Designing the CSTR (R-401 and D-401) for Manganese Dioxide Precipitation (Research Paper Sample)

Designing the CSTR (R-401 and D-401) for Manganese Dioxide Precipitation Student’s Name Course Name: Engineering Date: 19/08/2024 Table of Contents TOC \o "1-3" \h \z \u Table of Figures PAGEREF _Toc174984958 \h 4Designing the CSTR (R-401) for Manganese Dioxide Precipitation PAGEREF _Toc174984959 \h 5Introduction PAGEREF _Toc174984960 \h 51. Determining the Volumetric Flow Rate (Q) PAGEREF _Toc174984961 \h 52. Determining Reaction Kinetics and Residence Time (τ) PAGEREF _Toc174984962 \h 63. Determining Reactor Volume (V) PAGEREF _Toc174984963 \h 74. Determining CSTR Dimensions PAGEREF _Toc174984964 \h 8Height (H) and Diameter (D) PAGEREF _Toc174984965 \h 8Wall Thickness (t) PAGEREF _Toc174984966 \h 85. Selecting Material of Construction PAGEREF _Toc174984967 \h 9Designing the Fluidized Bed Dryer (D-401) PAGEREF _Toc174984968 \h 91. Determining Inlet Stream and Mass Flow PAGEREF _Toc174984969 \h 92. Drying Requirements and Heat Calculation PAGEREF _Toc174984970 \h 103. Determining Design Specifications for Dryer PAGEREF _Toc174984971 \h 114. Material of Construction PAGEREF _Toc174984972 \h 125. Safety Considerations PAGEREF _Toc174984973 \h 12References PAGEREF _Toc174984974 \h 14Appendices PAGEREF _Toc174984975 \h 15Appendix A: Residence time and Velocities for ICRs (Industrial Chemical Reactors) PAGEREF _Toc174984976 \h 15Appendix B: Design Dimensions for the CSTR PAGEREF _Toc174984977 \h 16 Table of Figures TOC \h \z \c "Figure" Figure 1: CSTR setup PAGEREF _Toc174984886 \h 3 Figure 2: Excel results for the kinetics PAGEREF _Toc174984887 \h 5 Figure 3: Reactor Volume PAGEREF _Toc174984888 \h 6 Figure 4: Types of impellers PAGEREF _Toc174984889 \h 11 Designing the CSTR (R-401 and D-401) for Manganese Dioxide Precipitation Introduction The Continuous Stirred Tank Reactor (CSTR), designated as R-401, is designed to facilitate the reaction between manganese chloride (MnCl2) and potassium permanganate (KMnO4) to produce manganese dioxide (MnO2). This reactor is critical in ensuring 100% conversion of the reactants. Figure SEQ Figure \* ARABIC 1: CSTR setup 1. Determining the Volumetric Flow Rate (Q) Extracting data from the stream table, the inlet stream (Stream 418) is showing an overall mass flow rate of 6715.296 Tpa (tonnes per annum). Assuming the solution density is approximately 1000 kg/m³, the volumetric flow rate Q is calculated as follows: Converting year to seconds: Now, calculating the mass flow rate in kg/s: This is for water since the density used is 1000 kg/m3. 2. Determining Reaction Kinetics and Residence Time (τ) Assuming first-order reaction kinetics, the rate law for the reaction is: Where: * CA is the concentration of manganese chloride, * k is the rate constant. For a first-order reaction, the rate of conversion X over time t is given by: In the determination of the residence time, Ꚍ, a rate of reaction constant k = 0.01 is used. This value is used in the MS Excel calculation. MS Excel was used to get the data for kinetics starting with X = 100. The above formula was used and the results obtained are shown below. Figure SEQ Figure \* ARABIC 2: Excel results for the kinetics The orange column (Ꚍ) is the residence time. The k = 0.01 constant used in this case was obtained from Youn-Woo Lee’s study CITATION Lee \l 1033 (Lee, n.d.) The density used is that of water. 3. Determining Reactor Volume (V) The reactor volume V is determined using the residence time τ and the volumetric flow rate Q: Figure SEQ Figure \* ARABIC 3: Reactor Volume 4. Determining CSTR Dimensions Height (H) and Diameter (D) The guide for the CSTR dimensions was used in designing height (H) and diameter. (D) Similarly, these guidelines were deployed to design the dimensions for the wall thickness (t). These dimensions are m, M, and mm, respectively. The following formula shows how the trio are obtained when designing the tank. Thus, determining the reactor diameter as 0.407 m and the height as 0.611 m. Wall Thickness (t) To calculate the wall thickness, using the formula: For safety and manufacturing practicality, using a minimum thickness of 5 mm. 5. Selecting Material of Construction Stainless Steel 316 is chosen for the construction due to its corrosion resistance, particularly in environments involving hydrochloric acid and potassium permanganate. This material ensures durability and safety over the reactor's operating life. Designing the Fluidized Bed Dryer (D-401) The Fluidized Bed Dryer, designated as D-401, is designed to dry the manganese dioxide produced in the CSTR (R-401). This step is crucial in ensuring the product meets the required moisture content specifications before further processing or packaging. 1. Determining Inlet Stream and Mass Flow The inlet stream, as per Stream 425, is carrying wet manganese dioxide with an overall mass flow of 442.68 Tpa. The moisture content in the wet manganese dioxide is approximately 5%. Calculating the Mass of Water in the Inlet Stream This water needs to be removed to achieve the desired dryness level in the final product. 2. Drying Requirements and Heat Calculation The Fluidized Bed Dryer is designed to reduce the moisture content by 98%, with the remaining 2% being expelled as steam. The heat required for drying is calculated using the specific heat capacity of water and the latent heat of vaporization. Heat Required to Raise the Temperature The specific heat capacity of water cp is 4.18 kJ/kg·K, and the drying process involves raising the temperature from 25°C to 110°C. Heat Required for Vaporization The latent heat of vaporization λ of water is 2260 kJ/kg. Total Heat Requirement The total heat required for drying the manganese dioxide is the sum of the heating and vaporization energies: 3. Determining Design Specifications for Dryer Airflow Rate The drying process r...