• The first recorded manufacture of soap was in 600BC.• A soap-like material found in clay cylinders during the excavation of ancient Babylon is evidence that soap- making was known as early as 2800 B.C. Such materials were later used as hair styling aids.• Records show that ancient Egyptians bathed regularly.• The Ebers Papyrus, a medical document from about 1500 B.C., describes combining animal and vegetable oils with alkaline salts to form a soap-like material used for treating skin diseases, as well as for washing.
• At about the same time, Moses gave the Israelites detailed laws governing personal cleanliness. He also related cleanliness to health and religious purification.• Soap got its name, according to an ancient Roman legend, from Mount Sapo, where animals were sacrificed.• Rain washed a mixture of melted animal fat, or tallow, and wood ashes down into the clay soil along the Tiber River. Women found that this clay mixture (soap) made their wash cleaner with much less effort.
• The first of the famous Roman baths, supplied with water from their aqueducts, was built about 312 B.C. The baths were luxurious, and bathing became very popular.• By the second century A.D., the Greek physician, Galen, recommended soap for both medicinal and cleansing purposes.• After the fall of Rome in 467 A.D. and the resulting decline in bathing habits, much of Europe felt the impact of filth upon public health. This lack of personal cleanliness and related unsanitary living conditions contributed heavily to the great plagues of the Middle Ages, and especially to the Black Death of the 14th century.
• It wasnt until the 17th century that cleanliness and bathing started to come back into fashion in much of Europe. History of SoapMaking___________________• Soap-making was an established craft in Europe by the seventh century. Vegetable and animal oils were used with ashes of plants, along with fragrance.• Italy, Spain and France were early centres of soap manufacturing, due to their ready supply of raw materials such as oil from olive trees.
History of Soap Making _• Italy, Spain and France were early centres of soap manufacturing, due to their ready supply of raw materials such as oil from olive trees.• The English began making soap during the 12th century.• The soap business was so good that in 1622, King James I granted a monopoly to a soap-maker for $100,000 a year.• In the 19th century, soap was heavily taxed as a luxury item in several countries. When the high tax was removed, soap became available to ordinary people, and cleanliness standards improved.
History of Soap Making _• A major step toward large-scale commercial soap-making occurred in 1791 when a French chemist, Nicholas Leblanc, patented a process for making soda ash*, or sodium carbonate, from common salt.• 20 years later - The science of modern soap-making was born with the discovery by Michel Eugene Chevreul, (another French chemist), of the chemical nature and relationship of fats, glycerine and fatty acids.• mid-1800s - Ernest Solvay (Belgian chemist)- the ammonia process, which used common table salt, or sodium chloride, to make soda ash. “Solvays process”
History of Soap Making_ • 1850 - soap-making, one of North Americas fastest- growing industries. Its broad availability changed soap from a luxury item to an everyday necessity.
• Soap is a cleansing agent created by the chemical reaction of a fatty acid with an alkali metal hydroxide.• water-soluble sodium or potassium salts of fatty acids• made from fats and oils, or their fatty acids, by treating them chemically with a strong alkali• has the general chemical formula RCOOX. COMPONENTS• The three main components of soap by both cost and volume are oils, caustic and perfumes.
The typical composition of a couple of common classes of commercial soap are:• Tallow soaps: 40-45% oleate, 25-30% palmitate, 15-20% stearate• Coconut oil soaps (even more impure): 45-50% various C12 carboxylates, 16-20% various C14 carboxylates, 8-10% various C16 carboxylates, 5-6% oleate, 10-15% various C12 or shorter carboxylates
A soap molecule has two ends with different properties:1. A long hydrocarbon part which is hydrophobic (i.e. it dissolves in hydrocarbon).2. A short ionic part containing COO-Na+ which is hydrophilic (i.e. it dissolves in water).
Fats and Oils - used in soap-making come from animal or plant sources.Each fat or oil is made up of a distinctive mixture of severaldifferent triglycerides.• In a triglyceride molecule, three fatty acid molecules are attached to one molecule of glycerine. There are many types of triglycerides; each type consists of its own particular combination of fatty acids. Fatty acids are the components of fats and oils that are used in making soap. They are weak acids composed of two parts: A carboxylic acid group consisting of one hydrogen (H) atom, two oxygen (O) atoms, and one carbon (C) atom, plus a hydrocarbon chain attached to the carboxylic acid group. Generally, it is made up of a long straight chain of carbon (C) atoms each carrying two hydrogen (H) atoms.
Alkali• - An alkali is a soluble salt of an alkali metal like sodium or potassium. Originally, the alkalis used in soap- making were obtained from the ashes of plants, but they are now made commercially. Today, the term alkali describes a substance that chemically is a base (the opposite of an acid) and that reacts with and neutralizes an acid.• The common alkalis used in soap-making are sodium hydroxide (NaOH), also called caustic soda; and potassium hydroxide (KOH), also called caustic potash.
Soaps are the product of the reaction between a fat andsodium hydroxide:
Soap is produced industrially in four basic steps:1. Saponification - A mixture of tallow (animal fat) and coconut oil ismixed with sodium hydroxide and heated. The soapproduced is the salt of a long chain carboxylic acid.*Saponification - process of making soap by the hydrolysis of fats and oils with alkalies
2. Glycerine removal - Glycerine is more valuable than soap, so most of itis removed. Some is left in the soap to help make it softand smooth. Soap is not very soluble in salt water,whereas glycerine is, so salt is added to the wet soapcausing it to separate out into soap and glycerine in saltwater.3. Soap purification - Any remaining sodium hydroxide is neutralizedwith a weak acid such as citric acid and two thirds of theremaining water removed.
4. Finishing - Additives such as preservatives, colour andperfume are added and mixed in with the soap and it isshaped into bars for sale.
THE COLGATE-PALMOLIVE SOAP MANUFACTURING PROCESS
This is a continuous process(Figure 1) which uses a plantbuilt by Binacchi & Co. Theprocess is best understood interms of two streams: soapflowing in the order given belowagainst a counter-current of lye.
This reaction is exothermic, and progresses quickly and efficiently ataround 125oC inside an autoclave type reactor.
• The raw materials are continually fed into a reactor in fixed proportions. Assuming a production rate of 1000 kg wet soap per hour and a 80:20 tallow:coconut oil mix.• These ingredients alone would give a low water, high glycerine soap. Soap needs to be about 30% water to be easily pumpable, and even then needs to be held at around 70oC, so excess lye is added to hydrate the soap and dissolve out some of the glycerine. The lye added is known as "half spent lye" and is the lye discharged from the washing column (see below). This lye already contains some glycerine, but it is further enriched by that formed in the saponification reaction.
• The wet soap is pumped to a "static separator" - a settling vessel which does not use any mechanical action. The soap / lye mix is pumped into the tank where it separates out on the basis of weight. The spent lye settles to the bottom from where it is piped off to the glycerine recovery unit, while the soap rises to the top and is piped away for further processing.
• The soap still contains most of its glycerine at this stage, and this is removed with fresh lye in a washing column. The column has rings fixed on its inside surface. The soap solution is added near the bottom of the column and the lye near the top. As the lye flows down the column through the centre, a series of rotating disks keeps the soap / lye mixture agitated between the rings. This creates enough turbulence to ensure good mixing between the two solutions.• The rate of glycerine production is calculated and the rate at which fresh lye is added to the washing column then set such that the spent lye is 25 - 35 % glycerine. Glycerine is almost infinitely soluble in brine, but at greater than 35% glycerine the lye no longer efficiently removes glycerine from the soap. The soap is allowed to overflow from the top of the column and the lye ("half spent lye") is pumped away from the bottom at a controlled rate and added to the reactor.
• The lye is added at the top of the washing column, and the soap removed from the column as overflow. As the lye is added near the overflow pipe the washed soap is about 20% fresh lye, giving the soap unacceptably high water and caustic levels. Separating off the lye lowers the electrolyte levels to acceptable limits. The soap and lye are separated in a centrifuge, leaving a soap which is 0.5% NaCl and 0.3% NaOH, and about 31% water. The lye removed is used as fresh lye.
• Although the caustic levels are quite low, they are still unacceptably high for toilet and laundry soap. The NaOH is removed by reaction with a weak acid such as coconut oil (which contains significant levels of free fatty acids), coconut oil fatty acids, citric acid or phosphoric acid, with the choice of acid being made largely on economic grounds. Some preservative is also added at this stage.
Glycerine recoveryAs has already been stated, glycerine is more valuablethan the soap itself, and so as much of it as possible isextracted from the soap. This is done in a three stepprocess.• Step 1 - Soap removal The spent lye contains a small quantity of dissolved soap which must be removed before the evaporation process. This is done by treating the spent lye with ferrous chloride.
• Step 2 - Salt removal Water is removed from the lye in a vacuumevaporator, causing the salt to crystallize out as thesolution becomes supersaturated. This is removed in acentrifuge, dissolved in hot water and stored for use asfresh lye. When the glycerine content of the solutionreaches 80 - 85% it is pumped to the crude settling tankwhere more salt separates out.
• Step 3 - Glycerine purification A small amount of caustic soda is added to thecrude glycerine and the solution then distilled undervacuum in a heated still. Two fractions are taken off - oneof pure glycerine and one of glycerine and water. Theglycerine thus extracted is bleached with carbon black thentransferred to drums for sale, while the water/glycerinefraction is mixed with the incoming spent lye and repeatsthe treatment cycle.
• The lye is a main effluent source in this industry and it mainly consists of unreacted fatty matter, caustic soda, sodium chloride and glycerol.• According to the above effluent analysis, it is shown that the effluent is highly polluted and that it should not be discharged into the surface drains. The effluent should be treated to satisfy the tolerance levels specified for discharge into inland surface waters.• Treatment could be done either to recover glycerol and sodium chloride from spent lye or by increasing the glycerol content of the spent lye to an economical level.
Advantages Disadvantages• Very effective as a • Oils and perfume are bactericide immiscible in water and if• It will form gels, emulsify spilled create havoc, oil and lower the surfaces although the oils do tension of water. solidify at room• Excellent everyday temperature. cleaning agent. • When used in hard water,• Good biodegradability soap can produced a scum. **Soaps, will react with metal ions in the water and can form insoluble precipitates (soap scum).
_________History of Detergents/DetergentMaking__________• The chemistry of soap manufacturing stayed essentially the same until 1916, when the first synthetic detergent was developed in Germany in response to a World War I- related shortage of fats for making soap.• Known today simply as detergents, synthetic detergents are washing and cleaning products without soap, "synthesized" or put together chemically from a variety of raw materials.
• Household detergent production in North America began in the early 1930s, but did not really take off until after World War II.• The first detergents were used chiefly for hand dishwashing and fine fabric laundering.• The breakthrough in the development of detergents for all- purpose laundry uses came in 1946, when the first "built" detergent (containing a surfactant/builder combination) was introduced in the United States.• By 1953, sales of detergents in the United States had surpassed those of soap. Now detergents have all but replaced soap-based products for laundering, dishwashing and household cleaning. Detergents (alone or in combination with soap) are also found in many of the bars and liquids used for personal cleansing.
• Detergents are the sodium salts of long chain benzene sulphuric acids.• uses a synthetic surfactant in place of the metal fatty acid salts used in soaps• both in powder and liquid form, and sold as laundry powders, hard surface cleansers, dish washing liquids, fabric conditioners etc.• primarily surfactants, which could be produced easily from petrochemicals. *Surfactants lower the surface tension of water, essentially making it wetter so that it is less likely to stick to itself and more likely to interact with oil and grease.• * SURFACTANTS - SURFACE ACTIV AGENTS
• The cleansing action is exactly similar to that of soaps whereby the formation of micelles followed by emulsification occurs. STRUCTURE *Detergents are similar in structure and function to soap, and for most uses they are more efficient than soap and so are more commonly used. In addition to the actual detergent molecule, detergents usually incorporate a variety of other ingredients that act as water softeners, free-flowing agents etc.
The first “self-acting” laundry detergentwas launched by Henkel in the Germanmarket on June 6, 1907, and was giventhe name “Persil”.The name derived from the two mostimportant chemical raw materials in theproduct, perborate and silicate.Today, both Henkel and Unilevermanufacture their own formulations. Persilis Unilevers premium brand in the UnitedKingdom and the Republic of Ireland.
• Step 1 - Slurry making The solid and liquid raw ingredients are dropped into a large tank known as a slurry mixer. As the ingredients are added the mixture heats up as a result of two exothermic reactions: the hydration of sodium tripolyphosphate and the reaction between caustic soda and linear alkylbenzenesulphonic acid. The mixture is then further heated to 85oC and stirred until it forms a homogeneous slurry.
• Step 2 - Spray drying The slurry is deaerated in a vacuum chamber andthen separated by an atomiser into finely divided droplets.These are sprayed into a column of air at 425oC, wherethey dry instantaneously. The resultant powder is knownas base powder, and its exact treatment from this point ondepends on the product being made.
• Step 3 - Post dosing Other ingredients are now added, and the airblown through the mixture in a fluidiser to mix them into ahomogeneous powder. Typical ingredients are listed inTable 3.
• Step 1 - Soap premix manufacture Liquid detergent contains soap as well assynthetic surfactants. This is usually made first as apremix, then other ingredients are blended into it. This stepsimply consists of neutralising fatty acids (rather than fatsthemselves) with either caustic soda (NaOH) or potassiumhydroxide.
• Step 2 - Ingredient mixing All ingredients except enzymes are addedand mixed at high temperature. The ingredients used inliquid detergent manufacture are typically sodiumtripolyphosphate, caustic soda, sulphonic acid, perfumeand water. The functions of these ingredients has beencovered above.
• Step 3 - Enzyme addition The mixture is cooled and milled, and theenzymes added in powder form.
Advantages Disadvantages• biodegradable • Their elimination from municipal wastewaters by• do not decompose in the usual treatments is a acidic medium. problem. • have a tendency to produce• As detergents are derived stable foams in rivers that from petroleum they save extend over several hundred on natural vegetable oils. meters of the river water. • danger to aquatic life.• can lather well even in • Some surfactants are hard water* incompletely broken down with conventional treatment processes • inhibit oxidation*
• Within the plant, all the process areas are also bunded, and the trade waste from there piped to an interception tank before draining to the councils trade waste system.• The contents of the interception tank are continuously monitored for acidity or alkalinity, and is designed to settle out excess solids or light phase chemicals.• If a spill is detected in the plant itself, a portion of the interception tank can be isolated off and the effects of the spill neutralized before the waste is dumped.• Often an off-spec product can be reprocessed and blended rather than dumped, and even washout water can be reprocessed to minimised the discharges from the plant.
• Phosphates can be removed from sewage and recycled, either back into industrial products, or into food production.• They are thus the only recyclable detergent ingredient.
PHYSICALThis information applies to ingredientsprocessed through household septic tanksystems as well as municipal treatmentplants.Two basic steps occur in the treatment ofwastewater in both systems.:• The first step, called primary treatment, consists of the removal of solid material, such as grit or grease, from the wastewater by physical means, i.e., settling and flotation in tanks.• The second step, called secondary treatment, removes the dissolved material by biological means, i.e., consumption by
Any small amounts of chemicals whichare not biodegraded or removed duringsewage treatment are diluted in surfacewaters, soil and the ocean. Theycontinue to biodegrade or be removedfrom water by attaching to solids, aprocess known as adsorption.
• The manufacturing process itself is closely monitored to ensure any losses are kept to a minimum. Continuous measurements of key properties such as electrolyte levels and moisture both ensure that the final product is being made to spec, and ensures the manufacturing process is working as it was designed to. Hence the losses in the plant will indirectly be minimised because the process itself is being monitored.
• To determine the safety of a cleaning product ingredient, industry scientists evaluate the toxicity of the ingredient.Number of Factors Affecting Exposure:- duration and frequency of exposure to the ingredient- the concentration of the ingredient at the time of exposure- the route and manner in which the exposure occurs
• Manufacturers constantly monitor the quality of their detergents, and they utilize the same testing methods to assess the effectiveness of new products. In one method, light is shined onto a piece of fabric that has been soiled and then washed in the test detergent. The amount of light reflected, compared to the amount reflected by a sample of the original fabric, is a measure of cleanliness. A reflection rate of 98 percent is considered quite good and indicates that the detergent has cleaned properly.• Another method involves laboratory burning of a small amount of material that has been soiled and then laundered. The weight of the ashes, plus the weight of the gaseous results of the burning, reveal how much of the dirt remained in the fabric after laundering. A result that is much higher than a clean test sample indicates that a significant amount of dirt was retained in the laundered sample. Naturally, the goal is to come as close to the weight of a clean control sample as possible.
Personal Cleansing laundry dishwashing Household Cleaning
Four General Categories:• Personal Cleansing – include bar soaps, gels, liquid soaps and heavy duty hand cleaners.• Laundry – available as liquids, powders, gels, sticks, spray pumps, sheets and bars• Dishwashing – include detergents for hand and machine dishwashing as well as some specialty products. (liquids, gels, powders, solids)• Household Cleaning – available as liquids, gels, powders, sheets and pads for use on painted, plastic, metal, porcelain, glass and other surfaces, and on washable floor coverings.
• The origins of the chemical industry in the Philippines can be traced back during the 19th century. This mainly involved the small-scale and rudimentary production involving some chemical processes.• As early as the 1950s, leather for slippers, harness, and soles were already being produced in Meycauayan, Bulacan, with the leather being tanned through the use of vegetable oil tannin extract from guamachili tree, or kamachile.• Shortly after, around 1875, soap making as a trade -- involving the mixing of coconut oil with alkali (lye) obtained from leaching wood ashes in small iron pots -- started in the country.
• It was not until the early 20th century that more significant and advanced chemical activities began to take place.• In 1911, the first modern soap factory was built, followed quickly by others. Intensive sales and advertising drives developed the Philippines market for soap.• By the time World War II broke out, there were already 135 soap establishments in the country, with only three processors using modern methods.
SOAP DETERGENT• They are metal salts of • These are sodium salts of long chain higher fatty long chain hydrocarbons acids. like alkyl sulphates or• prepared from vegetable alkyl benzene oils and animal fats. sulphonates.• cannot be used effectively • prepared from in hard water as they hydrocarbons of produce scum i.e., petroleum or coal. insoluble precipitates of • do not produce insoluble Ca2+, Mg2+, Fe2+ etc. precipitates in hard water. They are effective in soft, hard or salt water. • more soluble in water