Liquid products stability

We have our work divided into process engineering, process chemistry, catalysis, and support technology. As an example, one of the indirect liquefaction projects, tube wall reactor, deals with the design and operation of high thermal efficiency catalytic reactors for syn-gas conversion. Other activities are coal liquefaction properties of coal minerals, the role of catalysts, coal liquid product stability, and environmental impact—to name a few. 

A gas-processing plant, as described in Chapter 9, is designed to recover ethane, propane, butane, and other natural gas liquids from the gas stream. A condensate stabilizer also recovers some portion of these liquids. The colder the temperature of the gas leaving the overhead condenser in a reflux stabilizer, or the colder the feed stream in a cold-feed stabilizer, and the higher the pressure in the tower, the greater the recovery of these components as liquids. Indeed, any stabilization process that leads to recovery of more molecules in the final liquid product is removing those molecules from the gas stream. In this sense, a stabilizer may be considered as a simple form of a gas-processing plant. 

It is difficult to determine the point at which a condensate stabilizer becomes a gas plant. Typically, if the liquid product is sold as a condensate, the device would be considered a condensate stabilizer. If the product is sold as a mixed natural gas liquid stream (NGL) or is fractionated into its various components, the same process would be considered a gas plant. The least volatile NGL stream has an RVP between 10 and 14 and has sufficient light hydrocarbons such that 25% of the total volume is vaporized at 140°F. 

Structured laundry liquids are currently available in Europe and were recently introduced in the United States [50,51]. These products typically contain high levels of surfactants and builder salts, as well as enzymes and other additives. In the presence of high ionic strength, the combination of certain anionic and nonionic surfactants form lamellar liquid crystals. Under the microscope (electron microscope, freeze fracturing) these appear as round droplets with an onion-like, multilayered structure. Formation of these droplets or sperulites permits the incorporation of high levels of surfactants and builders in a pourable liquid form. Stability of the dispersion is enhanced by the addition of polymers that absorb onto the droplet surface to reduce aggregation. 

The catalytic degradation of polypropylene was carried out over ferrierite catalyst using a thermogravimetric analyzer as well as a fixed bed batch reactor. The activation of reaction was lowered by adding ferrierite catalyst, which was similar with that from ZSM-5. Ferrierite produced less gaseous products than HZSM-5, where the yields of i-butene and olefin over ferrierite were higher than that over HZSM-5. In the case of liquid product, main product over ferrierite is C5 hydrocarbon, while products were distributed over mainly C7-C9 over HZSM-5. Ferrierite showed excellent catalytic stability for polypropylene degradation. 

These properties were used to synthesize an organic cation (Table 17-10) with a higher efficiency as a clay stabilizer than the typical salts used in the oil industry to this point. These additives provide additional benefits when used in conjunction with acidizing and fracturing treatments. A much lower salt concentration can be used to obtain the same clay-stabilizing effectiveness [830, 833]. The liquid product has been proven to be much easier to handle and transport. It is environmentally compatible and biodegradable in its diluted form. 

Thickeners and binders such as acacia, agar, starch, sodium alig-nate, gelatin, methyl cellulose, bentonite, and silica are used to improve product stability and enhance the convenience of the administration of a liquid formulation. Surface-active agents, colors, flavors and preservatives may also be used in the final formulation (Garcia et ah. Bioseparation Process Science, Blackwell Science, Malden, Mass., 1999, p. 374). 

Primary container-closure system-related data will need to cover storage, transportation, and use. The choice of materials of construction, their description, and the ability of the container-closure system to protect from moisture and/or light will need to be considered. The compatibility of the container-closure and its contents will need to consider sorption, leaching, and safety. The performance of the container-closure system will also need to be considered in terms of dose delivery from any associated device that is to be supplied as part of the product. Container-closure components will require adequate specifications covering description, identification, critical dimensional tolerances, and test methodology (including pharma-copeial and noncompendial methods). More data are likely to be required for liquid or semi-liquid products than for solid dosage forms. In the latter, product stability data and container-closure system specifications may suffice. 

Reaction is terminated by acetonitrile quenching, or by liquid-liquid extraction with water-immiscible organic solvent, provided that the extraction efficiency and the effect of the organic solvent on product stability are tested at the small scale. Based on properties of product, the pH of the reaction mixture should be adjusted before termination to allow maximal recovery of the product. For example, acid is usually added to the acyl-glucuronide product mixture at the end of the reaction to minimize acyl migration. 

Design of liquid enzyme products with built-in liquid detergent stabilization system... 

Design of liquid enzyme products with built-in liquid detergent stabilization system 157 5.5.1 Enzyme Kinetics and Determination of K, in a Buffer System... 

The inclusion of the a routine microbial limit test in a marketed product stability protocol depends on the pharmaceutical dosage form. Typically, the test would be used only for nonsterile products, especially oral liquids, nasal sprays, and topical liquids, lotions, and creams that have sufficient water activity to support the growth of microorganisms. In contrast, tablets, powder- and liquid-filled capsules, topical ointments, vaginal and rectal suppositories, nonaqueous liquids and inhalation aerosols with a water activity too low to allow for the product to support the growth of microorganisms would not be routinely tested. 

Historically, these sulfonates have been difficult to produce in good quality and to formulate into laundry powders because of thermal and hydrolytic stability problems. Used basically as an anionic, oleochemically sourced replacement for LAS, FAE sulfonate benefits include good detergency at low concentration, low environmental load, and good supply of high quality material (71). To avoid possible thermal stability problems, these sulfonates have found application in liquid products. They are used in at least one U.S. dishwashing liquid, and the cocoyl derivative, Alpha-Step MC48, is marketed by Stepan Chemical Company. 

The product coming out of the reactor consists of excess hydrogen and a reformate rich in aromatics. Typically the dehydrogenation of naphthenes approaches 100%. From 0% to 70% of the paraffins are dehydrocyclized. The liquid product from the separator goes to a stabilizer where light hydrocarbons are removed and sent to a debutanizer. The debutanized platformate is then sent to a splitter where Cg and C9 aromatics are removed. The platformate splitter overhead, consisting of benzene, toluene, and nonaromatics, is then solvent extracted (46). 

In milk, the important interfaces are those between the liquid product and air and between the milk plasma and the fat globules contained therein. Studies of the surface tension (liquid/air) have been made to ascertain the relative effectiveness of the milk components as depressants to follow changes in surface-active components as a result of processing to follow the release of free fatty acids during lipolysis and to attempt to explain the foaming phenomenon so characteristic of milk. Interfacial tensions between milk fat and solutions of milk components have been measured in studies of the stabilization of fat globules in natural and processed milks. 

Economics, As with the alkyltin stabilizers, the market pricing of the mixed metal stabilizers tend to be directed by the particular application. The calcium—zinc and barium—cadmium packages are typically used at 2.0—4.0 parts per hundred of PVC resin (phr) in the formulation. These completely formulated products are sold for 2.50— 4.40/kg for the liquid products and 3.20— 6.50/kg for the solids and pastes. The higher efficiency products aimed at rigid applications tend toward the higher end of the cost range. 

Today, almost all inhibitors sold are liquid products and contain some water. It is generally not possible to obtain any formulation that does not contain at least 50 to 70% water, if only because almost all the starting-point raw materials (whether commodity or specialty ingredients) are supplied in aqueous solution. Typically these materials are extremely viscous liquids that contain approximately 50% water and 50% actives. Blending and stabilizing these raw materials and ensuring that they are readily pumpable normally requires the addition of some extra dilution water into the inhibitor formulation. 

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