Hydrogen recycle pump

In Figure 2-7, toluene is fed into a heated reactor containing the catalyst in a fixed bed. A small amount of hydrogen is pumped in to keep carbon deposition on the catalyst to a minumum. The reactor conditions are in the 650—950°C and 150—500 psi ranges. The effluent is cooled then the hydrogen is recovered and recycled The rest of the effluent is then triple... 

P-3 R-l H2S04 RECYCLE PUMP MAIN REACTION VESSEL TR-5 HYDROGEN PURIFICATION LOOP LN2 TRAP... 

Trends in short- and lOTiger-term directions for key fuel cell components including electrocatalysts/supports, membranes, and bipolar plates have been elaborated in this section improvement of the performance and durability of these components will directly impact the entire automotive fuel cell system requirements, complexity, and cost. Durable catalysts with enhanced ORR activity, durable membranes that perform at very low humidity and durable bipolar plates that have low contact resistance will not only increase the power density and cost of the fuel cell stack but also simplify and lower/eliminate system component costs of the air compressor, humidification systems, recycle pumps, radiator, start-up/shutdown and freeze-start-related components, etc. A combination of advances in all the fuel cell components discussed above, system simplification, governmental policies that are sensitive to sustainable clean energy, and development of a hydrogen infrastructure will enable achieving the projected technical and cost targets needed for automotive fuel cell commercialization. 

In 1963, liquid polymerization was introduced in which liquid propylene, catalysts, and hydrogen were pumped continuously into the reactor while polypropylene slurry was transferred to a cyclone separator. The unconverted monomer gas was removed, compressed, condensed, and recycled, and the polymer was treated to reduce the catalyst residue. This system also suffered from a poor catalyst yield, and the polymer produced lacked the required stereospecificity, so that it was necessary to remove the atactic portion of the polymer. 

Reflux overhead vapor recompression, staged crude pre-heat, mechanical vacuum pumps Fluid coking to gasification, turbine power recovery train at the FCC, hydraulic turbine power recovery, membrane hydrogen purification, unit to hydrocracker recycle loop Improved catalysts (reforming), and hydraulic turbine power recovery Process management and integration... 

Benzene (fresh or recycled) and tetrapropylene are fed in the reactor (R) over the dryer (D). The hydrogen fluoride is supplied to the reactor either from the connected settling tank (ST) or purified from the HF refining. From ST the organic phase is washed in washer W and from there it is pumped to the distillation. Here four fractions are obtained ... 

Electrolyzer, 2 —Evaporator. 3—Separator of licniid from vapour, i -Hydrogen peroxtrle coudenecrH,. 5 — Separated solution of ammonium hydrogen sulphate which is recycled to the electrolysis, ft — Piping to vacuum pump. 

In order to process SRC in the pilot plant equipment without using an extraneous solvent, a portion of the hydrotreated product was recycled to the feed reservoir as diluent. Recycle was essentially internal, and SRC and hydrogen were the only net feeds to the system. Pulverized SRC was added to the hot reservoir at a ratio of two parts SRC to three parts recycled product (combined feed ratio = 2.5). Vigorous stirring ensured that no undissolved solids were taken into the feed pump system. 

Fig. 12.14. Flow diagram for the manufacture of nylon 66 yarn (1) air (2) cyclohexane from petroleum (3) reactor (4) recycle cyclohexane (5) still (6) cyclohexanol-cyclohexanone (7) nitric acid (8) converter (9) adipic acid solution (10) still (11) impurities (12) crystallizer (13) centrifuge (14) impurities (15) adipic acid crystals (16) dryer (17) vaporizer (18) ammonia (19) converter (20) crude adiponitrile (21) still (22) impurities (23) hydrogen (24) converter (25) crude diamine (26) still (27) impurities (28) nylon salt solution (29) reactor (30) stabilizer (31) calandria (32) evaporator (33) excess water (34) autoclave (35) delustrant (36) water sprays (37) casting wheel (38) polymer ribbon (39) grinder (40) polymer flake (41) spinning machine (42) heating cells (43) spinnerette (44) air (45) draw twisting (46) inspection (47) nylon bobbin. (Note Whenever the demand for liquid polymer at a spinnerette is large, as, for example, in the spinning of tire yarn, it is pumped directly from the autoclave.)...

Part of the stream is washed countercurrently with a feed sidestream in the vent H2 absorber (9) for benzene recovery. The absorber overhead flows to the hydrogen purification unit (10) where hydrogen purity is increased to 90%+ so it can be recycled to the reactor. The stabilizer (11) removes light ends, mostly methane and ethane, from the flash drum liquid. The bottoms are sent to the benzene column (12) where high-purity benzene is produced overhead. The bottoms stream, containing unreacted toluene and heavier aromatics, is pumped to the recycle column (13). Toluene, C8 aromatics and diphenyl are distilled overhead and recycled to the reactor. A small purge stream prevents the heavy components from building up in the process. 

Ethylene, hydrogen, co-monomer and a super-high activity catalyst are fed into the reactors (1). Polymerization reaction occurs under a slurry state. The automatic polymer property control system plays a very effective role in product-quality control. Slurry from the reactors is pumped to the separation system (2). The wetcake is dried into powder in the dryer system (3). As much as 90% of the solvent is separated from the slurry and is directly recycled to the reactors without any treatment. The dry powder is pelletized in the pelletizing system (4) along with required stabilizers. 

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