Reactors atmospheric pressure, automated

Vapour-phase catalytic oxidation of isobutene was carried out at atmospheric pressure in a completely automated laboratory setup, including a fixed bed reactor (700 mm length, 10 mm inner diameter) with corundum as wall material. In order to ensure isothermicity, the heated section (200 mm in length) was divided into five independently heated zones and the catalyst bed was diluted with inert pellets (a-Al203). Inert pellets were placed above and below the catalyst bed to ensure a well-mixed feed stream, and to preheat the gas to the reaction temperature. Bi203 catalyst (Merck) was pressed into thin wafers and broken into small particles. Granules with a diameter of 0.8 -1.2 mm were used. 

As discussed above, it can be more efficient to have a single computer interfaced with several of these systems. Figure 11 shows a picture of the screen of a computer interfaced with three of these automated atmospheric pressure reactor systems. Each data point represents the time of introduction of the pulse of reactant gas. For room temperature reactions the standard low-pressure reactors shown in Figure 6 can be used with these systems. When temperature control is needed, jacketed versions of these reactors are used with the temperature maintained by a constant temperature recirculating bath. 

The Si is deposited by automated CVD with HF heating in a horizontal cold wall reactor chamber under atmospheric pressure for easy implementation in industry. For lower gas consumption and to stimulate the chemical reactions the coating process can be at low pressure, where the chemical reactivity is usually higher. Up-scaling from a laboratory scale or bench scale unit to industrial application is based on a totally computer-controUed laboratory process. Total automation eases transferability and integration with other industrial processes. 

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