PRODUCTS

TOFA

TOFA (Tall Oil Fatty Acid) is a by-product mixture of saponified fatty acids (30%–60%), resin acids (40%–60%, including mostly abietic and pimaric acids), and unsaponifiables (5%–10%) derived from the wood extractives of softwoods. Crude TOFA is isolated from acidified skimming of partially concentrated black liquor. It is collected and refined at special plants. The refined products are sold commercially for soaps, rosin size, etc. Typically, 30–50 kg/t (60–100 lbs/ton) on pulp may be recovered from highly resinous species representing about 30%–70% recovery. Tall Oil Fatty Acid is recovered from mills pulping resinous species such as the southern pines. The pulp and paper industry recovers about 450,000 tons of crude TOFA annually.

CAS No. : 61790-12-3
EC No. : 263-107-3

TOFA

TOFA, also known as “liquid rosin” or tallol or Tall Oil Fatty Acid, is a low cost, viscous yellow-black odorous liquid chemical compound that is a product of crude tall oil vacuum distillation. It is a member of the product family Oleic Acid.

Other Products of Tall Oil Fatty Acid (TOFA)
Extractives such as rosin and fatty acids are sometimes removed from the spent pulping liquor and processed into crude TOFA. In Canada, most crude TOFA is currently incinerated as fuel in the lime kilns of pulp mills to displace fossil fuel. In the south eastern United States, where extractive content of the wood is much higher, TOFA plants fractionate the crude TOFA into value-added components. Processes have also been proposed to convert both the fatty and rosin acid components of the crude TOFA into green diesel fuel. The processing of TOFA into a high-quality diesel additive has been researched in the laboratory and pilot scale. The later studies included promising road tests by Canada Post Corporation. Given that many kraft pulp mills already collect these extractives, their future utilization for fuels will be based on competing economic considerations. Fatty acids can be directly esterified by alcohols into diesel fuel, whereas the rosin acids can be converted by the “Super Cetane” hydrogenation process developed in Canada. Turpentine recovered from process condensates in Canadian mills is generally incinerated as fuel in one of the on-site boilers. Processing it into consumer grade products is possible but, in many cases, it is more valuable as a fuel.

Extractives (TOFA and Turpentine) as a Chemical Platform
The chemical and mechanical pulping of wood, in particular coniferous trees, generates large amounts of sidestreams such as crude TOFA (CTO) and crude turpentine (CT). The global TOFA production today is close to ~ 1.2 million tonnes/year, whereas the estimated worldwide production of turpentine is about 350,000 tonnes/year. They are the third and fourth largest chemical by-products after hemicellulose and lignin in the manufacturing of paper pulp from wood. In the kraft process, high alkalinity and temperature convert the esters and carboxylic acids in rosin into soluble sodium soaps that are skimmed off and collected and acidified to give CTO, while the crude sulfate turpentine (CST) is condensed from digester vapors. CTO consists of around 30%–50% fatty acids, 15%–35% rosin acids, and 30%–50% pitch, a bioliquid that is used for energy generation and by the chemical industry. The chemical composition varies with the wood age, wood species, geographic location of the coniferous trees, and the technological solutions of the pulping processes. High-purity terpenes are also recovered as a by-product in mechanical pulping processes by steam distillation and crude sulfite turpentine when CTO is skimmed from pulping liquor in the sulfite process, neutralized with NaOH or lime, and subsequently distilled. Chemically, turpentine is a mixture of numerous C10H16 monoterpene isomers, consisting of bicyclic compounds such as 3-carene, camphene, and α- and β-pinenes, which together with monocyclic limonene are the principal compounds of this raw material. The chemical composition of CT also varies strongly with the wood species, geographic location, pulping process or mill, and even harvesting season; For example, kraft turpentine from the United States can contain more β-pinene than α-pinene, whereas the opposite is true in Europe. However, in turpentine originating from sulfite pulping, ρ-cymene is typically the predominant compound. Because of the use of sulfur-containing cooking chemicals upon pulping, the sulfur content in CT can reach 3 wt%, whereupon the three main species present are methanethiol, dimethyl sulfide (DMS), and dimethyl disulfide (DMDS). The organoleptic properties of the aforementioned malodorous organics complicate the further use and upgrading of CT and the isolation and utilization of specific terpenes.

Traditionally, CTO from the pulp industry was viewed as low-value substance and burned as an alternative to heavy fuel oil, but over the last decade, it has emerged as a promising raw material for the production of commercially relevant synthetic fuels (biodiesel and diesel via hydrodeoxygenation), lubricants, solvents, and many other high-value materials (Scheme 3.12A). In fact, currently, there are several biorefineries and industries upgrading and marketing TOFA and TOFA-derived chemicals. Typically, various fractions of CTO are separated by distillation over wide pressure ranges, and they are marketed as wood-based chemicals for use in downstream applications. The resinic acids (TOR) are used as a critical ingredient in printing inks, photocopying and laser printing paper, varnishes, adhesives (glues), soap, paper sizing, soda, soldering fluxes, sealing wax, medical plasters, and ointments. It can also be used as a glazing agent in medicines and chewing gum, as an emulsifier in soft drinks, and as a flux used in soldering. In contrast, TOFA is used as a chemical platform or raw material for the production of high-value products such as biofuels (via catalytic esterification or deoxygenation). Notable examples of TOFA biorefineries include Arizona Chemicals (in Sweden and Finland); biorefinery (now a part of the Portuguese Repsol Group), Finland; and SunPine, Sweden. The former two specialize in CTO distillation and markets TOFA and TOR as the main products. On the other hand, SunPine is a recently established unique facility that is upgrading CTO to crude tall biodiesel (production capacity of 10,000 m3/year) that is fed to the classical petroleum refinery process of Preem in southern Sweden. The process uses CTO, acid vegetable oils, and methanol as starting materials and is based on the esterification of TOFA and vegetable acids with methanol to produced esters (biodiesel).

Other vegetable oils
TOFA. Crude TOFA (CTO) is separated from black liquor in the kraft sulfate pulping of mainly coniferous trees (Figure 7), which store triglycerides, fatty acids, resin acids, sterols, and sterol esters as nutrients in the parenchyma cells, while the radial resin ducts contain resin acids and turpentine for the wound healing of bark breaches. That is why pine balsam won by tapping is a source of rosin and terpenes but not of CTO.

The recovered black liquor is concentrated and left to settle. The top layer is known as TOFA soap and is skimmed off. The rest is recycled for further use in paper making. The soap is converted to CTO by acidulation with sulfuric acid. CTO is not a fatty oil but is actually a mixture of five components with different boiling points, which are split by fractionation into heads (which boils first), then ‘TOFA fatty acids’ (TOFAs), distilled TOFA (DTO, a mixture of fatty and rosin acids), ‘TOFA rosin’ (TOR, a mixture of eight closely related rosin acids, i.e., abietic, neoabietic, palustric, levopimaric, dehydroabietic, pimaric, sandaracopimaric, and isopimaric acid), and pitch (the unsaponifiable residue). TOFA is mainly oleic acid. Furthermore, TOFAs contain unusual isomers, such as octadecadienoic acids with double bonds in the 5,9- and 5,12-positions. Important applications of TOFA are the manufacture of alkyd resins and dimer acids.

TOFA
TOFA TOFA CAS# 61790-12-3, also known as “liquid rosin” or tallol, is a low cost, viscous yellow-black odorous liquid chemical compound that is a product of crude tall oil vacuum distillation. It is a member of the product family Oleic Acid.

TOFA, also called "liquid rosin" or tallol, is a viscous yellow-black odorous liquid obtained as a by-product of the Kraft process of wood pulp manufacture when pulping mainly coniferous trees. The name originated as an anglicization of the Swedish "tallolja" ("pine oil"). TOFA is the third largest chemical by-product in a Kraft mill after lignin and hemicellulose; the yield of crude TOFA from the process is in the range of 30–50 kg / ton pulp. It may contribute to 1.0–1.5% of the mill's revenue if not used internally.

Manufacturing of Tall Oil Fatty Acid (TOFA)
In the Kraft Process, high alkalinity and temperature converts the esters and carboxylic acids in rosin into soluble sodium soaps of lignin, rosin, and fatty acids. The spent cooking liquor is called weak black liquor and is about 15% dry content. The black liquor is concentrated in a multiple effect evaporator and after the first stage the black liquor is about 20–30%. At this stage it is called intermediate liquor. Normally the soaps start to float in the storage tank for the weak or intermediate liquors and are skimmed off and collected. A good soap skimming operation reduces the soap content of the black liquor down to 0.2–0.4% w/w of the dry residue. The collected soap is called raw rosin soap or rosinate. The raw rosin soap is then allowed to settle or is centrifuged to release as much as possible of the entrained black liquor. The soap goes then to the acidulator where it is heated and acidified with sulfuric acid to produce crude TOFA (CTO).

The soap skimming and acidulator operation can be improved by addition of flocculants. A flocculant will shorten the separation time and give a cleaner soap with lower viscosity. This makes the acidulator run smoother as well.

Most pines give a soap yield of 5–25 kg/ton pulp, while Scots pine gives 20–50 kg/ton. Scots pine grown in northern Scandinavia give a yield of even more than 50 kg/ton. Globally about 2 mill ton/year of CTO are refined.

Composition of Tall Oil Fatty Acid (TOFA)
See also: Resin acid
The composition of crude TOFA varies a great deal, depending on the type of wood used. A common quality measure for TOFA is acid number. With pure pines it is possible to have acid numbers in the range 160–165, while mills using a mix of softwoods and hardwoods might give acid numbers in the range of 125–135.

Normally crude TOFA contains rosins (which contains resin acids (mainly abietic acid and its isomers), fatty acids (mainly palmitic acid, oleic acid and linoleic acid) and fatty alcohols, unsaponifiable sterols (5–10%), some sterols, and other alkyl hydrocarbon derivates.
By fractional distillation TOFA rosin is obtained, with rosin content reduced to 10–35%. By further reduction of the rosin content to 1–10%, TOFA fatty acid can be obtained, which is cheap, consists mostly of oleic acid, and is a source of volatile fatty acids.

Applications of Tall Oil Fatty Acid (TOFA)
The TOFA rosin finds use as a component of adhesives, rubbers, and inks, and as an emulsifier. The pitch is used as a binder in cement, an adhesive, and an emulsifier for asphalt.

TOFA is a low-cost and vegetarian lifestyle-friendly alternative to tallow fatty acids for production of soaps and lubricants. When esterified with pentaerythritol, it is used as a compound of adhesives and oil-based varnishes. When reacted with amines, polyamidoamines are produced which may be used as epoxy resin curing agents.

TOFA, also called "liquid rosin" or tallol, is a viscous yellow-black odorous liquid obtained as a by-product of the Kraft process of wood pulp manufacture when pulping mainly coniferous trees. The name originated as an anglicization of the Swedish "tallolja" ("pine oil"). TOFA is the third largest chemical by-product in a Kraft mill after lignin and hemicellulose; the yield of crude TOFA from the process is in the range of 30–50 kg / ton pulp. Tall Oil Fatty Acid (TOFA) may contribute to 1.0–1.5% of the mill's revenue if not used internally.

Manufacturing of Tall Oil Fatty Acid (TOFA)

TOFA refinery in Rauma, Finland.
In the Kraft Process, high alkalinity and temperature converts the esters and carboxylic acids in rosin into soluble sodium soaps of lignin, rosin, and fatty acids. The spent cooking liquor is called weak black liquor and is about 15% dry content. The black liquor is concentrated in a multiple effect evaporator and after the first stage the black liquor is about 20–30%. At this stage it is called intermediate liquor. Normally the soaps start to float in the storage tank for the weak or intermediate liquors and are skimmed off and collected. A good soap skimming operation reduces the soap content of the black liquor down to 0.2–0.4% w/w of the dry residue. The collected soap is called raw rosin soap or rosinate. The raw rosin soap is then allowed to settle or is centrifuged to release as much as possible of the entrained black liquor. The soap goes then to the acidulator where it is heated and acidified with sulfuric acid to produce crude TOFA (CTO).

The composition of crude TOFA varies a great deal, depending on the type of wood used. A common quality measure for TOFA is acid number. With pure pines it is possible to have acid numbers in the range 160–165, while mills using a mix of softwoods and hardwoods might give acid numbers in the range of 125–135.

Normally crude TOFA contains rosins, which contains resin acids (mainly abietic acid and its isomers), fatty acids (mainly palmitic acid, oleic acid and linoleic acid) and fatty alcohols, unsaponifiable sterols (5–10%), some sterols, and other alkyl hydrocarbon derivates.

By fractional distillation TOFA rosin is obtained, with rosin content reduced to 10–35%. By further reduction of the rosin content to 1–10%, TOFA fatty acid can be obtained, which is cheap, consists mostly of oleic acid, and is a source of volatile fatty acids.

TOFA refers to mixtures of several related carboxylic acids, primarily abietic acid, found in tree resins. Nearly all TOFAs have the same basic skeleton: three fused rings having the empirical formula C19H29COOH. TOFAs are tacky, yellowish gums that are water-insoluble. They are used to produce soaps for diverse applications, but their use is being displaced increasingly by synthetic acids such as 2-ethylhexanoic acid or petroleum-derived naphthenic acids.

Botanical analysis of Tall Oil Fatty Acid (TOFA)
TOFAs are protectants and wood preservatives that are produced by parenchymatous epithelial cells that surround the resin ducts in trees from temperate coniferous forests. The TOFAs are formed when two-carbon and three-carbon molecules couple with isoprene building units to form monoterpenes (volatile), sesquiterpenes (volatile), and diterpenes (nonvolatile) structures.

Pines contain numerous vertical and radial resin ducts scattered throughout the entire wood. The accumulation of resin in the heartwood and resin ducts causes a maximum concentration in the base of the older trees. Resin in the sapwood, however, is less at the base of the tree and increases with height.

In 2005, as an infestation of the Mountain pine beetle (Dendroctonus ponderosae) and blue stain fungus devastated the Lodgepole Pine forests of northern interior British Columbia, Canada, TOFA levels three to four times greater than normal were detected in infected trees, prior to death. These increased levels show that a tree uses the resins as a defense. Resins are both toxic to the beetle and the fungus and also can entomb the beetle in diterpene remains from secretions. Increasing resin production has been proposed as a way to slow the spread of the beetle in the "Red Zone" or the wildlife urban interface.

Production in tall oil (chemical pulping byproduct)

The commercial manufacture of wood pulp grade chemical cellulose using the kraft chemical pulping processes releases TOFAs. The Kraft process is conducted under strongly basic conditions of sodium hydroxide, sodium sulfide and sodium hydrosulfide, which neutralizes these TOFAs, converting them to their respective sodium salts, sodium abietate, ((CH3)4C15H17COONa) sodium pimarate ((CH3)3(CH2)C15H23COONa) and so on. In this form, the sodium salts are insoluble and, being of lower density than the spent pulping process liquor, float to the surface of storage vessels during the process of concentration, as a somewhat gelatinous pasty fluid called kraft soap, or resin soap.

Kraft soap can be reneutralized with sulfuric acid to restore the acidic forms abietic acid, palmitic acid, and related TOFA components. This refined mixture is called tall oil. Other major components include fatty acids and unsaponifiable sterols.

TOFAs, because of the same protectant nature they provide in the trees where they originate, also impose toxic implications on the effluent treatment facilities in pulp manufacturing plants. Furthermore, any residual TOFAs that pass the treatment facilities add toxicity to the stream discharged to the receiving waters.

Variation with species and biogeoclimatic zone
The chemical composition of tall oil varies with the species of trees used in pulping, and in turn with geographical location. For example, the coastal areas of the southeastern United States have a high proportion of Slash Pine (Pinus elliottii); inland areas of the same region have a preponderance of Loblolly Pine (Pinus taeda). Slash Pine generally contains a higher concentration of TOFAs than Loblolly Pine.

In general, the tall oil produced in coastal areas of the southeastern United States contains over 40% TOFAs and sometimes as much as 50% or more. The fatty acids fraction is usually lower than the TOFAs, and unsaponifiables amount to 6-8%. Farther north in Virginia, where Pitch Pine (Pinus rigida)and Shortleaf Pine (Pinus echinata) are more dominant, the TOFA content decreases to as low as 30-35% with a corresponding increase in the fatty acids present.

In Canada, where mills process Lodgepole Pine (Pinus contorta) in interior British Columbia and Alberta, Jack Pine (Pinus banksiana), Alberta to Quebec and Eastern White Pine (Pinus strobus) and Red Pine (Pinus resinosa), Ontario to New Brunswick, TOFA levels of 25% are common with unsaponifiable contents of 12-25%. Similar variations may be found in other parts of the United States and in other countries. For example, in Finland, Sweden and Russia, TOFA values from Scots Pine (Pinus sylvestris) may vary from 20 to 50%, fatty acids from 35 to 70%, and unsaponifiables from 6 to 30%.

Characteristics of Tall Oil Fatty Acid (TOFA)
100% bio-based content
Low viscosity, liquid long fatty acid (C18) chain
Reactive polyunsaturation
Light color and good color stability (based on grade)
Low rosin content
Good air drying properties
Grades
Low color
Low sulfur
0.5% to 3% rosin content
Size available
Bulk rail car
Bulk tank truck
Totes (IBC)
Drums

Applications of Tall Oil Fatty Acid (TOFA)
Chemical manufacturing
Esters, amides, amines, soaps
CASE
Alkyd resins, plasticizers
Textiles
Spinning lubricants
Oilfield
Emulsifiers and corrosion inhibitors for drilling muds
Lubricants & metalworking
Group IV base oils, corrosion inhibitors, defoamers

TOFA is an ideal raw material for many chemical reactions and intermediates. The most common applications for TOFA are paints and coatings, biolubricants, fuel additives and performance polymer.

About 1949, with the advent of effective fractional distillation, the tall oil industry came of age, and TOFAs , generally any product containing 90% or more fatty acids and 10% or less of rosin, have grown in annual volume ever since, until they amount to 398.8 million pounds annual production in the U.S. in 1978. Crude tall oil is a byproduct of the Kraft process for producing wood pulp from pine wood. Crude tall oil is about 50% fatty acids and 40% rosin acids, the remainder unsaps and residues; actually, a national average recovery of about 1–2% of tall oil is obtained from wood. On a pulp basis, each ton of pulp affords 140–220 pounds black liquor soaps, which yields 70–110 pounds crude tall oil, yielding 30–50 pounds of TOFA. Separative and upgrading technology involves:
(a) recovery of the tall oil;
(b) acid refining;
(c) fractionation of tall oil; and occasionally
(d) conversion to derivatives.
TOFA of good quality and color of Gardner 2 corresponds to above 97% fatty acids with the composition of 1.6% palmitic & stearic acid, 49.3% oleic acid, 45.1% linoleic acid, 1.1% miscellaneous acids, 1.2% rosin acids, and 1.7% unsaponifiables.

TOFA, also known as “liquid rosin” or tallol, is is a light-colored TOFA produced via the fractional distillation of crude tall oil. It is most commonoly used as an intermediate to make various alkyd resins.

TOFA CAS# 61790-12-3, also known as “liquid rosin” or tallol, is a low cost, viscous yellow-black odorous liquid chemical compound that is a product of crude tall oil vacuum distillation. It is a member of the product family Oleic Acid. TOFAs are sold in markets that use them in raw form and as precursors to synthesize an array of products. TOFA derivatives include dimers, alkyds, PVC stabilizers, synthetic lubricant polyamides, and a variety of oilfield chemicals.

Low sulfur TOFA is designed specifically for the fuel segment as a diesel fuel additive. TOFAs is obtained by the fractional distillation of crude oil, a by-product from the pulping of pine trees.
TOFAs are used in dimer acids, alkyd resins, oilfield chemicals, metalworking fluids, liquid cleaners, textile chemicals, fuel additives, construction chemicals, rubber and tire, metallic stabilizers, ore flotation, and fatty derivatives.

Abstract
TOFAs consist primarily of oleic and linoleic acids and are obtained by the distillation of crude tall oil. Crude tall oil, a by‐product of the kraft pulping process, is a mixture of fatty acids, rosin acids, and unsaponifiables. These components are separated from one another by a series of distillations. Several grades of TOFA are available depending on rosin, unsaponifiable content, color, and color stability. Typical compositions of TOFA products are shown.

TOFAs have a variety of applications. The largest uses of TOFA traditionally have been in coatings, primarily alkyd resins where grades of higher rosin content predominate. Since the 1970s their use as chemical intermediates in applications, which includes manufacture of dimer acids and epoxidized TOFA esters, has exceeded their use in coatings. The more highly refined, low rosin grades are required for their application as intermediates. Other areas of significant use are in soaps, detergents, and ore flotation. Worldwide crude tall oil fractionating capacity and domestic production and prices of TOFA are given. TOFA pricing is strongly dependent on soya fatty acid prices since these materials are often used in the same application.

Normally crude tall oil contains rosins (which contains resin acids (mainly abietic acid and its isomers), fatty acids (mainly palmitic acid, oleic acid and linoleic acid) and fatty alcohols, unsaponifiable sterols (5–10%), some sterols, and other alkyl hydrocarbon derivates.

By fractional distillation tall oil rosin is obtained, with rosin content reduced to 10–35%. By further reduction of the rosin content to 1–10%, TOFA can be obtained, which is cheap, consists mostly of oleic acid, and is a source of volatile fatty acids.

The tall oil rosin finds use as a component of adhesives, rubbers, and inks, and as an emulsifier. The pitch is used as a binder in cement, an adhesive, and an emulsifier for asphalt.

Synonyms:
TOFA; Tall Oil Fatty Acid; Elaidic acid; Tall Oil Yağ Asidi; tol oyil fati asit; tall oıl fatty acid; töfa; t-o-f-a; disproportionated tall oil fatty acid; Oleic Acid; liquid rosin; resin acid; tall oil rosin; 68130-96-1; (Tall oil)imidazolinium dodecylbenzenesulfonate; EINECS 268-607-5; Benzenesulfonic acid, dodecyl-, compds. with 4,5-dihydro-1H-imidazole-1-ethanamine 2-nortall-oil alkyl derivs. (2:1); DTXSID30987613; 2-Imidazoline, 1-(2-aminoethyl)-2-(tall oil alkyl), di(dodecylbenzenesulfonic acid) salt; 2-Dodecylbenzene-1-sulfonic acid--2-(4,5-dihydro-1H-imidazol-1-yl)ethan-1-amine (2/1); TALL OIL FATTY ACID; Elaidic acid; 112-79-8; trans-9-Octadecenoic acid; trans-Oleic acid; (E)-octadec-9-enoic acid; 9-octadecenoic acid; (E)-Oleic acid; 9-Octadecenoic acid, (E)-; 9-octadecenoic acid, (9E)-; trans-Octadec-9-enoic acid; (9E)-octadec-9-enoic acid; trans-Elaidic acid; Elaidinsaeure; Elaidinsaure; acide elaidique; 9-elaidic acid; Octadec-9-enoic acid; Tall Oil Fatty Acid; 9E-octadecenoic acid; UNII-4837010H8C; trans-.DELTA.9-Octadecenoic acid; (9E)-Octadecenoic acid; EINECS 204-006-6; NSC 26988; 9-trans-Octadecenoic acid; trans-delta(sup 9)-Octadecenoic acid; D9-trans-Octadecenoic acid; trans-D9-Octadecenoic acid; Delta(9)-octadecenoic acid; TOFA; 9-Octadecenoic acid,(9E)-; AI3-15840; CHEMBL460657; CHEBI:27997; trans-Delta(9)-octadecenoic acid; NSC26988; Elaidic acid, 98%; C18:1, n-9; trans-.delta.(sup 9)-Octadecenoic acid; 4837010H8C; 18:1, n-9; 2027-47-6; 9 Octadecenoic Acid; delta9-Octadecenoic acid; (E)-9-Octadecenoic acid; Delta(9)-octadecenoate; Elaidinic acid; oleic_acid; 1lfo; elaidic acid group; EINECS 217-977-6; 1fe3; Oleic Acid 213 NF; Oleic Acid 221 NF; Oleic Acid 233 LL; Tall Oil Fatty Acid; cis 9 Octadecenoic Acid; Canola Fatty Acid 790; bmse000643; (9E)octadec-9-enoic acid; TALL OIL FATTY ACID; Octadec-9-enoic acid anion; Oleic acid, tall oil derived; DTXSID8058619; CHEBI:36021; Elaidic acid, analytical standard; HMS3649H19; Elaidic acid, >=99.0% (GC); 9-Octadecenoic acid, (E)- (9CI); Elaidic acid, analytical sample grade; TOFA; Oleic acid, from tall oil fatty acids; cis-9-Octadecenoic Acid, Elainic Acid; Oleic acid derived from tall oil fatty acids; Oleic Acid, 99% min (animal-origin free, vegetal-derived); Benzenebutanoic acid, 2-methyl-.alpha.,.gamma.-dioxo-, ethyl ester; tofa