Direct injection process

Equilibrium properties of the C02/sea-water system have been well researched from an experimental standpoint. In particular, the clathrate hydrate forming conditions T < 285K andP>4MPa) are well established. Several experiments have been performed under conditions mimicking the direct injection process and have attempted to study the dissolution rate of CO2 in seawater. Under direct injection conditions, the injected CO2 is in the form of a liquid droplet and a thin spherical shell of CO2 clathrate hydrate of structure I is observed to form around the CO2 drop, separating it from the sea water. The process of hydrate formation has many similarities with that of crystallization, i.e., it can be divided into a nucleation phase and a growth phase. For CO2 clathrates, the nucleation phase involves the formation of a... 

Figure 1 The direct injection process, including the optional dilution step.

After having dissolved the substance containing the RS to be looked for in an appropriate solvent, it is possible to directly inject into the system 100% of an aliquot of the solution (if packed columns are used) or partially through a split system (if capillary, narrow-bore and wide-bore columns are used). It is simple, accurate and repeatable (with an internal standard). The main drawback is that samples very often contain non-volatile substances which are retained by the column, leading rapidly to a loss of efficiency and a dramatic decrease in sensitivity. In the current literature dealing with the RS, the direct injection process is less frequently used. Nevertheless, publications have appeared until recently using split/ splitless injection. ... 

Solvay started to produce Solkane 365mfc (1,1,1,3,3-pentafluorobutane) commercially at the end of 2002. Blends with the non-flammable HFC-227ea (heptafluoropropane) were developed. Two blend ratios were identified as appropriate, i.e., 93 7 for direct injection processing, and 87 13 for fully formulated systems. 

A latex modified asphalt emulsion can be prepared using several methods addition of the latex in the aqueous emulsifier solution, direct injection in the asphalt hne just ahead of the coUoid mill or post-addition to the pre-manufactured emulsion, as schematically shown in Fig. 12-9. Addition to the aqueous phase is the most commonly used method. The direct injection process often helps to produce an emulsion with a desired high viscosity for chip seal application (Sect. 12.3.1). This is due to the narrow particle size distribution of the asphalt emulsion produced with this process. 

The output from the turbine might be superheated or partially condensed, as is the case in Fig. 6.32. If the exhaust steam is to be used for process heating, ideally it should be close to saturated conditions. If the exhaust steam is significantly superheated, it can be desuperheated by direct injection of boiler feedwater, which vaporizes and cools the steam. However, if saturated steam is fed to a steam main, with significant potential for heat losses from the main, then it is desirable to retain some superheat rather than desuperheat the steam to saturated conditions. If saturated steam is fed to the main, then heat losses will cause excessive condensation in the main, which is not desirable. On the other hand, if the exhaust steam from the turbine is partially condensed, the condensate is separated and the steam used for heating. 

The basis of this process was the injection of sodium carbonate solution into the viscose, although direct injection of carbon dioxide gas that reacts with the viscose soda to form sodium carbonate could also be used (44). The carbonate route yielded a family of inflated fibers culminating in the absorbent multilimbed super inflated (SI) fiber (Eig. 5c). 

The sources of particulate matter in the atmosphere can be primary, directly injected into the atmosphere, or secondary, formed in the atmosphere by gas-to-particle conversion processes (13). The primary sources of fine particles are combustion processes, e.g., power plants and diesel... 

The parameters of the injection process must be provided. They can either be estimated or, to be more exact, taken from the thermal and rheological layout. The position of a length with respect to flow direction is in practice an important influence. This is used primarily for glass-filled material but can also be used for unfilled TPs. 

The use of electric powered steam generators, steam-to-steam heat exchangers, or reboilers to provide steam to steamtables, humidifiers, autoclaves, and for direct injection into the process. Where this type of approach is employed, it generally is necessary to provide a high quality water source to avoid rapid internal deposition of crystalline scales and foulants. 

NH3. Ammonia is a colorless gas. It is a strong base, forms hydrogen bonds, is soluble in water, and is a fairly reactive molecule. Each year 12.4 million metric tons are manufactured by the Haber process (N2 + 3H2 2NH3 at 400°C and 250 atm), principally for nitric acid production, which is then used to make fertilizers and explosives. As a fertilizer, ammonia can be utilized in three ways first by direct injection... 

The conventional Cl-engine operates with a relatively high compression ratio and in an unthrottled manner. Delayed direct injection of fuel in the compression process prevents knocking combustion and enables load... 

While the decrease in extraction time is favourable for laboratories in general, it can be critical when laboratory analyses are used in feedback control of production cycles and quality control of manufacturing processes. The volume of solvents used in PFE can be some 10 times less than traditional extraction methods (cf. Table 3.36). PFE cuts solvent consumption by up to 95 %. Because so little solvent is used, final clean-up and concentration are fast direct injection in analytical devices is often possible. Automated PFE systems can extract up to 24 sample cells. 

In ICP-AES and ICP-MS, sample mineralisation is the Achilles heel. Sample introduction systems for ICP-AES are numerous gas-phase introduction, pneumatic nebulisation (PN), direct-injection nebulisation (DIN), thermal spray, ultrasonic nebulisation (USN), electrothermal vaporisation (ETV) (furnace, cup, filament), hydride generation, electroerosion, laser ablation and direct sample insertion. Atomisation is an essential process in many fields where a dispersion of liquid particles in a gas is required. Pneumatic nebulisation is most commonly used in conjunction with a spray chamber that serves as a droplet separator, allowing droplets with average diameters of typically <10 xm to pass and enter the ICP. Spray chambers, which reduce solvent load and deal with coarse aerosols, should be as small as possible (micro-nebulisation [177]). Direct injection in the plasma torch is feasible [178]. Ultrasonic atomisers are designed to specifically operate from a vibrational energy source [179]. 

The KOCAT Society (no patent reference known by authors), in South Korea, solved the DeNO problem of big burners, by directly injecting oxygenates on the catalyst at the outlet of the burner. This process involves the third function of our model. This example shows that only one model (the present one) for DeNO reaction can be used for either mobile or stationary sources. Pathways are the same what is changing is the nature of the reductant, which has to be activated, through its partial oxidation, at the temperature when N—O bonds (dinitrosyl species) are broken. 

Function 3 can be studied separately by direct injection of the CxHyO., oxygenates (alcohol, aldehyde, etc.) corresponding to the mild oxidation process of HC by N02. 

Direct injection of pretreated biological samples (also called online sample cleanup) greatly simplified sample preparation for LC/MS/MS analysis. The normal process involves sample aliquot steps, internal standard addition, and centrifugation. Compared to traditional off-line LLE and SPE sample preparation procedures, online methods are easier and faster. Two types of online SPE columns are commercially available. One is the restricted access media (RAM) column. The other is the turbulent flow chromatography (TFC) column. 

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