Total gas flow rate

The volume of the reactor is about 10 1. At a typical process pressure of 0.2 mbar and a total gas flow rate of 60 seem, the average residence time of molecules in the reactor amounts to about 1.3 s. 

Aeration of the downcomer can also be provided with a conical distributor plate (No. 3 flow) with greatly increased solids circulation rate as shown in Fig. 8. At lower downcomer aeration, the solids circulation rate is essentially similar to that without downcomer aeration at a distributor plate location ofL = 21.7 cm. At higher downcomer aeration, however, a substantial increase in solids circulation rate is realized with the same total gas flow rate. Apparently, a minimum aeration in the downcomer is required in order to increase substantially the solids circulation rate. For polyethylene beads, this critical aeration rate is at a downcomer superficial... 

The rate constant for hexane cracking is calculated from k = -FA/V In(l-E) where F is the total gas flow rate in ml s, at the reaction temperature, W is the weight of catalyst in... 

Experiments with the 802 coal (—72 B.S. mesh) in an argon plasma were undertaken using total gas flow rates through the jet ranging from 5-20 liters/min. at coal feed rates less than 0.3 gram/min., where under the normal experimental conditions (i.e., total gas flow 9.5 liters/min. and the 10-cm. extension tube) a 20% conversion to acetylene was obtained. The conversions to acetylene for various flow rates are given in Table V. Optimum flow conditions appear to be reached at rates between 10 and 15 liters/min. 

Catalyst batches were activated under two different activation conditions H2/CO (with 3% Ar) = 2.6 3.87 xmol/s (FT synthesis reaction mixture with H2/CO = 0.7) for 2 h at (1) 523 K and (2) 543 K. These conditions are based on temperatures and gases used by PETC to activate these catalysts for testing prior to a large scale pilot plant run. After activation, reactions were carried out over the catalyst samples in the same reactor tube at 523 K with H2/CO = 0.7 and a total gas flow rate of 6.47 pmol/s (with Ar as internal standard) at a pressure of 83.8 kPa (normal atmospheric pressure in Albuquerque). Two sets of samples were made, one for each of the two activation conditions. Each set consisted of three samples after activation, activation followed by FT reaction for 10 h, and activation followed by FT reaction for 45 h. In the case of the activation at 523 K, the first 2 h of the run were considered the activation step. Therefore, the activation in this case was at 523 K. For activation at 543 K, the catalyst bed was cooled to 523 K in the syngas mixture of activation. 

Air and gaseous S02 in the required ratio enter Mixer 6 to mix fully with each other, and the resulting pseudo flue gas is divided into two equal streams to enter Absorber 7. The air flow rate is adjusted by a butterfly valve in the pipeline and measured with a Pitot tube-pressure difference meter and that of S02 by the rotameter 5. The total gas flow rate is also monitored by a wind velocity meter of DF-3 type at the gas outlet of the reactor. For each run, gas-samplings are made at both inlet and outlet of the reactor, and the S02 concentrations in the samples are measured with the Iodine-quantitative method, a standard and authentic method of determining the integral amount of S02 absorbed in the reactor. 

The total gas flow rate (hydrocarbon and DMSO) out of the column is then ... 

A process computer (PDP 11/10) was used for the plant control and the data processing. The following process variables were changed simultaneously the toluene concentration at the reactor inlet, the reactor bath temperature and the total gas flow rate. 

Figure 3a. Time profiles of the uncorrelated changes of process variables. Ranges of variables temperature of reactor bath, 0-250°C toluene concentration at reactor inlet, 0-5 Vol% total gas flow rate, 0-1200 mol/h and total pressure 0-2.5 bar.

A sudden reduction of the hydrogen flow rate may thus be a reasonable explanation of the phenomena observed. However, according to the records the total gas flow rate was kept constant. 

Total gas flow rate through the distributor at the bottom of the dipleg, Ggd, splits into two paths through the dipleg, Ggl, and through the tapered spout, Ggv. Therefore,... 

The total gas flow rate through the medium Qc is obtained from... 

In contrast to LC detectors, GC detectors often require a specific gas, either as a reactant gas or as fuel (such as hydrogen gas as fuel for flame ionization). Most GC detectors work best when the total gas flow rate through the detector is 20-40 mL/min. Because packed columns deliver 20-40 mL/min of carrier gas, this requirement is easily met. Capillary columns deliver 0.5-10 mL/min thus, the total flow rate of gas is too low for optimum detector performance. In order to overcome the problem when using capillary columns, an appropriate makeup gas should be supplied at the detector. Some detectors use the reactant gas as the makeup gas, thus eliminating the need for two gases. The type and flow rate of the detector gases are dependent on the detector and can be different even for the same type of detector from different manufacturers. It is often necessary to refer the specific instrument manuals for details to obtain the information on the proper selection of gases and flow rates. All detectors are heated, primarily to keep the... 

Figure 2. Maximum temperatures reached at different axial positions in the bed under different experimental conditions. Series A Experiments carried out with a total gas flow rate of 2 l/min and 6% oxygen concentration in the feed. Series B 3 l/min, 10% oxygen concentracion. The catalyst bed used in series A was slightly longer.

Figjre 3. Temperature-time history of particles sampled at different positions in the bed. 7 coking/regeneration cycles. The regenerations were carried out with 6% oxygen concentration in th gas and a total gas flow rate of 2 l/min. 

After passing through their respective rotameters, N2, CO2, O2, and SOo fed into a common line which passed through the heated steam box, where steam was added to the mixture. At this point the dewpoint of the gas was about 46 °C and the lines were maintained at approximately 93 °C. The NO and NO2 were added and the entire mixture was passed through a heated rotameter to determine the total flow rate. The synthetic fiue gas was delivered through heated lines to the gas scrubbers. The composition of a typical blend was 350 ppm NO, 350 ppm NO2, 2400 ppm SO2, 3 mole % O2,12 mole % CO2,10 mole % steam, and the balance N2. In all experiments the total gas flow rate was equivalent to 3200 ml/min at 20°C and 1 atm. The actual line pressure was slightly above 1 atm. 

The catalytic tests were performed in a bench-size continuous-flow reactor as described elsewhere [23, 24]. The catalyst tested was a commercial NiMoP catalyst supported on y-alumina (composition 2.9 wt% Ni, 12.6 wt% Mo, 2.9 wt% P). We selected a catalyst containing phosphorus because the most active HDN catalyst presently available on the market contains Ais adAtive. The catalyst was in Ae oxide state (NiO, M0O3) when introduced in the reactor. It was pretreated in situ accorAng to a procedure which ensured an optimal catalyst sulphidation. The catalyst was first heated to 423 K under Ar and left at this temperature for half an hour. The activation gas — a H2S(15 vol%)/H2 mixture — was introduced afterwards and Ae temperature raised, first up to 573 K where it was maintained for half an hour, Aen up to 673 K for one hour. Between each step of the pretreatment procedure, the heating rate was 0.17 Ks The total gas flow rate was 1.67 10 m s l during the whole process. At Ae end of the pretreatment, Ae catalyst was maintained under the H2S-H2 atmosphere and Ae temperature was lowered to 573 K before starting the reaction. The reaction conAtions were ... 

The conversion could be enhanced for the forward reaction if the reverse reaction involving ethene and 2-butene is minimized. Further, since 2-butene desorption is a controlling factor due to its strong sorptive properties, 2-butene removal, in particular, will allow improved rate of reaction and product separation with the use of a sorbent such as y-Al203. The effect of the PSR operation (cycle time = 40 sec) on the reactor performance was tested through simulations and by conducting experiments. Step inputs in inlet feed composition containing propene with helium carrier were conducted with clean sorbent beds and constant total gas flow rates. The results, compared with theoretical predictions, are shown in Fig. 9. Because ethene has... 

In the basic two-phase model a prescribed fraction of the total gas flow rate through the bed, which is coinciding with the minimum fluidization operating conditions, is assumed to move through the emulsion phase [130, 29]. The relative velocity between the interstitial gas and the solids in the emulsion phase is thus Ue = The rest of the gas constitutes the bubble... 

The powdered catalysts were evaluated in an integral continuous fixed bed reactor (Ig cat, total gas flow rate 6 1/h), with on line gas analysis by gas chromatogral using both thermal conductivity detector and flame ionization detector. 

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