Compression Chemical Reactor

Keywords compression chemical reactor, methane pyrolysis, acetylene, natural gas conversion, hydraulic ram. 

Glushenkov, M., Kronberg, A., Vd Meer, Th. Liquid compression chemical reactors. NGCSIO, Doha - Qatar, March 2 - 7,2013, Book of Abstract 971. 

When we consider that we lose work potential in chemical reactors, in heat exchangers, and in mixing operations and combine this with the need for work in separation processes, pumping, and compression, it becomes dear that chemical processes are usually very inefficient from an energy standpoint. Of course, energy conservation is usually of secondary importance in chemical processing safety, quality, and productivity are more important, Nevertheless, it is economically sound... 

S. Atmospheric air is to be compressed and heated as shown in the figure before being ted into a chemical reactor. The ambient air is at 20 C and I bar, and is first compressed to 5 bar and then heated at constant pressure to 400 C.. Assuming air can be treated as a single-component ideal gas with Cy = 21 J/(mol K), and that the compressor operates adiabatically and reversibly. 

In the second step we introduce cost elements sensitive to recycles. For gas recycle we should account for the cost of compression plus compressor depreciation, both on annual basis. For liquid recycle we should consider the operating costs of the distillation column plus the recovery of investment. Preliminary heat integration around the chemical reactor has a feed-effluent heat exchanger (FEHE), as well as a furnace, necessary for start-up and control (Figure 17.3). A rigorous analysis will be present in the next section. 

Polymerization in Hquid monomer was pioneered by RexaH Dmg and Chemical and Phillips Petroleum (United States). In the RexaH process, Hquid propylene is polymerized in a stirred reactor to form a polymer slurry. This suspension is transferred to a cyclone to separate the polymer from gaseous monomer under atmospheric pressure. The gaseous monomer is then compressed, condensed, and recycled to the polymerizer (123). In the Phillips process, polymerization occurs in loop reactors, increasing the ratio of available heat-transfer surface to reactor volume (124). In both of these processes, high catalyst residues necessitate post-reactor treatment of the polymer. 

The BP Chemicals polymer cracking process is based at Grangemouth in Scotland and uses mixed plastics as the raw material. The reactor uses a fluidised bed which operates at 500 °C in the absence of air, and under these conditions the plastics crack thermally to yield hydrocarbons. These vaporize and are carried away from the bed with the fluidising gas. Solid impurities such as metals from PVC stabilisers accumulate in the bed or are carried away in the hot gas to be captured by a cyclone further along in the plant. PVC decomposes to HCl and this is neutralized on a solid lime absorbent to yield CaCl2 which is disposed of in landfill. The purified gas is cooled to condense most of the hydrocarbon which can be employed as commercially useful distillate feedstock. The light hydrocarbons which are less easy to condense are compressed, reheated and recycled as fluidising gas. 

The compressed ethylene and a peroxide initiator (catalyst) enter the autoclave reactor. An autoclave is any vessel that can be closed up and maintain pressure at elevated temperatures. In chemical applications, the ongoing reaction inside the autoclave generates heat and/or pressure. (When a doctor or dentist sterilizes his instruments in his office,. he uses an autoclave that generates superheated steam.)... 

Of the indirect liquefaction procedures, methanol synthesis is the most straightforward and well developed [Eq. (6)]. Most methanol plants use natural gas (methane) as the feedstock and obtain the synthesis gas by the steam reforming of methane in a reaction that is the reverse of the methanation reaction in Eq. (5). However, the synthesis gas can also be obtained by coal gasification, and this has been and is practiced. In one modern low-pressure procedure developed by Imperial Chemical Industries (ICI), the synthesis gas is compressed to a pressure of from 5 to 10 MPa and, after heating, fed to the top of a fixed bed reactor containing a copper/zinc catalyst. The reactor temperature is maintained at 250 to 270°C by injecting... 

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