Tannin, addition

Tannins occur in many plants and are separated by extraction. At present, only quebracho extract is used as a mud thinner in significant quantity in the United States. Quebracho is an acidic material and performs best at high pH. It is an excellent thinner for lime-treated and cement-contaminated muds. However, it is not effective at high salt concentrations. Sulfomethylated tannin products are functional over a wide range of pH and salinity and have either been treated with chromium for good thermal stabiUty (58) or are chrome free. Concentrations of tannin additives are ca 1.5—18 kg/m (0.5—6 lb/bbl). 

Powder form (n = 7) Liquid form (n = 4) Max.increase (/ng L-1 wine) caused by gum arabic (500mg L 1) median max Max. increase (/ng L-1 wine) caused by tannin addition (200mg L 1)... 

Model Fermentations. A chemically-defined grape juice medium at pH 3.5, with amino acids as the nitrogen source, was used for the model experiments (72). Sugar (D(+)-glucose 200 g/L) was included unless ofiierwise indicated. For those model fermentations that were conducted in the presence of tannins (1.5 g/L), the medium was sonicated for 15 minutes at room temperature after the tannin addition, and the insoluble material was removed by centrifugation at 48000 g for 15 minutes. In ferments containing added anthocyanins, the enriched anthocyanin preparation was sterile filtered (0.2 pm), and 1.6 mL were added to 47.4 mL of sterile filtered chemically-defined grape juice medium for each model fermentation. 

When a total of 10 g of tannin had been added to the 31 test vessels, the total gas production was about 1.31/day with a methane content of about 60%. At these levels of tannin addition, there was little difference between quebracho and wattle tannin treatments. The quebracho tannin was more inhibitory to the system than the wattle tannin at higher concentrations. With proper control, this approach would seem to be an effective process for reduction of both COD and color removal. 

Alfalfa hay DM intake was 258 g/d on average. Concentrate intakes with T6 and T12 were 12.6% and 27.2%, respectively, lower than that of TO (246 g/d), probably because of the taste of tannins. Herbage intake on pasture was not different between groups (997, 1159 and 924 (SEM 110) g of DM for TO, T6 and T12, respectively). Tannins didnot influence milk yield and milk fat and protein content (Table 1), which fell linearly throughout the period without differences between groups. Milk urea increased with time in all groups independently of tannin addition (data not shown). The... 

Fig. 1. An amplified outline scheme of the making of various wiaes, alternative products, by-products, and associated wastes (23). Ovals = raw materials, sources rectangles = wines hexagon = alternative products (decreasing wine yield) diamond = wastes. To avoid some complexities, eg, all the wine vinegar and all carbonic maceration are indicated as red. This is usual, but not necessarily tme. Similarly, malolactic fermentation is desired in some white wines. FW = finished wine and always involves clarification and stabilization, as in 8, 11, 12, 13, 14, 15, 33, 34, followed by 39, 41, 42. It may or may not include maturation (38) or botde age (40), as indicated for usual styles. Stillage and lees may be treated to recover potassium bitartrate as a by-product. Pomace may also yield red pigment, seed oil, seed tannin, and wine spidts as by-products. Sweet wines are the result of either arresting fermentation at an incomplete stage (by fortification, refrigeration, or other means of yeast inactivation) or addition of juice or concentrate.

Minerals, particularly Bentonite, ate used to remove proteins that tend to cause haze in white wines. The natural tannin of ted wines usually removes unstable proteins from them. Excess tannin and related phenols can be removed and haze from them prevented by addition of proteins or adsorbents such as polyvinylpyttohdone. Addition of protein such as gelatin along with tannic acid can even be used to remove other proteins from white wines. Egg whites or albumen ate often used to fine ted wines. Casein can be used for either process, because it becomes insoluble in acidic solutions like wines. 

The apphcation of vegetable tanning materials has an additive effect on the leather. The more vegetable tannins appHed the more the leather becomes like vegetable-tanned leather. The color is changed, the fullness of feel increases, and the leather can be worked and embossed like vegetable leather. 

A considerable quantity of oil can be extracted from waste material from shelling and processing plants, eg, the inedible kernels rejected during shelling and fragments of kernels recovered from shells. About 300 t of pecan oil and 300—600 t of English walnut oil are produced aimuaHy from such sources. The oil is refined and used for edible purposes or for the production of soap the cake is used in animal feeds (see Feeds and feed additives). Fmit-pit oils, which closely resemble and are often substituted for almond oil, are produced on a large scale for cosmetic and pharmaceutical purposes (143). For instance, leaves, bark, and pericarp of walnut may be used to manufacture vitamin C, medicines, dyes and tannin materials (144). 

Hplc techniques are used to routinely separate and quantify less volatile compounds. The hplc columns used to affect this separation are selected based on the constituents of interest. They are typically reverse phase or anion exchange in nature. The constituents routinely assayed in this type of analysis are those high in molecular weight or low in volatility. Specific compounds of interest include wood sugars, vanillin, and tannin complexes. The most common types of hplc detectors employed in the analysis of distilled spirits are the refractive index detector and the ultraviolet detector. Additionally, the recent introduction of the photodiode array detector is making a significant impact in the analysis of distilled spirits. 

By far the preponderance of the 3400 kt of current worldwide phenolic resin production is in the form of phenol-formaldehyde (PF) reaction products. Phenol and formaldehyde are currently two of the most available monomers on earth. About 6000 kt of phenol and 10,000 kt of formaldehyde (100% basis) were produced in 1998 [55,56]. The organic raw materials for synthesis of phenol and formaldehyde are cumene (derived from benzene and propylene) and methanol, respectively. These materials are, in turn, obtained from petroleum and natural gas at relatively low cost ([57], pp. 10-26 [58], pp. 1-30). Cost is one of the most important advantages of phenolics in most applications. It is critical to the acceptance of phenolics for wood panel manufacture. With the exception of urea-formaldehyde resins, PF resins are the lowest cost thermosetting resins available. In addition to its synthesis from low cost monomers, phenolic resin costs are often further reduced by extension with fillers such as clays, chalk, rags, wood flours, nutshell flours, grain flours, starches, lignins, tannins, and various other low eost materials. Often these fillers and extenders improve the performance of the phenolic for a particular use while reducing cost. 

Tannins can also be hardened by addition of hexamethylenetetramine (hex-amine) [146,147], whereby these boards show very low formaldehyde emission [16-18,148-151]. 

The autocatalytic hardening of tannins without addition of formaldehyde or another aldehyde as crosslinker is possible, if small traces of alkaline Si02 are present as catalyst and also a high pH is used, or with certain tannins just by the catalytic action induced by the wood surface [152-160]. 

A final are we should discuss is color removal. This is perhaps the most difficult impurity to remove from waters. In surface waters color is associated with dissolved or colloidal suspensions of decayed vegetation and other colloidal suspensions. The composition of this material is largely tannins and lignins, the components that hold together the cellulose cells in vegetation. In addition to their undesirable appearance in drinking water, these organics can cause serious problems in downstream water purification processes. For examples ... 

Locomotive diesels As larger volumes of coolant are required in railway locomotives than in road vehicles, the cost of inhibition is proportionally greater. An additional factor is the possibility of cavitation attack of cylinder liners. These considerations place a restriction on the choice of inhibitors. In the past, chromates have been used at concentrations of up to 0-4%, but their use presents handling and disposal problems. Chromates cannot be used with ethanediol antifreeze solutions. A IS I borate-metasilicate at a concentration of 1 % has been used in the UK. Nitrate is added to this to improve inhibition of aluminium alloy corrosion. Tannins and soluble oils are also used, but probably to a lesser extent than in the past. The benzoate-nitrite formulation (formerly BS 3151) is effective and has been used by continental railways . ... 

Tannin-containing woods also darken with ammonia, a process which is usefully employed in darkening oak furniture by fuming . Ammonia stains can originate from animal glue, amino-type adhesives and concrete additive sources, particularly where damp conditions exist. 

All large boiler plants and many smaller units employ mechanical deaerators to remove oxygen. In addition, various oxygen-scavenging chemicals are employed as consumable treatments such as sodium sulfite-bisulfite, hydrazine, various novel chemistry organics (hydrazine replacements), and certain tannins. 

Here, the use of inhibitor formulations having a less dramatic effect on TDS (such as certain tannins) may be extremely beneficial. Formulations are available that are based on tannin chemistry and contain blends that act as oxygen scavengers and metal passivators, with additional sludge dispersant and antifoam properties. 

Tannin blend concentrates primarily intended for oxygen-scavenging duty in steam boilers. They generally are offered as dark-brown to black, blended products of 25 to 50% active strength. Here, tannins provide an additional benefit of sludge conditioning at no extra cost. 

These condensed tannins and their derivatives, all of high molecular weight, function as anionic polyelectrolyte sludge conditioners, tending to sequester hardness salts and hinder their precipitation as crystalline scales. In addition, when precipitation does occur, the condensed tannins coagulate the particles, resulting in a mobile sludge that can be easily blown down. 

In addition, even where foaming is not a specific problem in a boiler, carryover may occur, especially in lower pressure boilers with very high TDS (i.e., over 10,000 to 15,000 ppm TDS) because of the collapse of surface bubbles. This leads to BW aerosol generation and entrainment of the spray in steam. Under these circumstances, antifoam agents such as polyamides are useful in preventing these entrainment problems. Furthermore, the antifoaming action of polyamides is often enhanced by protective colloid materials such as tannins, and consequently, formulations containing polyamide emulsions in an alkaline tannin base are available. 

Organophilic polyphenolic materials for oil-based drilling fluids have been described [407], The additives are prepared from a polyphenolic material and one or more phosphatides. The phosphatides are phosphoglycerides obtained from vegetable oils, preferably commercial lecithin. Humic acids, ligno-sulfonic acid, lignins, phenolic condensates, tannins the oxidized, sulfonated, or sulfomethylated derivatives of these polyphenolic materials may serve as polyphenolic materials. 

An additive described as reducing the water loss and enhancing other properties of well-treating fluids in high-temperature subterranean environments consists of polymers or copolymers from N-vinyl lactam monomers or vinyl-containing sulfonate monomers. Organic compounds like lignites, tannins, and asphaltic materials are added as dispersants [175]. 

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