Comparison of the structures of shell-and-tube methanol synthesis reactors

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Comparison of the Structures of Shell-and-Tube Methanol Synthesis Reactors, Shanghai Coking Plant, East China University of Science and Technology. Height of the methanol synthesis tower shell: 13,500 mm; Height of the methanol synthesis tower shell: 12,214 mm. Height of the cylindrical section: 8,400 mm; Height of the cylindrical section: 6,978 mm. Height of the upper and lower end caps: 2,000 mm; Height of the upper and lower end caps: 2,000 mm. Reinforcing plates are installed on the upper and lower parts of the shell; thickness of the shell cylinder: 100 mm. Reinforcing plates are installed on the upper and lower parts of the shell; thickness of the shell cylinder: 70 mm. Inner diameter of the cylinder: φ3,825 mm, with a thickness of about 80 mm; Inner diameter of the cylinder: φ4,094 mm, with a thickness of about 55 mm. Insulation layer thickness: 700 mm; Insulation layer thickness: 700 mm. Length of the tubes: 7,000 mm; Length of the tubes: 6,000 mm. Diameter of the tubes: φ44×2; Diameter of the tubes: φ38×2. Tube center distance: 51; Tube center distance: 44.5. Number of tubes: 4,610; Number of tubes: 6,713. Heat exchange area: 4,258 m²; Heat exchange area: 4,555 m² (5,061 m²). Flow area: 5.79 m²; Flow area: 6.09 m² (6.77 m²). Temperature of the gas entering the tower: 206.7°C; Temperature of the gas entering the tower: 225°C. Catalyst used: C302 or CN306. Volume of catalyst used: 44.57 m³; Catalyst used: C302, volume: 36.5 m³. The tubes are welded to the tube sheets, which in turn are welded to the cylinder. Both the tube sheets and the cylinder are made of the same material – 20MnMoNi55. Thickness of the tube sheets: 70 mm. The material for the upper and lower ball heads is 16Mo3. In the presence of a catalyst, CO reacts with iron to form iron carbide; carbon steel cannot be used for the pipes, as this would lead to the formation of iron carbide and paraffin. Stainless steel is also not suitable, as its coefficient of thermal expansion differs from that of the outer shell. It is recommended to use a special duplex alloy steel such as SAF2205 (austenite-ferrite), which has the same coefficient of thermal expansion as the outer shell. The pipes are welded to the tube sheet using duplex steel, with a welding overlay thickness of 7 mm. On the inner side of the upper head, starting from the upper tube sheet and extending 80 mm high, duplex steel is cladded with a thickness of 7 mm. The tubes are welded to the tube sheet, which in turn is welded to the cylinder. Both the tube sheet and the cylinder are made of the same type of material: 20MnMoNi55. The thickness of the tube sheet is 100 mm. The material for the upper and lower ball heads is 15Mo3. In the presence of a catalyst, CO reacts with iron to form iron carbide; carbon steel cannot be used for the pipes, as this would lead to the formation of iron carbide and paraffin. Stainless steel is also not suitable, as its coefficient of thermal expansion differs from that of the outer shell. It is recommended to use a special duplex alloy steel such as SAF2205 (austenite-ferrite), which has the same coefficient of thermal expansion as the outer shell. The pipes are welded to the tube sheet using duplex steel, with a welding overlay thickness of 7 mm. On the inner side of the upper head, starting from the upper tube sheet and extending 80 mm high, duplex steel is cladded with a thickness of 7 mm. At the upper part of the top head of the methanol reactor, there are two sets of thermocouple insertion ports with a diameter of approximately φ42×3 (engineering diameter DN40). Each set of thermocouples measures temperatures at 3 points: one point in the insulation layer and two points in the shell-and-tube layer. The location of the thermocouple insertion port is at φ1550 mm. Thermocouple measurement point: 1 point at the insulation layer, (measured upward from the upper tube sheet) 20 mm ； Shell and tube layer: 2 points (counting downward from the tube sheet), 2400 mm, 4800 mm. Logistics number: Triple supply, East China University of Science and Technology. Logistics name: Fresh gas. Composition of materials: kg/mol/h, mol%; Nm3/h, mol%: CO – 660.69, 27.85; 1889, 3.19; 28.21; CO2 – 79.36, 3.35; 2143.34, 3.20; H2 – 1615.55, 68.10; 45378.28, 67.76; CH4 – 0.32, 0.01; 151.22, 0.23; N2 – 13.24, 0.56; 400.96, 0.60; Ar; H2S – <0.1 P·P·m3, 3.88; CH3OH – 0.01; H2O – 3.08, 0.13. Total: 2372.24, 1006, 6971.01, 100. Average molecular weight M: 10.82. Temperature: °C, 35–20. Pressure: MPa(G), 2.95–5.4. Annual production capacity: 180,000 tons (for the plant’s scale); 200,000 tons (for the plant’s scale). Consumption rates: 2306 Nm3/t of CH3OH; 2397 Nm3/t of CH3OH. Daily production of pure alcohol: 553 t/day; 667 t/day. Exhaust gas volume: 120.74 Nm3/t of CH3OH; 174.86 Nm3/t of CH3OH. Flash vapor volume: 3.23 Nm3/t of CH3OH; 22.85 Nm3/t of CH3OH