Weight hourly space velocity WHSV

Catalytic evaluation of the different pillared clays was performed using a microactivity test (MAT) and conditions described in detail elsewhere (5). The weight hourly space velocity (WHSV) was 14-15 the reactor temperature was 510 C. A catalyst-to-oil ratio of 3.5-3.8 was used. The chargestock s slurry oil (S.O., b.p. >354 C), light cycle oil (LCGO, 232 C < b.p. <354 C) and gasoline content were 62.7 vol%, 33.1 vol% and 4.2 vol% respectively. Conversions were on a vol% fresh feed (FF) basis and were defined as [VfVp/V ] x 100, where is the volume of feed... 

The effect of pressure on the isomerization of n-heptane and n-octane was determined over the Pt//l-zeolite, Mo2C-oxygen-modified and M0O3-carbon-modified catalysts. The weight hour space velocity (WHSV) was changed with the pressure to keep the conversion at a similar level, enabling the effect on the isomerization selectivity and the product distributions to be seen. Other conditions were kept constant. 

A fixed bed reactor described by ASTM Method No. D3907 was employed for catalytic testing. A sour, imported heavy gas oil with properties described in Table II was used as the feedstock. Experiments were carried out at a reactor temperature of 800°K and catalyst residence time (9) of 30 seconds. Liquid and gaseous products were analyzed with gas chromatographs. Carbonaceous deposit on the catalyst was analyzed by Carbon Determinator WR-12 (Leco Corp., St. Joseph, MI). The Weight Hourly Space Velocity (WHSV) was varied at constant catalyst contact time to generate selectivity data of various products as a function of conversion. For certain experiments, conversion was also varied by varying the catalyst pretreatment conditions. 

According to this definition, the relative activities of two catalysts can be obtained without knowing function /, but they may be readily compared by fixing the temperature and varying the Weight Hourly Space Velocity (WHSV), to obtain a chosen degree of conversion [54]. This can be done with the MFBR system [34, 49], where space velocity can be varied individually for each reactor across the 48 library members. 

Typical operating conditions were 450°C, 30 bar total pressure, a hydrogen/oil ratio of 900 Nl/kg and a weight hourly space velocity (WHSV) of 1.5 kg/(kg h) for a period of 200 h. It was checked that at these conditions at the reactor inlet the criteria for wetting and plug flow for trickle-bed reactors [3,4] were met. Extreme conditions (higher temperatures and H2/oil ratios) led to extensive evaporation of the VGO such that the criteria mentioned were no longer adhered to. 

Hydrotreatment was carried out over a commercial UOP black oil conversion catalyst in bench-scale units of 200-800 mL catalyst capacity. Temperature range was 375°-450°C and the pressure range was 2000-3000 psig. Weight hourly space velocity (WHSV) varied from 0.1 to 1.0 depending on the heptane-insoluble content of the feed. A flow diagram of a typical plant is shown in Figure 1. The stripper bottoms usually... 

Fig. 14.2 Acetylation of anisole at 90°C in a fixed bed reactor. Ratio between the initial conversion of anisole and the maximum conversion which can be obtained vs. the inverse of the weight hourly space velocity (WHSV) for anisole...

In comparing catalyst activities, alternative 2 gives a measurable, quantitative result without the need to know the function f. This is not the same for alternatives 3 and 4. If the catalyst comparisons are done at fixed weight hourly space velocity (WHSV), and if the temperature is varied to achieve the desired conversion, applying alternative 3 and Equation 1 gives (Equation 3) ... 

The MTO reaction was investigated at 698 K at a weight hourly space velocity (WHSV) of 57-384 g/(gcat h) with a methanol partial pressure of 7.2 kPa. Because the catalyst underwent rapid deactivation, the MTO reaction was investigated by using 3-min interrupted pulses with GC analysis carried out after 2 min for each pulse (this is the integrated pulse method). The time between pulses was about 40 min, allowing for completion of the GC analysis of each pulse. The reactant... 

The HZSM-5 catalyst prepared through SiCLt liquid deposition has also been successfully applied to the synthesis of p-i sopropyI methylbenzene (p-cymene), which is an important intermediate for the production of pesticides, bactericides, and perfumes, from toluene and propan-2-ol.[72,74] After modification, the para-selectivity of the catalyst increases by 20%, and at 270°C under the conditions of weight hourly space velocity (WHSV) 6.5 g/g h and toluene/propan-2-ol ratio 11, the selectivity and yield of p-isopropylmethylbenzene reach 94 and 84%, respectively. 

Carbon laydown increases as the hydrogen-to-hydrocarbon ratio (HHCR) decreases.47 The variation of ageing rate with HHCR is very steep for HHCR < 10 molar (Fig. 6.5).27 Lowering the Weight-Hourly Space Velocity (WHSV) at constant HHCR increases carbon laydown.47... 

Hydroconversion of n-octane was carried out using a fixed-bed, downflow, tubular SS reactor at 2.0MPa and reaction temperatures fi-om 310 to 370°C at a weight-hourly space velocity (WHSV) (h" ) of 3.3 and H2/n-Cg (mol) ratio of 10. The catalyst powder was pelletized and sieved to 0.25-0.4 mm size, and 2 g of the powder was loaded into the reactor. Before activity measurements, the catalyst was activated at 400°C in a flow of hydrogen (120 mL/min) for 1 h. The n-parafEn reactant was fed using an Eldex micro-pump (USA). After time-on-stream of 5 h reaction products were analyzed using a HP-5890A GC unit... 

The reforming reaction was carried out in a continuous flow quartz-fixed-bed reactor (i.d., 6 mm) under atmospheric pressure, at 973 K, and with a ratio of CH4/CO2 1.05. 150 mg catalyst was loaded into the reactor and weight hourly space velocity (WHSV) was controlled at 12.5 h. The catalyst was reduced again in situ at the reaction temperature in the H2 flow for 2 hrs. The flow rates of the feed gases were controlled by mass flow meters (Matheson Mass Flow Controller Model 8240). The temperature of the catalyst bed was measured by a chromel-alumel thermocouple, and it was kept constant within 1 K. The composition of reactants/products mixture was analyzed with an on-line SP-3420 gas chromatograph equipped with a TCD and a Porapak QS column. The catalysts were characterized after 4 hrs reaction. 

Other terms that are used when feeding liquids to a reactor are the weight hourly space velocity (WHSV) and the liquid hourly space velocity (LHSV) [3]. Both have units of hr but are defined differently ... 

In this paper, we report results for the effects of weight hourly space velocity (WHSV), temperature, the co-feeding of methanol, yield estimates, and the relative performance of selected model compounds. 

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