Transcript No Slide Title - Industrial ISD

Introduction to
Process Technology
Unit 5
Applied Chemistry
Agenda
•
•
•
•
•
•
•
•
•
•
What is Chemistry?
Chemistry in process industry
Organic and Inorganic
Chemical and Physical Properties
Terminology
Reactions
Chemical Formulas, Calculating Mass
Acid, Base, pH
Hydrocarbons
Review
Chemistry in the Process Industry
• Chemistry – the science that describes
matter, its chemical and physical
properties, the chemical changes it
undergoes, and the energy changes that
accompany those processes.
Chemistry in the Process Industry
• Through chemistry, scientists and process
technicians are able to understand various
elements and compounds, their properties,
and how they interact with one another in the
presence of heat, cold, catalyst, and other
variables.
• By understanding these principles, the
process industries are able to produce better
products and safer processes.
Chemistry in Process Industry
• How Chemistry Applies to Process Tech
– Turning raw materials into products
– Proper management of waste
– Understand chemistry concepts that occur
during manufacturing process
– Understand terminology
– Understand concepts to troubleshoot
problems and improve quality, efficiency
Structure of Matter
• Atoms – smallest particle of an element that retains the properties of
that element
– Protons – positively charged subatomic particle found in
the nucleus of an atom
– Neutrons – subatomic particle found in the nucleus of
an atom that has no charge
– Electrons – negatively charged subatomic particle found in
orbiting the nucleus of an atom
-- Valence Electrons – outermost electrons which provide links
for bonding
• Molecule – neutral chemically bonded groups of atoms that
act as a unit
Structure of Matter (Continued)
• Atomic Number – the number of protons in the
nucleus of an atom of an element
• Atomic Mass (Molecular Weight) – weighted
average of the masses of the isotopes of an element
predominantly from masses of protons & neutrons
• Determining Molecular Weight –
– Add all masses of each element. Remember to
multiply if more than 1 present.
The Periodic Table (cont.)
(Sodium Atoms)
Organic and Inorganic
• Chemistry – science that deals with the composition,
behavior, and transformation of matter
• Organic – carbon based
– Hydrocarbon – contains only hydrogen and carbon
• Inorganic – no carbons
– Such as salts, acids, bases, metals
– Many agricultural products
Physical Properties
• Density – mass (weight) per unit volume
• Specific Gravity – comparison of density to that of
water for solids and liquids and to air for gases
• Hardness – ability of one substance to scratch/mark
another
• Odor – smell of substance
• Color – optical sensation produced by effect of light
waves stiking surface
Chemical Properties
• The ability of a substance to form new
substances under given conditions.
• A listing of all chemical reactions of a
substance and the conditions under
which the reactions can occur.
Reactivity of a Chemical
• The ability of a substance to form new
substances under given conditions
• A listing of all chemical reactions of a
substance and the conditions under which
the reactions can occur
Types of Bonds
• Ionic – metal and non-metal. Electrons
are transferred
• Covalent – non-metals. Electrons are
shared
• Metallic – metal to metal. Electrons free
flow
Terminology
• Matter – anything occupying space that has mass
• Element – simplest form of matter
• Compound – pure substance made up of elements
that are chemically combined
• Mixture - mixed together, but no chemical reaction
• Solution - a homogenous mixture of 2 or more substances in
a single phase (usually liquid). Solute and solvent.
Terminology (Continued)
• Solvent – substance that dissolves
• Solute – substance that is dissolved
– Solubility : how well solvent dissolves the
solute
• Freezing Point
• Melting Point
Terminology (Continued)
• Boiling Point
– When vapor pressure of liquid equals
system pressure
– As vapor pressure increases, boiling point
decreases
– As pressure increases, so does boiling point
– The higher the vapor pressure the more
easily a material evaporates
Terminology (Continued)
• Homogenous
– Same throughout
– Can’t tell one part of mixture from another
• Heterogeneous
– Different
• Equilibrium
– Rate of reactants forming products = rate of
products forming reactants
• Anion – atom or group of atoms with negative charge
• Cation - atom or group of atoms with positive charge
Chemical Reactions
• Chemical Reactions
–
–
–
–
Endothermic – needs/absorbs heat
Exothermic – gives off heat
Neutralization – acid + base
salt + water
Combustion –
• fuel + oxygen
combustion products + heat + light
– Replacement – removes minerals from water
Chemical Reactions are
Affected By
• Heat --- increases molecular activity and
reaction rate (rates double with each 10°)
• Pressure – slows molecular movement and
changes boiling point
• Surface Area – solids
• Concentration of liquid and gas
components
• Flow Rates of reactants and products
Chemical Reactions
• Catalyst
– Helps a reaction go at a lower temp or
increases rate of reaction
– Is not consumed in the reaction
Types of Catalysts
• Adsorption – solid that attracts and holds
reactant molecules so more collisions
can occur. Also stretches bonds of
reactants making them easier to break,
which requires less energy.
Types of Catalysts
• Intermediate – attaches to reactant
molecules and slows it down so
collisions can occur
• Inhibitor – decreases reaction rate
• Poisoned / Spent – no longer functions
due to contamination or has been used
up
– Some can be regenerated
Chemical Equations
• Like a recipe
• Must be balanced (same number of
atoms of each element in reactants as
products
2H2 + O2
2H2O
reactants
products
Mass Relationships
• Allows us to take a balanced equation
and use it to determine the actual
mass/weight needed for reactants and
how much product can be produced
Mass Relationships - Steps
• Find molecular weight of each element on
periodic table (AMUs, but represent grams,
pounds, etc.)
– Example H = 1.008 O = 16.00
• Multiply by number of atoms (if > 1)
– Example
H x 2 = 2.016
• Total these up to determine actual weight of
entire molecule
– Example H2O = 2.016 + 16.00 = 18.016
• Note how reactant mass = product mass
Mass Relationships - Steps
• Determine how many moles (amounts) of
a reactant are needed to produce a set
amount of product
– Example
N2 + 2O2  2NO2
– So you need 1 mole of N2 and 2 moles of O2 to
make 2 moles of NO2
Mass Relationships - Steps
• Determine the relative volume of
reactant or product you have
– Example if you only have 16 pounds of O, you
only have 0.25 volume (16/64)
• Multiply the relative volume by the
amount of product you can make
– Example – 0.25 x 2NO2 = 0.5 volume of NO2
Mass Relationships - Steps
• Multiple the volume you can make by the
molecular weight of material
– Example – 0.5 volume x 46 * = 23 kg, lbs, tons
N=
14.00 kg, lbs, tons
O = 16.00 x 2 = 32.00 kg, lbs, tons
* 46.00 kg, lbs, tons
Material Balances
• Method used to determine the exact
amount of reactants needed to produce the
specified products in the quantity desired
• Steps
– Determine the weight of each molecule
– Ensure reactant total weight equals product
total weight
– Determine relative number of reactant atoms
or ions
Percent by Weight Solutions
• Weight of solute (material that is
dissolved) is taken in relationship to
entire solution
• 650 pound barrel has 10% catalyst
solution
– 650 lb x 0.10 (percent as decimal) = 65 lbs
Acid, Base and pH
• pH – measurement of hydrogen ions in solution
• Acid (pH > 0 and < 7)
– Sour taste
– Vinegar, Hydrocholoric Acid, Hydrofluoric Acid
• Base (pH > 7 and < 14)
– Bitter taste, slippery
• Alkaline
• Caustic –pungent odors
– Lye, sodium hydroxide, caustic soda
• Neutral – pH = 7
• The stronger the acid or base the more hazardous to
body tissue and metal
Acids and Bases (cont.)
Hydrocarbons
• Compound that contains both hydrogen
and carbon
• Fossil fuels – oil & natural gas, and their
refined products (gasoline, ethylene)
Hydrocarbons
• Major groups
– Alkanes – single covalent bond (methane, propane,
ethane, etc)
– Olefins – not naturally occurring. Produced by
cracking oil. At least one double bond (hence the
high energy when used)
•
•
•
•
Alkenes – double bonds (ethylene, propylene)
Alkyne – triple bonds (acetylene – only one used widely)
Cycloalkane – contains a ring or cycle of carbons
Aromatic – contains at least one highly unsaturated sixcarbon ring
Aromatic Hydrocarbons
• Include both hydrocarbons and
compounds that cannot be classified as
hydrocarbons
• Most common - benzene
Alcohols
• Compounds that contain OH goups
connected to an alkyl carbon.
– Ethanol – commonly referred to as grain
alcohol since often produced from corn, rye,
wheat, molasses (from sugar cane), grapes
and potatoes.
• Becoming popular as gasoline additive or main
fuel.
Alcohols
• Methanol – referred to as wood alcohol,
because it was originally derived from
wood.
– Now produced by subjecting H to CO3 at high
temp. in presence of catalyst.
– Used as solvent in paints, varnishes,
production of formaldehyde, cleaners.
Alcohols
• Isopropyl Alcohol – most common is
rubbing alcohol used externally for
cooling skin, disinfect cuts, cosmetic
solvent
Phenols
• Similar to alcohols, but have an OH group
connected directly to an aromatic ring.
• Used in antiseptics, dyes, aspirin, and at
one time throat lozenges
Ethylene Glycol
• Highly reactive ethylene oxide is reacted with water
• Commonly used as antifreeze in vehicle radiators
because of unique abiltiy to lower freezing point of
water.
• Also has higher boiling point than water so better
suited to high and low temp. variations due weather
extremes.
• Because of toxicity when ingested there is a move to
switch to less toxic propylene glycol – which many
countries in Europe have already done
Applied Concepts
• Distillation – separation of various
fractions in a mixture by individual
boiling points
• Reactors – designed to break or make
chemical bonds which changes
reactants into products
Applied Concepts
• Catalytic Cracking – splits side stream of
fractionating column into smaller, more
useful molecules – for example, kerosene
into hexane and hexene
• Hydrocracking – process used to boost
gasoline yield
• Alkylation – uses a reactor to make one
large molecule out of smaller ones. For
example isobutane and olefins into high
octane alkylates
Review
• List importance of applied chemistry to
process technicians
• Re-write all vocabulary words and their
definitions
• Understand difference between the following:
– Organic and inorganic
– Endothermic and exothermic
– Acids and bases
• Define the 4 basic chemical reactions most
common to process industry
Work
• Read CAPT Chapter 11 (pages 158 – 169)
– Do questions 1 – 13 on pages 170 & 171)
• Read Thomas Chapter 13 (pages 281 – 302
– Do questions 1 – 21 on page 303
• Module 5, Exercise 1 – Chemistry Supplement
• Major Grade
• In class example worked by group
Independent Project
• Internet or literature search
• Write a paper on the importance of chemistry
to 2 different process industries
• List raw materials, products
• List what chemical reactions, terms apply
• Identify associated safety and environmental
measures and/or concerns