Low Pressure Nitrogen

Low pressure nitrogen blanket supply High pressure nitrogen supply Vacuum ]ine Water supply... 

In a 1-1. round-bottomed flask are placed 36.0 g. (0.132 mole) of 2-(/>-tolylsulfonyl)dihydroisoindole,1 2 36.0 g. (0.38 mole) of phenol, 270 ml. of 48% hydrobromic acid (Note 1), and 45 ml. of propionic acid. A few boiling chips are added, and the flask is fitted with a reflux condenser in the top of which is placed a T-tube connected to a source of low-pressure nitrogen and to a mercury bubbler. The mixture is heated under reflux for 2 hours in an atmosphere of nitrogen. The deeply colored reaction mixture is cooled to room temperature, transferred to a 1-1. separatory funnel, and washed with two 200-ml. portions of ether (Note 2). The aqueous phase is then added dropwise over a 1-hour period to a vigorously stirred (Note 3) solution of 200 g. of sodium hydroxide in 600 ml. of water in a 2-1. Erlenmeyer flask immersed in an ice bath. The solution is transferred to a 3-1. separatory funnel and extracted with five 300-ml. portions of ether. The ethereal extracts are combined, dried over anhydrous potassium carbonate (Note 4), and filtered. The solvent is distilled, and the dark residual oil is transferred to a distillation... 

The same authors reported the possibilities of using a membrane made by PVA modified by LiCl, whose surface has been modified by exposure to low-pressure nitrogen plasma [31], The best results have been obtained for 0.05 wt% of LiCl in PVA membrane at 25 °C (selectivity 14 and flux 250 g m"2lT ). 

The only example of all the unimolecular reactions known where such a difficulty has actually arisen in an acute form is the decomposition of nitrogen pentoxide. It appears that at low pressures nitrogen pentoxide reacts at a rate which is considerably greater than the maximum possible rate of activation by collision, however great a value of n be assumed. There is a limit to the maximum rate theoretically possible, since, when n is increased beyond a certain point, the increase in the term E — EArrhenius + n- )RT produces a decrease in the calculated rate which more than compensates for the increase due to the term (E/RT)1l2n 1 multiplying the exponential term. 

Table 5. Experimental kinetic constants for nitriding of titanium, niobium and molybdenum immersed in a low pressure nitrogen discharge at floating potential (according to Ref.189b- A is the preexponential factor,...

For the mitigated and unmitigated cases the carbon disulfide is contained in a vertical steel tank having a diameter of 4.3 m and a height of 6.5 m. The accidental release comes from a 50-mm diameter nozzle located at the base of the tank. The tank is filled to 60% of capacity. The tank has a low-pressure nitrogen purge. 

Micropore Size Distribution Analysis. Low pressure nitrogen adsorption and desorption of fresh and coked catalysts were carried out using an Omicron Technology Omnisorp lOOCX. The data for the adsorption isotherms were collected at very low partial pressures of nitrogen (P/Pq < 10 ) to determine the BET surface area and the micropore volume. The micropore volume was estimated from the t-plots. The desorption isotherm was obtained to measure meso and macro pore volume which correspond to the pore volume larger than pore radius of Inm. 

Low pressure nitrogen adsorption isotherms of coked catalysts, in Figure 5 showed smaller amount of volume adsorbed in the coked unstabilized catalyst than stabilized catalyst samples. This is due to a large difference in micropore volume, shown in Table II. 

Figure 5. Low pressure nitrogen adsorption isotherms of catalysts.

In this study, we have prepared and characterized montmorillonite pillared with Al and La in different proportions. The structural and textural parameters of the materials were compared with those of montmorillonite pillared only with Al. We have applied classical and new models to low pressure nitrogen adsorption data to obtain a quantitative evaluation of the microporosity of the synthesized materials and their evolution under thermal treatments. 

For a condenser operating at atmospheric pressure, an adequate vent is all that is necessary. However, air is often not suitable for contact with the process due to concern about contamination or flammability. In these cases, the vent may be connected to a source of low pressure nitrogen, or other inert gas. For vacuum operation, the vent must also be connected to a vacuum pump or steam jet (eductor), as shown in Figure 3.11(B). The pressure controller adjusts the split range control valves such that as its output decreases, first PV-2 closes then PV-1 opens. Normal operation would... 

Darmstadt, H., Roy, C., Kaliaguine, S., et al. (2003). Pore structure and graphitic surface nature of ordered mesoporous carbons probed by low-pressure nitrogen adsorption. Microp. Mesop. Mater., 60, 139—49. 

Figure 18.4 Low-pressure nitrogen adsorption isotherms of various nonmicroporous carbon blacks (CB) with different graphitic order and of microporous CB. (Adsorption data taken from Refs [[39], [40], and [50]] for the graphitized, the thermal CB, and the furnace, respectively.)...

Figure 18.5 Low-pressure nitrogen adsorption isotherms of various ordered mesoporous carbons (OMCs) synthesized at different temperatures. (Reprinted with permission from Ref. [13].)...

In addition to the pore size distribution and surface area, surface chemistry is one of the most important properties of carbon materials. The surface chemistry can be studied by spectroscopy methods such as X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectroscopy (SIMS). However, these techniques can only be applied to the external surface. In the case of micro- and mesoporous carbons (e.g., activated carbons and OMCs), the external surface represents only a small portion of the surface. The largest portion of the surface is located in the pores. How information on the graphitic character of the surface of OMC can be obtained from low-pressure nitrogen adsorption data is discussed in this chapter. 

Figure 5.5 A schematic of the Costain nitrogen removal process. I) heat exchanger, 2) heat exchanger (subcooling), 3) subcooler by low pressure nitrogen, 4) low pressure column, 5) condenser/reboiler, 6) high pressure distillation column, 7) hydrocarbon pump. Source [11].

Auxiliary systems which exist in the HCF include material handling equipment (cranes hoists, transporters, etc.), low pressure nitrogen, compressed air, hydraulic systems, process waste water collection system, rainwater collection drains, communications systems, and oxygen monitors. Additionally, HCF activities are supported by operations in B6595, B6596, and B6597. 

Remove stopper and replace with quick-fit adaptor connected to a low-pressure nitrogen supply. 

GAN = Caseous low pressure nitrogen PGOX = Pressurized gaseous oxygen... 

The ability of the single site carbon dioxide optimised PSD to predict the low pressure nitrogen adsorption isotherm, but not the reverse, recommends carbon dioxide as a probe gas. 

Low Pressure Nitrogen foam molding for nucleation and extra weight reduction. 

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