Reactor Hastelloy

The activity tests of the catalyst were carried out in a microflow reactor set-up in which all the high temperature parts are constructed of hastelloy-C and monel. The reactor effluent was analyzed by an on-line gas chromatograph with an Ultimetal Q column (75 m x 0.53 mm), a flame ionization detector, and a thermal conductivity detector. The composition of the feed to the reactor can be varied, besides the temperature, pressure, and space velocity. The influence of the recycle components CHCIF2 and methane was tested by adding these components to the feed. In total five stability experiments of over 1600 hours were performed. In each... 

The hydrogenation reactor consisted of a 1-L Hastelloy C autoclave (Model 464IM, Parr instmment company, Moline Illinois) equipped with a belt-driven, magnetic stirrer (1000 rpm). 

HT and large scale experiments were performed as described in [7], In HT runs, 116 2-ml GC vials (thin film, no stirring) were heated at 100° C for 3 h under 1500 psi of 02/C0 (10% 02 in CO) The presented results are the average of at least two runs (three of four when RSD data presented). Large-scale (60 g) experiments were carried out in 450 mL Hastelloy C Parr reactor under the same conditions in the presence of 3 A molecular sieves (35 g) s a desiccant. 

Readily available Hastelloy C-276 is a suitable SCWO reactor liner material for VX. 

Reactor materials. One drawback that could be mentioned is the high corrosivity of iodide. Hydrogen iodide is very corrosive, but the presence of iodide salts makes it even worse. Carbon monoxide will also react with many metals under the reaction conditions (30 bar of CO, 180 °C). Hastelloy-C is an inert material which is used in the laboratory. For the actual plants titanium cladded reactors have been mentioned as a possible solution. 

The heart of the system is the oxidation vessel depicted in Figure 1. This vessel is a high pressure, 1000 cc, Hastelloy C-276, bolted closure reactor manufactured by Autoclave Engineers Inc. Hastelloy C-276 was chosen as the material of construction due to its excellent corrosion resistance to a wide variety of chemical process environments, which include processes utilizing strong oxidizers (5,6,7). The unit is fitted with 1/8" and 1/4" Hastelloy C-276 feed delivery and product outlet lines... 

Reactor material Carbon steel Hastelloy B or Gunite cement Nickel... 

Another factor to be considered is the time required to fabricate additional liners if the initial supply is depleted. Recently, General Atomics claimed it was able to fabricate 20-mil thick liners of the required diameter for the reactor. General Atomics plans to float a precious-metal liner in a cylindrical Hastelloy pressure vessel and use cooled elastomeric O-rings that have performed satisfactorily on other SCWO systems to form the SCWO reactor. The annular space between the liner and the vessel wall will be monitored for leaks to indicate when change-out of the liner is required. No decision has been made yet on whether to use platinum or Pt-20%Ir. Because they have markedly different mechanical properties, these two liner materials may require significantly different fabrication methods. Platinum is relatively weak and very ductile Pt-20%Ir is less ductile but 10 times stronger. Final selection of the liner material for use at the NECDF was scheduled for early 2000. Fabrication... 

The use of small amounts of bromide ions (typically 5-30 ppm) and an acidic medium (addition of H2S04, H3P04, while HC1 should be avoided) improves the performances, particularly limiting the consecutive decomposition of H202. However, the addition of acids and halides causes the reaction medium to become strongly corrosive towards metallic materials, particularly stainless steel. Hastelloy or glass-lined reactors could thus be necessary. 

But the nature of the autoclave has a great influence on the formation of byproducts. A Russian team [274] has shown that for a vessel made of nickel, the addition of CF3I to HFP led mainly to (CF3)3CI whereas for similar reaction in Hastelloy reactor, no by-product was observed. 

NREL reported that the pretreatment reactor built using Hastelloy C would cost 2,505,084, which is 50% more expensive than to build with... 

Figure 1. Supercritical flow reactor. Key (I) Mettler balance (2) flask with 1 0 (filtered and deaerated) (3) HPLC pump (4) bypass (three-way) valve (5) feed cylinder (6) weather balloon with feed solution (7) probe thermocouple (type K) (8) ceramic annulus (9) Hastelloy C-276 tube (10) entrance cooling jacket (11) entrance heater (12) furnace coils (13) quartz gold-plated IR mirror (14) window (no coils) (15) guard heater (16) outlet cooling jacket (17) ten-port dualloop sampling value (18) product accumulator (19) air compressor (20) back-pressure regulator and (21) outflow measuring assembly.

Figure 13. Corrosion behavior of reduction reactor materials samples in anhydrous environment (O), Hastelloy C276 Cartech CB3 (V), Incoloy 825 (A), Inconel 625 (O), SS 310 and (0), SS 18-18-2. Furnace temperature, 482°C (900°F) anhydrous S03 12 cc/min argon 128 cc/min. Erratic erosion rate behavior of SS 310 and Cartech 20CB3 is caused by the spalling of the corrosion product. Negative values indicate weight gain per unit area.

An important concern in industrial processes is corrosion. Transition metal complexes under certain conditions can facilitate corrosion of the reaction vessels. The consequences are not only fouling of the surfaces but also loss of expensive catalyst. So the reactors are generally made of materials that are resistant to corrosion. Two such materials are stainless steel 316 (containing 16-18% Cr, 10-14% Ni, 1-3% Mo, <0.1% C, and the rest iron) and Hastelloy C (containing 14-19% Mo, 4-8% Fe, 12-16% Cr, 3-6% W, and the rest Ni). The latter is ideal for chlorides and acids but is 3-4 times more expensive than the former. Wacker s process is operated under highly corrosive conditions (high concentrations of H+ and Cl ) (see Section 8.2) hence it requires expensive, titanium-lined reactors. 

Since corrosion is a severe problem of hydrothermolytical oxidation, corrosion control deserves close attention in the course of further development. The presented process offers the possibility to use common reactor materials e.g. high-grade steel 1.4541 or in selected applications even carbon steel St 1203. If calciumborate as corrosion inhibitor is used special alloys like hastelloy or inconel are not absolutly necessary for wet oxidation in presence of chloride-ions. 

In previous designs of SCWO reactors, special materials such as Hastelloy, Inconel or Gold1 were needed to withstand such drastic operation condition of temperature and pressure to reduce corrosion effects imposed by the oxidizing atmosphere... 

Synthesis, which takes place in a reactor with an internal lining of corrosioa-resstaiif bricks, and whose dimensions, for a unit production capacity of 70,000 t/year, are 2.6 to 2.7 m in diameter and 12 m high, for a ma.ximum size of about 150,000 t/year. Hydrochloric acid stripping in the vapor phase requires the use of hastelloy B for the parts of the equipment in contact with this acid. 

For experimental procedures and examples, see Houben-Weyl, Vol. 5/3, pp 88-93. Handling of sulfur tetrafluoride is not easy because of its toxicity and aggessive nature. As materials for reactors, stainless steel. Monel or Hastelloy C should be used. A reactor for routine handling of sulfur tetrafluoridc and hydrogen fluoride has been described. ... 

Using the propyl chlorides as an example (eq. 11, Table II), after five minutes at 140° in a 45 cc Hastelloy C reactor charged with aluminum chloride and 2-chloropropane the pressure was 500 psig of which 71% was propane by mass spectrometric analysis. 

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