Rosin production

Derivatives. Most rosin products are sold as derivatives, which extends their utiUty. The carboxyl group or the double bonds are usually involved in the reactions. 

The rosin column spHt is controUed by the fatty acid content specified for rosin. This is usuaUy set at 2% fatty acids. At the high temperature near the bottom of the column and the reboUer, rosin dimerizes to some extent. By taking rosin from the column as a sidestream above the bottom, its rosin dimer content is minimized. Because of its high purity, sidestream rosin product is prone to crystallization. 

One important factor influencing the solubility of rosin derivatives is its tendency to crystallize. Initially, a rosin product may appear to be soluble in a given solvent, but on standing, the rosin will crystallize out of soluble solution. This tendency of rosin to ciystallize can be overcome by derivatization, mainly esterification. 

Furfural is obtained commercially by mealing pentosan-rich ugricullural residues (corncobs, oat hulls, cottonseed hulls, hagasse. rice hulls) with a dilute acid and removing the furfural by steam distillation. Major industrial uses of furfuraldehyde include (1) the production of t urnns and tetrahydrofurans where the compound is an intermediate (2) Ihc solvent refining of petroleum and rosin products (3) the solvent binding of bonded phenolic products and (4) the extractive distillation of butadiene from other C4 hydrocarbons. 

Conifer needles also contain volatile products which are mainly composed of mono- and sesquiterpenoids. The volatile turpentine constituents are used in the production of flavors and perfumes and in various technical and pharmaceutical products. The turpentine and rosin production of trees can be increased considerably by injecting suspensions of pitch canker fungus or chemicals such as "paraquat" (1,r-dimethyl-4,4 -bipyridinium salt) which has been found to be very effective. 

There are many kinds of rosin products, each of which has a slight difference in burning character from the others. The two most popular items are described here. 

Tall oil rosin production has recently been driven by demand for its co-product, tall oil fatty acid. United States production of tall oil rosin in 1994 was 265,000 metric tons, exceeding consumption by nearly 50,000 metric tons. Therefore, the rosin acid fraction of crude tall oil is an under-used byproduct in abundant supply, with attractive characteristics as a precursor to high value chemicals. Two components, abietic acid and dehydroabietic acid, con rise about 70% of the rosin acid fraction of tall oil. Therefore, it is a relatively single mixture, which is also a beneficial characteristic for its use as a feedstock. 

The total world rosin production tended to decline between the 1960s and the 1980s. However, statistics published in the 1980s [3] and in 1994 [4], show that the rosin production stabilized at around 1.0-1.2 million tons per year. According to the 1994 survey [4], gum rosin amounted to 60 per cent of world production, tall oil rosin to around 35 per cent and wood rosin to only a few percent. 

Rosin is a complex mixture, mainly consisting of various isomers of rosin acid. When exposed to air for a long period, rosins are easily discolored by oxidation. High-pressure DSC (HPDSC) can be used to determine oxidative stability of various rosins and rosin products. The measurement method is as follows ... 

Naval Stores Review 1986 Global rosin production lower in 1985. Naval Stores Review 96(2) 13... 

The market for rosin sizes consumes over 30% of rosin production. However, competition from synthetic sizes has increased, with particular pressure being seen in alkaline papermaking applications. 

Usually these rosin oil blends are made strictly for use In the rubber industry. However, pine rosin and pine tar are commonly used by the adhesives industry. Also tall oil (byproduct from paper manufacture) Is used as a feedstock In destructive distillation to manufacture various fatty acid and rosin products. 

Feiser, L.F. Feiser, M. Natural Products Related to Phenanthrene Reinhold New York, 1949. Rosin Product of the Forest, Arizona Chemicals Products Bulletin. 

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