Reactor lining

In the chemical process industry molybdenum has found use as washers and bolts to patch glass-lined vessels used in sulphuric acid and acid environments where nascent hydrogen is produced. Molybdenum thermocouples and valves have also been used in sulphuric acid applications, and molybdenum alloys have been used as reactor linings in plant used for the production of n-butyl chloride by reactions involving hydrochloric and sulphuric acids at temperatures in excess of 170°C. Miscellaneous applications where molybdenum has been used include the liquid phase Zircex hydrochlorination process, the Van Arkel Iodide process for zirconium production and the Metal Hydrides process for the production of super-pure thorium from thorium iodide. 

The work reported here used a tubular reactor of approx. 2.5 cm id and 150 meters in length. The reactor, lined with a fluorinated polymer, was coiled in a helical shape. The recipe employed standard concentrations of initiator and emulsifier. 

Titanium tetrachloride is produced on an industrial scale by the chlorination of titanium dioxide-carbon mixtures in reactors lined with silica. During the reactor operation, the lining comes into contact not only with chlorine but also with titanium tetrachloride. There appears to be no attack on silica by either of these as the lining remains intact. However, the use of such a reactor for chlorinating beryllium oxide by the carbon-chlorine reduction chlorination procedure is not possible because the silica lining is attacked in this case. This corrosion of silica can be traced to the attack of beryllium chloride on silica. The interaction of beryllium chloride with silica results in the formation of silicon tetrachloride in accordance with the reaction... 

You have to shake your head in wonder when you think about how the largest selling plastic was developed—by accident. In 1933, the scientists at the ICI labs in England were attempting to make styrene by the high-pressure reaction of benzaldehyde with ethylene. Instead, they ended up with a reactor lined with a solid, white, wax-like material—polyethylene. 

Feed to the FCC unit is mixed with hot catalyst and steam in a reactor line called a riser. The ratio of catalyst oil feed can typically range from 4 1 to 9 1 by weight. Overall, FCC is an endothermic process. Heat provided by the hot, circulating catalyst is the prime source of energy driving the FCC process. In the riser, vaporized oil is cracked catalytically in less than two seconds. The vapors and catalyst flow out of the riser and into the reactor. At this point, most cracking reactions have occurred. 

In Figure 2, dN/dW is plotted as a function of W for two series of commercial samples withdrawn from an experimental continuous reactor line in which butadiene and styrene were copolymerized in emulsion using a 1500-type recipe at 5°C. The conversion marking the onset of predominant crosslinking is given by the point at which the curves cut the W axis—that is, at 53 and 57% conversions. 

The results show that the plant reactor falls between the plug flow and backmixing reactor lines. The distance between lines (2) and (3) in Figure 5-41 measures the degree of backmixing. There is considerable departure from the theoretical plug flow curve. This shows... 

Commercial plants Thirty-five reactor lines are operating, in design or under construction worldwide representing around 6 MMtpy production with capacities ranging from 50,000 tpy to 350,000 tpy. Designs up to 450,000 tpy are also available. 

Commercial plants Twenty-five reactor lines are in operation, engineering design or construction worldwide with a total production capacity of over 2.5 MMtpy. 

Commercial plants Eighty-two reactor lines are either in operation or construction worldwide and account for 34% of worldwide capacity. 

The reactor effluent was analyzed by on-line GC-analysis prior to condensation. Each reactor line was equipped with a HP 5890 GC with flame ionization detector (FID), interfaced with a PC for data handling and storage. The method of analysis, based on HP s PONA analysis, included all important hydrocarbons up to C,. Heavier components than this were only present in trace amounts, and were not analyzed. Research octane numbers (RON) were calculated from GC-analysis based on an adapted version of the method presented by Anderson et al. (5). The hydrogen yield was calculated from GC-analysis as the hydrogen balance over the reactor. 

The Chernobyl catastrophe and the resulting pressure of public opinion prevented the further development of this interesting reactor line in the Federal Republic of Germany. 

Sulfur tolerances of the zeolite SCR catalysts (20/50 mesh size) were determined in a fixed-bed flow reactor system with a reaction mixture containing 500 ppm of NO, 1,000 ppm of C2H4 or 2,000 ppm of C3HJ, 4.2% of Oj, 1,000 ppm SO2 and He (balance). To observe the simultaneous effect of both SOj and HjO on the removal reaction, 7.3% H2O was also fed to the reaction system in addition to die reactants described above. H2O was injected to the feed gas stream by bubbling He into a water saturator with a small-pore frit immers in deionized water. To avoid condensation of H2O vapor after the bubbler, reactor lines were heated to a temperature higher than the saturation temperature of the feed gas stream including H2O. A gas flow rate of 300 cmVmin was employed for the present study, corresponding to a space velocity of 13,200 h . 

Carbon deposition rates were measured in a microreactor connected to a Sartorius 4436 high pressure microbalance [11]. The catalyst (17-70 mg) was placed on quartz wool in a perforated quartz basket in a stainless steel reactor lined with an alumina tube (i.d. = 15 mm) and hung from one arm of the microbalance by a quartz fiber. Water was fed using a Lewa M3 pump. A flow of inert gas was always maintained through the microbalance. The composition of the product gas could be determined by on-line gas chromatography. 

This process operates in the aqueous phase at 250 C and 65.10 Pa absolute, in the presence of cobalt iodide as catalyst The high-pressure reactor lined with hastelloy C for corrosion resistance features internal agitation of the liquid obtained by gas injection ( air lift type). It is continuously supplied with a stream of methanol, dimethyl ether, carbon monoxide if required, and water preheated to between 40 and 80°C. The amount of water added is one-third of that of methanol by weight The arid mixture and the unreacted gases are collected at the top of the reaction tower, cooled, and brought to 1.10 Pa absolute in a flash drum. The methyl iodide and header components in, the Hashed gases are recovered by scrubbing with methanol feed. ... 

Fusion Tritium breeder materials (zirconates and silicates of Li, Li20) fusion reactor lining (C, SiC, Si3N4)... 

This process was formerly the most widely used for the manufacture of butadiene by dehydrogenation. Using a feed containing 95 per cent or more n-C. it produces a mixture of butenes and butadiene in a single step. The butadiene is separated, and the unconverted butenes and butane are recycled. The catalyst, activated alumina containing 18 to 20 per cent weight of chromium oxide, has a life of more than six months. It is placed in a series of horizontal reactors lined with refractory bricks. The inert alumina is mixed with the catalyst to achieve the uniform distribution of the heat required for the reaction and a high heat capacity of the catalyst bed. 

Commercial plants The UNIPOL PE Process has over 40 years of proven capability with over 100 reactor lines in operation or under construction that range in capacity from 40 million tpy to 650 million tpy. 

When the valve switches from nitrogen to air, the flow of gas will change abruptly if the vent line and reactor line are inadequately equilibrated the pressure at both exits of the four-way valve must be equalized. This may be accomplished by a back pressure regulator. Whereas a pressure regulator reduces the supply pressure at the inlet to a lower pressure at the outlet, a back pressure regulator throttles the flow downstream to maintain the inlet pressure. A needle valve or a back pressure regulator is required at the vent line to match the pressure across the reactor, process lines, and analytical equipment. 

Hydrocracking (heater tubes, reactor internals) Hydrodesulfidation (heater tubes, reactor linings, and internals)... 

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