Chemical Process Technology final g.pptx

CHEMICAL PROCESS
TECHNOLOGY
CATUC BAMENDA

INTRODUCTION TO CHEMICAL PROCESS
TECHNOLOGY
• Chemical process technology involves the process of manufacturing or
producing chemicals.
• It involves the full description of process flow, Raw materials used, unit
operation used, reactions involved
• So Basically it's a course dedicated to the various plants with help of flow
sheets and process description.

CHAPTER ONE
SUGAR MANUFACTURING
INTRODUCTION
• The sugar industry processes sugar cane and sugar beets to manufacture
edible sugar.
• More than 60% of the world's sugar production is from sugar cane ; the
balance is from sugar beets.
• Sugar manufacturing is a highly seasonal industry, with season lengths of
about 6–18 weeks for beets and 20–32 weeks for cane.

SUGAR MANUFACTURING
INTRODUCTION

SUGAR MANUFACTURING
INTRODUCTION
• There are 3 types of sugar cane namely
• Saccharum officinarum(tropical sugarcane),
• Indian cane(Saccharum barberi or Saccharum sinensis) &
• Saccharum spontaneum/robustum(wild sugarcane).
• The main commercial sugarcane is a hybrid from wild sugar(Saccharum
spontaneum) & it's cultivated in sugarcane production Countries.

BY PRODUCTS IN SUGARCANE INDUSTRY
• The four main byproducts of the sugarcane are:
• Cane tops
• Bagasse
• Filter mud / press mud and Spent Wash
• Molasses

CANE TOPS
• Cane tops
• Cane tops have no real market value
• They can be compared to fair quality fodder with an average feed value,
• when fresh, of about 2.8 MJ of metabolizable energy per kilo of dry matter.
• However cane tops should be collected and transported from the cane fields
to the feedlot

BAGASSE
• It is the fibrous residue of the cane stalk left after crushing and extraction of the juice
• It consists of fibres, water and relatively small quantities of soluble solids - mostly sugar
• Utilizations are:
• Electricity
• Particle board
• Paper
• Methane
• Furfural

BAGASSE
• Furfural
• It is a colorless, inflammable, volatile, aromatic liquid
• 25 tonnes of bagasse to produce 1 tonne of furfural
• Furfural has many industrial uses:
• Selective solvent for the refining of lubricating oils
• As an intermediate in the production of nylon and resins

FILTER MUD / PRESSMUD
• The precipitated impurities contained in the cane juice, after removal by
filtration, form a cake of varying moisture content called filter mud
• This cake contains much of the colloidal organic matter anions that precipitate
during clarification, as well as certain non-sugars included in these precipitates

FILTER MUD / PRESSMUD
• As animal feed has not proved economically rewarding, the main constraints being the
magnitude of the drying process involved and the low digestibility of the dried scums
• As soil nutrient there is limitations
• Higher values of C.O.D. (chemical oxygen demand) and B.O.D (biochemical oxygen demand)
• Wax percentage in substantial quantity which prevents microbial action
• High concentration of various chemicals which are detrimental to survival of beneficial microflora
• Bio-degradation being exothermic reaction survival of microbes except thermophiles is difficult
• Due to above mentioned difficulties, bio-degradation of pressmud and spent wash is a difficult
process

MOLASSES
• Molasses is the final effluent obtained in the preparation of sugar by
repeated crystallization
• It is the residual syrup from which no crystalline sucrose can be obtained by
simple means
• The yield of molasses is approximately 3.0 percent per tonne of cane
• but it is influenced by a number of factors (2.2 to 3.7 percent)

MOLASSES
• The composition of molasses varies but, on average, would be as follows:
• Water 20%
• Other carbohydrates 4%
• Sucrose 35%
• Nitrogenous compounds 4.5%
• Fructose 9%
• Non-nitrogenous acids 5%
• Glucose 7%
• Ash 12%
• Other reducing sugars 3%

MOLASSES
• Uses of molasses
• For distillery industry
• Alcohol and related products
• Export to some developed countries as raw materials
• It is an ingredient to animals feed

SUGAR PROCESSING
• Sugar production involves two distinct operations:
• (a) processing sugar cane or sugar beets into raw sugar and
• (b) processing the raw sugar into refined sugar

SUGAR PROCESSING
CANE HAVERSTING
• Hand cutting is the most common harvesting method throughout the world but
some locations (e. g., Florida, Louisiana and Hawaii) have used mechanical
harvesters for several years.
• After cutting, the cane is loaded by hand, mechanical grab loaders, or
continuous loaders.
• Cane is transported to the mills using trailers, trucks, railcars, or barges,
depending upon the relative location of the cane fields and the processing
plants.
• When the cane is cut, rapid deterioration of the cane begins.

SUGAR PROCESSING
CLEANING
• At the mill, the cane is mechanically unloaded, placed in a large pile, and,
prior to milling, the cane is cleaned

SUGAR PROCESSING
MILLING
• The milling process occurs in two steps:
• breaking the hard structure of the cane and
• grinding the cane
• Breaking the cane uses revolving knives, shredders, crushers, or a combination
of these processes.

SUGAR PROCESSING
MILLING
• For the grinding, or milling, of the crushed cane, multiple sets of three-roller
mills are most commonly used although some mills consist of four, five, or six
rollers in multiple sets
• Conveyors transport the crushed cane from one mill to the next

SUGAR PROCESSING
MILLING
• Imbibition is the process in which water or juice is applied to the crushed cane
to enhance the extraction of the juice at the next mill.
• water or juice from other processing areas is introduced into the last mill and
transferred from mill to mill towards the first two mills while the crushed cane
travels from the first to the last mill.

SUGAR PROCESSING
MILLING
• The crushed cane exiting the last mill is called bagasse.
• The juice from the mills is strained to remove large particles and then clarified

SUGAR PROCESSING
STRAINING AND CLARIFICATION
• The juice from the mills is strained to remove large particles and then clarified.
• In raw sugar production, clarification is done almost exclusively with heat about 95°C and lime(Calcium
hydroxide)
• raw cane juice has low pH and contains dissolved impurities.
• Hydrated lime is added to the juice to raise the pH and to react with the impurities to form insoluble
calcium organic compounds that can be removed.
• Excess lime is removed by carbonation or by the addition of phosphoric acid. This process may be
repeated several times depending on the purity of final product required.
• Between 5 and 10 pounds of lime is required for each ton of cane sugar produced.

SUGAR PROCESSING
STRAINING AND CLARIFICATION
• The use of lime in the production of sugar from sugar beets is similar, except
that much more lime is required than for cane sugar, approximately one
quarter ton for each ton of beet sugar produced.
• Because of a large quantities of lime required, many beet sugar refiners
maintain on-site lime kilns to provide their lime requirements. They also reclaim
calcium carbonate from the sugarmaking process for reuse.

SUGAR PROCESSING
CLARIFICATION
• A heavy precipitate forms which is separated from the juice in the clarifier.
The insoluble particulate mass, called “mud”, is separated from the limed juice
by gravity or centrifuge.
• Clarified juice goes to the evaporators without additional treatment. The mud
is filtered and the filtercake is washed with water.

SUGAR PROCESSING
EVAPORATION
• Evaporation is performed in two stages:
• in an evaporator station to concentrate the juice and
• then in vacuum pans to crystallize the sugar.

SUGAR PROCESSING
EVAPORATION
• The clarified juice is passed through heat exchangers to preheat the juice and then to
the evaporator stations.
• Evaporator stations consist of a series of evaporators, termed multiple-effect
evaporators; typically, a series of five evaporators.
• Steam from large boilers is used to heat the first evaporator, and the steam from the
water evaporated in the first evaporator is used to heat the second evaporator.
• This heat transfer process continues through the five evaporators and as the
temperature decreases (due to heat loss) from evaporator to evaporator, the pressure
inside each evaporator also decreases which allows the juice to boil at the lower
temperatures in the subsequent evaporator.

SUGAR PROCESSING
EVAPORATION
• The evaporator station in cane sugar manufacture typically produces a syrup
with about 65 percent solids and 35 percent water.
• Following evaporation, the syrup is clarified by adding lime, phosphoric acid,
and a polymer flocculent, aerated, and filtered in the clarifier. From the
clarifier, the syrup goes to the vacuum pans for crystallization.

SUGAR PROCESSING
CRYSTALLIZATION
• Crystallization of the sugar starts in the vacuum pans, whose function is to
produce sugar crystals from the syrup.
• In the pan boiling process, the syrup is evaporated until it reaches the
supersaturation stage.
• At this point, the crystallization process is initiated by “seeding” or “shocking”
the solution with isopropyl alcohol and ground sugar

SUGAR PROCESSING
CRYSTALLIZATION
• In the crystallation process the syrup is boiled at low temperatures under
partial vacuum and some seedings are added which causes the development
and growth of sugar crystals called massecuite which is a combination of raw
sugar mixed with molasses
• The sugar crystals and molases are then separated in centrifuges

SUGAR PROCESSING
CRYSTALLIZATION
• There are normally 3 vacuum pans A, B, C
• Syrup coming from evaporators enter pan A, where boiling takes place and
crystallization begins giving a thicker liquid( messecute) which comes out and
enters the centrifuge

SUGAR PROCESSING
CENTRIFUGATION
• the massecuite is transferred to high-speed centrifugal machines (centrifugals),
in which the mother liquor (termed “molasses”) is centrifuged to the outer shell
and the crystals remain in the inner centrifugal basket.
• The crystals are washed with water and the wash water centrifuged from the
crystals.

• The final molasses from the third stage (blackstrap molasses) is a heavy,
viscous material used primarily as a supplement in cattle feed.
• After cooling, the cane sugar is transferred to packing bins and then sent to
bulk storage.
• Cane sugar is then generally bulk loaded to trucks, railcars, or barges.

REFINED SUGAR PRODUCTION
• Cane sugar is refined either at the same location where it was produced as
part of an integrated facility or at separate raw sugar refineries.
• The initial step in cane sugar refining is washing the sugar, called affination,
with warm, almost saturated syrup to loosen the molasses film.

• affination is followed by separation of the crystals from the syrup in a
centrifugal and washing of the separated crystals with hot water or a high
purity sweetwater.

• The washed raw sugar is sent to a premelter and then to a melter, where it is
mixed with high-purity sweetwaters from other refinery steps and is steam
heated.
• The resultant syrup is passed through a screen to remove any particulate in
the syrup and sent to the clarification step.

• The syrup from the crystal washing, called affination syrup, is transferred to a
remelt processing station or reused in the raw sugar washing step.
• In the remelt station, the syrup volume is reduced to form the massecuite, and
the sugar crystals are separated from the syrup.

• The separated liquor is blackstrap molasses. The sugar crystals are sent to a melter
and then to the clarification step.
• Two clarification methods are commonly used:
• pressure filtration and chemical treatment;
• chemical clarification is the preferred method.
• Two chemical methods are commonly used:
• phosphatation and
• carbonation;
• both processes require the addition of lime.

• The phosphatation uses phosphoric acid, lime (as lime sucrate to increase
solubility), and
• polyacrylamide flocculent to produce a calcium phosphate floc.
• Air flotation is usually used to separate the floc from the liquor and the floc
skimmed from the liquor surface.

• The clarifier systems yield either presscakes, muds, or scums which are treated
to remove entrapped sugar, and then sent to disposal.

DECOLORIZATION
• decolorization removes soluble impurities by adsorption.
• The two most common adsorbents are granular activated carbon and bone
char, manufactured from degreased cattle bones.
• Powdered carbon and synthetic resins are less commonly used
• Spent adsorbent is removed from the bed, regenerated, and stored for reuse.

DECOLORIZATION
• The decolorized sugar liquor is sent to heaters (at some refineries), followed
by multiple-effect evaporators, and then to the vacuum pans;
• this is the same sequence used in cane sugar manufacture.
• When the liquor in the pans has reached the desired level of supersaturation,
the liquor is “seeded” to initiate formation of sugar crystals

CENTRIFUGAL
• In the centrifugal, the white sugar is retained in the inner basket and the liquor
centrifuged to the outer shell.
• The sugar liquor is returned to a vacuum pan for further volume reduction and
white or brown sugar production
• The white sugar is washed one time in the centrifugal; the separated wash
water, containing liquor and dissolved sugar, is returned to the vacuum pans.
• The moist sugar from the centrifugals contains about 1 percent water by weight.

SCREENING
• To produce refined granulated sugar, white sugar is transported by conveyors
and bucket elevators to the sugar dryers.
• Dryer drums typically operate at a temperature of about 110°C (230°F).
• From the granulators, the dried white sugar crystals are mechanically
screened by particle size using a sloping, gyrating wire mesh screen or
perforated plate

• From the granulators, the dried white sugar crystals are mechanically
screened by particle size using a sloping, gyrating wire mesh screen or
perforated plate

PACKAGING
• After screening, the finished, refined granulated sugar is sent to conditioning
bins, and then to storage bins prior to packaging or bulk loadout.
• Almost all packaged sugar uses either multiwall paper containers, cardboard
cartons, or polyethylene bags; bulk loadout is the loadout of the sugar to
specially designed bulk hopper cars or tank trucks.

• In addition to granulated sugar, other common refined sugar products include
confectioners' (powdered) sugar, brown sugar, liquid sugar, and edible
molasses. There are about six other less common sugar products.

CEMENT
INTRODUCTION
• Cement is known to be one of the most important construction materials in the
world. It is primarily used in the manufacture of concrete.
• Concrete is a combination of inert mineral aggregates such as sand, gravel,
crushed stones and cement.

CEMENT
INTRODUCTION
• Cement is a binder, a substance that sets and hardens and can bind other
materials together.
• Cements used in construction can be characterized as being either hydraulic or
non-hydraulic, depending upon the ability of the cement to be used in the
presence of water.

CEMENT
INTRODUCTION
HYDRAULIC OR NON-HYDRAULIC,
• Hydraulic Cement is made out of limestone, clay and gypsum. Non Hydraulic Cement is
composed of lime, gypsum plaster and oxychloride.
• Hydraulic Cement hardens when there is a chemical reaction between anhydrous cement
powder with water. Non hydraulic Cement hardens when there is a reaction due to
carbonation with the carbon di oxide which is naturally present in the air.
• Hydraulic Cement hardens under water or when in contact with wet weather. Hence it is
suitable to work with in any climatic conditions. Non Hydraulic Cement should be kept dry to
attain strength.
• Hydraulic cement is used in multiple applications like concrete, mortar in masonry, swimming
pools, marine construction, foundations, manholes, reservoirs etc Non hydraulic cement is
becoming redundant and obsolete due to the long duration of time taken for setting of cement

CEMENT
INTRODUCTION
USES
• Cement mortar for Masonry work, plaster and pointing etc.
• Concrete for laying floors, roofs and constructing lintels,beams,weather shed,stairs,pillars
etc.
• Construction for important engineering structures such as bridge, culverts, dams, tunnels,
light house, clocks,etc.
• Construction of water,wells, tennis courts,septic tanks, lamp posts, telephone cabins etc.
• Making joint for joints,pipes,etc.
• Manufacturing of precast pipes,garden seats, artistically designed wens, flower posts, etc.
• Preparation of foundation, water tight floors, footpaths, etc.

TYPES OF PORTLAND CEMENT
• Portland cement is a closely controlled chemical combination of
• calcium,
• silicon,
• aluminum,
• iron and
• small amounts of other compounds, to which gypsum is added in the final grinding
process to regulate the setting time of the concrete.

• Some of the raw materials used to manufacture cement are
• limestone,
• shells, and
• chalk or marl,
• combined with shale, clay, slate or blast furnace slag, silica sand, and iron
ore.
• Lime and silica make up approximately 85 percent of the mass.

• The term "Portland" in Portland cement originated in 1824 when an English
mason obtained a patent for his product, which he named Portland Cement. This
was because his cement blend produced concrete that resembled the color of
the natural limestone quarried on the Isle of Portland in the English Channel.
• Many types of cements are available in markets with different compositions and
for use in different environmental conditions and specialized applications.

• Ordinary Portland cement ( type I )
• Ordinary Portland cement is the most common type of cement in general use around the
world. This cement is made by heating limestone (calcium carbonate) with small quantities
of other materials (such as clay) to 1450°C in a kiln, in a process known as calcination,
whereby a molecule of carbon dioxide is liberated from the calcium carbonate to form
calcium oxide, or quicklime, which is then blended with the other materials that have
been included in the mix.
• The resulting hard substance, called 'clinker', is then ground with a small amount of
gypsum into a powder to make 'Ordinary Portland Cement'(often referred to as OPC).

ORDINARY PORTLAND CEMENT ( TYPE I )
• Lime saturation Factor is limited between i.e. 0.66 to 1.02.
• Free lime-cause the Cement to be unsound.
• Percentage of (AL2O3/Fe2O3) is not less than 0.66.
• Insoluble residue not more than 1.5%.
• Percentage of SO3 limited by 2.5% when C3A < 7% and not more than 3% when C3A >7%.
• Loss of ignition -4%(max)
• Percentage of Mg0-5% (max.)
• Fineness -not less than 2250 cm2/g

RAPID HARDENING PORTLAND CEMENT ( TYPE III )
• This type develops strength more rapidly than ordinary Portland cement.
• The initial strength is higher, but they equalize at 2-3 months .Setting time for
this type is similar for that of ordinary Portland cement
• It contains more C3S are less C2S than the ordinary Portland cement.
• Its 3 days strength is same as 7 days strength of ordinary Portland cement.

RAPID HARDENING PORTLAND CEMENT
USES
• a) The uses of this cement is indicated where a rapid strength development is
desired (to develop high early strength, i.e.( its 3 days strength equal that of 7
days ordinary Portland cement), for example:
• Where sufficient strength for further construction is wanted as quickly as
practicable, such as concrete blocks manufacturing, sidewalks and the places that
cannot be closed for a long time, and repair works needed to construct quickly.
• b) For construction at low temperatures, to prevent the frost damage of the
capillary water.
• c) This type of cement is not use at mass concrete constructions

LOW HEAT PORTLAND CEMENT ( TYPE IV)
• Its composition contains less C3S and C3A percentage, and higher percentage
of C2S in comparison with ordinary Portland cement.
• Properties
• 1) Reduce and delay the heat of hydration.
• 2) It has lower early strength compared with ordinary Portland cement.
• 3) Its fineness is not less than 3200 cm2/g
Uses
• It is used in mass concrete constructions:

SULPHATE RESISTING PORTLAND CEMENT ( TYPE V)
• Maximum C3A content by 3.5% and minimum fineness by 2500 cm'/g.
• Firmer than ordinary potland cement.
• Sulphate forms the sulpha-aluminates which have expensive properties and so causes
disintegration of concrete.
• The clinkers of cement are ground with about 60 to 65 percent of slag.
• Properties
•  Low early strength.
•  Its cost is higher than ordinary Portland cement – because of the special requirements
of material composition, including addition of iron powder to the raw materials.

PORTLAND BLAST FURNACE CEMENT ( TYPE IS)
• This type of cement consists of an intimate mixture of Portland cement and
ground granulated blast furnace slag.
• Slag – is a waste product in the manufacture of pig iron.
• Chemically, slag is a mixture of 42% lime, 30% silica, 19% alumina, 5%
magnesia, and 1% alkalis, that is, the same oxides that make up Portland
cement but not in the same proportions.

PORTLAND BLAST FURNACE CEMENT ( TYPE IS)
PROPERTIES
• - Its early strength is lower than that of ordinary cement, but their strength is equal at late ages (about
2 months).
• - The requirements for fineness and setting time and soundness are similar for those of ordinary Cement.
• - The workability is higher than that of ordinary cement.
• - Heat of hydration is lower that of ordinary cement.
• - Its sulfate resistance is high.
• Uses
• - Mass concrete
• - It is possible to be use in constructions subjected to sea water (marine constructions).
• - May not be use in cold weather concreting.

POZZOLANIC CEMENT
• This type of cement consists of an intimate mixture of Portland cement and
pozzolana.
• American standard limit the pozzolana content by 15-40% of Pozzolanic cement.
• Pozzolana, can be defined as – a siliceous or siliceous and aluminous material which
in itself possesses little or no cementitious value but will, in finely divided form and in
the presence of moisture, chemically react with calcium hydroxide at ordinary
temperatures to form compounds possessing cementitious properties.
Properties & Uses
• They are similar to those of Portland blastfurnace cement.

WHITE CEMENT
• White Portland cement is made from raw materials containing very little iron
oxide (less than 0.3% by mass of clinker) and magnesium oxide (which give
the grey color in ordinary Portland cement). white clay is generally used,
together with chalk or limestone, free from specified impurities.
• Its manufacture needs higher firing temperature because of the absence of
iron element that works as a catalyst in the formation process of the clinker

WHITE CEMENT
• Properties
• - It has a slightly lower specific gravity (3.05-3.1), than ordinary Portland cement.
• -The strength is usually somewhat lower than that of ordinary Portland cement.
• -Its fineness is higher (4000-4500 cm2/g) than ordinary Portland cement
• -It used in architectural purposes Swimming pools, for painting garden furniture,
moulding sculptures and statues etc.

COLOURED PORTLAND
• It is prepared by adding special types of pigments to the Portland cement. The pigments added to
the white cement (2-10% by weight of the cement) when needed to obtain light colors, while
• it added to ordinary Portland cement when needed to obtain dark colors.
• Pigment properties
•  It is required that pigments are insoluble and not affected by ambience.
•  They should be chemically inert
•  Don’t contain gypsum that is harmful to the concrete.
•  Don’t affect on strength development of concrete.

EXPANSIVE CEMENT
• This type of cement is produced by adding an expanding medium like
sulphoaluminate and a stabilising agent to the ordinary cement.
• The expanding cement is used for the construction of water retaining structures
and for repairing the damaged concrete surfaces.

HIGH ALUMINA CEMENT
• This cement is produced by grilling clinkers formed by calcining bauxite and
lime. It can stand high temper lures.
• If evolves great heat during setting. It is therefore not affected by frost

THE CEMENT MANUFACTURING PROCESS
PORTLAND CEMENT
• Portland cement is made by mixing substances containing CaCO3 with substances containing
• SiO2, Al2O3, Fe2O3 and heating them to a clinker which is subsequently ground to powder and
mixed with 2-6 % gypsum.
• Raw Materials Necessary for Portland Cement Manufacture Must Provide the Following
• Calcium
• Silica
• Alumina
• Iron

THE CEMENT MANUFACTURING PROCESS
PORTLAND CEMENT
PRODUCTION STEPS
• 1. Raw materials are crushed, screened & stockpiled.
• 2. Raw materials are mixed with definite proportions to obtain “raw mix”. They are mixed either dry
(dry mixing) or by water (wet mixing).
• 3. Prepared raw mix is fed into the rotary kiln.
• 4. As the materials pass through the kiln their temperature is raised up to 1300-1600 °C. The process
of heating is named as “burning”. The output is known as “clinker” which is 0.15-5 cm in diameter.
• 5. Clinker is cooled & stored.
• 6. Clinker is ground with gypsum (3-6%) to adjust setting time.
• 7. Packing & marketting.

REACTIONS IN THE KILN
• • ~100°C free water evaporates.
→
• • ~150-350C° loosely bound water is lost from clay.
→
• • ~350-650°C decomposition of clay SiO2&Al2O3
→ →
• • ~600°C decomposition of MgCO3 MgO&CO2 (evaporates)
→ →
• • ~900°C decomposition of CaCO3 CaO&CO2 (evaporates)
→ →
• • ~1250-1280°C liquid formation & start of compound formation.
→
• • ~1280°C clinkering begins.
→
• • ~1400-1500°C clinkering
→
• • ~100°C clinker leaves the kiln & falls into a cooler.
→
•  Sometimes the burning process of raw materials is performed in two stages:
• preheating upto 900°C & rotary kiln

CHEMICAL COMPOSITION OF ORDINARY
PORTLAND CEMENT

CHAPTER THREE
REFINING VEGETABLE
• Introduction
• Vegetable oils and fats are important constituents of foods and are essential components
of our daily diet .
• Vegetable oils are obtained by mechanical expelling or solvent extraction of oleaginous
seeds (soybeans, rapeseed, sunflower, etc.) or oleaginous fruit like palm and olive .
• Vegetable oils generally contain triglycerides (about 98 g/100 g), triesters resulted
from a reaction between glycerol and fatty acids, and other substances in a minority
proportion (Figure 1) .

REFINING VEGETABLE
INTRODUCTION
• Some of them such as diglycerides, vitamins, phytosterols, tocopherols, and
polyphenols have important health benefits in humans, and therefore they
should not be removed during processing
• Other compounds known for their negative effect on the quality and stability
of oils, include free fatty acids, unsaponifiable matters, waxes, pigments, solid
impurities (mainly fibers), oxidation products (peroxides, aldehydes, ketones,
alcohols, and oxidized fatty acids)

REFINING VEGETABLE
INTRODUCTION
DISADVANTAGES OF REFINING
• Although refining extends oil shelf life, it has several disadvantages.
• One of the main disadvantages is the loss of substances responsible for healthy,
pharmaceutical properties and technological interest in the oils, such as
• tocopherols,
• phospholipids,
• squalene,
• polyphenols, and
• phytosterols.

REFINING VEGETABLE
INTRODUCTION
DISADVANTAGES OF REFINING
• Another notable disadvantage of refining is the formation of undesirable
compounds such as
• glycidyl ester,
• 3-MCPD-esters(3-monochloropropanediol),
• harmful trans-fatty acids , and
• polymeric triacylglycerols . ,
these can directly influence the safety level of refined oils.

VEGETABLE REFINING PROCESS
• There are two main industrial technologies used for vegetable oils’ refining,
namely,
• chemical refining and
• physical refining.

• Chemical refining removes free fatty acids by soda neutralization.
• Physical refining eliminates undesirable compounds (deacidification) by
distillation under a high vacuum with steam injection.

CHEMICAL REFINING OF OIL
• Chemical refining is the traditional method used since ancient times.
• It can be used for all fats and oils even when they have been slightly
degraded.
• Each step of the refining process has specific functions for removing some
undesirable compounds.
• chemical refining has several drawbacks as each process step participates in
removing also certain bioactive molecules,
• these consist mainly of tocopherols and polyphenols,
• which can act as antioxidants. Likewise, chemical refining requires higher cost
and might result in the release of polluting effluents.

• Chemical refining follows six processes:
• Degumming with the goal of the elimination of phospholipids and mucilaginous gums
• Neutralization, which allows the elimination of free fatty acids (FFA), phospholipids, metals,
and chlorophylls.
• Washing and drying in order to eliminate residuals of soaps and water
• Bleaching aims at eliminating pigments, peroxides, and residuals of both fatty acids and
salts.
• Dewaxing has as main objective removing the waxes in the case of oils rich in waxes
• The final stage of chemical refining is deodorizing, which allows the elimination of volatiles,
carotenoids, and free fatty acids.

DEGUMMING
• Degumming is a crucial step in the refining process of vegetable oils.
• It allows the elimination of “gums” or “mucilage,” composed mainly of
phospholipids from the crude oil as well as compounds such as carbohydrates,
proteins, and trace of metal.

DEGUMMING
• Phospholipids or phosphatides are naturally present in oils.
• These compounds are important biochemical inter mediates in the growth and
functioning of plant cells.
• the major types of phospholipids are:
• Phosphatidylcholine (PC), Hydratable
• phosphatidylethanolamine (PE),
• phosphatidylserine (PS), and
• phosphatidylinositol (PI) Hydratable

DEGUMMING
• There are generally two different types of phospholipids present in the crude oil
depending upon their hydration levels:
• Hydratable or Water Degumming
• Non-Hydratable or Acid Degumming
• There are four types of degumming processes, namely,
• water degumming,
• acid degumming,
• dry degumming, and
• enzymatic degumming.

WATER DEGUMMING,
• In water degumming method, the crude oil is hydrated by mixing calculated
amount of water. Since hydrated gums are insoluble in oil, hence it gets
precipitated. These hydrated gums are then separated from oil. In this stage,
only hydratable gums are removed.
• Water Degumming is also employed for Low FFA(Free Fatty Acids) Crude
Oils
• where degumming is followed by Neutralization and Water Washing.

Acid degumming process:
• For removal of Non-hydratable gums, water degumming is not suitable and the oil is
conditioned by acid media such as phosphoric acid.
• The content of phosphoric acid addition depends on the amount of gums present as well
as the type of oil being refined.
• Acid Degumming is perfectly suitable for High FFA Crude Oils where acid washing is
followed by Water Washing and ensures total degumming.
• Due to the variable content of phospholipids in crude oils, analysis of phosphorus prior to
acid treatment is necessary to ensure that the acid dosage is correct.

Neutralization
• Vegetable oils containing a high percentage of free fatty acids which must be
refined to edible form.
• The presence of these compounds in crude oils poses many problems for the
storage and result in an undesirable colour and odour in the final product.
• Free fatty acids influence the chemical quality and the organoleptic instability of
oil.
• In chemical refining, the oil is treated with an alkali solution (caustic soda) that
reacts with the free fatty acids (FFA) present as per the following equation and
converts them into soap stock:

Washing and drying.
• This operation eliminates alkaline substances present in the oil coming out of the
neutralization step (caustic soda and excess soap) as well as last metallic and
phospholipids traces and other impurities.
• It is preferable to use softened water and washing water should be sampled regularly for
a visual check of the quantity of fat carried away (after natural decantation or, even
better, after centrifugation)
• The oil, free of gums, traces of soapstock, and other impurities, is pumped through a plate
heat exchanger where it is heated by steam.
• After this treatment, water- washed oil is dried with a vacuum dryer until the moisture level
of the oil falls below 0.1%.

Bleaching.
• the objective of bleaching (or decolorizing) is to reduce the levels of colored
pigments (carotenoids and chlorophylls).
• It also further removes residue traces of phosphatide, soap, phospholipid
contaminants, lipid peroxidation products, and other impurities.
• Finally, it indirectly impacts the deodorized oil colour.

Bleaching.
• To perform bleaching, adsorption bleaching clays, activated carbon, special silica, or a
combination of these are used.
• bleaching earth is the most popular adsorbent for decolourization of oil and the most widely
used adsorbent material by the oil industry.
• The purpose of Bleaching is to remove the colour pigments contained inside Vegetable Oils.
The neutralized oil is heated at additional temperature through thermic boilers to ultimately
raise the temperature of oil up to 120o
C to 130o
C.
• The oil is then treated with Bleaching Clays that adsorb the colour pigments. The addition
amount for bleaching clay varies from oil to oil.
• It also depends on the colour content of the crude oil and the desired quality oil colour index.

Dewaxing or winterization.
• Waxes are esters of long chain primary alcohols and long fatty acids.
• The presence of wax affects the quality aspect of the oil, which gives it a cloudy
appearance especially during the winter season.
• Its hazy appearance is due to the precipitation of dissolved waxes
• The dewaxing process is also called winterization.
• The term “winterization” appears as during winter when the temperature is low,
waxes present in the oil crystallize, thereby giving a hazy appearance to the oil.

Dewaxing or winterization
• The dewaxing process includes three main processing steps.
• In the first one, the bleached oil should be heated to 328°K (55°C) to make
sure the oil is completely liquid.
• Secondly, the oil is cooled slowly to 283–288K (10–15°C). Ideally, the chilled
oil is held for several hours at this temperature.
• In the third step, after finishing the crystallization, the cooled oil is pumped
into a filter machine to separate the wax from vegetable oil. The filtration
yields a clear liquid oil and the by-product waxes.

deodorization
• Deodorization is a simple distillation process
• This operation allows for the elimination of free fatty acids and removes
odours,
• different off-flavor components,
• contaminants (pesticides,
• light polycyclic aromatic hydrocarbons, and
• other volatile components.

deodorization
• Deodorization also removes residues of mineral oil saturated hydrocarbons
(MOSH) and mineral oil aromatic hydrocarbons (MOAH)
• Careful execution of this process also improves the stability and color of the
oil,

deodorization
• The process involves the passage of steam through layers of oil held in trays
and heating to high temperatures 453–513K (180–240°C) using a high-
pressure steam boiler.
• Utilizing a very high vacuum, between 2 and 8 mmHg, the process removes
undesirable odours caused by aldehydes, ketones, alcohols, short-chain fatty
acids, and thermolabile pigments.

PHYSICAL REFINING
• The process consists of the same steps described in chemical refining, except for the
alkali neutralization process.
• The difference between chemical and physical refining is illustrated in the Figure above.
• Chemical refining consists of removing free fatty acids by adding caustic soda and
separating the soap by centrifugation (mechanical separation), while physical refining, in
the last step, removes free fatty acids and other compounds by steam distillation.
• This process is also known as steam refining.

CHAPTER FOUR
INDUSTRIAL FERMENTATION PROCESSES
INTRODUCTION
• Industrial fermentation is an interdisciplinary science that applies principles
associated with biology and engineering.
• The biological aspect focuses on microbiology and biochemistry.
• The engineering aspect applies fluid dynamics and materials engineering.

CHAPTER FOUR
INTRODUCTION
• Industrial fermentation is associated primarily with the commercial exploitation
of microorganisms on a large scale.
• The microbes used may be natural species, mutants, or microorganisms that have
been genetically engineered.
• Many products of considerable economic value are derived from industrial
fermentation processes.
• Common products such as antibiotics, cheese, pickles, wine, beer, biofuels,
vitamins, amino acids, solvents, and biological insecticides and pesticides are
produced via industrial fermentation.

CHAPTER FOUR
INTRODUCTION
• The goal of industrial fermentation is to improve biochemical or physiological processes that
microbes are capable of performing while yielding the highest quality and quantity of a
particular product.
• The development of fermentation processes requires knowledge from disciplines such as
• microbiology,
• biochemistry,
• genetics,
• chemistry,
• chemical and bioprocess engineering,
• mathematics, and computer science.

CHAPTER FOUR
INTRODUCTION
• The major microorganisms used in industrial fermentation are fungi (such as yeast) and bacteria.
• Fermentation is performed in large fermenters or other bioreactors often of several thousand
liters in volume.
• Industrial fermentation is a part of many industries, including
• microbiology,
• food,
• pharmaceutical,
• biotechnology, and
• chemical.

CHAPTER FOUR
INTRODUCTION
• Industrial fermentation is based on microbial metabolism.
• Microbes produce different kinds of substances that they used for growth and
maintenance of their cells.
• These substances can be useful for humans.
• The goal of industrial fermentation technology is to enhance the microbial
production of useful substances.

INDUSTRIAL FERMENTATION ORGANISMS.
• Different organisms, such as bacteria, fungi, and plant and animal cells, are
used in industrial fermentation processes.
• An industrial fermentation organism must produce the product of interest in
high yield, grow rapidly on inexpensive culture media available in bulk
quantities, be open to genetic manipulation, and be non-pathogenic.

FERMENTATION MEDIA
• To make a desired product by fermentation, microorganisms need nutrients
(substrates).
• Nutrients for microbial growth are known as media. Most fermentation
requires liquid media or broth.
• General media components include carbon, nitrogen, oxygen, and hydrogen in
the form of organic or inorganic compounds.

FERMENTATION SYSTEMS.
• Industrial fermentation takes place in fermenters, which are also called
bioreactors.
• Fermenters are closed vessels (to avoid microbial contamination) that reach
vast volumes, as many as several hundred thousand liters.
• Designed by engineers, the main purpose of a fermenter is to provide
controllable conditions for growth of microbial cells or other cells.

• Parameters such as pH, temperature, nutrients, fluid flow, and other variables
are controlled.
• There are two kinds of fermenters,
• Anaerobic processes (oxygen-free) and
• Aerobic processes.

• Aerobic fermentation is the most common in industry.
• Aerobic fermenters are more complicated. The most critical part in these
systems is aeration.
• In a large-scale fermenter transfer of oxygen is very important. Oxygen
transfer and dispersion are provided by stirring with impellers or oxygen (air)
sparging.
• Anaerobic fermenters can be as simple as stainless-steel tanks or barrels.

FERMENTATION CONTROL AND MONITORING.
• Industrial fermentation control is very important to ensure that organisms
behave properly.
• In most cases computers are used for controlling and monitoring the
fermentation process.
• Computers control temperature, pH, cell density, oxygen concentration, level of
nutrients, and product concentration.
•

APPLICATIONS AND PRODUCTS
food, beverages,food additives, and supplements
• There are a wide range of industrial fermentation products and applications.
• Food, Beverages,Food additives, and supplements.
• Industrial fermentation plays a major role in the production of food. Food products
traditionally made by fermentation include
• Dairy products (cheeses, sour cream, yogurt, and kefir);
• Food additives and supplements (flavors, proteins, vitamins, and carotenoids);
• Alcoholic beverages (beer, wines, and distilled spirits);
• Plant products (bread, coffee, soy sauce, tofu, Sauer- kraut); and
• Fermented meat and fish (pepperoni and salami).

antibiotics and other health care products.
• Antibiotics are chemicals that are produced by fungi and bacteria that kill or
inhibit the growth of other microbes.
• They are the second most significant product of industrial fermentation.
• Most antibiotics are generated by molds or bacteria called actinomycetes.

chemicals.
• Numerous chemicals, such as
• amino acids,
• polymers,
• organic acids (citric, acetic, and lactic), and
• bio-insecticides are produced by industrial fermentation.
• Amino acids are used as a food and animal feed, as well as in the
pharmaceutical, cosmetic, and chemical industries.

enzymes
• Enzymes are used in many industries as catalysts.
• Microorganisms are the favored source for industrial enzymes.
• Seventy percent of these enzymes are made from Bacillus bacteria via
fermentation.
• Most commercial microbial enzymes are hydrolases, which break down
different organic molecules such as proteins and lipids.

biomass production.
• During biomass production by fermentation, the cells produced are the products.
• One major product of this application of industrial fermentation is baker’s yeast biomass.
• Baker’s yeast is required for making bread, bakery products, beer, wine, ethanol,
microbial media, vitamins, animal feed, and biochemical for research.
• Yeast is produced in large aerated fermenters of up to 200,000 liters.
• Molasses is used as a nutrient source for the cells.
• Yeast is recovered from fermentation liquid by centrifugation and then dried.
• It can then be sold as compressed yeast cakes or dry yeast.

BEER PRODUCTION
• The basic ingredients for most beers are
• malted barley,
• water,
• hops and
• yeast.
• Compared to most other alcoholic beverages, beer is relatively low in alcohol.

BEER PRODUCTION
• The highest average strength of beer (alcohol by volume (ABV) indicates the
millilitres of ethanol per 100 ml of beer) in any country worldwide is 5.1%
and the lowest is 3.9%.
• By contrast, the ABV of wines is typically in the range 11–15%.

PROCESS OF BEER PRODUCTION: BREWING
• Brewing is a huge-scale complex process that transforms water, grains and hop
to produce what we call beer, and this is achieved mostly with the help of yeast.
• Basically the large variety of beer is due to the different conditions
(temperature, kind of grain, etc.) established during the stages of production
• The body of the beer is provided by barley, more specifically barley malt and
in general, a few hundreds of grams are used for one litre of beer
• The malt may be partly substituted by starch-rich adjuncts such as rice, corn or
wheat.

BEER MANUFACTURE
TYPES OF BEER
• The flavour and aroma of any beer is, in large part is determined by the
yeast strain employed together with the wort composition.
• Proprietary strains, belonging to individual breweries, are usually jealously
guarded and conserved.
• With the genetic manipulation of yeasts, numerous varietal strains have been
bred, this, along with modifications in the brewing process have led to
different types of beers.

BEER MANUFACTURE
TYPES OF BEER
• Those most often seen beers include:
• Lager: Beers made with yeast that settle on the bottom (Saccharomyces
carlsbergensis) of the container used. Thus, all the yeast and other material
settles on the bottom which results in a clear beer.
• Pilsner: A colorless lager beer originally brewed in the city of Pilsen. Water
used for this style of beer tend to be harder, with a higher calcium and
magnesium content than water used for lager. The color of pilsner is also
lighter than that of lager beer.

BEER MANUFACTURE
TYPES OF BEER
• Ale: Beers made with yeast that floats (Saccharomyces cerevisiae) to the top of the
brewing vats, resulting in a cloudier beer. They tend to have a higher alcohol content
than lagers.
• Porter: A very dark ale. The darker colour and special flavour comes from toasting
the malt before brewing. This usually results in a stronger taste and higher alcohol
content.
• Stout: A very dark, almost black ale. The dark colour and roasted flavor is derived
from the roasted barley, and/or roasted malt (Wong, 2003)

PROCESS OF BEER PRODUCTION: BREWING
• In the production of beer there are 8 stages of brewing, these are
represented schematically below:

PROCESS OF BEER PRODUCTION
STAGE ONE: MALTING & MILLING
• STAGE ONE: MALTING & MILLING
• barley must be subjected to a controlled germination, during which these
enzymes are formed in the barley grain
• Such germinated barley is known as barley malt.
• The malt may be partly substituted by starch-rich adjuncts such as rice, corn or
wheat.

PROCESS OF BEER PRODUCTION
STAGE ONE: MALTING & MILLING
• The barley has been modified to malt by the maltster and its milled
immediately prior to use.
• Each beer has its own formulation with regards to the blend of different malts.

STAGE TWO: MASHING & LAUTERING
• The tank has a mixing paddle to ensure that the mix of water and malt is
constantly agitated during mashing.
• The malt is mixed with hot water to allow the starch to be converted into
sugar by enzymes.
• The temperature of the mixture is crucial, as the type of sugar converted is
temperature dependent: some sugars are fermentable, while others are non-
fermentable, giving richness feel to the finished beer.
• This mashing process takes about two hours.

STAGE TWO: MASHING & LAUTERING
• The sweet liquid, now called wort, can pass through the screens of the false
bottom while the grain stays behind. This is called Lautering
• The wort is then pumped into the kettle. This process takes about 1.5 hours
• Afterwards, the spent grain is collected for cattle feed.

STAGE THREE: BOILING & WHIRLPOOL
• Once all the wort is in the kettle, the liquid is boiled for 60-90 minutes. This ensures that the
wort is sterile.
• Boiling also evaporates some water, concentrating the wort and intensifying the colour
somewhat.
• Hops are added to the kettle at the start of boil for bitterness and at the end of boil for
aroma and flavor
• The wort is then recirculated through a whirlpool effect which ensures the residual hop
product and proteins and enzymes are coagulated, and settle out of the liquid as a sludge
called trub.
• This trub is partially removed from the bottom of the kettle which ensures the bitter wort is
nice and clear when transferred through to the next stage.

STAGE FOUR: COOLING THROUGH HEAT EXCHANGER
• Once boiling is complete, the wort is cooled to around 20oC through a heat
exchanger on its way to the fermenter. This process takes about 1 hour.
• By heat exchanging, we recover the energy used to boil the wort, i.e. cold
water becomes hot water, and returned to the Hot Liquor Tank which is then
used to brew more beer or for cleaning.

STAGE FIVE: FERMENTATION & MATURATION
• Once all the wort is in the tank, the yeast is added.
• This is called pitching the yeast
• The yeast will ferment the wort and turn it into beer.
• Primary fermentation will take about 3 – 4 days to complete.
• Primary fermentation gives green beer
• Fermentation temperatures will vary depending on beer styles, a lager is fermented
below 16 C, ales are fermented above 20 C.
̊ ̊

STAGE FIVE: FERMENTATION & MATURATION
• At the end of fermentation, the finished beer is chilled to 10 C and then 4 C
̊ ̊
and kept in the tank for maturation, usually around three weeks.
• Yeast is harvested from the cone section at the bottom of the fermenter, to be
used to ferment another batch of beer.

STAGE SIX: FILTERING INTO A BRIGHT BEER TANK
• When the beer is required for packaging, either in kegs or bottles, the beer is
earth filtered into a Bright beer tank (BBT).
• Filtering removes yeast, leaving the beer crystal clear. Some beers are not
filtered at all and still contain yeast.
• The CO2 (carbon dioxide) is adjusted in the BBT and it is then ready to be
packaged.
• Beer is kept freezing cold

STAGE SEVEN: PACKAGING
• Beer is packaged into either kegs or bottled in 330ml glass bottles.
• Each keg holds 30 litres or 50 pints or 50 litres, about 85 pints.
• If bottled, the beer is counter pressure filled (double pre-evacuation) to
reduce oxidation and capped on foam to ensure it is free of any nasty
microbes and will remain stable in the bottle.

STAGE EIGHT: DISTRIBUTION
• Kegs are delivered to the bars and pubs and also used for festivals and
promotions.
• Bottles are delivered to off-licences, restaurants, pubs, sporting clubs etc.
• Beer is consumed and enjoyed.

• PROCEDURE FOR MAIZE BEER PRODUCTION

WINE
• Wine is an alcoholic beverage produced by the fermentation of sugars in fruit
juices, primarily grape juice.
• In general, wines are classified into two types based on alcohol content:
• table wines (7 percent to 14 percent, by volume) and
• dessert wines (14 percent to 24 percent, by volume).
• Table wines are further subdivided into still and sparkling categories,
depending upon the carbon dioxide (CO2) content retained in the bottled wine.
• table wines are divided into three groups: red, rosé (blush), and white, based
on the color of the wine.

AN OVERVIEW OF WINE MAKING
• The basic steps in vinification (wine production) include harvesting, crushing,
pressing, fermentation, clarification, aging, finishing, and bottling.

PROCESS DESCRIPTION
HARVESTING, STEMMING AND CRUSHING
• Harvesting of grapes is usually conducted during the cooler periods of the day to
prevent or retard heat buildup and flavor deterioration in the grape.
• Most wineries transport the whole grapes but some crush the grapes in the
vineyard and transport the crushed fruit to the winery.
• Stemming and crushing are commonly conducted as soon as possible after harvest.
• These two steps are currently done separately using a crusher-stemmer, which
contains an outer perforated cylinder to allow the grapes to pass through but
prevents the passage of stems, leaves, and stalks.

PROCESS DESCRIPTION
HARVESTING, STEMMING AND CRUSHING
• Crushing the grapes after stemming is accomplished by any one of many procedures.
• The three processes generally favoured are:
• (1) pressing grapes against a perforated wall;
• (2) passing grapes through a set of rollers; or
• (3) using centrifugal force.
• Generally, 25 to 100 milligrams (mg) of liquified sulfur dioxide (SO2) are added
per liter of the crushed grape mass to control oxidation, wild yeast contamination,
and spoilage bacteria.

PROCESS DESCRIPTION
MACERATION
• Maceration is the breakdown of grape solids following crushing of the grapes.
• The major share of the breakdown results from the mechanical crushing but a small
share results from enzymatic breakdown.
• In red and rosé wine production, the slurry of juice, skins, seeds, and pulp is termed
the "must".
• In white wine production, the skins, seeds, and pulp are separated from the juice
before inoculation with yeast and only the juice is fermented.
• A fermenting batch of juice is also called "must". Thus, the term "must" can refer to
either the mixture of juice, seeds, skins, and pulp for red or rosé wines or only the
juice for white wines.

PROCESS DESCRIPTION
MACERATION
• gravity flow juicers may be used initially to separate the majority of the juice
from the crushed grapes and the press used to extract the juice remaining in
the mass of pulp, skins, and seeds (pomace).
• There are three major types of presses.
• The horizonal press is used for either crushed or uncrushed grapes.
• A pneumatic press can be used for either crushed or uncrushed grapes as well
as for fermented "must".
• continuous screw press

PROCESS DESCRIPTION
FERMENTATION
• Fermentation is the process whereby the sugars (glucose and fructose) present in the
"must" undergo reaction by yeast activity to form ethyl alcohol (ethanol) and CO2
• Fermentation may be initiated by the addition of yeast inoculation to the "must".
• The fermentation process takes place in tanks, barrels, and vats of a wide variety of
shapes, sizes, and technical designs.
• The fermentation process is an exothermic reaction and requires temperature control
of the fermenting "must".
• Red wines are typically fermented at 25° to 28°C (70° to 82°F) and white wines at
8° to 15°C (46° to 59°F).

PROCESS DESCRIPTION
MATURATION
• After fermentation, all wines undergo a period of adjustment (maturation) and
clarification prior to bottling.
• The process of maturation involves the precipitation of particulate and colloidal
material from the wine as well as a complex range of physical, chemical, and
biological changes that tend to maintain and/or improve the sensory characteristics of
the wine.
• The major adjustments are acidity modification, sweetening, de-alcoholization, color
adjustment, and blending.

PROCESS DESCRIPTION
STABILIZATION
• Following the fermentation process, a preliminary clarification step is
commonly accomplished by decanting the wine from one vessel to another,
called racking, in order to separate the sediment (lees) from the wine
• Current racking practices range from manually decanting wine from barrel to
barrel to highly sophisticated, automated, tank-to-tank transfers.
• In all cases, separation occurs with minimal agitation to avoid suspending the
particulate matter.

PROCESS DESCRIPTION
STABILIZATION
• Stabilization and further clarification steps follow maturation and initial
clarification to produce a permanently clear wine with no flavor faults.
• The steps entail various stabilization procedures, additional clarification
(fining), and a final filtration prior to bottling.
• The most common stabilization technique used for many red wines and some
white wines is aging the wine for a period of months or years.

PROCESS DESCRIPTION
BOTTLING
• Glass bottles are the container of choice for premium quality wines and for sparkling wines.
• Because of disadvantages such as weight and breakage, glass bottles are sometimes being
replaced by new containers, such as bag-in-box, for many standard quality, high volume
wines
• Precaution is taken to minimize contact with air during filling and thereby to reduce
oxidation.
• This is done by either flushing the bottle with inert gas before filling or flushing the
headspace with inert gas after filling.

CHAPTER FIVE
AGRO-CHEMICALS-NATURAL RUBBER
• Many of the production methods used for plastics are also applicable to
rubbers.
• However, rubber processing technology is different in certain respects, and
the rubber industry is largely separate from the plastics industry.
• The rubber industry and goods made of rubber are dominated by one
product: tires.
• Tires are used in large numbers on automobiles, trucks, aircraft, and bicycles

RUBBER PROCESSING AND SHAPING
• Production of rubber goods consists of two basic steps:
1. Production of the rubber itself
• Natural rubber is an agricultural crop
• Synthetic rubbers are made from petroleum
2. Processing into finished goods, consisting of:
• Compounding
• Mixing
• Shaping
• Vulcanizing

RUBBER PROCESSING AND SHAPING
• Production of raw Natural Rubber NR might be classified as an agricultural
industry because latex, the starting ingredient, is grown on plantations in
tropical climates.
• By contrast, synthetic rubbers are produced by the petrochemical industry.
Finally, processing into tires and other products occurs at processor
(fabricator) plants, commonly known as the rubber industry.
• The company names include Goodyear, B. F. Goodrich, and Michelin, all
reflecting the importance of the tire.

NATURAL RUBBER / LATEX

NATURAL RUBBER / LATEX
• Natural rubber comes from the Havea brasiliensis tree, which grows in tropical
regions.
• They typically reach 20-30 metres in height on rubber plantations, and are
able to produce commercial quantities of latex at about 7 years of age,
depending on climate and location.
• Economical life span of a rubber tree is between 10 to 20 years, but may
extend past 25 years in the hands of a skilled tapper and bark consumption.

DRY RUBBER PRODUCTION
TAPPING RUBBER TREES
• Havea trees are not tapped any more often than once per day, with 2 or 3
per day being the norm.
• In countries such as Thailand, tapping usually takes place in the early hours of
the morning, prior to dawn due to the high day time temperatures and the
protective clothing worn to protect against snakes etc

DRY RUBBER PRODUCTION
TAPPING RUBBER TREES
• A tapper uses a sharp hook shaped knife to shave a thin layer of fresh bark
from the tree. This exposes the latex vesicles.
• The cut is typically done at 25-30° to the horizontal, as this exposes the
maximum number of vesicles.
• The same incision is re-opened the next time (typically the next day) by
shaving off a small amount of bark.

PROCESSING OF NATURAL RUBBER
• Processing of natural rubber involves the addition of a dilute acid such as
formic acid.
• The coagulated rubber is then rolled to remove excess water.
• Polyisoprene (C5H8)n is the chemical substance that comprises rubber, and its
content in the emulsion is about 30%.
• The latex is collected in large tanks, thus blending the yield of many trees
together.

• The preferred method of recovering rubber from latex involves coagulation -
adding an acid such as formic acid (HCOOH);
• coagulation takes about 12 hours.
• The coagulum, now soft solid slabs, is then squeezed through a series of rolls
which drive out most of the water and reduce thickness to about 3 mm (1/8 in).
• The sheets are then draped over wooden frames and dried in smokehouses.
• Several days are normally required to complete the drying process

• The resulting rubber, now in a form called ribbed smoked sheet, is folded into
large bales for shipment to the processor.
• It has a characteristic dark brown colour, In some cases, the sheets are dried in
hot air rather than smokehouses, and the term air-dried sheet is used; this is
considered to be a better grade of rubber.
• A still better grade, called pale crepe rubber, involves two coagulation steps,
followed by warm air drying. Its colour is light tan.

SYNTHETIC RUBBER
• Most synthetic rubbers are produced from petroleum by the same
polymerization techniques used to synthesize other polymers.
• Unlike thermoplastic and thermosetting polymers, which are normally supplied
to the fabricator as pellets or liquid resins, synthetic rubbers are supplied to
rubber processors in the form of large bales.

COMPOUNDING
• Rubber compounding or formulation refers to the addition of certain chemicals
to raw rubber in order to obtain the desired properties.
• The well-known chemicals are crosslinking agents, reinforcements, anti-
degradants and colorants.
• The crosslinking agents are required for establishing the crosslinks to
interconnect at molecular level thus improving the strength and elasticity.

COMPOUNDING
• Rubber is always compounded with additives. Compounding adds chemicals
for vulcanization, such as sulphur.
• Additives include fillers which act either to enhance the rubber's mechanical
properties (reinforcing fillers) or to extend the rubber to reduce cost (non-
reinforcing fillers).
• It is through compounding that the specific rubber is designed to satisfy a
given application in terms of properties, cost, and processability.

COMPOUNDING
• The single most important reinforcing filler in rubber is carbon black, a
colloidal form of carbon, obtained by thermal decomposition of hydrocarbons
(soot)
• Its effect is to increase tensile strength and resistance to abrasion and tearing
of the final rubber product
• Carbon black also provides protection from ultraviolet radiation
• Most rubber parts are black in colour because of their carbon black content

COMPOUNDING
• Other Fillers and Additives in Rubber
• China clays - hydrous aluminum silicates (Al2Si2O5(OH)4) provide less reinforcing than
carbon black but are used when black is not acceptable
• Other polymers, such as styrene, PVC, and phenolics
• Recycled rubber added in some rubber products, but usually 10% or less
• Antioxidants; fatigue- and ozone-protective chemicals; coloring pigments; plasticizers and
softening oils; blowing agents in the production of foamed rubber; and mold release
compounds

MIXING
• The additives must be thoroughly mixed with the base rubber to achieve
uniform dispersion of Ingredients.
• Uncured rubbers have high viscosity so mechanical working of the rubber can
increase its temperature up to 150o
C (300o
F).
• To avoid premature vulcanization, a two-stage mixing process is usually
employed

MIXING
• Stage 1 - carbon black and other non-vulcanizing additives are combined with
the raw rubber. The term master batch is used for this first-stage mixture
• Stage 2 - after stage 1 mixing has been completed, and time for cooling has
been allowed, stage 2 mixing is carried out in which vulcanizing agents are
added.

MIXING
• Filament Reinforcement in Rubber Products
• •Many products require filament reinforcement to reduce extensibility but
retain the other desirable properties of rubber
• Examples: tires, conveyor belts
• Filaments used for this purpose include cellulose, nylon, and polyester
• Fiber-glass and steel are also used (e.g., steel-belted radial tires)
• Continuous fiber materials must be added during shaping; they are not mixed
like the other additives.

SHAPING AND RELATED PROCESSES
• Shaping processes for rubber products can be divided into four basic
categories:
• 1. Extrusion
• 2. Calendering
• 3. Coating
• 4. Molding and casting

EXTRUSION

CALENDERING
• Calendering
• Stock is passed through a series of gaps of decreasing size made by a stand
of rotating rolls.
• Rubber sheet thickness determined by final roll gap.

SHAPING
ROLLER DIE PROCESS
• Combination of extrusion and calendering that results in better quality product
than either extrusion or calendering alone.

SHAPING
• Coating or Impregnating Fabrics with Rubber
• An important industrial process for producing automobile tires, conveyor belts,
inflatable rafts, and waterproof cloth tents and rain coats.

MOLDED RUBBER PRODUCTS
• Molded rubber products include shoe soles and heals, gaskets and seals,
suction cups, and bottle stops Also, many foamed rubber parts are produced
by molding.
• In addition, molding is an important process in tire production.

MOLDED RUBBER PRODUCTS
• Molding Processes for Rubber
• Principal molding processes for rubber are:
• (1) compression molding,
• (2) transfer molding, and
• (3)injection molding.
• Compression molding is the most important technique because of its use in tire
manufacture

VULCANIZATION
• It is the treatment that accomplishes cross-linking of elastomer molecules, so
that the rubber becomes stiffer and stronger but retains extensibility
• A typical soft rubber has 1 or 2 cross-links per 1000 units (mers)
• As the number of cross-links increases, the polymer becomes stiffer and
behaves more and more like a thermosetting plastic (hard rubber)
•

VULCANIZATION
VULCANIZATION CHEMICALS AND TIMES
• Vulcanization Chemicals and Times
• As it was first invented by Goodyear in 1839, vulcanization used sulfur (about 8 parts
by weight of S mixed with 100 parts of NR) at 140o
C (280o
F) for about 5 hours
• Vulcanization with sulfur alone is no longer used today, due to the long curing times
Various other chemicals are combined with smaller doses of sulfur to accelerate and
strengthen the treatment
• The resulting cure time is 15-20 minutes.
• A variety of non-sulfur vulcanizing treatments have also been developed.

TIRES AND OTHER RUBBER PRODUCTS
• Tires are the principal product of the rubber industry. Tires are about 75% of total rubber tonnage
• Other important products:
• Footwear
• Seals
• Shock-absorbing parts
• Conveyor belts
• Hose
• Foamed rubber products
• Sports equipment

CHAPTER SIX
PULP AND PAPER
• Paper products and chemicals based on cellulose are highly significant for a
nation,
• The per capita consumption of paper is a measure of the educational, social,
cultural and industrial activities of a country.

PULP AND PAPER RAW MATERIALS
• Different types of raw material used in pulping

CHEMISTRY OF RAW MATERIALS
COMPONENTS OF WOOD:
• Cellulose: It is made by polymerization of glucose in the shape of a very long
chain of cells. These contents should be in higher quantity for a suitable raw
material.
• Lignin: The complex polymer in plant cell walls that gives the plant rigidity
and strength, and is the major component of wood
• Hemi-Cellulose: If a number of joined molecules is less in the chain that is
called hemicellulose and better than cellulose. Hemicellulose is unlike cellulose
dissoluble in water. This should also be in less quantity

CHEMISTRY OF RAW MATERIALS
COMPONENTS OF WOOD:
• Ash content: These are actually mineral of soil taken up by plants through roots with
soil moisture. They impart coloration to paper. They should not be more than 10%
otherwise more chemicals will be required to whiten the paper, which is not economical.
• Extractives: This fraction termed extractive is composed of a variety of material that
generally is not considered a part of the cell wall. These organic extraneous
compounds may be included low molecular weight. They should also be in less quantity
or amount.
• Pulp: A substance consisting of wood fiber isolated from wood by mechanical or
chemical means and used for the manufacturing of paper called Pulp. The process of
isolating wood fiber is called Pulping.

GENERAL PROCESS
CHEMICAL WOOD PULPING
• Chemical wood pulping involves the extraction of cellulose from wood by dissolving
the lignin that binds the cellulose fibers together.
• The processes principally used in chemical pulping are
• kraft,
• sulfite,
• neutral sulfite semichemical (NSSC), and
• soda.

GENERAL PROCESS
CHEMICAL WOOD PULPING
• The kraft process alone accounts for over 80 percent of the chemical pulp
produced
• The choice of pulping process is determined by the desired product, by the
wood species available, and by economic considerations.

KRAFT PULPING
• The kraft pulping process involves the digesting of wood chips at elevated
temperature and pressure in "white liquor", which is a water solution of sodium
sulfide and sodium hydroxide.
• The white liquor chemically dissolves the lignin that binds the cellulose fibers
together.
• There are 2 types of digester systems, batch and continuous.

KRAFT PULPING
• Most kraft pulping is done in batch digesters, although the more recent
installations are of continuous digesters.
• In a batch digester, when cooking is complete, the contents of the digester are
transferred to an atmospheric tank usually referred to as a blow tank.
• The entire contents of the blow tank are sent to pulp washers, where the spent
cooking liquor is separated from the pulp.
• The pulp then proceeds through various stages of washing, and possibly bleaching,
after which it is pressed and dried into the finished product.
• The "blow" of the digester does not apply to continuous digester systems.

KRAFT PULPING
• The balance of the kraft process is designed to recover the cooking chemicals and
heat.
• Spent cooking liquor and the pulp wash water are combined to form a weak black
liquor which is concentrated in a multiple-effect evaporator system to about 55
percent solids
• The black liquor is then further concentrated to 65 percent solids in a direct-contact
evaporator, by bringing the liquor into contact with the flue gases from the recovery
furnace, or in an indirect-contact concentrator.

KRAFT PULPING
• The strong black liquor is then fired in a recovery furnace.
• Combustion of the organics dissolved in the black liquor provides heat for
generating process steam and for converting sodium sulfate to sodium sulfide.
• Inorganic chemicals present in the black liquor collect as a molten smelt at the
bottom of the furnace.

BLEACHING PROCESS
• Raw pulp contains an appreciable amount of lignin and other discoloration, it
must be bleached to produce light colored or white papers preferred for
many products.
• The fibers are further delignified by solubilizing additional lignin from the
cellulose through chlorination and oxidation.
• These include chlorine dioxide, chlorine gas, sodium hypochlorite, hydrogen
perioxide, and oxygen.

BLEACHING PROCESS
• Sodium Hydroxide, a strong alkali is used to extract the dissolved lignin from
fibers surface.
• The bleaching agents and the sequence in which they are used depend on a
number of factors, such as the relative cost of the bleaching chemicals, type
and condition of the pulp.

PAPERMAKING PROCEDURE
• Bleached or unbleached pulp may be further refined to cut the fibers and roughen the surface
of the fibers to enhance formation and bonding of the fibers as they enter the paper machine.
• Water is added to the pulp slurry to make a thin mixture normally containing less than 1
percent fiber.
• The dilute slurry is then cleaned in cyclone cleaners and screened in centrifugal screens before
being fed into the ‘wet end’ of the paper-forming machine. The dilute stock passes through a
head-box that distributes the fiber slurry uniformly over the width of the paper sheet to be
formed.

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