CHEMICAL ENGINEERING For additional information concerning heat transfer and Ethers fluid mechanics, refer to the HEAT TRANSFER, THER- Ethers are generally designated by naming the alkyl groups MODYNAMICS, MECHANICAL ENGINEERING or and adding the word ether. The group RO is known as an FLUID MECHANICS sections. alkoxyl group. Ethers may also be named as alkoxy For additional information concerning chemical process derivatives of hydrocarbons. control, refer to the COMPUTERS, MEASUREMENT, Carboxylic Acids AND CONTROLS section. The name of each linear carboxylic acid is unique to the For additonal information concerning statistical data number of carbon atoms it contains. 1: (one carbon atom) analysis, refer to the following. Formic. 2: Acetic. 3: Propionic. 4: Butyric. 5: Valeric. 6: Confidence Intervals Caproic. 7: Enanthic. 8: Caprylic. 9: Pelargonic. 10: Capric. See the subsection in the ENGINEERING PROBABILITY Aldehydes AND STATISTICS section of this handbook. The common names of aldehydes are derived from the acids Statistical Quality Control which would be formed on oxidation, that is, the acids See the subsection in the INDUSTRIAL ENGINEERING having the same number of carbon atoms. In general the ic section of this handbook. acid is dropped and aldehyde added. Linear Regression Ketones See the subsection in the ENGINEERING PROBABILITY The common names of ketones are derived from the AND STATISTICS section of this handbook. acid which on pryrolysis would yield the ketone. A second One-Way Analysis of Variance (ANOVA) method, especially useful for naming mixed ketones, See the subsection in the INDUSTRIAL ENGINEERING simply names the alkyl groups and adds the word ketone. section of this handbook. The name is written as three separate words. SELECTED RULES OF NOMENCLATURE IN ORGANIC CHEMISTRY Alcohols Three systems of nomenclature are in general use. In the first the alkyl group attached to the hydroxyl group is named and the separate word alcohol is added. In the second system the higher alcohols are considered as derivatives of the first member of the series, which is called carbinol. The third method is the modified Geneva system in which (1) the longest carbon chain containing the hydroxyl group determines the surname, (2) the ending e of the corresponding saturated hydrocarbon is replaced by ol, (3) the carbon chain is numbered from the end that gives the hydroxyl group the smaller number, and (4) the side chains are named and their positions indicated by the proper number. Alcohols in general are divided into three classes. In primary alcohols the hydroxyl group is united to a primary carbon atom, that is, a carbon atom united directly to only one other carbon atom. Secondary alcohols have the hydroxyl group united to a secondary carbon atom, that is, one united to two other carbon atoms. Tertiary alcohols have the hydroxyl group united to a tertiary carbon atom, that is, one united to three other carbon atoms. 101 CHEMICAL ENGINEERING (continued) Common Names and Molecular Formulas of Some Industrial (Inorganic and Organic) Chemicals Molecular Common Name Chemical Name Formula Muriatic acid Hydrochloric acid HCl Cumene Isopropyl benzene C6H5CH(CH3)2 Styrene Vinyl benzene C6H5CH = CH2 — Hypochlorite ion OCl–1 –1 — Chlorite ion ClO2 –1 — Chlorate ion ClO3 –1 — Perchlorate ion ClO4 Gypsum Calcium sulfate CaSO4 Limestone Calcium carbonate CaCO3 Dolomite Magnesium carbonate MgCO3 Bauxite Aluminum oxide Al2O3 Anatase Titanium dioxide TiO2 Rutile Titanium dioxide TiO2 — Vinyl chloride CH2=CHCl — Ethylene oxide C2H4O Pyrite Ferrous sulfide FeS Epsom salt Magnesium sulfate MgSO4 Hydroquinone p-Dihydroxy benzene C6H4(OH)2 Soda ash Sodium carbonate Na2CO3 Salt Sodium chloride NaCl Potash Potassium carbonate K2CO3 Baking soda Sodium bicarbonate NaHCO3 Lye Sodium hydroxide NaOH Caustic soda Sodium hydroxide NaOH — Vinyl alcohol CH2=CHOH Carbolic acid Phenol C6H5OH Aniline Aminobenzene C6H5NH2 — Urea (NH2)2CO Toluene Methyl benzene C6H5CH3 Xylene Dimethyl benzene C6H4(CH3)2 — Silane SiH4 — Ozone O3 Neopentane 2,2-Dimethylpropane CH3C(CH3)2CH3 Magnetite Ferrous/ferric oxide Fe3O4 Quicksilver Mercury Hg 2 Heavy water Deuterium oxide (H )2O — Borane BH3 Eyewash Boric acid (solution) H3BO3 2 — Deuterium H — Tritium H3 Laughing gas Nitrous oxide N2O — Phosgene COCl2 Wolfram Tungsten W –1 — Permanganate ion MnO4 –2 — Dichromate ion Cr2O7 +1 — Hydronium ion H3O Brine Sodium chloride NaCl (solution) Battery acid Sulfuric acid H2SO4 102 CHEMICAL ENGINEERING (continued) CHEMICAL THERMODYNAMICS Often at system pressures close to atmospheric: L sat Vapor-Liquid Equilibrium fi ≅ Pi ˆ For a multi-component mixture at equilibrium The fugacity coefficient Φi for component i in the vapor is ˆf V = ˆf L , where calculated from an equation of state (e.g., Virial). i i Sometimes it is approximated by a pure component value ˆ V fi = fugacity of component i in the vapor phase, and from a correlation. Often at pressures close to atmospheric, Φˆ = 1. The fugacity coefficient is a correction for vapor ˆ L i fi = fugacity of component i in the liquid phase. phase non-ideality. Fugacities of component i in a mixture are commonly For sparingly soluble gases the liquid phase is sometimes calculated in the following ways: represented as For a liquid ˆf L = x γ f L , where ˆ L i i i i fi =xiki xi = mole fraction of component i, where ki is a constant set by experiment (Henry’s constant). γi = activity coefficient of component i, and Sometimes other concentration units are used besides mole L fraction with a corresponding change in ki. fi = fugacity of pure liquid component i. Reactive Systems ˆ V ˆ For a vapor f i = yi Φ i P , where Conversion: moles reacted/moles fed yi = mole fraction of component i in the vapor, Extent: For each species in a reaction, the mole balance ˆ may be written: Φi = fugacity coefficient of component i in the vapor, and molesi,out = molesi,in + viξ where P = system pressure. ξ is the extent in moles and vi is the stoichiometric The activity coefficient γi is a correction for liquid phase coefficient of the ith species, sign of which is non-ideality. Many models have been proposed for γi such negative for reactants and positive for products. as the Van Laar model: Limiting reactant: reactant that would be consumed first if −2 ⎛ A x ⎞ reaction proceeded to completion. Other reactants ⎜ 12 1 ⎟ lnγ1=A12 ⎜1+ ⎟ are excess reactants. ⎝ A21x2 ⎠ −2 , where Selectivity: moles of desired product formed/moles of ⎛ A x ⎞ ⎜ 21 2 ⎟ undesired product formed. lnγ 2 =A21 ⎜1+ ⎟ ⎝ A12 x1 ⎠ Yield: moles of desired product formed/moles that would have been formed if there were no side reactions γ1 = activity coefficient of component 1 in a two- component system, and limiting reactant had reacted completely. Chemical Reaction Equilibrium γ2 = activity coefficient of component 2 in a two- component system, and For reaction A12, A21 = constants, typically fitted from experimental data. aA + bB⇋cC + dD o The pure component fugacity is calculated as: ∆G = –RT ln Ka L sat sat L sat cd fi = Φi Pi exp{vi (P – Pi )/(RT)}, where aaˆˆ ( CD)( ) νi sat K== aˆ , where aiab ∏() Φi = fugacity coefficient of pure saturated i, i (aaˆˆAB)( ) P sat = saturation pressure of pure i, i ˆ L fi vi = specific volume of pure liquid i, and âi = activity of component i = f o R = Ideal Gas Law Constant. i o fi = fugacity of pure i in its standard state νi = stoichiometric coefficient of component i ∆Go = standard Gibbs energy change of reaction Ka = chemical equilibrium constant 103 CHEMICAL ENGINEERING (continued) For mixtures of ideal gases: In the conversion of A, the fractional conversion XA is o defined as the moles of A reacted per mole of A fed. fi = unit pressure, often 1 bar XA = (CAo – CA)/CAo if V is constant fˆ = y P = p i i i The Arrhenius equation gives the dependence of k on where pi = partial pressure of component i. temperature c d c d −ERTa (pC )(pD ) c+d −a−b (yC )(yD ) kAe= , where Then K a = K p = a b = P a b ()()pA pB ()()y A yB A = pre-exponential or frequency factor, For solids âi = 1 Ea = activition energy (J/mol, cal/mol), For liquids âi = xi γi T = temperature (K), and The effect of temperature on the equilibrium constant is R = gas law constant = 8.314 J/(mol⋅K). d lnK ∆H o For values of rate constant (ki) at two temperatures (Ti), = dT RT 2 RTT⎛⎞ k E = 12ln 1 where ∆Ho = standard enthalpy change of reaction. a ⎜⎟ ()TT12− ⎝⎠ k 2 HEATS OF REACTION Reaction Order For a chemical reaction the associated energy can be defined x y If – rA = kCA CB in terms of heats of formation of the individual species ∆Hˆ o ( f ) the reaction is x order with respect to reactant A and y order at the standard state with respect to reactant B. The overall order is ˆˆoo ˆ o ( ∆=HHrf) ∑∑ υ∆−ii( ) υ∆( H f) n = x + y productsii reactants BATCH REACTOR, CONSTANT T AND V The standard state is 25°C and 1 bar. Zero-Order Reaction The heat of formation is defined as the enthalpy change – r = kC o = k (1) associated with the formation of a compound from its A A atomic species as they normally occur in nature (i.e., O2(g), – dCA /dt = k or H2(g), C(solid), etc.) CA = CAo – kt The heat of reaction for a combustion process using oxygen dXA /dt = k/CAo or is also known as the heat of combustion. The principal CAo XA = kt products are CO and H O . 2g()2 () First-Order Reaction CHEMICAL REACTION ENGINEERING – rA = kCA A chemical reaction may be expressed by the general – dCA/dt = kCA or equation ln (CA/CAo) = – kt aA + bB ↔ cC + dD.