Chemical Process Industry

8/10/2019 Chemical Process Industry

http://slidepdf.com/reader/full/chemical-process-industry 1/58



• Chemical engineering – as separate discipline about

1910, it was realized that neither mechanical engineering

nor chemistry offered valid approach to chemical plant

design.

• Unit operations – physical operations necessary for

manufacturing chemicals. (Heat transfer, Filtration,

distillation, fluid flow etc.,)

• 1930 – P.H. Groggins – suggested Unit process to refer

Chemical operations (Nitration, Sulfonation, Oxidation,Chlorination, etc.)

• Chemical Conversion – chemical reactions applied to

industrial processing.



• Discussion will consider costs of reaction materials, energyused in the process, effect of efficiency. (efficiency andprofitability)

• Principal chemical conversion• Acylation * Dehydration * Hydrolysis/Hydration

• Alcoholysis * Dehydrogenation * Ion exchange• Alkylation * Diazotization and coupling * Isomerization

• Amination by reduction* Double decomposition * Neutralization

• Ammonolysis * Electrolysis * Oxidation

• Esterification * Nitration *Polymerization

• Calcination * Fermentation * Hydrogenation

• Carboxylation * Fischer-Tropsch reaction * Reduction

• Causticization * Friedel-crafts reaction * Halogenation

• Combustion * Pyrolysis or cracking * SilicateFormation

• Hydroformylation (oxo) * Aromatization or cyclization• Sulfonation and sulfation



• Each chemical conversion is one of a family of numerousindividual reactions.

• Factory segregation

• Close relationship among equipments used for making

different products.• Small or variable production : equipment can be used to

manufacture another product based on the same chemicalconversion.

• Chemical conversion classification enables a chemical

manufacturer to move from group performances to that of newindividual chemical related class

• Chemical Reaction (main basis)

• Chemical conversion arrangements (rather considering uniquereactions)



• Chemical Engineer – apply chemistry of a particular process

through the use of coordinated scientific and engineering

principles.

• Yield is the fraction of raw material recovered as the main

product.• Conversion is the fraction changed to something else

(products and by products)

• Conversion = Yield

• Batch or Continuous Processes• Pilot plants are small scale units designed to allow

experiments that obtain design data for larger plants and

sometimes to produce significant quantities of new product to

permit user evaluation of it.



• Safety: Hazard such as fire or toxic materials

• Carcinogens – substance causing cancer

• Teratogens – substance causing fetal malformation

• Construction of Plant

• Management for Productivity and Creativity

• Training for plant procedures

• Labor

• Research and Development

• Patents - is a grant of exclusive right to the inventor to

his invention for a limited period of time.

• Invention – is the act of finding something new



• Water conditioning and environmental protection * Nuclear Industries• Energy, fuels, air conditioning and refrigeration * Glass Industries

• Photographic products industries * Coal chemicals

• Explosives, propellants, and toxic chemical agents * Fuel gases

• Surface coating industries * Industrial gases

• Food and food by-product industries * Industrial carbon

• Fragrances, flavors, and food additives * Ceramic industries

• Portland cement, calcium and magnesium compounds * AgrichemicalIndustries

• Salt and miscellaneous sodium compounds * Soap anddetergents

• Chlor-alkali industries: soda ash, caustic soda, chlorine * FermentationIndustries

• Man made fiber and film industries * NitrogenIndustries

• Sulfur and sulfuric acid * PharmaceuticalIndustries

• Hydrochloric acid and miscellaneous inorganic chemicals * Oil, Fats and

waxes• Su ar and starch industries * Rubber Industries *



• Industrial water

• Surface water

• Groundwater (often use for cooling) harder may cause scaling.

• Hard waters contain objectionable amounts of dissolve salts ofcalcium and magnesium. Calcium, magnesium silicate, silica.

• Hardness is expressed in terms of the dissolved calcium andmagnesium salts calculated as calcium carbonate equivalent.

• Carbonate (temporary hardness) – can be greatly reduced byheating. It is caused by bicarbonates of calcium and magnesium

• Non carbonate (permanent hardness) – requires chemical agents. It

is caused by sulfates and chlorides of calcium and magnesium.• Total dissolve solids

• Suspended insoluble matter (turbidity), organic matter, color,dissolved gases (free carbon dioxide, oxygen, nitrogen, in sulfurwater (hydrogen sulfide)



• Water conditioning• Trivia: Thomas Clark (England, 1841) patented the lime process for the

removal of carbonate or temporary hardness.

• Porter – developed the use of soda ash to remove non-carbonate orpermanent hardness

• Robert Gans (Gemany, 1906) applied zeolites to commercially use for watersoftening purposes.

• Softening – is the term applied to processes which remove or reducethe hardness of water.

• Purification – as distinguished from softening, refers to the removalof organic matter and microorganisms from water.

• Clarification may be combined with cold water softening byprecipitation.

• Ion Exchange (1852, Way) removal of ammonia from aqueous liquidpassing through a certain soil (calcium containing silicate)• Trivia : Adams and Holmes (first to publish about anion-exchange resin)



• Ion exchange – a chemical reaction in which mobile hydratedions of a solid are exchanged, equivalent for equivalent, forions of the same charge in solution.

• Zeolites (aluminum silicates

• Organic : sulfonated natural products (coal, lignite or peat)• Polymer – SDVB poly-styrene-divinylbenzene

• Sodium-cation-exchange process – softening water (NaCl)

• Hydrogen-cation-exchange process – Sulfuric acid (regen)

• Anion Exchangers (highly basic and weakly basic)• HB and WB – remove sulfuric, hydrochloric, nitric ; HB – silicic and

carbonic

• HB – caustic soda (regen); WB – caustic soda, soda ash,ammonium hydroxide



• Lime soda processes – uses slaked lime or soda ash(calcium carbonate and magnesium hydroxide) Hot orcold process.• Note 1 mole of lime for 1 calcium bicarbonate while 2 mole of lime

for magnesium bicarbonate.• Cold lime – partial softening , reduce calcium hardness to

35 ppm, (aluminum sulfate or ferric sulfate act ascoagulant) replace by organic polyelectrolytes (iron andaluminum carryover)

• Accelerator – in the equipment developed by Infilco Inc.,,method of reducing supersaturation in the cold limeprocess is contacting the previously precipitated sludge.When this material is exposed to the raw water andchemicals, the like surfaces, or seeds, accelerate the

precipitation.



• Permutit Spaulding Precipitator consists of twocompartments, one for mixing and agitating and the otheris for settling and filtering the softened water as it passesupward through the suspended blanket of sludge.

• Permutit Spiractor – reduces the volume and watercontent of the residual sludge. (wet sand)

• Hot lime soda process – conditioning boiler feedwater.(operates at the boiling point of water) 20-25 ppm

• Phosphate conditioning – cobd bfw, Orthophosphate,trisodium phosphate, sodium hexametaphosphate(complex) to precipitate remains of calcium ion. SHMP isadvantageouos t0 alkaline, it can revert to acidorthophosphate.



• Silica Removal – partially removed by cold/hot lime process,can be removed by using dolomitic lime or activated magnesiain the softener. (blowdown)(demineralization)

• Deaeration – oxygen can be removed by electrodepolarization , organic inhibitors, protective salts (chromates,silicates, phosphates and alkalies) – forming film over anodicor active sites.

• Oxygen scavenging sodium sulfite or hydrazine hydrate (Hightemp boiler)

• Demineralization and desalting – if silica removal in not imptHCEU , WBAEU, degasifier, if needed HCEU, degasifier(remove CO2), SBAEU + mixed bed

• Distilled or deionized water are transported (SST, glass,aluminum, tin(soft), PVC, PP, PE, Pcarbonates



• Desalination – saline water (35000 ppm dissolve salt) – electrodialysis and reverse osmosis (20-30% cheaperthan thermal). Multi-stage flash evaporation, vertical tubeevaporation, vapor compression, vacuum-freeze vapor

compression.• Electrodialysis – utilizes ion-exchange membranes in an

electric field. When a dielectric current is passed throughsaline water in a series of closely spaced, alternatelyplaced, cation exchanger and anion exchanger

membranes, cation pass through the cation exchangermembranes and anions through the anion exchangermembranes, resulting in a salinity decrease in one spaceand salinity increase in the next space.

•



• Reverse Osmosis – utilizes the application of pressure

above the osmotic pressure to force pure water through

semi-permeable membrane from the concentrated brine

solution. Types : Bundles of very fine capillaries and

spiral wound sheets. (membrane material: celluloseacetate – brackish water or polyamides –sea water)

• Purification

• Chloramine (feeding ammonia in chlorinated water), ozone,

chlorine dioxide.• Chlorine added to destroy pathogenic microorganisms

• Activated carbon remove odors and improve flavor



• Seven criteria pollutants (air pollutants)

• Ozone, carbon monoxide, hydrocarbons, sulfur dioxides, oxides of

nitrogen, lead and particulates.

• Particular sewage treatment is based on

• Amount of suspended solids

• BOD biochemical oxygen demand (amount of molecular oxygen

needed by a microbial population to stabilized biodegradable

organic material.

• even criteria pollutants (air pollutants)• Ozone, carbon monoxide, hydrocarbons, sulfur dioxides, oxides of

nitrogen, lead and particulates.



• Frasch Process(HermanFrasch late1890s) – melting the

sulfurunderground orunder the seaand thenpumping it up

to the surface.• Melting temp

Sulfur = 115oC

• Hot water =160oC



• Sulfur from fuel gas

• H2S – removed from natural gas, coke oven gas,

petroleum refinery gas by dissolving in potassium

carbonate solution or ethanolamine.

• H2S is burned to give sulfur dioxide elemental sulfur

(Claus Process)



• Sulfur from other sources (Sulfide ores, smelting ores,burning spent acid or acid sludge from petroleumrefining)

• Copper Smelters

• Sulfur from pyrite ores (Outokumpu flash smelterprocess, Orkla process and the Noranda process)



• 1900-1925 Platinum as catalysts

• Mid 1920s Vanadium was used to replace platinum.

• Catalysts : 7% V2O5 (commercial catalysts(sulfates,

pyrosulfates))

• Plugging due to acid mist can be a problem.

• Cylindrical shape – hallow cylindrical shape to increase

surface area

• Iron oxide and platinum replaced by vanadium• Water cannot be used because direct contact of sulfur

trioxide and water results in an acid mist that is

impossible to absorb.



• Cellulose is the most abundant organic substance

available.

• 2500-2000 BC made from tall reed called papyrus.

Papyrus is a thick paper like material produced from

the pith of the papyrus plant.

• Cotton and linen rags – major sources of fiber for paper

and now replaced by wood pulp.

• Pulping process aims to release the fibrous cellulose

from its surrounding lignin while keeping the

hemicellulose and cellulose intact.

• Major process are : sulfate or Kraft Process,

Groundwood and thermomechanical process,

semichemical process, sulfite process



• Alkaline process

• Outgrowth of the obsolete soda process (12% solution

NaOH and Na2CO3)

• Na2SO

4is added to cooking liquor (Sulfate process)

Na2S, NaOH and Na2CO3

• Most cases used coniferous woods

• Digester – volatilizing turpentine and noncondesable

gases

• Chlorine or hypochlorite is used in bleaching to destroy

the dyes and tannins of the woods.



• Soda pulping – similar procedure to kraft the difference

is the solvent, NaOH/Na2CO3

• Sulfite Pulping – water pollution is the main concern

• Spruce, balsam, hemlock are used

• Digestion of the wood in aqueous solution containing

calcium bisulfite and excess sulfur dioxide

• Semichemical or NSSC Pulping Neutral sulfite semi-

chemical pulping uses substantially less chemicals in

pulping than the full chemical processes. Sodium sulfite

buffered with sodium carbonate cooking medium)

• Used in linerboard or corrugating paper



• Mechanical and thermomechanical pulping - involvesno chemical.

• At elevated temperature the lignin are softened makingmechanical pulping less difficult.

• (Spruce and Balsam) Wood is steamed at 975 kPa andrefining is carried out at 170oC (fiberboard)

• New pulping process – solvent pulping (ethanol,phenol, delignifying solvent)

• Secondary fiber pulping – deinked with (NaOH, sodiumcarbonate and Na2O(SiO)

• Rag Pulping – cotton, (finest grade), clippings fromtextile and clothing manufacturing plants



• Wet process

• (surface, opacity, strength

and feel)

• Two general process

(beating and refining)

• Beater (Hollander)

• Refiner (mills, conical

refiner or jordan engine)



• Alum – added to coat thefibers and coagulate thematerials present.

• Fillers are added to give

smoother surface, morebrilliant whiteness, improvedopacity, printability andsmoothness (not applicable totissue, filter and towels).

• Fillers (finely ground inorganicsubstance) – talc, clay,titanium oxide, silico-aluminates or calciumcarbonates

• Sizing is added to paper toimprove resistance topenetration by liquids. (Rosinsoap made of tall oil, waxemulsion)



• Fourdrinier machine

• Cylinder machine - used for manufacture of heavy paper,

cardboard, nonuniform paper.



• Carbon Dioxide

• Thiolier – produced solid carbon dioxide (used for

refrigeration

• Liquid carbon dioxide – carbonated beverages (fire

extinguisher)

• Gaseous carbon dioxide – production of salicylic acid

• Manufacturing

• Recovery from synthesis gas in ammonia production

• Recovery as a by-product in the production of SNG (substitute

natural gas)

• Recovery from the production of ethanol by fermentation

• Recovery form natural gas



• Carbon dioxide

• Girbotol process (absorbing solution made of hot,concentrated potassium carbonate andmonoethanolamine)

• Hydrogen• Derived from carbonaceous materials (hydrocarbons) or

water

• Electrical, chemical or thermal

• Electrolysis of water, steam reforming of hydrocarbons,thermal dissociation of natural gas

• Electrolytic method – theoretical decomposition voltage is1.23 V at room temp

• 15% NaOH, iron cathode and nickel-plated-iron anode



• Hydrogen

• Steam hydro carbon reforming process – catalytically

reacting a mixture of steam and hydrocarbons at an

elevated temperature to form mixture of H2 and oxides ofcarbon

• Catalysts

• Nickel – steam-hydrocarbon reforming, methanation, mamonia

cracking or dissociation• Iron oxide – for CO conversion

• Hydrogen Purification

• Carbon monoxide removal – conversion to hydrogen via

water gas shift reaction, or scrubbing of complex copperammonium salts

• Carbon dioxide, hydrogen sulfide removal – MEA, hot

potassium carbonate, physical solvent process,

adsorptive purification and cryogenic liquid purification



• MEA Monoethanolamine (Girbotol process) CO2 removal

• Hot potassium carbonate – catalytic promoter

(Giammarco-Vetrocoke and Catacarb processes)• Physical solvent process – Rectisol process using cold

methanol, fluor solvent process using propylene

carbonate, sulfinol process using sulfolan, selexol

process using dimethyl ether and polyethylene glycol,

purisol process using N-methyl-2-pyrrolidine

• Adsorptive purification (CO2, water, methane, ethane,

CO, Ar and N2) : thermal swing process low - high,

pressure swing adsorption process (PSA) high-low

• Cryogenic liquid purification – cooling to the appropriate

cryogenic temp, where the impurities will condensed and

can then be separated as liquid stream



• Oxygen and Nitrogen – liquefaction and rectification

• Oxygen - Production of steel (basic use)

• Nitrogen - Tank blanketing



• Air is liquefied by the Linde process, in which air is

alternately compressed, cooled, and expanded, the

expansion resulting each time in a considerable reduction

in temperature. With the lower temperature the molecules

move more slowly and occupy less space, so the airchanges phase to become liquid.

• Air can also be liquefied by Claude's process in which

the gas is allowed to expand adiabatically twice in two

chambers so that the liquefaction occurs quickly. Thisliquefaction takes place by the Joule Thompson effect.



• Soda ash – Solvay process (LeBlanc process was used)

• 99.3% Na2CO3

• LeBlanc based on roasting salt cake with carbon and

limestone in rotary furnace and subsequently leaching

the product with water. (crude product – black ash)

• Ernest Solvay – 1861, ammonia-soda process

• Sodium hydroxide is made by causticization of LeBlanc

soda ash

• Sold based on Na2O content 76% Na2O = 98%NaOH



• Solvay process• Uses salt, limestone, and coke or natural gas as raw materials and

ammonia as cyclic reagent

• Ammonia, water and carbon dioxide ammonium bicarbonatereacts with NaCl sodium bicarbonate (roasted) soda ash

• Ammonium is recovered from ammonium chloride reacts with lime toform calcium chloride and ammonia.

• Chlorine and caustic soda – produce by electrolysis of aqueoussolution of alkali metal chloride.

• Diaphragm cells – made of asbestos fibers (separates anode –

graphite and cathode –cast iron)• Membrane cells – made of semipermeable membrane

• Mercury cells –anode made of graphite and cathode is flowing poolof mercury



• Joseph Aspdin, 1824 patented artificial cement made by thecalcination of an argillaceous limestone, he named it Portland(resembles the famous building stone obtained from Isle ofPortland near England).

• Portland cement – the product obtained by pulverizing clinker

consisting essentially of hydraulic calcium silicates, usuallycontaining one or more forms of calcium sulfates as aninterground addition.

• Materials needed for manufacture cement• One rich in calcium (calcareous) ex limestone, chalk etc

• One rich in silica (argillaceous) ex clay

• Clinker is lumps or nodules, usually 3 –25 mm in diameter,produced by sintering limestone and alumino-silicate (clay)during the cement kiln stage.



• An explosive is a material that, under the influence of thermalor mechanical shock decomposes rapidly and spontaneouslywith the evolution of a great deal of heat and much gas.

• Three types of explosives• Mechanical

• Atomic

• Chemical (Detonating , high explosive, a. Primary or initiatingexplosives b. booster and secondary explosives or Deflagrating, lowexplosive - )

• Initiating explosives materials that are quite shock and heat

sensitive. (mercury fulminate, lead azide etc)• Booster – materials that are insensitive to both mechanical

shock and flame but that explode with great violence (PETNpentaerythritoltetranitrate) cyclotrimethylenetrinitramine RDX

I d i l l i



• Industrial explosives

• Nitroglycerine and dynamite

• Nitroglycerine – produced by nitration of glycerol.

• Dynamite is made by absorbing nitroglycerine into kieselguhr,a kind of clay. Modern dynamite uses wood flour, ammoniumnitrate or sodium nitrate to absorb nitroglycerine.

• Propellants, rockets and missiles

• Black powder – oldest known propellant

• Smokeless powder replace black powder due to superiorpower and better storage characteristics.

• Propellants – LOX or LH2, liquid oxygen or liquid hydrogen,high specific impulse and low cost

• Solid propellants – heterogeneous or composite porpellants

(oxidizer and reducer present in two distinct phase) andhomogeneous or double based (oxidizer and reducer presentin a dingle or colloidal phase)



• Oils and fats – mixture of glycerides and various fatty acids

• Cottonseed oil, soybean oil, linseed oil (flaxseed), coconut oil,corn oil, palm oil, peanut oil 9hydraulic press or andersonexpeller), tung oil (tung tree), castor oil, safflower oil (linoleicacid)

• Processing of oil• Degumming or steam refining, adsorptive bleaching, hydrogenation,

and deodorization

• Degumming (phosphoric acid) centrifugation

• Bleaching – bentonite clays (if will be used for salad oils – winterizing treatment) 5oC

• Hydrogenation or hardening (applied to fats and oils) – odor,taste• Nickel is used as catalysts

• Deodorization – blowing superheated steam

• Hexane is used as solvent



• Wax – mixture of polyhydric alcohols (except glycerol)

and fatty acids.

• Beeswax – (honeycomb) candles

• Carnauba wax – (carnauba palm) floor, automobile,

furniture polishes, carbon paper, candles and molded

product

• Spermaceti - (sperm whale) ointments, low surface

tension lubricant.



• Soaps – form insoluble compounds with the calcium and

magnesium ions present in hard water, the insoluble

compounds precipitate out and reduce foaming and

cleaning action.

• Detergents – react with the hard water ions, but theresulting products are either soluble or remain colloidally

dispersed in the water.

• Detergent four groups: anionic, cationic, nonionic,

amphoteric• Soil removal is accomplished by wetting, emulsifying,

dispersing, or solubilizing the soil by the cleaning agent.



• Tallow – the principal fatty material in soap making.

• Comprises of sodium or potassium salts of various fatty

acids.



• Perfume• CONSTITUENTS

• Vehicles – (Solvent) ethyl alcohol

• Fixatives – substance of lower volatility than the perfume oils,

which retard and even up the rate of evaporation of the variousodorous constituents

• Odoriferous element – essential oil, isolates, synthetic or

semisynthetic chemicals

• Essential oil – volatile, odoriferous oils of vegetable origin. Usually

obtained by steam distillation.• Isolates- pure chemical compound whose source is an essential

oil or other natural perfume material

• Synthetic or semisynthetic – produce by chemical synthetic

procudure



• Liquid paint is a dispersion of a finely divided pigment in aliquid composed of resin or binder and a volatile solvent. Theliquid portion is known as the vehicle.

• Paint constituents

• 1. Vehicles• Nonvolatile

• Solvent based : oils and/or resin plus driers and additives

• Lacquers : cellulosics, resins, plasticizers, additives

• Water based : styrene-butadiene, Polyvinyl acetate, acrylic,polymer, emulsions, copolymer plus additive

• Volatile

• Ketones, esters, acetates, aromatics, aliphatics

• 2. Pigment (opaque, transparent, special purpose type)

• Pigment – usually inorganic / if organic dye (toner)



Pigment usually inorganic / if organic dye (toner)

• Pigment extenders (fillers) – reduce cost of the paint andincrease durability

• Pigment and fillers – aesthetic and protective byreflecting destructive light rays

• Oils – as part of vehicle, but also helps to form protectivefilm and to plasticize it.

• Many paints contains both natural and synthetic drying

oils.• Pigments

• White pigments ( Lithopone (zinc sulfide and bariumsulfate), titanium dioxide, barium sulfate)

• Black pigments (carbon blacks)• Blue Pigments (Ultramarine blue (sodium aluminum

silicate and sulfide), Phthalocyanine blues, ferrocyanideblues)

• Red pigments – red lead (Pb3O

4), ferric oxide, basic lead

chromate

• Green pigments (phthalocyanine green, chromium oxide



Green pigments (phthalocyanine green, chromium oxide

green, guignet’s green (hydrated chromium oxide),

Chrome green

• Brown pigment burnt sienna (heat iron containing clays)burnt ocher, burnt umber

• Varnishes – is an unpigmented colloidal dispersion or

solution of synthetic and/or natural resins in oils and/or

thinners used as protective and/or decorative coating for

various surfaces and which dries by evaporation,

oxidation, and polymerization of potions of its

constituents

Chemical Process Industry

Documents

Transcript of Chemical Process Industry