Slip stream

Selective catalytic reduction (SCR) is cmrently the most developed and widely applied FGT technology. In the SCR process, ammonia is used as a reducing agent to convert NO, to nitrogen in the presence of a catalyst in a converter upstream of the air heater. The catalyst is usually a mixture of titanium dioxide, vanadium pentoxide, and hmgsten trioxide. SCR can remove 60-90% of NO, from flue gases. Unfortunately, the process is very expensive (US 40- 80/kilowatt), and the associated ammonia injection results in an ammonia slip stream in the exhaust. In addition, there are safety and environmental concerns associated with anhydrous ammonia storage. 

It is envisioned that this new LAB technology would be most readily applicable industrially as a retrofit to existing LAB commercial units, possibly as a slip-stream reactor.19,20 The manufacturer would then have the flexibility to tailor the 2-phenyl content of their LAB and LAS products according to the customer s specific needs. Alternative solid acid reactor configurations have been presented at an earlier Organic Reactions Catalysis Meeting.21... 

This is based on a sample fast loop with a sample take-off probe in the main process line, and a retnm to either a pnmp-snction or ambient pressnre sample recovery system (Fignre 5.22). The fast loop provides a filtered slip-stream to the analyzer, along with flow control and monitoring (low-flow alarm), and freqnently some form of sample antograb facility for sample capture. The slipstream flow to the internal analyzer sample flow cell is relatively low volnme and allows for a very high degree of sample temperature control (typically... 

Molecular sieves are typically regenerated using a slip stream of the treated gas at elevated temperature and reduced pressure. This regeneration step creates an enriched hydrogen sulfide stream which must then be further treated if the sulfur is to be recovered. A typical molecular sieve adsorption unit is shown schematically in Figure 2. 

The fractionation section of the alkylation plant consists of a deisobutanizer, a debutanizer, and a rerun tower in series, and a depropanizer. The deisobutanizer overhead, which contains about 90% isobutane, recycles to the reactor. The deisobutanizer bottoms stream passes to the debutanizer, which removes normal butane diluent as an overhead stream. The debutanizer bottoms or raw alkylate stream then goes to a rerun tower for removal of the high boiling alkylate bottoms or trimers. The rerun overhead requires no further treatment to be satisfactory as an aviation gasoline blending stock. The depropanizer removes propane diluent from a slip-stream portion of the recycle isobutane stream to prevent propane build-up in the reaction system. 

The design flowrate of the pilot-scale test system is 10 gph or 900 L/day, which is adequate for small quantity generators, or a slip stream from a higher capacity operation could be used. Once onsite testing is completed, the system may be transported to an operating facility for demonstration testing. The test system will be constructed in four modules to simplify transportation. When the modules are prepared for shipment, only Interconnected piping will need to be separated and capped. 

Carbon dioxide removal by slurry absorption is attractive down to about -75°C, a temperature easily achieved by slurry regeneration to slightly above one atmosphere carbon dioxide pressure. For example, with a -75°C exit gas temperature, slurry absorption reduces the carbon dioxide content of a 1000 psia synthesis gas from about 13 to about 4 mole percent, a 70% reduction in carbon dioxide content. The exact level to which carbon dioxide can be removed from a treated gas by slurry absorption also depends on the solubility of solid carbon dioxide in the treated gas the solubility of solid carbon dioxide in synthesis gas (3H2 CO) is illustrated in Figure 10 for several synthesis gas pressures. Fine removal of carbon dioxide to lower levels is accomplished by conventional absorption into a slip stream of the slurry solvent which is regenerated to meet particular product gas carbon dioxide specifications. 

Electrophoresis can also be conducted on-line, as an element of industrial process monitoring and/or control. In this case a slip-stream sample is usually withdrawn from a process vessel, diluted in a mixing tank to reduce the sample turbidity, and then pumped through an electrophoresis cell that is fitted with stop-flow solenoid valves. The flow is stopped for long enough to make an electrophoresis measurement and then resumed. The sampling can be either intermittent or continuous. An example is described in reference [265]). 

A slip-stream (1/5 to 1/3) of the second growth product can be sent to the first transalkylation reactor rather than the second. This procedure is required in order to balance this growth scheme. 

The sticker liquid, which is in the tank shown below the forward edge of the wing, is metered into a mixing chamber located immediately below the funnel-like structure located behind the tank. A wind-driven propeller mixes the sticker and the flake, which originates in the funnel structure, and forces the mixture out of the chamber via a screw-type arrangement toward a terminus equipped with a blade-like arrangement that rotates rapidly in flight. With the aid of the slip stream, the blade dispenses the flakes as individual particles. 

If a naphtha fraction has been used in the dilution and as the en-trainer, it is left in as a diluent for reducing the viscosity in pumping the oil to the refinery. Alternatively, some or all is removed as a slip stream from the reflux going to the top of the azeotropic column. If toluene or other aromatic solvent is used, it would be so removed or removed in a separate distillation for recycle. 

A dry gas containing 10.0% NH3 by volume is contacted with water at 10 C and I atm in a single-stage bubble contactor. The effluent liquid and gas streams may be considered to be in equilibrium with each other. A small slip stream taken from the effluent liquid is fed to a continuous densitometer, which indicates that the liquid density is 0.9534 g/mL. 

Aerodynamic diameter Impactor Inertial penetration of particle through slip stream as air flow is curved around impactor plate +... 

Note S-995,3-mm spheres, in a semi industrial fixed-bed reactor treating a slip stream of flue gas from a commercial ethylene cracker furnace. (From Ref. 19.)... 

Field tests were conducted on a slip-stream connected downstream of the multicyclone, on a 5MW-bark fired boiler. The instrumentation of the set-up was as indicated in Fig. 2. Connections for isokinetic dust sampling (gravimetrical determination) were mounted on the upstream and downstream side of the filter unit. The following signals were connected to the data acquisition unit for continuous sampling of Pressure difference, between filter inlet and outlet (PTl) volume flow... 

From a practical perspective near-real-time measurements are made with online process monitors. These systems utilize sensors in the sample stream with calibration usually performed by moving the sensors into a separate calibration stream. This requires some redundancy in the system if continuous monitoring is needed. Direct measurements can be made in sample streams or in a slip stream, where all the sensing is performed. 

Most of the first year was occupied in setting up the 5-ton per day pilot plant gasifier to operate in thermally ballasted mode and preparing the slip stream for gas conditioning studies. 

If the recycle soot in the feedstock is too viscous to be pumped at low temperature, naphtha is used to extract the carbon from the water slurry. Naphtha is used rather than oil feedstock to facilitate the water-hydrocarbon separation. A slip stream of oil feedstock is then used to extract the soot from the carbon-naphtha slurry and a naphtha stripper is used to recover the naphtha for recycle. The oil-carbon slip stream is recombined with the feed to the reactor and the unreacted carbon is recycled to extinction. 

A small slip stream of catalyst is treated with oxygen and heated to about 170°C (340°F) to decompose nonvolatile by-products. 

A slip stream of catalyst solution is treated with air and steam to regenerate catalyst contaminated by chlorinated by-products. 

Electrophoresis can also be conducted online, as an element of industrial process monitoring and/or control. In this case, a slip-stream sample is usually withdrawn from a process vessel, diluted in a mixing tank to reduce the sample... 

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