Norit Extra carbon

The carbon support used was a Norit activated carbon (RX3 extra) having a surface area of 1190 m2.g 1 and a pore volume of 1.0 cm3.g . The Co/C catalyst (4.1 wt% Co) was prepared by pore volume impregnation with an aqueous solution of cobalt nitrate (Merck p.a.) followed by drying in air at 383 K (16 h). The promoted catalyst (1.5 wt% Co, 7.7 wt% Mo) was prepared in a special way to ensure a maximum amount of the Co-Mo-S phase (11). Mossbauer spectroscopy of this promoted catalyst clearly showed that only the Co-Mo-S phase was present after sulfiding (11) and furthermore that this Co-Mo-S is probably a Co-Mo-S type II phase, meaning a minor influence of active phase-support interaction (11,12). The catalytic activity of the sulfided catalysts was determined by a thiophene HDS measurement at 673 K and atmospheric pressure, as described elsewhere (10). The thiophene HDS reaction rate constant kHDg per mol Co present (approximated as a first order reaction) was found to be 17 10 s 1 for Co/C and 61 10 3s 1 for Co-Mo/C. 

Two high surface area carbons were investigated. The first carbon, derived from activation of carbonized poly(ethylene terephthalate) (APET) was ash-free [1]. The second, a commercially available carbon in wide use (R1 Extra, Norit), had an ash content of 6.2%. 

A commercial high snrface area carbon (Norit R1 Extra) was exposed to concentrated nitric acid for 3 h at room temperature, then thoroughly washed with distilled water and dried 1 450 mVg, surface carbon/oxygen ratio=9.4 atomic%). The... 

Figure 6. Carbon Norit R 0.8 Extra PSD determined by nitrogen desorption data (N2), and PSDs of pores filled by water unfrozen in different environments at T < 273 K.

Abstract. Activated carbon Norit R 08 Extra, and molecular sieve type 4A, were investigated using dynamic (tert-butylbenzene (TBB), cyclohexane (CHX) and water vapour) adsorption methods. The TBB, CHX and water breakthrough plots for fixed activated carbon - molecular sieve beds were analyzed. It was found that the type of bed composition with mechanically mixed activated carbon with molecular sieve, or separated activated carbon and molecular sieve layers, affects the dynamic adsorption characteristics. 

Two different adsorbents, activated carbon Norit R 0.8 Extra (Norit N.V., The Netherlands) and molecular sieve (type 4A, Merck), were used to study tert-butylbenzene, cyclohexane, and water vapour breakthrough dynamics. Structural parameters of the carbon adsorbent were calculated from benzene vapour adsorption-desorption isotherms measured gravimetrically at 293 K using a McBain-Bakr quartz microbalance, and nitrogen adsorption-desorption isotherms recorded at 77.4 K using a Micromeritics ASAP 2405N analyzer described in detail elsewhere.22,24 Activated carbon Norit has a cylindrical... 

Abstract. The influence of an inert impregnant (NaCl) on the adsorption properties of activated carbon Norit R 0.8 Extra was studied on breakthrough dynamics of tert-butylbenzene (TBB) and dimethylmethylphosphonate (DMMP). Pre-adsorbed NaCl (5-20 wt.%) strongly affects both structural (e.g. volume of nanopores and mesopores) and adsorption (adsorption potential, breakthrough time, kinetic saturation capacity, etc.) characteristics. 

Isotherms of various microporous solids (activated carbons, zeolites, ACF s), involving different adsorbates (N2, CO2, Ar), have been measured Norit R1 Extra (N2, CO2), Norit RBI (N2), Norit C Granular (N2), Chemviron BPL-HA (N2), Chemviron ASC-TEDA (N2), an experimental activated carbon AC 147 (N2), a pitch-based activated carbon fibre (P3200-C02/900°C) manufactured at DSTL-Porton Down (N2), zeolite 13X14H (N2) and zeolite 13X12L (Ar). The last one was copied from the reference isotherms provided with the Mi-cromeritics ASAP 2010 poresizer that was used to measure the different isotherms. 

Activated carbons used in this application are high steam activated and acid washed extrudates like the NORIT RX 3 EXTRA. 

The process is carried out in the gas phase at a temperatures above 160°C. The reaction is exothermic, so heat control in the production process is important. Vinylacetate is used as intermediate in a large number of production processes. The catalysts can be produced by impregnation of an activated carbon with zinc acetate, followed by drying. The zinc concentration is in the order of 11 up to 13%. The optimal activated carbon support is a high steam activated and acid washed 3 or 4 mm extrudate like the NORIT RX 3 EXTRA or NORIT RX 4 EXTRA. Important characteristics of the impregnated carbon are ... 

An example for the integral and differential pore distribution of an activated carbon (Norit R1 Extra) determined at BAM Berlin with a commercial mercury porosimeter is shown in Figures 1.3, 1.4. 

Figure 1.3. Cumulative or integral volume ofpores Vp(r) per unit mass of sorbent as function of the pore radius (r) for activated carbon Norit R1 Extra at 298 K (Hg-intrusion) [1.36],...

Determination of the volume of activated carbon Norit R1 Extra by helium expansion measurements at 298 K in a commercial gas pycnometer (Micromerites, Accu Pyc 1330). 

Once V is known, m = m (p, T, m ) can be calculated from Eq. (1.5). Such a situation is very common for gravimetric measurements of helium gas adsorption equilibria. An example is sketched in Figure 1.8 showing gravimetric adsorption data of activated carbon Norit R1 Extra exerted to He (5.0). As can be seen, for high pressures the reduced mass data ( ) easily can be linearly correlated, i. e. adsorption of helium has reached a state of saturation. Hence, Vhc can be determined via Eq. (1.6) and also the mass of helium adsorbed initially at low gas pressures can be calculated from Eq. (1.5) as ... 

Figure 1.8. Adsorption isotherm of helium on activated carbon (AC) Norit R1 Extra at 293 K.

Figure 1.11. Adsorption of helium added to activated carbon Norit R1 Extra in a nitrogen atmosphere of p = 0, 5, 7, 10, 13 MPa at T = 298.15 K. The reduced mass (fi), Eq. (1.6), referring to helium gas pressure. Data for p = 7, 10, 13 MPa indicate that hehum is not adsorbed additionally to nitrogen, but that the volume (V ) of the sorbent sample (s) loaded with increasing amounts of nitrogen (a) as seen by the hehum molecules is also increasing monotonously. The p = 5 MPa-data show adsorption. But this simply may be adsorption of N2 due to poor mixing of the He- and the N2 gas immediately after adding helium to the system [1.48].

However, for high gas densities (p — Po) or, equivalently, high gas pressures both quantities are becoming different. Consequences of this are demonstrated in Figure 1.22 below showing (m g, m )-data of nitrogen adsorbed on activated carbon Norit R1 Extra [1.50]. 

To elucidate consequences of all four different model assumptions (P1...P4) for the volume of a porous sorbent/sorbate system, adsorption data (Q) of nitrogen N2 (5.0) on activated carbon (AC) Norit R1 Extra which have been measured gravimetrically at 298 K, and the adsorbed masses calculated from these data are shown in Figure 1.22, [1.50]. The lowest curve presents the Q-data. Note that these decrease at high gas densities as then seemingly the increase in buoyancy of the sorbent/sorbate sample is larger than the uptake of nitrogen gas, cp. Eq. (1.31). The other curves present data as follows ... 

Table 1.7. Adsorption equilibria of nitrogen N2 (5.0) on activated carbon (AC) Norit R1 Extra at T = 298 K. Parameters of data correlation for different models of V = V + V using a generalized Langmuir adsorption isotherm Eqs. (1.41, 1.42).

Figure 3.8. Differential pore volume of the activated carbon (AC) NORIT Rl EXTRA in the micropore region, calculated from the AI given in Fig. 3.7B by the Horvath-Kawazoe-method [3.29].

Figure 3.9. Adsorption equilibria of helium (5.0) on activated carbon (AC) NORIT R1 EXTRA at T = 298.15 K and T = 323.15 K. Data of the apparent weight of the sorbent sample are sketched as function of the density of the helium gas (pHe) within the region (0 < pne < 2 kg / m ) corresponding to the pressure range (0 < p < 2.5 MPa). Data were always taken 15 minutes after increase of hehum gas pressure at a relative mass change rate of (Am / m At = 5.10 g / (gh)).

Figure 3.10. Gibbs excess adsorption isotherms of (CO2, CH4, CO, N2) on activated carbon NORIT R1 EXTRA at T = 298.15 K, [3n.27], Data have been correlated using an isotherm of the generalized Langmuir type (3.38).

High pressure adsorption of N2 and CO2 on activated carbon NORIT R1 EXTRA in the temperature range 298 K - 343 K for pressures up to 50 MPa. 

We here present only adsorption measurements of He and CO2 on activated carbon (AC) Norit R1 Extra at 293 K. Physico-chemical parameters of this sorbent material have been given in Chap. 3, Sect. 2.3. Also, some... 

Figure 5.6 shows a top view of the ring slit on the disk of the pendulum filled with activated carbon Norit R1 Extra powder. Uniform distribution of the powder within the slit is mandatory to get reproducible results of oscillometric measurements. 

Figure 5.6. Ring sUt of pendulum (Rj=3.75cm, R,=5.5cm) filled with activated carbon powder (Norit R1 Extra).

Figure 5.7. Reduced masses (Hose, f grav) resulting from oscillometric and gravimetric adsorption measurements of He on activated carbon (Norit R1 Extra) at 293 K. Gibbs excess masses adsorbed (= 0, ) are calculated from (f2o c>...

Carbon monoxide (CO, 3.7) on molecular sieve (MS13X, UOP) (Fig. 6.13) Sorptive gas mixture methane-carbon monoxide (CH4 CO=90% 10%mol) on activated carbon Norit R1 Extra (Norit, Netherlands) (Fig. 6.14). 

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