C_4.pdf

Answers 1. What is the optimum O2 concentration from the ASU for oxy-fuel technology? A. 90-95% B. 75-80% C. 80-85% D. 97-98% Answer: 97-98% (D) The optimum O2 concentration from the ASU for oxy-fuel technology is around 97-98%. 2. What is the primary component of the flue gas recirculation rate for...

Answers 1. What is the optimum O2 concentration from the ASU for oxy-fuel technology? A. 90-95% B. 75-80% C. 80-85% D. 97-98% Answer: 97-98% (D) The optimum O2 concentration from the ASU for oxy-fuel technology is around 97-98%. 2. What is the primary component of the flue gas recirculation rate for oxy-fuel technology? A. N2 and O2 B. NOx and SOx C. CO and H2 D. CO2 and H2O Answer: CO2 and H2O (D) The primary component of the flue gas recirculation rate for oxy-fuel technology is CO2 and H2O. 3. What is the reason for considering oxy-fuel technology in power generation? A. Reduces CO2 emissions only B. Eliminates N2 from combustor outlet simplifying the carbon capture step C. Adds complexity to the carbon capture process D. Increases NOx emissions Answer: Eliminates N2 from combustor outlet simplifying the carbon capture step (B) Oxy-fuel technology is considered in power generation because it eliminates N2 from the combustor outlet, simplifying the carbon capture step. 4. What is the expected O2 to the boiler with a 70% flue gas recirculation rate? A. 40-45% B. 15-20% C. 50-55% D. 25-30% Answer: 25-30% (D) With a 70% flue gas recirculation rate, the expected O2 to the boiler is 25-30%. 5. What is the ASU in the context of oxy-fuel technology? A. Air separation unit B. Ammonia synthesis unit C. Aqueous separation unit D. Atmospheric supply unit Answer: Air separation unit (A) ASU stands for air separation unit in the context of oxy-fuel technology. 6. What is the typical adiabatic flame temperature calculation based on for oxy-fuel technology? A. Natural gas combustion B. Oil combustion C. Biomass combustion D. Coal combustion Answer: Coal combustion (D) The typical adiabatic flame temperature calculation for oxy-fuel technology is based on coal combustion. 7. What is the expected O2 concentration from the ASU for oxy-fuel technology? A. 97-98% B. 80-85% C. 75-80% D. 90-95% Answer: 97-98% (A) The expected O2 concentration from the ASU for oxy-fuel technology is around 97-98%. 8. What is the total enthalpy change of the stoichiometric combustion process C(s) + O2(g) → CO2(g) under adiabatic, isobaric conditions? A. $\Delta H_T = nCO2 ( H_{CO2}(T_f) - H_{CO2}(T_o) )$ B. $\Delta H_T = nI ( H_I(T_f) - H_I(T_o) ) + nCO2 ( H_{CO2}(T_f) - H_{CO2}(T_o) )$ C. $\Delta H_T = 0$ D. $\Delta H_T = nI ( H_I(T_f) - H_I(T_o) )$ Answer: $\Delta H_T = nI ( H_I(T_f) - H_I(T_o) ) + nCO2 ( H_{CO2}(T_f) - H_{CO2}(T_o) )$ (B) The total enthalpy change is given by $\Delta H_T = nI ( H_I(T_f) - H_I(T_o) ) + nCO2 ( H_{CO2}(T_f) - H_{CO2}(T_o) )$ 9. What is the value of $T.....f$ for the pure O2 feed to the combustion process with $T.....o = 298K$? A. $T_f = 2,184 K$ B. $T_f = 3,000 K$ C. $T_f = 4,000 K$ D. $T_f = 5,598 K$ Answer: $T_f = 5,598 K$ (D) For pure O2 feed, $T_f = 5,598 K$ 10. What is the heat capacity of CO2 for the air feed to the combustion process? A. $C_pCO2 = 80.0 J/mol.K$ B. $C_pCO2 = 33.4 J/mol.K$ C. $C_pCO2 = 70.29 J/mol.K$ D. $C_pCO2 = 54.6 J/mol.K$ Answer: $C_pCO2 = 54.6 J/mol.K$ (D) For air feed, the heat capacity of CO2 is $C_pCO2 = 54.6 J/mol.K$ 11. What is the ratio of $nI/nCO2$ for the air feed to the combustion process? A. $nI/nCO2 = 3.76$ B. $nI/nCO2 = 5.0$ C. $nI/nCO2 = 1.0$ D. $nI/nCO2 = 2.0$ Answer: $nI/nCO2 = 3.76$ (A) For air feed, the ratio is $nI/nCO2 = 3.76$ 12. What is the mole fraction of N2 in the air separation using distillation at operating pressures of between 1-20 bar? A. Mole fraction of N2 is ~78% B. Mole fraction of N2 is ~1% C. Mole fraction of N2 is ~21% D. Mole fraction of N2 is ~50% Answer: Mole fraction of N2 is ~78% (A) The mole fraction of N2 in air is approximately 78% 13. What is the primary design variable for the mass transfer area of the membrane module in air separation using membranes? A. Mole fraction B. Pressure C. Permeance D. Temperature Answer: Permeance (C) The primary design variable for the mass transfer area is the permeance 14. What is the preferred option for large-scale Oxygen requirements at this time? A. Membrane separation B. Air compression C. Cryogenic distillation D. Adsorption Answer: Cryogenic distillation (C) The preferred option for large-scale Oxygen requirements at this time is cryogenic distillation 15. What does the Robeson plot illustrate? A. The relationship between O2/N2 selectivity and O2 concentration in retentate B. The relationship between membrane area and degree of recovery C. The relationship between O2/N2 selectivity and O2 permeability for polymeric membranes D. The relationship between pressure and total molar flowrates Answer: The relationship between O2/N2 selectivity and O2 permeability for polymeric membranes (C) The Robeson plot is a fundamental tool in the field of membrane science and engineering, illustrating the trade-off between O2/N2 selectivity and O2 permeability for polymeric membranes. 16. What is the formula for calculating the mass transfer area of a membrane? A. $ ext{selectivity} imes ext{degree of recovery}$ B. $rac{ ext{selectivity}}{ ext{degree of recovery}}$ C. $ ext{selectivity} + ext{degree of recovery}$ D. $rac{1}{ ext{selectivity} imes ext{degree of recovery}}$ Answer: $ ext{selectivity} imes ext{degree of recovery}$ (A) The mass transfer area of the membrane can be calculated using the product of selectivity and degree of recovery. 17. What are the three stages of operation for oxygen ion transport membranes (OTMs)? A. O2 desorption, oxygen bulk diffusion, and pressure-driven permeation B. O2 adsorption, oxygen bulk diffusion, and surface reaction C. O2 adsorption, oxygen bulk diffusion, and pressure-driven permeation D. O2 desorption, oxygen bulk diffusion, and surface reaction Answer: O2 adsorption, oxygen bulk diffusion, and surface reaction (B) OTMs operate in three stages: O2 adsorption, oxygen bulk diffusion, and surface reaction, which are crucial for their performance in oxygen separation applications. 18. What are the disadvantages of oxygen transport membranes (OTMs)? A. Low operating temperatures and pressure-dependent performance B. High operating temperatures and the need to ensure only surface reaction controls C. Low operating temperatures and high energy efficiency D. High operating temperatures and high selectivity Answer: High operating temperatures and the need to ensure only surface reaction controls (B) Disadvantages of OTMs include high operating temperatures and the need to ensure only surface reaction controls, which present challenges in practical applications. 19. What does the design of an oxygen transport membrane module involve calculating? A. The pressure ratio of retentate to feed B. The total molar flowrate of retentate C. The selectivity of the membrane D. The membrane area required for oxygen separation Answer: The membrane area required for oxygen separation (D) The design of an oxygen transport membrane module involves calculating the membrane area required for oxygen separation, which is essential for efficient operation. 20. What is the application of oxygen transport membranes demonstrated in the text? A. Operation in a chemical processing plant and in a desalination facility B. Operation in a natural gas production facility and in a water treatment plant C. Operation in an automobile and in a coal-fired plant D. Operation in a pharmaceutical manufacturing facility and in a food processing plant Answer: Operation in an automobile and in a coal-fired plant (C) A case study for oxy-fuel operation in an automobile and in a coal-fired plant demonstrates the application of oxygen transport membranes in real-world scenarios. 21. What is the limitation of current membrane systems mentioned in the text? A. Limited to less than 200 tonnes of O2 per day B. Limited to less than 800 tonnes of O2 per day C. Limited to less than 400 tonnes of O2 per day D. Limited to less than 600 tonnes of O2 per day Answer: Limited to less than 400 tonnes of O2 per day (C) Current membrane systems are limited to less than 400 tonnes of O2 per day, highlighting a current constraint in oxygen production using membrane technology. 22. What is the equation for the minimum power requirements for oxy-fuel combustion CO2 capture? A. $Minimum Power = \left( \frac{\ln\left(\frac{\frac{y_2}{X}}{\frac{y_{O2}}{2}}\right)}{\ln\left(\frac{p_1}{p}\right)} - \frac{\ln y_{O2} + \frac{y_2}{X}}{y_{O2}}\right) \times \left(\frac{RT}{F_{CO2}}\right)$ B. $Minimum Power = \left( \frac{\ln\left(\frac{\frac{y_{O2}}{2}}{\frac{y_{2}}{X}}\right)}{\ln\left(\frac{p}{p_1}\right)} - \frac{\ln y_{O2} + \frac{y_{2}}{X}}{y_{O2}}\right) \times \left(\frac{RT}{F_{CO2}}\right)$ C. $Minimum Power = \left( \frac{\ln\left(\frac{\frac{y_{2}}{X}}{\frac{y_{O2}}{2}}\right)}{\ln\left(\frac{p}{p_1}\right)} - \frac{\ln y_{O2} + \frac{y_{2}}{X}}{y_{O2}}\right) \times \left(\frac{RT}{F_{CO2}}\right)$ D. $Minimum Power = \left( \frac{\ln\left(\frac{\frac{y_{O2}}{X}}{\frac{y_{2}}{2}}\right)}{\ln\left(\frac{p}{p_1}\right)} - \frac{\ln y_{O2} + \frac{y_{2}}{X}}{y_{O2}}\right) \times \left(\frac{RT}{F_{CO2}}\right)$ Answer: $Minimum Power = \left( \frac{\ln\left(\frac{\frac{y_2}{X}}{\frac{y_{O2}}{2}}\right)}{\ln\left(\frac{p_1}{p}\right)} - \frac{\ln y_{O2} + \frac{y_2}{X}}{y_{O2}}\right) \times \left(\frac{RT}{F_{CO2}}\right)$ (A) The equation for the minimum power requirements for oxy-fuel combustion CO2 capture is given by the formula: $Minimum Power = \left( \frac{\ln\left(\frac{\frac{y_2}{X}}{\frac{y_{O2}}{2}}\right)}{\ln\left(\frac{p_1}{p}\right)} - \frac{\ln y_{O2} + \frac{y_2}{X}}{y_{O2}}\right) \times \left(\frac{RT}{F_{CO2}}\right)$ 23. What is the value of total CO2 emissions used in the calculation of minimum power requirements? A. 2,370 kmol/s B. 2,470 kmol/s C. 2,570 kmol/s D. 2,670 kmol/s Answer: 2,470 kmol/s (B) The total CO2 emissions used in the calculation of minimum power requirements is 2,470 kmol/s. 24. What is the temperature at which the pure CO2 product is compressed to 100 bar? A. 288K B. 318K C. 308K D. 298K Answer: 298K (D) The pure CO2 product is compressed to 100 bar at a temperature of 298K. 25. What is the value of yO2 in the equation for minimum power requirements? A. 0.309 B. 0.209 C. 0.109 D. 0.409 Answer: 0.209 (B) The value of yO2 in the equation for minimum power requirements is 0.209. 26. What is the total EU power demand? A. 2320 GW B. 2520 GW C. 2220 GW D. 2420 GW Answer: 2320 GW (A) The total EU power demand is 2320 GW. 27. What is the approximate EU electric power demand? A. 350 GW B. 450 GW C. 650 GW D. 550 GW Answer: 450 GW (B) The approximate EU electric power demand is around 450 GW. 28. What is the reason for considering this technology, as mentioned in the text? A. Eliminates N2 from combustor outlet simplifying the carbon capture step. B. Significant reduction in CO2 emissions. C. Complex technology with advanced development. D. Highly competitive CO2 capture cost compared to other technologies. Answer: Eliminates N2 from combustor outlet simplifying the carbon capture step. (A) The reason for considering this technology is that it eliminates N2 from the combustor outlet, simplifying the carbon capture step. 29. What is the value of the minimum power requirement for oxy-fuel combustion CO2 capture? A. 68.3 GW B. 78.3 GW C. 58.3 GW D. 48.3 GW Answer: 58.3 GW (C) The value of the minimum power requirement for oxy-fuel combustion CO2 capture is 58.3 GW. 30. What is the effect of the technology on NOx emissions? A. No impact on NOx emissions. B. Increase in NOx emissions. C. Reduction in CO2 emissions. D. Significant reduction in NOx. Answer: Significant reduction in NOx. (D) The technology has a significant reduction in NOx emissions.