This document discusses a process for producing hydrogen and oxygen fuel from lunar water resources. It begins by introducing the motivation for in-situ lunar fuel production to reduce launch mass. It then describes the specific process, which involves electrolysis of water to produce hydrogen and oxygen gases, followed by compression and cooling steps to liquefy the gases. The process uses a thermal regeneration cycle with helium to provide the extreme cooling needed. It analyzes the thermodynamics and estimates the overall energy requirements. Producing 1 kg of water would require 1603 kJ of energy. The document also discusses some considerations for scaling up the process to support a lunar colony.
This Presentation mainly focuses on Thermal Energy Generation in Sri Lanka and Energy conservation techniques which are using for effective and efficient thermal energy generation.
This document discusses supercritical technology used in power plants. It begins with an overview of the basic Rankine cycle used in conventional power plants. It then discusses how operating above the critical point of water in a supercritical Rankine cycle can significantly improve efficiency. Key points include operating at pressures above 221.2 bar and temperatures above 374.15°C to remain in the supercritical phase. Modern materials allow higher turbine inlet temperatures up to 700°C. Boiler and turbine design must account for the high pressures and temperatures in supercritical systems.
Power plants are industrial facilities that generate electricity from primary energy sources, such as coal, natural gas, nuclear, solar, or wind energy. Most power plants use one or more generators that convert mechanical energy into electrical energy.
What is the most common type of power plant? A steam turbine power generating plant is the most common type of power plant today. This type of plant converts heat into electricity usually using a boiler, and a turbine to drive an electric generator
Currently, in Pakistan, there are six major producers of fertilizers which include Fauji Fertilizer, Engro Fertilizer Company, Dawood Hercules, and Fatima Fertilizers. Media reports suggest that the Chinese government is keenly looking for avenues to enter Pakistan's agriculture and fertilizer sector.
The two types of fertilizers - inorganic and organic. In the broadest sense, all types of fertilizers include any substance, living, or inorganic which aids in plant growth and health. We exclude water, CO2, and sunlight.
This document discusses vapor power cycles and combined power cycles. It covers the Carnot vapor cycle and how the Rankine cycle is better suited as a model for vapor power plants. Methods to increase the efficiency of the Rankine cycle are analyzed, including lowering the condenser pressure, superheating steam, increasing boiler pressure, using reheat cycles, and regenerative cycles. Combined cycles and cogeneration are also introduced.
This document provides an overview of cryogenic processes and cryogenic manufacturing. It discusses what cryogenics and cryogenic processes are, and explains that cryogenics involves producing and maintaining very low temperatures. It then describes several common cryogenic manufacturing processes like air separation, production of liquid oxygen and nitrogen, liquid carbon dioxide production, and argon gas production. Diagrams of typical cryogenic processes and plants are included. The document lists several references for further information on topics like cryogenic treatment of materials, history of cryogenics, and properties of gases produced through cryogenic processes.
In any thermal power generation plant, heat energy converts into mechanical work. Then it is converted to electrical energy by rotating a generator which produces electrical energy.
This Presentation mainly focuses on Thermal Energy Generation in Sri Lanka and Energy conservation techniques which are using for effective and efficient thermal energy generation.
This document discusses supercritical technology used in power plants. It begins with an overview of the basic Rankine cycle used in conventional power plants. It then discusses how operating above the critical point of water in a supercritical Rankine cycle can significantly improve efficiency. Key points include operating at pressures above 221.2 bar and temperatures above 374.15°C to remain in the supercritical phase. Modern materials allow higher turbine inlet temperatures up to 700°C. Boiler and turbine design must account for the high pressures and temperatures in supercritical systems.
Power plants are industrial facilities that generate electricity from primary energy sources, such as coal, natural gas, nuclear, solar, or wind energy. Most power plants use one or more generators that convert mechanical energy into electrical energy.
What is the most common type of power plant? A steam turbine power generating plant is the most common type of power plant today. This type of plant converts heat into electricity usually using a boiler, and a turbine to drive an electric generator
Currently, in Pakistan, there are six major producers of fertilizers which include Fauji Fertilizer, Engro Fertilizer Company, Dawood Hercules, and Fatima Fertilizers. Media reports suggest that the Chinese government is keenly looking for avenues to enter Pakistan's agriculture and fertilizer sector.
The two types of fertilizers - inorganic and organic. In the broadest sense, all types of fertilizers include any substance, living, or inorganic which aids in plant growth and health. We exclude water, CO2, and sunlight.
This document discusses vapor power cycles and combined power cycles. It covers the Carnot vapor cycle and how the Rankine cycle is better suited as a model for vapor power plants. Methods to increase the efficiency of the Rankine cycle are analyzed, including lowering the condenser pressure, superheating steam, increasing boiler pressure, using reheat cycles, and regenerative cycles. Combined cycles and cogeneration are also introduced.
This document provides an overview of cryogenic processes and cryogenic manufacturing. It discusses what cryogenics and cryogenic processes are, and explains that cryogenics involves producing and maintaining very low temperatures. It then describes several common cryogenic manufacturing processes like air separation, production of liquid oxygen and nitrogen, liquid carbon dioxide production, and argon gas production. Diagrams of typical cryogenic processes and plants are included. The document lists several references for further information on topics like cryogenic treatment of materials, history of cryogenics, and properties of gases produced through cryogenic processes.
In any thermal power generation plant, heat energy converts into mechanical work. Then it is converted to electrical energy by rotating a generator which produces electrical energy.
This document contains 6 exercises related to calculating the thermal efficiency of steam power plants operating on different Rankine cycle configurations including:
1) Ideal Rankine cycle
2) Ideal reheat Rankine cycle
3) Reheat Rankine cycle with specified turbine inlet/exit conditions
4) Regenerative Rankine cycle with one open feedwater heater
5) Reheat-regenerative cycle with one open feedwater heater, one closed feedwater heater, and one reheater.
The 6th exercise asks to determine the fractions of steam extracted from the turbine and the thermal efficiency for a plant operating on the reheat-regenerative cycle described in item 5 above.
1. Ammonia is industrially synthesized from nitrogen and hydrogen through the Haber process. It is produced on a large scale, exceeding 130 million tonnes annually.
2. The synthesis of ammonia is an equilibrium reaction that is exothermic and favored by high pressure and low temperature. Industrial production occurs at 400-500°C and 150-300 atmospheres using an iron catalyst.
3. Haber optimized the process by implementing a recycling system to increase space-time yield, improving economic production. His recycling design is still used as the basis for industrial ammonia synthesis.
The document discusses thermal power cycles and the Rankine cycle in particular. It provides details on:
- The basic energy flow in a thermal power plant from chemical to mechanical to electrical energy.
- The Rankine cycle most closely models the steam power cycle used in most power plants. It involves heating water to steam to drive a turbine and then condensing the steam to recycle the water.
- Ways to improve the efficiency of the Rankine cycle include increasing the average temperature of heat addition by superheating steam or increasing boiler pressure, and decreasing the average temperature of heat rejection by lowering the condenser pressure.
A detailed explanation about Rankine cycle or vapour power cycle for mechanical 2nd year students.Areas of uses of vapour power cycle or steam power cycle.
This document describes the design of a 1 MW power plant based on a superheated Rankine cycle. Key components include a steam generator with economizer, boiler and superheater sections, a high pressure turbine operating from 100-20 bar, a low pressure turbine from 20-0.1 bar, a condenser, an open feedwater heater containing a deaerator, a closed feedwater heater, and a reheater. Thermodynamic calculations are shown to select locations and operating conditions for these components. Performance is calculated with a net work output of 968.28 kW, heat input of 2557.14 kW, and heat rejected of 2358.52 kW.
This document describes an ideal regenerative Rankine cycle with feedwater heating. It has three key points:
1. It raises the temperature of feedwater before it enters the boiler using steam extracted from the turbine. This improves thermal efficiency.
2. The device that heats the feedwater is called a regenerator or feedwater heater. It can be an open or closed system and prevents deaeration of the feedwater.
3. Benefits include reduced steam flow, smaller equipment, easier turbine operation, and less erosion. Regeneration provides higher efficiency than reheating without the complexity and costs of reheating systems.
The document discusses thermal power cycles. It begins by explaining that a thermal power plant involves heating water to create steam that spins a turbine and generates electricity.
The basic energy flow in a thermal power plant is: chemical energy is converted to mechanical energy by the steam turbine, which is then converted to electrical energy. Various fuel sources can be used.
It then discusses the key power cycles used in thermal plants like the Carnot, Rankine, Diesel, Otto, and Brayton cycles. It also covers the laws of thermodynamics and important thermodynamic processes.
The Rankine cycle most closely models actual steam power plants. It involves pumping water, boiling it to create steam, expanding the steam
ME6301 ENGINEERING THERMODYNAMICS SHORT QUESTIONS AND ANSWERS - UNIT IIIBIBIN CHIDAMBARANATHAN
This document provides an overview of thermodynamics concepts related to properties of pure substances and steam power cycles. It includes definitions of key terms like enthalpy of steam, latent heat of evaporation, superheated steam, dryness fraction, and critical point. The document also summarizes the assumptions and components of the Rankine cycle, methods to improve its efficiency including reheating, and comparisons to other cycles like Carnot. Overall, the document serves as a study guide for engineering thermodynamics topics focusing on steam as the working fluid.
This document provides information about gas turbine and steam power plant cycles. It describes the Brayton cycle used in gas turbines and the Rankine cycle used in steam power plants. It discusses components, processes, thermal efficiencies and improvements to the cycles such as regeneration, intercooling and reheating. Examples are provided to calculate efficiency, work and heat inputs/outputs for simple and improved cycles.
This document presents information on the Rankine cycle. It contains the following key points:
1. The Rankine cycle converts heat into work through a closed loop that uses water as the working fluid. It generates about 90% of the world's electric power.
2. An ideal Rankine cycle involves isothermal and isobaric processes, while a real cycle involves non-reversible and isentropic compression and expansion.
3. Variations like the reheat cycle and regeneration cycle can improve the efficiency by reheating steam before the turbine or preheating feedwater, but increase costs.
This document discusses various thermodynamic power cycles including:
- The Carnot cycle, which is the most efficient but impractical cycle.
- Rankine cycles, which are more practical vapor power cycles that use steam as the working fluid.
- Simple Rankine cycles involve heating water to steam then expanding it in a turbine before condensing it back to water.
- Rankine cycles with superheated steam, which increase efficiency by heating steam above its saturation temperature.
- The efficiencies of different cycles are calculated and compared in examples. Superheated steam cycles have higher efficiencies than simple Rankine cycles due to higher average temperatures.
This document discusses the reheat cycle in thermodynamics. The reheat cycle is a modification of the Rankine cycle that is used in steam power plants. It works by reheating the steam after it expands in the high-pressure turbine and before it expands further in the low-pressure turbine. This increases the efficiency by raising the mean temperature of heat addition and reducing moisture content in the steam. Reheating allows for higher turbine work extraction and thermal efficiency compared to the basic Rankine cycle. The document examines the working of reheat cycles in steam turbines and thermal power plants, and their advantages in improving efficiency and reducing blade erosion.
The document summarizes the manufacturing of ammonia. It describes Haber's process which uses nitrogen from air and hydrogen from natural gas to produce ammonia through a catalytic reaction. Key conditions for the reaction include temperatures of 400-450°C, pressures of around 200 atmospheres, and an iron catalyst. The modern process involves desulphurization of hydrocarbons, steam reforming to produce hydrogen and carbon monoxide, shift conversion to increase hydrogen, and purification before the synthesis reaction and separation of ammonia. The main uses of ammonia include production of fertilizers, nitric acid, explosives, fibers, refrigeration and pharmaceuticals.
The document discusses various methods to improve the efficiency of the Rankine cycle, which is the most common thermodynamic cycle used in conventional steam power plants. These include lowering the condenser pressure, superheating steam to higher temperatures, increasing the boiler pressure, using reheat cycles, and employing feedwater heaters. Reheat cycles can improve efficiency by 4-5% by increasing the average heat addition temperature. Feedwater heaters also raise efficiency by preheating feedwater with extracted steam. Modern plants operate at supercritical pressures over 22.06 MPa and have efficiencies as high as 40%.
ME 6301 ENGINEERING THERMODYNAMICS SHORT QUESTIONS AND ANSWERS - UNIT IIBIBIN CHIDAMBARANATHAN
This document provides a summary of key concepts in engineering thermodynamics for a third semester mechanical engineering course. It covers topics like the second law of thermodynamics, Carnot cycle efficiency, heat pumps, refrigerators, coefficient of performance, availability analysis, and vapor compression refrigeration cycles. The document is compiled by an assistant professor and contains 33 questions and answers on these thermodynamics topics.
This document discusses methods to improve the efficiency of a Rankine cycle steam power plant. It describes lowering the condenser pressure, superheating steam to high temperatures using reheat, increasing the boiler pressure, implementing an ideal regenerative Rankine cycle with open feedwater heaters, using closed feedwater heaters, and utilizing cogeneration to make use of waste heat. The key methods discussed are lowering condenser pressure, superheating steam, increasing boiler pressure, and implementing regenerative feedwater heating to improve the average heat addition and cycle efficiency.
Engineering applications of thermodynamicsNisarg Amin
The document discusses different thermodynamic cycles used in steam power plants, including Rankine, reheat, and regeneration cycles. It provides diagrams and equations to analyze each cycle. The Rankine cycle involves boiling water to steam, expanding the steam in a turbine, condensing it back to water, and pumping the water to high pressure. Both the reheat and regeneration cycles improve the Rankine cycle efficiency by adding additional heat transfer processes. The reheat cycle reheats steam after the high-pressure turbine, while regeneration uses feedwater heating to preheat water before boiling.
Design of open volumetric receiver for air &supercritical CO2 Brayton cycleM. Ahmad
High-temperature receiver designs for solar powered supercritical CO2 Brayton cycles that can produce ~50 MW of Electricity is being investigated. Advantages of a supercritical CO2 closed-loop Brayton cycle with recuperation include high efficiency (~50%) and a small footprint relative to equivalent systems employing steam Rankine power cycles. Heating for the supercritical CO2 system occurs in a high-temperature solar receiver that can produce temperatures of at least 700 °C. Depending on whether the CO2 is heated directly or indirectly, the receiver may need to withstand pressures up to 20 MPa (200 bar). Designs for direct heating of CO2 include volumetric receivers and indirect volumetric receiver.
This document provides lecture notes on gas power cycles from a mechanical engineering course. It covers the ideal gas relation, specific heats of gases, and the first law of thermodynamics as they relate to closed systems. Formulas are presented for the ideal gas law in various forms, as well as specific heat capacities for air. The notes also define important terms used in analyzing thermodynamic cycles, such as pressure ratio, compression ratio, and cutoff ratio. An example problem is included to demonstrate calculating maximum pressure, net specific work, and thermal efficiency for a diesel engine cycle.
1) The document describes an air refrigeration system, also known as the Bell-Coleman cycle or reversed Brayton cycle.
2) In this cycle, air is compressed in a compressor, cooled in a heat exchanger, expanded in an expander, and absorbs heat in an evaporator to cool an object.
3) The key assumptions of the Bell-Coleman cycle analysis are that the compression and expansion processes are reversible and adiabatic, there is perfect intercooling in the heat exchanger, and no pressure losses occur in the system.
The document discusses various components of a thermal power plant including a boiler, air preheater, and ash handling plant. It provides details on the types, operation, and technical specifications of these systems. The boiler section describes supercritical boilers and includes diagrams of boiler components. The air preheater section explains regenerative and recuperative types. The ash handling plant introduces the collection and disposal of ash from coal combustion.
The document provides information on supercritical Rankine cycles and supercritical boilers. Some key points:
1) A supercritical Rankine cycle operates above the critical point of the working fluid, where it behaves as a supercritical fluid with properties between a liquid and gas. This improves efficiency over subcritical cycles.
2) Supercritical boilers operate at pressures above 221.2 bar and temperatures above 374°C for water. Special high-temperature alloys are needed to withstand these conditions.
3) Boiler design considerations include symmetric shapes for uniform temperatures, downfired burners, and optimized dimensions. Materials like Inconel 740 are commonly used in supercritical boiler components.
This document contains 6 exercises related to calculating the thermal efficiency of steam power plants operating on different Rankine cycle configurations including:
1) Ideal Rankine cycle
2) Ideal reheat Rankine cycle
3) Reheat Rankine cycle with specified turbine inlet/exit conditions
4) Regenerative Rankine cycle with one open feedwater heater
5) Reheat-regenerative cycle with one open feedwater heater, one closed feedwater heater, and one reheater.
The 6th exercise asks to determine the fractions of steam extracted from the turbine and the thermal efficiency for a plant operating on the reheat-regenerative cycle described in item 5 above.
1. Ammonia is industrially synthesized from nitrogen and hydrogen through the Haber process. It is produced on a large scale, exceeding 130 million tonnes annually.
2. The synthesis of ammonia is an equilibrium reaction that is exothermic and favored by high pressure and low temperature. Industrial production occurs at 400-500°C and 150-300 atmospheres using an iron catalyst.
3. Haber optimized the process by implementing a recycling system to increase space-time yield, improving economic production. His recycling design is still used as the basis for industrial ammonia synthesis.
The document discusses thermal power cycles and the Rankine cycle in particular. It provides details on:
- The basic energy flow in a thermal power plant from chemical to mechanical to electrical energy.
- The Rankine cycle most closely models the steam power cycle used in most power plants. It involves heating water to steam to drive a turbine and then condensing the steam to recycle the water.
- Ways to improve the efficiency of the Rankine cycle include increasing the average temperature of heat addition by superheating steam or increasing boiler pressure, and decreasing the average temperature of heat rejection by lowering the condenser pressure.
A detailed explanation about Rankine cycle or vapour power cycle for mechanical 2nd year students.Areas of uses of vapour power cycle or steam power cycle.
This document describes the design of a 1 MW power plant based on a superheated Rankine cycle. Key components include a steam generator with economizer, boiler and superheater sections, a high pressure turbine operating from 100-20 bar, a low pressure turbine from 20-0.1 bar, a condenser, an open feedwater heater containing a deaerator, a closed feedwater heater, and a reheater. Thermodynamic calculations are shown to select locations and operating conditions for these components. Performance is calculated with a net work output of 968.28 kW, heat input of 2557.14 kW, and heat rejected of 2358.52 kW.
This document describes an ideal regenerative Rankine cycle with feedwater heating. It has three key points:
1. It raises the temperature of feedwater before it enters the boiler using steam extracted from the turbine. This improves thermal efficiency.
2. The device that heats the feedwater is called a regenerator or feedwater heater. It can be an open or closed system and prevents deaeration of the feedwater.
3. Benefits include reduced steam flow, smaller equipment, easier turbine operation, and less erosion. Regeneration provides higher efficiency than reheating without the complexity and costs of reheating systems.
The document discusses thermal power cycles. It begins by explaining that a thermal power plant involves heating water to create steam that spins a turbine and generates electricity.
The basic energy flow in a thermal power plant is: chemical energy is converted to mechanical energy by the steam turbine, which is then converted to electrical energy. Various fuel sources can be used.
It then discusses the key power cycles used in thermal plants like the Carnot, Rankine, Diesel, Otto, and Brayton cycles. It also covers the laws of thermodynamics and important thermodynamic processes.
The Rankine cycle most closely models actual steam power plants. It involves pumping water, boiling it to create steam, expanding the steam
ME6301 ENGINEERING THERMODYNAMICS SHORT QUESTIONS AND ANSWERS - UNIT IIIBIBIN CHIDAMBARANATHAN
This document provides an overview of thermodynamics concepts related to properties of pure substances and steam power cycles. It includes definitions of key terms like enthalpy of steam, latent heat of evaporation, superheated steam, dryness fraction, and critical point. The document also summarizes the assumptions and components of the Rankine cycle, methods to improve its efficiency including reheating, and comparisons to other cycles like Carnot. Overall, the document serves as a study guide for engineering thermodynamics topics focusing on steam as the working fluid.
This document provides information about gas turbine and steam power plant cycles. It describes the Brayton cycle used in gas turbines and the Rankine cycle used in steam power plants. It discusses components, processes, thermal efficiencies and improvements to the cycles such as regeneration, intercooling and reheating. Examples are provided to calculate efficiency, work and heat inputs/outputs for simple and improved cycles.
This document presents information on the Rankine cycle. It contains the following key points:
1. The Rankine cycle converts heat into work through a closed loop that uses water as the working fluid. It generates about 90% of the world's electric power.
2. An ideal Rankine cycle involves isothermal and isobaric processes, while a real cycle involves non-reversible and isentropic compression and expansion.
3. Variations like the reheat cycle and regeneration cycle can improve the efficiency by reheating steam before the turbine or preheating feedwater, but increase costs.
This document discusses various thermodynamic power cycles including:
- The Carnot cycle, which is the most efficient but impractical cycle.
- Rankine cycles, which are more practical vapor power cycles that use steam as the working fluid.
- Simple Rankine cycles involve heating water to steam then expanding it in a turbine before condensing it back to water.
- Rankine cycles with superheated steam, which increase efficiency by heating steam above its saturation temperature.
- The efficiencies of different cycles are calculated and compared in examples. Superheated steam cycles have higher efficiencies than simple Rankine cycles due to higher average temperatures.
This document discusses the reheat cycle in thermodynamics. The reheat cycle is a modification of the Rankine cycle that is used in steam power plants. It works by reheating the steam after it expands in the high-pressure turbine and before it expands further in the low-pressure turbine. This increases the efficiency by raising the mean temperature of heat addition and reducing moisture content in the steam. Reheating allows for higher turbine work extraction and thermal efficiency compared to the basic Rankine cycle. The document examines the working of reheat cycles in steam turbines and thermal power plants, and their advantages in improving efficiency and reducing blade erosion.
The document summarizes the manufacturing of ammonia. It describes Haber's process which uses nitrogen from air and hydrogen from natural gas to produce ammonia through a catalytic reaction. Key conditions for the reaction include temperatures of 400-450°C, pressures of around 200 atmospheres, and an iron catalyst. The modern process involves desulphurization of hydrocarbons, steam reforming to produce hydrogen and carbon monoxide, shift conversion to increase hydrogen, and purification before the synthesis reaction and separation of ammonia. The main uses of ammonia include production of fertilizers, nitric acid, explosives, fibers, refrigeration and pharmaceuticals.
The document discusses various methods to improve the efficiency of the Rankine cycle, which is the most common thermodynamic cycle used in conventional steam power plants. These include lowering the condenser pressure, superheating steam to higher temperatures, increasing the boiler pressure, using reheat cycles, and employing feedwater heaters. Reheat cycles can improve efficiency by 4-5% by increasing the average heat addition temperature. Feedwater heaters also raise efficiency by preheating feedwater with extracted steam. Modern plants operate at supercritical pressures over 22.06 MPa and have efficiencies as high as 40%.
ME 6301 ENGINEERING THERMODYNAMICS SHORT QUESTIONS AND ANSWERS - UNIT IIBIBIN CHIDAMBARANATHAN
This document provides a summary of key concepts in engineering thermodynamics for a third semester mechanical engineering course. It covers topics like the second law of thermodynamics, Carnot cycle efficiency, heat pumps, refrigerators, coefficient of performance, availability analysis, and vapor compression refrigeration cycles. The document is compiled by an assistant professor and contains 33 questions and answers on these thermodynamics topics.
This document discusses methods to improve the efficiency of a Rankine cycle steam power plant. It describes lowering the condenser pressure, superheating steam to high temperatures using reheat, increasing the boiler pressure, implementing an ideal regenerative Rankine cycle with open feedwater heaters, using closed feedwater heaters, and utilizing cogeneration to make use of waste heat. The key methods discussed are lowering condenser pressure, superheating steam, increasing boiler pressure, and implementing regenerative feedwater heating to improve the average heat addition and cycle efficiency.
Engineering applications of thermodynamicsNisarg Amin
The document discusses different thermodynamic cycles used in steam power plants, including Rankine, reheat, and regeneration cycles. It provides diagrams and equations to analyze each cycle. The Rankine cycle involves boiling water to steam, expanding the steam in a turbine, condensing it back to water, and pumping the water to high pressure. Both the reheat and regeneration cycles improve the Rankine cycle efficiency by adding additional heat transfer processes. The reheat cycle reheats steam after the high-pressure turbine, while regeneration uses feedwater heating to preheat water before boiling.
Design of open volumetric receiver for air &supercritical CO2 Brayton cycleM. Ahmad
High-temperature receiver designs for solar powered supercritical CO2 Brayton cycles that can produce ~50 MW of Electricity is being investigated. Advantages of a supercritical CO2 closed-loop Brayton cycle with recuperation include high efficiency (~50%) and a small footprint relative to equivalent systems employing steam Rankine power cycles. Heating for the supercritical CO2 system occurs in a high-temperature solar receiver that can produce temperatures of at least 700 °C. Depending on whether the CO2 is heated directly or indirectly, the receiver may need to withstand pressures up to 20 MPa (200 bar). Designs for direct heating of CO2 include volumetric receivers and indirect volumetric receiver.
This document provides lecture notes on gas power cycles from a mechanical engineering course. It covers the ideal gas relation, specific heats of gases, and the first law of thermodynamics as they relate to closed systems. Formulas are presented for the ideal gas law in various forms, as well as specific heat capacities for air. The notes also define important terms used in analyzing thermodynamic cycles, such as pressure ratio, compression ratio, and cutoff ratio. An example problem is included to demonstrate calculating maximum pressure, net specific work, and thermal efficiency for a diesel engine cycle.
1) The document describes an air refrigeration system, also known as the Bell-Coleman cycle or reversed Brayton cycle.
2) In this cycle, air is compressed in a compressor, cooled in a heat exchanger, expanded in an expander, and absorbs heat in an evaporator to cool an object.
3) The key assumptions of the Bell-Coleman cycle analysis are that the compression and expansion processes are reversible and adiabatic, there is perfect intercooling in the heat exchanger, and no pressure losses occur in the system.
The document discusses various components of a thermal power plant including a boiler, air preheater, and ash handling plant. It provides details on the types, operation, and technical specifications of these systems. The boiler section describes supercritical boilers and includes diagrams of boiler components. The air preheater section explains regenerative and recuperative types. The ash handling plant introduces the collection and disposal of ash from coal combustion.
The document provides information on supercritical Rankine cycles and supercritical boilers. Some key points:
1) A supercritical Rankine cycle operates above the critical point of the working fluid, where it behaves as a supercritical fluid with properties between a liquid and gas. This improves efficiency over subcritical cycles.
2) Supercritical boilers operate at pressures above 221.2 bar and temperatures above 374°C for water. Special high-temperature alloys are needed to withstand these conditions.
3) Boiler design considerations include symmetric shapes for uniform temperatures, downfired burners, and optimized dimensions. Materials like Inconel 740 are commonly used in supercritical boiler components.
Hydrogen can be produced through various methods such as steam reforming of natural gas, gasification of biomass/coal, and electrolysis of water. Steam reforming involves a reaction of methane and steam over a nickel catalyst to produce hydrogen and carbon monoxide. Gasification converts carbon sources through partial oxidation to produce syngas. Electrolysis uses electricity to split water into hydrogen and oxygen through redox reactions. Hydrogen has the highest energy density by mass of common fuels and can help enable a green energy economy when produced from renewable resources.
pdf on modern chemical manufacture (1).pdfgovinda pathak
1. Ammonia is produced by heating nitrogen and hydrogen gases at high pressures of 200-900 atm and temperatures of 380-450°C in the presence of an iron catalyst.
2. Sulfuric acid is produced via the contact process, which involves catalytically oxidizing sulfur dioxide to sulfur trioxide and absorbing it in concentrated sulfuric acid.
3. Sodium hydroxide is produced through the electrolysis of sodium chloride solution using a diaphragm cell, where chlorine gas forms at the anode and hydrogen gas forms at the cathode.
This document summarizes key concepts related to the second law of thermodynamics. It introduces the second law and explains that while a process must satisfy the first law, the first law alone does not ensure the process will occur. The second law is useful for predicting process direction and establishing equilibrium conditions. It then provides examples of processes that cannot occur spontaneously even though they satisfy the first law. The document proceeds to define the Kelvin-Planck and Clausius statements of the second law. It also discusses heat engines, thermal efficiency, Carnot cycles, and introduces entropy as a measure of system disorder or heat unavailability to do work.
Carbon Sequestration Final Proposal (LINKEDIN)Alex Rojas
This report proposes a design to capture and store carbon dioxide emissions from Cornell University's power plant. The major components are a water spray cooler to lower the temperature of flue gas from the plant, a series of MEA columns to separate CO2 from the flue gas, and a pipeline to transport CO2 16.5 miles to a storage site near another power plant. The total estimated cost is $80 million to capture 65,000 lbs/hr of CO2, and the project would take 5.5 years to construct with storage lasting 125 years. Risks like pipeline failures and groundwater displacement are also analyzed.
Bidirectional syngas generator TSW work on advanced large scale non steady st...Steve Wittrig
This document summarizes a unique reactor for producing synthesis gas (CO and H2) from catalytic partial oxidation of natural gas with air. The reactor operates adiabatically and autothermally near atmospheric pressure using nickel catalyst at 800°C. It consists of three packed beds - a central reaction zone surrounded by upper and lower heat exchange zones. The reactor periodically reverses gas flow directions to efficiently transfer heat between the beds and maintain a constant average temperature without external energy. Experimental testing on laboratory and pilot scales validated the concept. A mathematical model was developed to simulate the reactor's unsteady-state thermal and compositional behavior.
Thermal power plants presentation (bathinda)Lovesh Singla
The document describes the key components of a thermal power plant's air and flue gas circuit. It discusses the primary components including the primary air fan, forced draft fan, and induced draft fan which work to move air and flue gases through the system. The air preheater helps further utilize heat from flue gases to preheat air entering the combustion chamber. Fly ash is also removed from flue gases using electrostatic precipitators before being released through the chimney. The overall circuits in a coal-based thermal power plant include feed water/steam, coal/ash, air/flue gas, and cooling water.
This document summarizes a lecture on thermodynamics that discusses various topics:
1) The working fluid in a thermodynamic system can exist as a liquid, vapor, or gas. Water can be a liquid, vapor, or gas depending on temperature and pressure conditions.
2) Phase change points from liquid to vapor and vaporization are plotted on PV diagrams. The saturated liquid and vapor lines denote boiling and vaporization points.
3) Wet vapor is a mixture of liquid and dry vapor that exists at state points within the liquid-vapor dome on the PV diagram.
This document describes the design and fabrication of a solar powered lithium bromide vapor absorption refrigeration system. It uses lithium bromide and water as the working fluids, with solar energy powering the generator to separate the water vapor from the lithium bromide solution. The water vapor then condenses and evaporates to provide cooling, while the strong lithium bromide solution absorbs the water vapor back into a weak solution to complete the cycle. The document provides details on the system components, operating principles, and achievable COP between 0.7-0.8 using this environmentally friendly solar powered system.
The Suratgarh Thermal Power Station is located in Suratgarh, Rajasthan. It has 6 operational units that each have a capacity of 250MW, for a total capacity of 1500MW. There are also 2 additional units under construction that will each have a capacity of 660MW. The power station has been operating since 1999. A boiler is a closed vessel that uses heat to transfer energy from combustion to water and produce steam. Proper boiler design and maintenance is important for high efficiency and reducing heat loss. Boiler efficiency is calculated based on heat transferred to steam versus total heat input.
Increasing the temperature in the Gibbs reactor from 800°C to 5000°C:
- Hydrogen production increases significantly, reaching a maximum around 1600°C then decreasing.
- Carbon monoxide production also increases to a maximum at 1600°C then decreases with further temperature rise.
- Carbon dioxide production decreases steadily as temperature increases.
- Methane production increases slightly with temperature over most of the range tested.
This document provides information on the properties of various cryogenic liquids including liquid methane, neon, nitrogen, oxygen, argon, air, hydrogen, helium, and helium-3. It discusses their normal boiling points, densities, common uses as refrigerants and rocket fuels. Specific phenomena associated with liquid helium such as superfluidity below 2.17K, the lambda transition, third and fourth sound propagation, and thermo-mechanical effects are also summarized.
The document discusses fundamental concepts and definitions related to thermodynamics, including dependent properties, thermodynamic equilibrium, macroscopic and microscopic points of view, system boundaries, open and closed cycles, and quasi-static processes. It also covers the first and second laws of thermodynamics, defining concepts like entropy, reversible and irreversible processes, Carnot's theorem, heat engines, refrigerators, and heat pumps. Several sample problems are provided relating to thermodynamic processes, cycles, and calculating work, heat, and efficiency.
This document provides an overview of fuel cells, including:
1. Fuel cells convert chemical energy directly into electricity through electrochemical reactions. They can produce electricity continuously as long as fuel and oxygen are supplied.
2. Fuel cells are classified based on fuel/oxidizer type and electrolyte. Common types include hydrogen-oxygen, hydrocarbon, alkaline, phosphoric acid, and molten carbonate fuel cells.
3. Proton exchange membrane fuel cells (PEMFCs) operate at lower temperatures (50-100°C) and use a proton-conducting polymer membrane. They are being developed for transport and portable power applications.
Hydrogen energy sources - generation and storageShantam Warkad
Hydrogen is the simplest and most abundant element on earth
It consists of only one proton and one electron.
Hydrogen can store and deliver usable energy, but it doesn't typically exist by itself in nature and must be produced from compounds that contain it.
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AA | In-Situ Lunar Propellant Production and Processes
I. Introduction
Imagine a gallery where there were Earth-launching rockets, all stood like soldiers standing
attention to their commander. Alongside those rockets, is a small gold-colored rectangle, with
facts about those rockets. One thing that may stand out to the visitor is that the mass of the fuel
relative to the rest of the rocket is large. The mass ratios of Earth-launching rockets are very
high, to the point where most of the rocket is fuel. For a Mars-bound trip like this, a lot of fuel
would be required. Attempting to transport all the fuel to even just LEO seems a bit cost-
prohibitive. Therefore, Lunar in-situ propellant production should be considered as a way to
decrease the initial mass in LEO.
II. Introduction to Lunar H2 and O2 Fuel Processing
The motivation of lunar in-situ H2 and O2 production is to provide access to a long term
sustainable supply of propellant to power the spaceships of tomorrow. This section will assume
the lunar colonists have chosen Shackleton Crater as a colony site and have readily available
liquid water in order to explore the steps behind the H2 and O2 propellant production process.
III. H2 and O2 Propellant Production Thermodynamic Analysis
In this section, we will explore the subsystems necessary to produce H2 and O2 from liquid
water. The H2 and O2 propellant production process is split up into two main subsystems: the
propellant production process and the thermal & power regeneration process. We will in the next
few pages explore the thermodynamics behind it. Throughout the analysis, all processes are
assumed to be 100% isentropic and have zero pressure drops across heat exchangers. While such
assumptions are unrealistic in practice, it will provide a basic understanding what is necessary to
achieve in-situ H2 and O2 propellant production on the Moon.
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Figure AA.1: The complete H2 and O2 Production Cycle
A. Propellant Production Process
The purpose of the propellant production process is to take in liquid water and output liquid H2
and liquid O2. This system accomplishes with the use of four main subsystems: the PEM
electrolysis, the liquid O2 condenser, the gaseous H2 compressor, and the liquid H2 condenser.
1. PEM Electrolysis
The purpose of the PEM Electrolysis is to convert liquid water into gaseous H2 and O2 via
electrolysis. The liquid water enters at a temperature of 400 K and a pressure of 250 kPa. After
the electrolysis process, a gaseous H2 and O2 mixture exits at a temperature of 400 K and a
pressure of 250 kPa. The electrolysis process will be considered adiabatic. We will be assuming
that all of energy used in the electrolysis will be used direct towards splitting up the water
molecule and not towards raising the average temperature of the output gas mixture. In addition,
we will also assume the electrolysis process to be isobaric. The reasoning is the PEM electrolyze
process is under two phase conditions, therefore the pressure of the H2 and O2 gas mixture must
equal the pressure of the liquid water.
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The amount of energy required by the electrolysis process can be examined by evaluating the
enthalpy of reaction, shown in the following expression:
H2O → H2(g) +
1
2
O2(g), ∆H = 286,000
KJ
Kmol
(AA. 1)
Therefore in order to electrolyze 1 Kg of water, we require roughly 15,900 KJ. We should also
note, in order to promote favorable electrolysis conditions, we would want to have the liquid
water to be at a high pressure. This is due to the Le Chatelier principle.
Finally the gaseous H2 and O2 will be filtered in order to produce two separate flows of pure H2
and O2.
2. Liquid Oxygen Condenser
The purpose of the liquid oxygen condenser serves two main functions: to liquefy the gaseous
oxygen into liquid oxygen and to provide the helium cycle energy. In this section, we will only
focus on the liquefaction of oxygen.
At a pressure of 250 kPa, the gaseous oxygen will condenser at a temperature of 90 K. We will
accomplish this cooling through the use of super cooled helium. Heat from the gaseous oxygen
will be transferred to the helium until the gaseous oxygen condenses. After this exchange, we
can expect the exiting liquid oxygen be at a temperature of 90 K and at a pressure of 250 kPa.
From this point, the liquid oxygen can be stored in tanks for future use.
3. Hydrogen Compressor
Liquid hydrogen has an extremely low boiling point. At 100 kPa, liquid hydrogen has a boiling
point of 20 K. We can increase the boiling point of hydrogen by increasing the pressure.
Therefore to achieve this, we will need to run the gaseous hydrogen through a compressor.
Compressing the hydrogen more will reduce the energy required to liquefy the hydrogen, but
will cost the compressor higher power. However the energy required to liquefy the hydrogen, as
we will examine later, is eventually used to power the power and thermal regenerative system.
Therefore we opt to reduce the compressor power requirement because the energy required to for
liquefaction will be reused later on. With a CPR of 1.4, the exiting hydrogen gas will have a
pressure of 350 kPa and a temperature of 440 K.
4. Liquid Hydrogen Condenser
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The purpose of the liquid hydrogen condenser serves two main functions: to liquefy the
gaseous hydrogen into liquid hydrogen and to provide the helium cycle energy. In this section,
we will only focus on the liquefaction of hydrogen.
At a pressure of 350 kPa, the gaseous hydrogen will condenser at a temperature of 40 K. We
will accomplish this cooling through the use of super cooled helium. Heat from the gaseous
hydrogen will be transferred to the helium until the gaseous hydrogen condenses. After this
exchange, we can expect the exiting liquid hydrogen be at a temperature of 40 K and at a
pressure of 350 kPa. From this point, the liquid hydrogen can be stored in tanks for future use.
B. Thermal and Power Regeneration Cycle
The purpose of the thermal and power regeneration cycle to cool the hydrogen and oxygen to
extremely low temperatures. The regeneration cycle is comprised of four main subsystems, the
hydrogen liquefier, helium turbine, oxygen liquefier, helium compressor, and radiator.
1. Hydrogen liquefier (Helium Side)
As previously discussed, the liquid water condenser serves two main functions. This section
will focus on the heat transfer between the water vapor and the helium. The helium enters the
liquid water condenser at a temperature of 20 K and a pressure of 800 KPa and exits at a
temperature of 30 K and a pressure of 800 KPa. Due to the second law of thermodynamics, we
will need to outlet temperature of helium to be lower than or equal to the exit temperature of the
liquid water. Thus the exit temperature of the helium was set at a temperature of 400 K, since it
was our max allowable exit temperature. With a known exit temperature value, the inlet
temperature will be determined by power and mass constraints. A higher inlet temperature will
require a higher helium mass flow rate to achieve the same amount of cooling, while reducing
the overall system power requirement more. Biased towards power reduced again, the inlet
temperature of the helium was set at 20 K. The pressure of the helium was set equal to the
pressure of the water vapor since we would ideally want constant pressure heat transfer between
the water vapor and the helium.
2. Helium Turbine
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The purpose of the turbine is to provide power to the helium compressor and to reduce the
pressure of the helium so we can have isobaric heat transfer for the oxygen liquefier. Therefore
the exit condition pressure of the helium turbine will be 250 KPa. Using the equation below, we
can also determine the temperature after the turbine as well:
P1 = P2 ∙ [
T2
T1
]
−𝛾
𝛾−1
(AA. 3)
The exit temperature of the turbine was found to be 19 K. This temperature is low enough for
the helium to cool the oxygen gas into liquid form.
3. Oxygen liquefier (Helium Side)
The helium enters the liquid water condenser at a temperature of 19 K and a pressure of 250
KPa and exits at a temperature of 33 K and a pressure of 250 KPa. Through the processes of
liquefying the oxygen, the exit temperature of the helium was calculated to be 20.5 K. The
cooling process was again assumed to be isobaric, so the exit pressure of the helium was 250
KPa.
4. Helium Compressor
The purpose of the helium compressor is to raise the pressure of the helium back to 800 KPa so
we can have constant pressure conditions for the hydrogen liquefier. Since we know the pressure
ratio between the inlet and outlet condition, we can the following equation to determine the exit
temperature:
T2 = T1 ∙ CPR
(𝛾−1)
𝛾 (AA. 4)
The exit temperature was calculated to be 33 K. However this temperature is too high to for the
hydrogen liquefier therefore we need to cool down the helium down.
5. Helium Radiator
Since the helium will face a temperature raise across the compressor, we need to cool the
helium down before the helium enters the hydrogen liquefier. So a solution to cool the helium
from 33 K to 20 K is with the use of a radiator. A radiator would prove extremely useful since
Shackleton Crater has permanently shadowed areas, so the ambient radiative temperature will be
extremely low.
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C. Propellant Production Power Requirements
There will be two main sources of power consumption: the PEM electrolysis and the hydrogen
compressor. The following table details the energy consumption of each of the major power
consuming subsystem as percent of total energy required.
Table AA.1: Major Power Consuming Subsystem as Percent of Total Energy Required
Major Power Consuming Subsystems Percent of Total Energy Required
PEM Electrolysis ~ 0.99%
Hydrogen Compressor ~ 0.016%
From Table AA.1, we can see the energy consumption from the PEM electrolysis represents
nearly all of the energy consumption for the entire propellant production power requirements..
Therefore further studies should be made on how to reduce the power requirement for splitting
the water into hydrogen and oxygen.
Overall, using the water extraction and processing system design above, we will need 1603 KJ
of energy for every 1 Kg of water. The power requirement for the propellant production system
can be easily calculated by factoring in the time frame in which we will be required to produce
the water.
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IV. Introduction to Lunar Silicon Processing
One great way to minimize initial mass in LEO is by getting resources from places aside from
the Earth. In-situ lunar resource processing allows us to shift some of the mass from LEO to
GEO or L1, greatly decreasing the amount of propellant we would need. One of the materials
we could harvest from the surface of the Moon is solid silicon.
V. Lunar Regolith
We first identified the amount of silicon that is possibly available from the lunar surface. To
do that, we looked at the composition of the lunar regolith.
Like terrestrial soil, lunar regolith is varying, with the exact composition depending on the
location. We looked at some of main minerals of the regolith, which were ilmenite, anorthite,
fayalite, forsterite, and enstatite.
Table A.1 details the mineral properties. We picked these minerals because they were the
most common ones in Shackleton Crater [3].
Table A.1: Some of the minerals from the lunar regolith have their regolith displayed
here; the percentages are approximations.
Mineral Chemical Formula % of Regolith
Ilmenite FeTiO3 20
Anorthite CaAl2Si2O8 40
Enstatite MgSiO3 15
Fayalite Fe2SiO4 10
Forsterite Mg2SiO4 15
For heat capacity of the minerals, we recognized that the value would not be constant as
temperature rose, so we opted to use empirical relations during the calculation of energy
needed. Table A.2 shows the values that eq. A.1 [1,4] takes in.
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𝑐 𝑝 = 𝑘0 + 𝑘1 𝑇−
1
2 + 𝑘2 𝑇−2
+ 𝑘3 𝑇−3
(𝐴. 1)
Table A.2: The empirical relations for heat capacity are displayed.
Mineral k0 k1 k2 k3
Ilmenite 164.47 -0.09905 -5.092*10-5
-4.875*10-7
Anorthite 439.37 -0.37341 0 -31.702*10-7
Enstatite 139.96 -0.0497 -44.002*10-5
53.571*10-7
Fayalite 248.93 -0.19239 0 -13.91*10-7
Forsterite 238.64 -0.20013 0 -11.624*10-7
VI. Regolith Processing
The process that is detailed in this report comes from a report by Geoffrey A. Landis [2]. The
major products that come from the process are diatomic oxygen and solid silicon, with pure
metals and metal oxides being byproducts. A diagram of this entire process is shown in fig.
A.1.
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Figure A.1: The lunar regolith processing system, with mass inputs and outputs.
The process uses heat and diatomic fluorine to break apart the minerals in the regolith furnace
(1). Gaseous products go to condensers, which are used to separate out the different gases, while
the liquid products go to a reduction furnace (2). The silicon tetrafluoride is sent to the plasma
chamber as a liquid, where the silicon and fluorines are separated (5). Liquid potassium in the
reduction furnace is used to separate out some of the fluorine from the metals, outputting pure
metals (3). The rest of the fluorides, along with oxygen, go on to the oxidation furnace, where
metal oxides are output and potassium salts are sent to the crucible (4). At the crucible, the salts
are separated into solid potassium and diatomic fluorine (6). Diatomic fluorine goes to a holding
tank, which is where the regolith furnace gets its fluorine (7).
For this study, we looked at the stages where silicon is present in some form.
Specifically, we looked at the regolith furnace, the titanium tetrafluoride condenser, silicon
tetrafluoride condenser, and the plasma chamber. This subsystem had inputs of diatomic
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fluorine and lunar regolith, and outputs of solid silicon, diatomic oxygen and fluorine, and metal
fluorides. Figure A.2 shows this subsystem. We assumed that there would be no heat losses,
both during each process and between each process. Furthermore, we assumed stoichiometric
situations for the input and output of each part. All calculations were done at atmospheric
pressure.
Figure A.2: The subsystem that considers all steps that have silicon in it.
A. Regolith Furnace
The regolith furnace is where the lunar regolith first enters. For this study, we considered the
regolith entering in at 88 K, with the composition that was detailed in section II. However, the
regolith could come in at 330 K, as dry regolith from the water processing cycle. The
stoichiometric chemical equations for the minerals are seen in eq. A.1.
𝐶𝑎𝐴𝑙2 𝑆𝑖2 𝑂8(𝑠) + 8𝐹2(𝑔) ⇨ 𝐶𝑎𝐴𝑙𝐹5(𝑙) + 𝐴𝑙𝐹3(𝑙) + 2𝑆𝑖𝐹4(𝑔) + 4𝑂2(𝑔)
𝐹𝑒𝑇𝑖𝑂3(𝑠) + 3𝐹2(𝑔) ⇨ 𝐹𝑒𝐹2(𝑙) + 𝑇𝑖𝐹4(𝑔) + 1.5𝑂2(𝑔)
𝑀𝑔𝑆𝑖𝑂3(𝑠) + 3𝐹2(𝑔) ⇨ 𝑀𝑔𝐹2(𝑙) + 𝑆𝑖𝐹4(𝑔) + 1.5𝑂2(𝑔)
𝐹𝑒2 𝑆𝑖𝑂4(𝑠) + 4𝐹2(𝑔) ⇨ 2𝐹𝑒𝐹2(𝑙) + 𝑆𝑖𝐹4(𝑔) + 2𝑂2(𝑔)
𝑀𝑔2 𝑆𝑖𝑂4(𝑠) + 4𝐹2(𝑔) ⇨ 2𝑀𝑔𝐹2(𝑙) + 𝑆𝑖𝐹4(𝑔) + 2𝑂2(𝑔)
(𝐴. 1)
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The regolith is heated up to 770 K, which causes the silicon and titanium tetrafluorides to
become gaseous, while keeping the other metal fluorides liquid. Diatomic fluorine and oxygen
also come out as gases at that temperature. The gaseous products go on to the condensers, while
the liquid ones go to the reduction chamber.
The thermal energy required for the mixture, on a molar basis, is 4.566 MJ/mol. This was
calculated using eq. A.2.
𝐸̅ = ∑ [(% 𝑐𝑜𝑚𝑝𝑜𝑠𝑖𝑡𝑖𝑜𝑛)𝑐 𝑝 𝛥𝑇]
𝑚𝑖𝑛𝑒𝑟𝑎𝑙𝑠
+ ∑ [(% 𝑐𝑜𝑚𝑝𝑜𝑠𝑖𝑡𝑖𝑜𝑛)𝛥ℎ]
𝑟𝑒𝑎𝑐𝑡𝑎𝑛𝑡𝑠
(𝐴. 2)
B. Condensers
The condensers take in the gaseous products from the regolith furnace. There are four sets of
condensers. Each condenser uses a radiator towards space to cool the products inside. The first
condenser is at 520 K, which allows the titanium tetrafluoride to become liquid. That is sent to
the reduction furnace. Silicon tetrafluoride is condensed at 175 K and sent to the plasma
chamber. Diatomic oxygen is liquefied at 90 K in the third, and fluorine at 85 K in the fourth.
The oxygen is pumped towards the oxidation furnace, while the fluorine is pumped to the
fluorine tank.
C. Plasma Chamber
The plasma chamber takes in the liquid silicon tetrafluorine from the condenser at 175 K. It
is then heated up to 570 K, making it gaseous. Electrical energy is put into the gas, separating
the silicon and fluorine. With a bond energy of 541 kJ/mol [2], the total energy that is required
for this step is 4.328 MJ/mol of silicon.
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D. Reduction and Oxidation Furnaces
The reduction furnace takes in the liquefied metal fluorides from the regolith furnace and
titanium tetrafluorine condenser, and melted potassium from the potassium tank. These
reactants are at 770 K. The reactions that go on are seen in the stoichiometric equations in eq.
D.1.
𝑇𝑖𝐹4(𝑙) + 4𝐾(𝑙) ⇨ 𝑇𝑖(𝑠) + 4𝐾𝐹(𝑙)
𝐹𝑒𝐹3(𝑙) + 3𝐾(𝑙) ⇨ 𝐹𝑒(𝑠) + 3𝐾𝐹(𝑙)
𝐴𝑙𝐹3(𝑙) + 3𝐾(𝑙) ⇨ 𝐴𝑙(𝑠) + 3𝐾𝐹(𝑙)
(𝐷. 1)
The calcium and magnesium fluorides do not break apart in the reduction furnace. The
metals exit the system at this point, which could be used as a way to harvest titanium, iron, and
aluminum on the Moon.
The oxidation furnace takes in liquid oxygen from the oxygen condenser and the products of
the reduction furnace. Reactants are heated up to 790 K, which allow the stoichiometric
conditions in eq. D.2 to occur.
4𝐾(𝑙) + 𝑂2(𝑙) ⇨ 2𝐾2 𝑂(𝑙)
𝐶𝑎𝐹2(𝑙) + 𝐾2 𝑂(𝑙) ⇨ 2𝐾𝐹(𝑙) + 2𝐶𝑎𝑂(𝑠)
𝑀𝑔𝐹2(𝑙) + 𝐾2 𝑂(𝑙) ⇨ 2𝐾𝐹(𝑙) + 2𝑀𝑔𝑂(𝑠)
(𝐷. 2)
The metal oxides exit the system at this point. They could stay as byproducts of the system,
or have the oxygen be used for potential fuel production. Potassium salts in the latter two
reactions are sent to the crucible, where they are electrolyzed at 950 K to make solid potassium
and diatomic fluorine. The metallic potassium gets sent back to the reduction furnace, while the
fluorine gas goes to a tank for later use.
E. Conclusion
Silicon can be harvested from the Moon, along with several other chemicals. The process
used mainly consisted of a furnace heating and separating the chemicals. Silicon tetrafluorine is
condensed and then put into the plasma chamber, where it is broken apart to create solid silicon.
This silicon could potentially be used for solar cell production or silane fuel production.
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Overall, the energy requirements for were fairly low. Assuming a power plant with an output
of 40 kW, a mole of silicon can be produced approximately every 3.706 minutes. However,
there were several approximations made, and several steps were not fully calculated. For future
work, the reduction and oxidation chambers and the crucible need energy values calculated.
References:
[1] Navrotsky, A., Hon, R., Weill, D. F., and Henry, D. J., “Thermochemistry of glasses
and liquids in the systems,” Geochimica et Cosmochimica, Vol. 44, 1980
[2] Landis, G. A., “Materials refining on the Moon,” Acta Astronautica, Vol. 60, 2007
[3] Seboldt, W., Lingner, S., et al, “Lunar Oxygen Extraction Using Fluorine,”
[4] Berman, R. G., and Brown, T. H., “Heat Capacity of minerals in the system,”
Contributions to Mineralogy and Petrology, 1985