M. TECH. SEMINAR CHE 702 ENVIRONMENTAL CONTROL & LIFE SUPPORT SYSTEMS PRESENTED BY: SANJAY KATHERIA Atmospheric Control of Closed Systems

AIR REVITALAIZATION

TEMPERATURE & HUMIDITY CONTROL WASTE WATER MANAGEMENT SOLID WASTE MANAGEMENT AIR REVITALIZATION ECLSS M. Tech Seminar Sanjay Katheria 17 th April, 2012

AIR REVITALIZATION OXYGEN PRODUCTION CO 2 REMOVAL TRACE CONTAMINANT CONTROL TRACE CONTAMINANT CONTROL HUMIDITY CONTROL M. Tech Seminar Sanjay Katheria 17 th April, 2012

SPACECRAFT CABIN AIR QUALITY PARAMETERS Source: Report on AIR PURIFICATION IN CLOSED ENVIRONMENTS: OVERVIEW OF SPACECRAFT SYSTEMS by Jay L. Perry, NASA George C. Marshall Space Flight Center * Spacecraft maximum allowable concentration

AIR REVITALIZATION OXYGEN PRODUCTION M. Tech Seminar Sanjay Katheria 17 th April, 2012 Solid Fuel Oxygen Generator Electrolysis of Water

H 2 O + Electricity H O 2 - Source of water: Water from waste water recovery section of ECLSS system. Main source of oxygen in shuttle. - For emergency purpose oxygen bottles and SFOG’s. M. Tech Seminar Sanjay Katheria 17 th April, 2012 AIR REVITALIZATION Electrolysis of Water: Elektron

M. Tech Seminar Sanjay Katheria 17 th April, 2012 AIR REVITALIZATION - Electrolysis of water by 30% KOH solution electrolysis cells - Oxygen supplied to cabin while hydrogen is vented in space. - The decomposition of 1 kg (2.2 1bs) of water yields 25 L (0.88 ft³) of oxygen per hour at a pressure of 760 mmHg, which is enough to support one crew member for one day. - Power consumption of the process is ~1 kW.

M. Tech Seminar Sanjay Katheria 17 th April, 2012 AIR REVITALIZATION - Chemical Oxygen Generator: Solid Fuel Oxygen Generator (SFOG) -A replaceable cartridge with an igniter, a striker mechanism, a filter, a dust collection filter, and a fan that are located inside one case. Solid Fuel Oxygen Generator: Vika & TTK

M. Tech Seminar Sanjay Katheria 17 th April, 2012 AIR REVITALIZATION - Release of oxygen by means of chemical reaction - Use of Lithium Perchlorate (LiClO 4 ), at 400 o C decomposes in oxygen and Lithium Chloride. - Mixing of N 2 to cool down and to form air mixture. - One cartridge yields 600 L (21.2 ft³) of oxygen. The contents of the cartridge take 5-20 minutes to decompose at a reaction temperature of °C ( °F). Temperature of the outer surface of the ТГК may reach 50°C (122°F). - Emergency supply of oxygen in Aircrafts.

AIR REVITALIZATION Carbon dioxide Removal Assembly: Vozdukh These beds contains alternative layers of Silica Gel and Zeolite 13X. CDR Bed Containing Zeolite 5A

M. Tech Seminar Sanjay Katheria 17 th April, 2012 AIR REVITALIZATION - The Vozdukh system can be divided into three parts: 1) The Preliminary Purification unit 2) A heat exchanger unit 3) An atmosphere purification unit (CDR Bed) - This system consists of three molecular sieve beds, two desiccant beds, two electrical heating units, an air-to-air heat exchanger, an air-to-liquid heat exchanger, a vacuum pump, eight valves, and a fan. The desiccant material is silica gel. - Carbon dioxide is removed from the atmosphere by molecular sieves, consisting of Zeolite, a solid porous adsorbent material.

M. Tech Seminar Sanjay Katheria 17 th April, 2012 AIR REVITALIZATION - Once saturated, the Zeolite is regenerated by exposing the bed to vacuum. - The air must first be dehumidified because the Zeolite in the molecular sieve bed preferentially adsorbs water. - Moisture absorption by silica-gel is an exothermic process, generating a bed temperature of 30-50°C (86-120°F). - Carbon dioxide absorbent canisters The lithium oxide-based carbon dioxide absorbent canisters of the SM provide a backup means of removing carbon dioxide from the atmosphere of habitable compartments.

AIR REVITALIZATION M. Tech Seminar Sanjay Katheria 17 th April, 2012 TRACE CONTAMINANT CONTROL SUBASSEMBLY (TCSS) - Trace contaminant sources: 1) from off-gassing (from structural materials, electronic equipment or materials used in experiments, etc.) 2) from system failures (leaks, equipment overheating, fires, etc). 3) from the crew itself (metabolic products). 4) from ECLSS itself.

TCCS Activated carbon bed treated with phosphoric acid to absorb ammonia. Catalyst bed containing Pt group component on alumina base To remove any acidic oxidation products.

AIR REVITALIZATION - TCCS consists of following main components: two regenerable activated-charcoal cartridges, a cartridge containing a catalytic oxidizer, a filter, a fan, and valves. - The charcoal beds adsorb high molecular weight trace contaminants. The catalyst oxidizes carbon monoxide to carbon dioxide, and the hydrogen to water. - The process flow rate is 15.3 m3/h through the carbon bed, which contains 22.7 kg of granular activated carbon treated with 10% by weight phosphoric acid. - The cartridges must be regenerated every 20 days for a 12-hour period. During regeneration, the cartridges are heated to 200°C (390°F). - M. Tech Seminar Sanjay Katheria 17 th April, 2012

AIR REVITALIZATION M. Tech Seminar Sanjay Katheria 17 th April, 2012

AIR REVITALIZATION - Humidity levels are controlled within manned spacecraft using condensing heat exchangers. - All drinking water aboard the Mir Space Station either originates from reclaimed humidity condensate, or resupply from the ground. M. Tech Seminar Sanjay Katheria 17 th April, 2012 HUMIDITY CONTROL

Current Research & Future Challenges - improvements are needed to further minimize air purification system mass, power, volume, and logistics requirements. - Solid amine chemical adsorbent media for carbon dioxide control. - Structured oxidation catalyst substrates that improve mass transfer, allow direct catalyst heating, and compact reactor design. - Structured adsorbent substrates to eliminate adsorbent bed dust generation caused by size attrition and reduce volume, mass, and power required for temperature swing adsorption systems. M. Tech Seminar Sanjay Katheria 17 th April, 2012

Report on “Air purification in closed environments: Overview of spacecraft systems” by Jay L. Perry NASA George C. Marshall Space Flight Center and M. Douglas LeVan, Department of Chemical Engineering, Vanderbilt University, Nashville, Tennessee, USA. Astronaut Training Manuals for the ISS, RSA (Oragon State University, USA) Wikipedia: Source & references

Thank You Presentation M. Tech Seminar Sanjay Katheria 17 th April, 2012