CGS System
• American Engineering System

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BASE UNITS
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Multiple Units

• Tera (T) 1012
• Giga (G) 109
• Mega (M) 10 6
• Kilo (k) 103
• Centi (c) 10-2
• Milli (m) 10-3
• Micro (µ) 10-6
• Nano (n) 10-9

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CONVERSION OF UNITS
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CONVERSION OF UNITS

• Conversion factors
• 1 cm 10 mm
• 10 mm 1 cm
• Convert 36 mg to grams.

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Conversion the Chemical Engineer way!!

• Convert 1 cm/s2 to it equivalent in km/yr2 .
• The Gas Constant R 8.314 m3-Pa/mol K. What is
  the value of R in lit-bar/mol K and cal/mol-K.

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PROBLEM!!

• A supersonic aircraft consumes 5320 imperial
  gallons of kerosene per hour of flight and flies
  an average of 14 hours per day. It takes roughly
  seven tons of crude oil to produce one ton of
  kerosene. The density of kerosene is 0.965 g/cm3.
  How many planes would it take to consume the
  entire annual world production of 4.02109 metric
  tons of crude oil?

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FORCE AND WEIGHT

• Force mass acceleration
• Units Newton (SI) Dyne (CGS)
• Pound-force (FPS)
• 1 N 1 kg.m/s2
• 1 dyne 1 g.cm/s2
• 1lbf 32.174 lbm .ft/s2

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More conversions

• What force would be required to accelerate a mass
  of 4 lbm at a rate of 9 ft/s2 ?
• 1 kg.m/s2 32.174 lbm.ft/s2
• gc
• 1 N 1 lbf

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DO NOT CONFUSE gc WITH g

• g acceleration due to gravity
• 9.8066 m/s2
• 980.66 cm/s2
• 32.174 ft/s2
• Water has a density of 62.4 lbm/ft3 . How much
  does 2 ft3 of water weigh at sea level and in
  Colorado where the altitude is 5374 ft and the
  gravitational acceleration is 32.139 ft/s2 ?

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PROBLEM 2.14

• A poundal is the force required to accelerate a
  mass of 1 lbm at a rate of 1 ft/s2 and a slug is
  the mass of an object that will accelerate at a
  rate of 1 ft/s2 when subjected to a force of 1
  lbf.
• Calculate the mass in slugs and the weight in
  poundals of a 175 lbm man on (i) earth and (ii)
  on the moon where the acceleration of gravity is
  one-sixth of its value on earth
• A force of 355 poundals is exerted on a 25.0-slug
  object. At what rate (m/s2) does the object
  accelerate?

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PROCESS DATA REPRESENTATION AND ANALYSIS

• Interpolation or extrapolation can be done by
• Two point linear interpolation/ extrapolation
• Graphical interpolation / extrapolation
• Curve fitting
• Linear regression or method of least squares

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SCIENTIFIC NOTATION, SIGNIFICANT FIGURES AND
PRECISION

• Significant figures of a number are the digits
  from the first nonzero digit on the left to
  either
• the last digit on the right if there is a
  decimal point or
• the last nonzero digit of the number if there is
  no decimal point

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RULES

• When two or more quantities are combined by
  multiplication and/or division, the number of
  significant figures in the result should equal
  the lowest number of significant figures of any
  of the multiplicants or divisors
• When two or more numbers are added and or
  subtracted, the positions of the last significant
  figures of each number relative to the decimal
  point should be compared. Of these positions, the
  one farthest to the left is the position of the
  last permissible significant figure of the sum or
  difference.

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CHAPTER 3

• PROCESS AND PROCESS VARIABLES

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MASS AND VOLUME

• Density mass per unit volume
• Kg/m3, g/cm3, lbm/ft3
• Specific Volume 1/density
• Specific Gravity ratio of density of a
  substance to the density of a reference substance
  at a specific condition (Units?)

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• Calculate the density of mercury in lbm/ft3.
  Specific gravity of mercury at 20C is 13.546.
  Also calculate the volume in ft3 occupied by 215
  kg mercury.

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EFFECT OF TEMPERATURE

• Temperature variation may be in either direction.
• Perrys Chemical Engineers Handbook,
• pp. 2-128 to 2-131

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FLOW RATE

• Mass flow rate
• Volumetric flow rate