Feed-catalyst mixing

Increasing feed/catalyst mix zone temperature. Conversion and LPG yield can be increased by injecting a portion of the feed, or naphtha, at an intermediate point in the riser (see Figure 6-1). Splitting or segregation of the feed results in a high-mix zone temperature, producing more LPG and more olefins. This practice... 

The main mechanical conditions that affect octane are the type and condition of the feed nozzles. Low-efficiency feed nozzles actually increase the gasoline octane due to promotion of thermal reactions in the mix zone. High-efficiency feed nozzles improve feed/catalyst mixing and increase the gasoline yield, but decrease gasoline octane. 

The test conditions for this Microscale Simulation Test (MST) correspond to the low vapor contact times as applied in today s FCC riser technology. An effective feed preheat and feed dispersion is ensured, while the isothermal reactor bed is set to the dominating kinetic temperature in the riser, being approximately the feed catalyst mix temperature. The MST conditions enable the testing of high Conradson Carbon residue feedstocks. 

Figure 5 demonstrates how the correct gasoline composition can be obtained by setting the MST temperature at the level of the reactor riser feed catalyst mix temperature. 

Figure 11.4-2 shows process flows for an HF alkylation unit. The three sections are 1) reaction, 2). settling and 3) fractionation. In the reaction section isobutane feed is mixed with the olefin feed (usually propylene and butylene) in approximately a 10 or 15 to 1 ratio. In the presence of the HF acid catalyst the olefins react to form alkylate for gasoline blending. The exothermic reaction requires water cooling. The hydrocarbon/HF mixture goes to the settling... 

In this process, the feed is mixed with hydrogen, heated to the proper temperature, and introduced to the reactor containing the catalyst. The... 

The gas feed and mixing system consists mainly of glass flowmeters or electronic mass flowmeters connected to gas bottles. For reactants that are in liquid state at room conditions (e. g. methanol) a saturator is normally used through which helium is sparged and then mixed with the other reactants. In this case all lines connected to the reactor are heated (e.g. at 150°C) to avoid condensation in the lines. In certain cases the gases from the bottles should be pretreated in order to avoid contamination of the catalyst. For example, a... 

The reformer feeds and combustor air flow in a counter current manner as shown in Fig. 2. In order to transfer heat to the reformer evenly throughout the interface between reformer and combustor, the combustor is designed to feed the fuel through the holes distributed over the combustor. In this manner, the feed will mix with air incrementally and generate heat throughout the combustor plate evenly. The combustor plate is packed with a Pd catalyst and the reformer uses a Ni/Al203 catalyst. 

A refers to alumina prepared from aluminum isopropoxide. A(10% pip.) refers to reaction on catalyst A where the alcohol feed was mixed with 10% by weight of piperidine. B2 refers to alumina prepared from sodium aluminate and washed twice. 

The feed consists of isobutylene, fresh methanol, and recycled methanol. The isobutylene comes mixed with other C4 s (normal butylenes, iso-, and normal butane). As in Figure 13 1, the feed is charged to a fixed bed reactor and passes through the catalyst bed, indicated by the X. The solid catalyst, an acidic ion-exchange resin, sits loosely in the vessel to allow easy passage but intimate feed/catalyst contact. The combination of only moderate temperatures and the catalyst promotes the reaction between the methanol and the isobutylene. The reaction takes place at 120-200°F and 300 psi. It is slightly exothermic, and heat needs to be removed to keep the temperature below 210 F, or by-products will abound. About 90% of the isobutylene converts to MTBE in this reactor. 

Unit modifications that can improve the operation start with the riser and the feed injection system [6,7], The riser should be straight and have the desired velocities at both ends, which reduces excessive slip at the bottom and excessive erosion and turbulence at the outlet. A reduced diameter section is normally included at the lower end of the riser, just above the feed nozzles, to accelerate the feed/catalyst mixture. This improves contacting between the catalyst and hydrocarbons and minimizes back mixing of the catalyst. 

The oxygen is not mixed with the hydrocarbon until both are inside the reactor. Therefore, the catalyst is present when the feeds first mix at reaction temperature and the reaction proceeds immediately. This means that the oxygen partial pressure begins to drop at once. The fluid bed process allows significantly higher levels of oxygen to be safely employed in the conversion of acetic acid and ethylene to vinyl acetate without the danger of flammability (4). 

The carbon monoxide and chlorine gas feeds are mixed in the T-junction of the reactor and then guided through the catalyst bed of the reactor. The catalyst, carbon particles with a diameter of 53-73 pm, is preconditioned by heating the reactor at 150 °C for 2 h under a constant argon flow. A mixture of 2/3 CO and 1/3 chlorine (4.5 seem min-1) is fed into the reactor. The reactor was incrementally heated to 220 °C the pressure at the inlet was -132 kPa and nominally atmospheric at the outlet [39],... 

The Difasol reaction involves a mechanically stirred reactor and settlers. An injection of fresh catalyst components is defined to compensate the detrimental effects of accidental impurities present in the feed and slight carryover of the catalyst. Mixing of the solvent phase with the organic phase ensures advantageous butene conversion. However, importantly, the stirring power combined with a high... 

Steam reforming is a catalytic process for the conversion of light hydrocarbons and steam into hydrogen and carbon oxides. Most of the side reactions are retarded by the use of excess steam. First, the hydrocarbon feed is mixed with steam and passed over catalyst at a high temperature. 

The dehydrogenation of butenes in the presence of steam was developed initially by Esso, Shell and Phillips. In accordance with the operating principles of this type of process, the preheated feed is mixed with superheated steam and then sent to adiabatic reactors containing catalyst beds 80 to 90 cm thick. The temperature, initially 620 C, must be raised progressively as catalyst activity decreases. The latter is regenerated by simple steam treatment The reaction pressure is 0.1 to 0.2.10A Pa absolute, and reaches 0.5. 1C6 Pa absolute during regeneration. 

Following sulfur removal (1), the feed is mixed with steam, heated and split into two streams. One stream flows to the autothermal reformer (ATR) (2) and the other to the tube side of the reforming exchanger (3), which operates in parallel with the ATR. Both convert the hydrocarbon feed into raw synthesis gas using conventional nickel catalyst. 

The RAM II process configuration is as follows Feed is mixed with make-up and heated up in (1) to a first catalytic reactor (2) in which organometallic mercury compounds are converted to elemental mercury, and organic arsenic compounds are converted to arsenic-metal complexes and trapped in the bed. Lead, if any, is also trapped on the bed. The second reactor (3) contains a specific mercury-trapping mass. There is no release of the contaminants to the environment, and spent catalyst and trapping material can be disposed of in an environmentally acceptable manner. 

Olefinic oligomers with a reduced degree of branching were produced with a silica-rich ZSM-22 outer layer catalyst in the oligomerization of a feed containing mixed butenes, diluted with butanes, with the approximate proportions 65% olefins and 35% saturates. It was reported that a high viscosity index lubricant was produced by oligomerization of lower olefins, essentially the C3-C4 fractions, with a medium-pore, shape-selective aluminosilicate HZSM-22 catalyst. ... 

UOP Side-by-side configuration for delta coke limited operations Spent catalyst recycle line from reactor stripper to mixing vessel at base of riser with slide valve control Regenerated catalyst and spent catalyst mixed prior to acceleration and contacting with fresh feed ... 

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