How to distill crude glycerin

Glycerin boiling point is 290 ℃ under atmospheric pressure,begin to decompose and polymerize when the temperature is 204 ℃,so crude glycerol distillation needs to be done under pressure.Under the pressure of 20mmHg, the boiling point of glycerol is 181.34 ℃, while under 10mmHg the pressure is 166.11 ℃,in order to further reduce the evaporation temperature during glycerol distillation, the steam distillation under pressure can be used in industry.

The distillation process of crude glycerol is transfer glycerol to glycerol vapour with high temperature,it is distilled with water and separated from other components that cannot be steamed at this temperature.Then condense the glycerinevapor and water vapor sectionally, separate the glycerine from the water.Glycerol products with a content of 99% or more can be obtained under good control.

According to the principle of distillation, each component of mixed liquid will produce steam when heated,The vapor pressure on the mixed liquid level meter is equal to the partial vapor pressure of each component at this temperature.If the vapor pressure is equal to the external pressure, the mixture begins to boil.If water vapor passes through the mixture,the vapor pressure on the liquid surface consists of the water steam pressure and the vapor pressure of the distilled liquid.At this point, the mixture will boil and evaporate at a lower temperature.During the distillation of glycerin, when outside pressure is 30mmHg, glycerol boiling gasification at the temperature of 190.87 ℃.The water vapor pressure on the crude glycerine is 15mmHg when connect with water steam,the vapor pressure of glycerol is 30- 15= 15mmHg,glycerin becomes boiling evaporation at the temperature of 174. 86 ° C .The reduction of distillation temperature reduces the decomposition and polymerization of glycerol,increase the distillation yield and quality of the glycerol.So the lower distillation temperature the better, usually distillation temperature is under 170 ℃.
When the saponified waste liquid crude glycerol is distilled, the salts in the crude glycerol are gradually separated out and deposited in the distillation kettle or salt box.Therefore, the salt should be pressed out of the salt box regularly,after filtration, the filtrate is redistilled and the salt is washed back to the boiling process.The condenser can use hot air (1980s) or water as the condensing medium, domestic now use hot water and cold water as the medium.By controlling the temperature of the condensing medium of first cooling and second cooling, the glycerine concentration of first cooling condensate can reach above 98%.High quality pharmaceutical or explosive grade glycerol is obtained by decolorization, decolorization or step – by – step ion exchange.

Harm and benefit of glycerin

Glycerin – an important component, which is part of the vast majority of cosmetics. In tandem with water, it provides a good moisturizing of the skin. But in the network you can find a lot of misconceptions about glycerine. He is accused of drawing moisture from the skin and withering it. 

It gets to the manufacturers of cosmetics – they allegedly often use low-grade synthetic glycerin, which negatively affects the skin condition. And how things really are? Is the glycerin used in cosmetics so harmful, as they say? 

Among fans of natural cosmetics, rumors are circulating that glycerin and organic are not compatible. The information given in the article will reveal the truth about the famous humidifier and refute common misconceptions. 

Myths and truth about glycerin: 

Myth	Disclaimer
Glycerin draws moisture from the skin, thereby dehydrating it	In dilute form, the substance is a good moisturizer. It’s all about the ability of glycerin to attract moisture and form on the surface of the epidermis the thinnest film that saves water. Dehydration occurs only if the humidifier is used in its pure form. But this substance without dilution with water in cosmetology is not applied.
Glycerin belongs to the category of cheap moisturizing substances, and cheap – it means bad	The substance is used for various purposes and has a different degree of purification. Glycerin, derived from natural ingredients (for example, from the best quality vegetable oil) and passed through all stages of purification, has no harmful impurities and only benefits the skin.
At low humidity, glycerol begins to absorb moisture from the layers of the epidermis	The main task of the humidifier is to penetrate the inside of the skin and keep moisture in its layers. Once in the deep layers, the molecules of the substance structure the extracellular fluid, thereby protecting the cells from negative osmotic pressure. Low humidity of the environment can dry only 2-3 layers of horny cells, while the rest remain hydrated.Therefore, neither glycerin nor the percentage of air humidity on the water balance of the skin in any way affect.

Numerous laboratory studies have proved that the famous moisturizer used in cosmetics has a beneficial effect on the skin condition. There are scientific works on the rapid regeneration of the affected skin with a mixture of water and glycerin in combination with other care and moisturizing components.  

Useful properties of glycerol 

• Hygroscopicity. Molecules of matter absorb and accumulate moisture. Due to their small size, they penetrate deeply into the skin and promote the saturation of all its layers with water; 
• An important component of the epidermis. It’s unlikely that opponents of glycerin know that the substance is produced by the cells of the human body. Glycerin is an active participant in the internal system of water circulation in cell membranes. If, for some reason, the production of the substance by the body has decreased, then the cosmetic with its content will help fill the missing moisture; 
• Protective function. Due to its ability to fill small wrinkles and microcracks with moisture, the substance prevents dust and microorganisms from entering the upper skin layers, thereby protecting the epidermis from inflammation and irritation. Also glycerol-containing products are endowed with the ability to protect the skin from ingress of irritating substances (for example, sodium lauryl sulfate). 

Harmful properties of glycerin 

Harm to the skin can only “pure” glycerin, that is undiluted by water. Dangerous and high concentration of the substance in the cosmetic agent. Long-term exposure to such a moisturizer leads to the formation of acne, darkening and excessive dryness of the skin.  

Although the harm of glycerin for the face is not proven, for those who are in doubt, it can be advised to use products with a plant moisturizer. In organic glycerin there are no harmful impurities, so it is much easier to clean it. In the synthesized substance obtained by laboratory, the probability of containing harmful components is significantly increased. 

Concentration of cosmetic glycerin in moisturizers

Moisturizing creams and lotions contain up to 65-80% water. This volume accounts for up to 15% of glycerin, as an active moisture-saving component. If the concentration of the substance is much higher than the permissible norm, then after application of the agent on the skin a non-drying film forms. The agency of the US Department of Health and Human Services in its normative documents specifies the allowable content of this substance as a moisturizing ingredient, from 20 to 45%. 

But the problem is that the amount of glycerin can not be determined, since its percentage does not appear on the product packaging. The only way out is to acquire a remedy, where the humidifier is not at the head of the list, but near the end. Ingredients in the composition are usually indicated in descending order, so you are so insured from surplus substances in the selected product. 

Facts in favor of glycerol

Numerous scientific studies confirm that glycerin in an acceptable concentration is useful for the skin, as it increases its elasticity and removes dryness. There are cases when glycerin, which is part of the face cream, promoted the rapid restoration of the epidermis, damaged by surface-active substances, dermatitis and psoriasis.  

One of the studies carried out in practice has proved that glycerin plays an important physiological role in the transport of water and is one of the primary factors of moisture retention in the stratum corneum. The experiments showed that even with a relative humidity of no more than 35%, a sample of the epidermis treated with a moisturizer cream contained much more moisture than that impregnated with ordinary water.

Glossary for the Modern Soap Maker

A collection of terms, definitions and acronyms related to the art of soap making.

A|B|C|D|E|F|G|H|I|J|K|L|M|N|O|P|R|S|T|U|V|W|X

AAbsolute – A concentrated alcohol soluble aromatic base. Separated from the fatty acids and waxes in a concrete using alcohol and vacuum distillation.

Aleppo Soap – A hot processed, olive oil based soap made in Aleppo, Syria as early as 1300.

Almond Oil – Obtained from the nuts, almond oil is used in skin care preparations as an emollient or as a carrier oil.

Aloe Vera – The juice or gel obtained from the leaves of this plant are used in cosmetics for its soothing and healing properties.

Anhydrous – A liquid or a compound that does not contain water.

Antioxidant – Prevents or retards the reaction of a substance with oxygen. Inhibits oxidation, the damage from free radicals.

Apricot Kernel Oil – Derived from the seeds, used in skin care preparations for its moisturizing properties.

Aromatherapy – The use of fragrance or essences from plants to alter a person’s mental or emotional well being.

Aromatic – Having a strong fragrance or odor.

Ascorbic Acid – Vitamin C.

Astringent – Constricts or tightens the skin, used in facial preparations, also removes oils from the skin.

Avocado Oil – Obtained from the pulp of the fruit, avocado oil is high in unsaponifiables. Used in cosmetics and skin care preparations for its moisturizing and nourishing properties.

Awapuhi Kuahiwi – Hawaiian wild pinecone ginger or shampoo ginger. The thick, sudsy juice squeezed from the mature flower heads is used as a shampoo or hair conditioner.

B 

Balsam – Aromatic resinous substances containing benzoic and cinnamic acid, such as Balsam of Peru.

Beeswax – Wax obtained from processing the honeycomb. Used in candles, soaps and lip balms.

Biodegradable – Able to be decomposed by biological agents, such as bacteria.

Biopein^® – All natural preservative and stabilizing ingredient manufactured from a blend of botanical extracts.

Bleaching – The process to remove or neutralize the color of an oil or fat.

Borax – Sodium borate, a white crystalline mineral generally used as an emulsifier or cleanser. Used in cream preparations as an emulsifier.

Botanical – Obtained from a plant or plants, related to plants or botany.

Botanical Name – The Latin name assigned to distinguish one species from another, the scientific name composed of the genus followed by the species.

C 

Carrier Oil – A vegetable or nut base oil used to dilute essential oils prior to the application on your skin.

Castile – A region in Spain known for producing olive oil based soaps in the 13th century. Today, a soap made with 100% olive oil is loosely referred to as a Castile soap.

Castor Bean Oil – Derived from the beans of the plant, castor oil is also used medicinally.

Caustic Potash – See potassium hydroxide.

Caustic Soda – See sodium hydroxide.

Chandler – A dealer of specific goods, a tallow chandler is a maker and seller of candles and soap.

Citric Acid – A natural acidic ingredient extracted from citrus and other acidic fruits such as pineapples. Used as a flavoring and preservative in foods and beverages; also used in bath products.

Citricidal – See Grapefruit Seed Extract.

Cocoa Butter – Obtained from the cocoa bean, high in unsaponifiables with a chocolate scent.

Coconut Oil – The semisolid fat obtained from the meat of the coconut. Used in soap making, it contributes hardness and lather.

Cold Kettle – See cold process.

Cold Pressed – The process in which oils are extracted under mechanical pressure at low temperatures, typically less than 125° Fahrenheit.

Cold Process – A method of soap making without utilizing any external heat source.

Comedogenic – Tends to aggravate or produce acne.

Concrete – A thick, fragrant material extracted from a botanical base through solvent extraction. Contains the essential oils, fatty acids and wax from the plant base.

Continuous Process – A modern method of commercial soap making in which saponification takes place under pressure. Allows for the addition of base ingredients throughout the soap making process.

Copra – The dried flesh or meat from a coconut from which coconut oil is derived.

Cosmeceutical – Used by the cosmetics industry to refer to cosmetic products that have medicinal or drug-like benefits. This term is not recognized by the FDA.

Cosmetic – Product applied to the human body for cleansing, beautifying, promoting attractiveness, or altering the appearance without affecting the body’s structure or functions.

Cosmetic Grade – Refers to the approval for use in cosmetics, such as colorants, dyes or fragrance oils which will come into direct contact with your skin.

CPHP – Crock Pot Hot Process. A method of soap making utilizing the heat from an electric crock pot during the soap making process.

Cruelty Free – Not tested on animals.

D 

D&C – Prefix used to designate the approved use in drugs and cosmetics, such as D&C Red#7.

DBHP – Double Boiler Hot Process. Hot process soap making using a double boiler to apply heat during processing.

Decoction – A tea or infusion brewed from hard plant material such as bark and roots.

Deodorize – The process in which odoriferous matter is removed from an oil or fat.

Detergent – A petroleum based surfactant other than soap. Developed during WWII when soap making oils were scarce.

DHHP – Direct Heat Hot Process. Hot process soap making utilizing externally applied heat during processing.

DOS – Dreaded Orange Spots. Small dark orange spots radiating to yellow occurring on the surface of cold processed soap. The primary cause is thought to be unsaponified oils turning rancid.

DWCP – Discounted Water Cold Process. A cold process method of soap making utilizing a lower percentage of water in the formula for a stronger lye solution.

E

Embeds – Used in loaf, tube and column molds. Soap embeds are of a contrasting color and shape such as moon and stars, curls and ribbons.

Emollient – An additive used to soften or soothe your skin. Cocoa butter or Shea butter are added to handmade soap as an emollient.

Emu Oil – Refined from the fat of the bird, the oil is used in a variety of cosmetics for it’s skin nourishing properties.

Emulsifying Wax – Used to combine oils with water when manufacturing lotions and creams.

Emulsion – A stabilized blend of oils and water such as a lotion, the suspension of one liquid within a second liquid which normally do not mix.

Enfleurage – The process of extracting the aromatic essences from plants using odorless fats to absorb the oils from flowers. The fat is then dissolved in alcohol to separate the essence from the fat and distilled to remove the alcohol.

EO – Essential oil.

Epsom Salt – Hydrated magnesium sulfate. A white crystalline powder used in bath preparations and foot soaks. Originally obtained from the mineral waters found in Epsom, England.

Essential Oil – Highly concentrated volatile oil extracted from aromatic plants, most commonly through pressing or steam distillation. Used for fragrance and flavorings.

Exfoliant – An abrasive added to slough off dead skin cells, such as oatmeal or ground cinnamon.

Expeller Pressed – The process in which an oil is extracted from a base by mechanically crushing and pressing the material at temperatures less than 220° Fahrenheit.

F

FCC – Food Chemicals Codex – The industry standard for listing food grade ingredients.

FD&C – Prefix used to designate the approved use in foods, drugs and cosmetics.

Felting – Encasing a bar of soap in a non-woven fabric made of unspun wool fibers matted together using heat and water.

Fixative – Used to anchor or stabilize a scent or fragrance, to slow evaporation.

Fixed Oils – The non-volatile oils obtained from botanical bases such as vegetable oils.

Flash Point – The lowest temperature that a liquid can form an ignitable mixture with air (vapor) near the surface of the liquid.

Floral Water – See hydrosol.

FO – Fragrance oil.

Formula – A listing of ingredients in fixed proportion, usually expressed in percentages.

Fragrance Free – Contains no added fragrance products. There is no regulated definition for this term, and it is best to consult the ingredients list as some commercial fragrance free or unscented products contain a masking fragrance.

Fragrance Oil – Synthetic oils formulated to mimic natural fragrances. Sometimes blended with essential oils.

G 

Germaben II – An oil and water soluble anti-microbial preservative used in personal care products.

Glycerin – A triatomic alcohol (glycerol) byproduct created during saponification. Used in food, cosmetics, soaps and lubricants.

Goat Milk Soap – Cold processed soap made with fresh, previously frozen or powdered goats milk.

Grapefruit Seed Extract – Derived from the seeds and pulp, it used as a preservative in handmade toiletries. It is thought to have antibiotic, antioxidant and antiseptic properties.

GSE – Grapefruit Seed Extract.

H

Hand Milled Soap – Soap fashioned through rebatching cold processed soap.

Handcrafted Soap – Soap crafted from a ready made soap base using the melt and pour process. Also used to refer to handmade soap.

Handmade Soap – Soap fashioned by combining a base oil with an alkali using a variety of traditional methods including hot and cold processing.

Hemp Seed Oil – Obtained from viable or sterilized seeds, hemp seed oil is high in essential fatty acids that are easily absorbed by the skin. Contributes moisturizing properties to soaps and cosmetics.

Herb – An aromatic plant used in medicine or as a seasoning that does not produce woody tissue and usually dies back at the end of the growing season.

Hot Process – A method of soap making utilizing an external heat source to accelerate the saponification process, such as a crock pot, double boiler or oven.

Humectant – A substance that attracts and holds moisture unto itself, such as glycerin.

Hydrogenation – A chemical process of converting a vegetable oil from a liquid into a solid using hydrogen.

Hydrolat – See hydrosol.

Hydrosol – The condensate water produced during steam distillation of botanical bases when making essential oils. Used in skin care preparations and bath products. Also known as hydrolat or floral water.

Hypoallergenic – Unlikely to cause an allergic reaction.

I

INCI Name – International Nomenclature of Cosmetic Ingredients. The INCI name is required when labeling cosmetics marketed in the USA.

Infusion – Made by steeping botanicals in oil or water.

Insoluble – Not dissolvable in a liquid, such as water or alcohol.

Irritant – Causes irritation or inflammation of the skin.

J 

Jojoba Oil – Liquid wax obtained from the seeds. Jojoba oil is used in numerous skin care preparations.

K

Karite Butter – See Shea butter.

Kokum Butter – Also known as Goa Butter. Extracted from the fruit kernels of the Garcinia indica tree, native to India.

KOH – Potassium Hydroxide.

Kukui Nut Oil – Also known as candle nut oil, it is obtained from the fruit of the tree and used in skin care preparations. Hawaiians have used kukui nut oil for generations to treat dry skin.

L

Lanolin – Wool fat. A fatty substance (wax) obtained from wool and used in soaps and cosmetics as a moisturizer.

Lard – The semi-solid or solid fat rendered from a hog.

Layering – The process of pouring multiple layers of soap, usually of varying colors.

Loofa – The dried fibrous section of the fruit from the plant (Luffa aegyptiaca) used as an exfoliating sponge. Also spelled loofah or luffa.

Lye – The common name for sodium hydroxide.

M

Macadamia Nut Oil – Also known as Queensland nut oil, obtained from the nut of the tree. Used as an emollient in soaps and cosmetics.

Mango Butter – Expeller pressed and refined from the fruit kernels. Used as a base ingredient or as an added emollient in cosmetics.

Marseille Soap – Savon de Marseille. A traditional olive oil soap made around Marseille, France, since the 14th century.

Melt & Pour Soap – M&P is a method of handcrafting soap by melting a ready made soap base, adding fragrances and shaping using molds.

Melting Point – The temperature at which a solid becomes a liquid.

Milling – A process during commercial manufacturing where the soap is blended with fragrance, colorants and other ingredients using mechanical rollers.

Mineral Oil – A refined synthetic petroleum based oil. Widely used in commercial cosmetics. Mineral oil creates a barrier and interferes with the skins normal functions. A poor choice for skin care preparations.

MSDS – Material Safety Data Sheet. Provided by the manufacturer or distributor to define the health, safety and fire risks associated with products that are considered hazardous.

N

NaOH – Sodium Hydroxide.

Natural Soap – A soap made from natural ingredients, free from petroleum, chemical or other artificial ingredients.

Natural Source – Obtained or derived from a natural source such as that from a botanical base.

Neem Oil – Used in skin care preparations for its antiseptic properties. Also used in insect repellents.

O

OHP – Oven Hot Process; Hot process soap making utilizing an oven to apply heat during processing.

Olfactory – Of or pertaining to the sense of smell.

Olive Oil – Obtained from the fruit of the tree through pressing and solvent extraction, varying grades of olive oil are available. Used in soap making as it does not interfere with the skins normal functions.

P

Palm Kernel Oil – Obtained from the kernels of the oil palm.

Palm Oil – Obtained from the pulp of the fruit from the oil palm.

Paraffin – A petroleum based solid wax, used in candles and cosmetics.

Peanut Oil – Obtained from pressing shelled peanut kernels, rich in vitamin E and easily absorbed into the skin.

Potassium Hydroxide – A caustic white solid, KOH, used in the manufacturing of soft or liquid soaps.

Pumice – A light and porous lava. Used in solid and powdered form as an abrasive.

R

RBD – Refined, Bleached, Deodorized.

Rebatching – The process of liquefying pre-made cold processed soap, adding fragrance and molding. Also known as hand milling.

Recipe – A list of ingredients in precise quantities with directions for preparing and making your soap.

Refined – The process of removing impurities from the natural or crude base.

Rendering – The process of heating lard or tallow to a liquid state to remove solids or impurities.

Rosemary Oil Extract – Rosemary Oleoresin is an anti-oxidant used as a preservative in personal care products.

S 

SAP Value – Saponification value. The amount of potassium hydroxide in milligrams required to saponify 1 gram of oil.

Saponaceous – Exhibits the characteristics of, or having the qualities of soap.

Saponification – The process or reaction of combining a base (fat) with an alkali (sodium hydroxide) to produce a salt (soap) and a free alcohol (glycerin).

Sea Salt – Salt produced by evaporation of sea water either by solar or kiln drying.

Seize – The unexpected thickening and uneven hardening of the soap mixture during processing. Usually caused when adding synthetic fragrance oils to the mixture.

Shea Butter – Used as a base ingredient or as an emollient in handmade soaps and skin preparations. Has a high content of unsaponifiables which contribute to its moisturizing properties.

Soap – A simple cleansing agent, the sodium salt resulting from the combination of oils and fats with an alkali.

Soap Casting – The art of creating handcrafted soaps using melt and pour soap base.

Sodium Bicarbonate – Baking soda. White crystalline powder, used in bath preparations as a water softener.

Sodium Cocoate – Saponified coconut oil, the sodium salt of coconut oil.

Sodium Hydroxide – A strong alkaline compound, NaOH, used to produce hard or bar soaps.

Sodium Palmate – Saponified palm oil, the sodium salt of palm oil.

Sodium Stearate – Saponified stearic acid, the sodium salt of stearic acid.

Sodium Tallowate – Saponified tallow, the sodium salt of tallow.

Solar Sea Salts – Sun evaporated sea salts from sea water, not mined or mechanically processed. This method preserves the natural mineral content.

Soluble – Dissolvable in a liquid, as in alcohol or water soluble.

Solvent Extraction – A method of separating oils from their base using a liquid in which the oil is soluble. The oil is then distilled and the solvent is evaporated leaving the oil.

Soybean Oil – Obtained from soybeans, this is the primary ingredient in vegetable shortening.

Specific Gravity – The ratio of weight of a given volume of a substance relative to the weight of the identical volume of water.

Steam Distillation – A process in which essential oils are extracted from plant materials using steam and pressure. The volatile oils are separated from the hydrosol after condensation.

Stearic Acid – Obtained from animal and vegetable fats. Used in soaps, candles and other products.

Sunflower Seed Oil – Obtained from the seeds, sunflower oil contains vitamin E and is used as an emollient.

Superfatted – The addition of extra oils or butters that remain unsaponified within the finished soap. These excess oils and butters contribute to the moisturizing properties of the soap.

Surfactant – Surface-active agent. A substance that reduces the surface tension of a liquid in which it is dissolved, such as a detergent.

Synthetic – Artificially produced, not of natural origin.

T

Tallow – The suet or fat from animals such as sheep or cows.

Tocopherol – Any of the four forms (alpha-, beta-, delta- or gamma-) of Vitamin E, an antioxidant added to soaps and lotions as an emollient due to its moisturizing properties. Alpha-tocopherol has greatest amount of vitamin E.

Trace – A point in soap making where the mixture reaches a certain consistency or thickness most noticeable when the soap is drizzled upon itself and leaves a trail before disappearing back into the mixture.

Turbinado Sugar – Unrefined raw cane sugar, used in sugar scrubs and body polishes.

U

Unrefined – The natural unaltered base, such as the oil obtained from the first pressing.

Unsaponifiables – Components that do not react with sodium hydroxide during saponification and remain in their original state. These components contribute moisturizing or other skin nourishing properties to the finished soap.

Unscented – Contains no added fragrance. See Fragrance Free.

V

Vegetable Shortening – A solid fat made from vegetable oils. These oils are converted to a solid state through hydrogenation.

Viscosity – The resistance to flow of a liquid or semi-liquid.

Volatile Oils – Oils that evaporate or vaporize easily at room temperatures such as essential oils.

W

Water Soluble – Dissolvable in water.

Wildcrafted – Refers to herbs and botanicals grown in the wild without the use of pesticides or other chemicals.

X

Xanathan Gum – A derivative of corn sugar used as a thickening agent in cosmetics and foods.