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

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

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. Structure of Matter (Continued)

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 –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 2H 2 + O 2 2H 2 O reactantsproducts

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 = 1.008O = Multiply by number of atoms (if > 1) –ExampleH x 2 = Total these up to determine actual weight of entire molecule –Example H 2 O = = 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 N 2 + 2O 2  2NO 2 –So you need 1 mole of N 2 and 2 moles of O 2 to make 2 moles of NO 2

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 2NO 2 = 0.5 volume of NO 2

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 = kg, lbs, tons O = x 2 = kg, lbs, tons * 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 six- carbon 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 CO 3 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