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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 613 records · Page 34
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Blending as an In-Tank Waste Processing Strategy: Year 1 Progress Report

The Hanford Site stores approximately 56 million gallons of radioactive legacy defense waste in underground tanks. Direct feed of southeast quadrant tank waste to a high-level waste treatment facility is currently being explored to accelerate tank treatment activities. This study seeks to de-risk waste transfers by favorably altering the resuspension and critical velocities of wastes through strategic waste blending. Wastes rich in aluminum- and zirconium-bearing solids pose significant risks due to their high settled strength and density. A series of tests explores how solid phase particle size and suspending phase chemistry alter waste transport properties, quantified through the just-suspended mixing speed (NJS), for pure and blended aluminum- and zirconium-bearing waste solid simulants. The study utilizes a range of gibbsites (three sizes spanning 10 to 90 µm) and zirconia solids (three sizes spanning 10 to 100 µm). As expected, the NJS of pure solids largely follows predictions based on literature correlations; blends of gibbsite and zirconium-bearing solids of differing particle sizes exhibit NJS maxima attributed to dense packing of the mixed-size settled solids. The findings of this study will assist in developing strategies to optimize the transport of waste solids for the safe and efficient delivery of tank waste.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

Mapping of a Novel Zero-Liquid Discharge Desalination System Based on Humidification–Dehumidification onto the Field of Existing Desalination Technologies

It is well-established that increasing demands for fresh water are paving the way for desalination technologies. However, this correlates with an increase in brine production whose treatment and disposal can be complicated and expensive. This paper presents a thermodynamic model to bound the operation and development of a novel Humidification–Dehumidification-based system featuring Zero-Liquid Discharge and off-grid capabilities. The model employs conservation laws to find feasible state points to meet a baseline operation of 10 kg/h of product water separated from a hypersaline feed stream with 100 g/kg salt concentration. The system incurs in a 1039 kWh/m3 energy intensity that can be supplied completely by an electric source or in combination with heating steam. Follow-up sensitivity analysis highlights the robustness of the system in handling variations of 25% in product flowrate and 75% in feed salinity, practically without incurring any additional energy demands. The proposed system operating costs between 72 USD/m3 and 96 USD/m3 are comparable to those of existing brine disposal techniques. Furthermore, an operational map of existing desalination technologies suggests a niche characterized by high recovery rates and high feed salinities that are generally unfulfilled by conventional desalination methods. Overall, the proposed system shows potential for off-grid hypersaline brine treatment. This study sets the stage for future development of physics-based and data-driven predictive models as the proposed system iterates into a pilot plant deployment.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1972

Space tug propulsion system failure mode, effects and criticality analysis

For purposes of the study, the propulsion system was considered as consisting of the following: (1) main engine system, (2) auxiliary propulsion system, (3) pneumatic system, (4) hydrogen feed, fill, drain and vent system, (5) oxygen feed, fill, drain and vent system, and (6) helium reentry purge system. Each component was critically examined to identify possible failure modes and the subsequent effect on mission success. Each space tug mission consists of three phases: launch to separation from shuttle, separation to redocking, and redocking to landing. The analysis considered the results of failure of a component during each phase of the mission. After the failure modes of each component were tabulated, those components whose failure would result in possible or certain loss of mission or inability to return the Tug to ground were identified as critical components and a criticality number determined for each. The criticality number of a component denotes the number of mission failures in one million missions due to the loss of that component. A total of 68 components were identified as critical with criticality numbers ranging from 1 to 2990.

Boyd, J. W.↗
NASA NTRS1994

(abstract) Asteroid Radar Astronomy at Goldstone in the 1990s

Since 1990, much effort has been devoted to optimizing Goldstone's capability to study near-Earth objects (NEOs). Three different configurations are now available. The nominal system on the 70-m antenna (DSS 14) uses separate feed horns for transmitting and receiving, and the 15-plus seconds required for transmit-to-receive switching renders the system useless for targets much closer than about 0.025 AU (about 10 lunar distances, about 25 seconds of echo time delay) and unwieldy even for targets twice that far. However, an additional, recently installed single horn system shrinks switching time to about 5 seconds, letting DSS 14 observe NEOs as close as about 5 lunar distances. Closer targets will require two-station observations, with DSS 14 transmitting continuously while DSS 13, a 34-m antenna 22 km away, receives. That configuration, first used for Toutatis, will also be required for delay-Doppler imaging that places thousands of pixels on any NEO whose rotation period P(h) and echo roundtrip time delay RTT (s) satisfy P > RTT. Between January 1990 and June 1994, the Goldstone radar has detected 11 asteroids. During the next 2 years, seven asteroids are scheduled for Goldstane observations. After completion of the Arecibo upgrade, Goldstone will play an important complementary role to that much more sensitive instrument.

asteroids radar Goldstone delay-Doppler imaging Ar↗
NASA NTRS2009

Turboelectric Distributed Propulsion Engine Cycle Analysis for Hybrid-Wing-Body Aircraft

Meeting NASA's N+3 goals requires a fundamental shift in approach to aircraft and engine design. Material and design improvements allow higher pressure and higher temperature core engines which improve the thermal efficiency. Propulsive efficiency, the other half of the overall efficiency equation, however, is largely determined by the fan pressure ratio (FPR). Lower FPR increases propulsive efficiency, but also dramatically reduces fan shaft speed through the combination of larger diameter fans and reduced fan tip speed limits. The result is that below an FPR of 1.5 the maximum fan shaft speed makes direct drive turbines problematic. However, it is the low pressure ratio fans that allow the improvement in propulsive efficiency which, along with improvements in thermal efficiency in the core, contributes strongly to meeting the N+3 goals for fuel burn reduction. The lower fan exhaust velocities resulting from lower FPRs are also key to meeting the aircraft noise goals. Adding a gear box to the standard turbofan engine allows acceptable turbine speeds to be maintained. However, development of a 50,000+ hp gearbox required by fans in a large twin engine transport aircraft presents an extreme technical challenge, therefore another approach is needed. This paper presents a propulsion system which transmits power from the turbine to the fan electrically rather than mechanically. Recent and anticipated advances in high temperature superconducting generators, motors, and power lines offer the possibility that such devices can be used to transmit turbine power in aircraft without an excessive weight penalty. Moving to such a power transmission system does more than provide better matching between fan and turbine shaft speeds. The relative ease with which electrical power can be distributed throughout the aircraft opens up numerous other possibilities for new aircraft and propulsion configurations and modes of operation. This paper discusses a number of these new possibilities. The Boeing N2 hybrid-wing-body (HWB) is used as a baseline aircraft for this study. The two pylon mounted conventional turbofans are replaced by two wing-tip mounted turboshaft engines, each driving a superconducting generator. Both generators feed a common electrical bus which distributes power to an array of superconducting motor-driven fans in a continuous nacelle centered along the trailing edge of the upper surface of the wing-body. A key finding was that traditional inlet performance methodology has to be modified when most of the air entering the inlet is boundary layer air. A very thorough and detailed propulsion/airframe integration (PAI) analysis is required at the very beginning of the design process since embedded engine inlet performance must be based on conditions at the inlet lip rather than freestream conditions. Examination of a range of fan pressure ratios yielded a minimum Thrust-specific-fuel-consumption (TSFC) at the aerodynamic design point of the vehicle (31,000 ft /Mach 0.8) between 1.3 and 1.35 FPR. We deduced that this was due to the higher pressure losses prior to the fan inlet as well as higher losses in the 2-D inlets and nozzles. This FPR is likely to be higher than the FPR that yields a minimum TSFC in a pylon mounted engine. 1

Felder, James L.↗
DOE OSTI2024

Direct air capture with amino acid solvent: Operational optimization using a crossflow air‐liquid contactor

Direct air capture (DAC) is a negative emission technology for removing CO2 from the atmosphere to maintain the CO 2 level within a reasonable range so as to address greenhouse effects. In this study, the operational optimization of lab-scale DAC has been investigated using a crossflow air-liquid contactor loaded with a three dimensionally printed Gyroid packing structure and a potassium sarcosinate solvent. The effects of various parameters, including feed air flow rate, liquid solvent flow rate, contactor geometry, and ambient temperature, are examined. The results demonstrate that the Gyroid packing design achieves comparable CO 2 capture performance to conventional packed beds but with a significantly lower pressure drop of up to 77.8%, suggesting its potential as an efficient and cost-effective solution for gas–liquid contactors in DAC. Additionally, the study explores the climate impact on CO 2 capture performance and finds that as the air temperature increases from 35 to 95°F at a fixed relative humidity of 80%, the CO 2 capture rate increased from 23.2% to 46.8% with better stability. The research highlights the importance of optimizing contactor design and operational conditions to improve the CO 2 capture rate and feasibility of DAC systems as a negative emission technology for addressing greenhouse effects.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2022

Improving the Economic Viability of Biological Utilization of Coal Power Plant CO 2 by Improved Algae Productivity and Integration with Wastewater Treatment

The overall goal of this project was to improve the cost-effectiveness of systems using algae to capture and beneficially utilize CO 2 from the flue gas of coal-fired power plants. Algal biomass cultivation is an attractive alternative for carbon capture and utilization because it can uptake more CO 2 per land area than any other photosynthetic crop. Also, the resulting biomass can be used to make valuable large-market commodity products, such as biofuels and animal feed. However, the use of algal carbon capture has been limited by several factors including: (1) high costs for growing algae (>$\$1,300$/ton), (2) large land requirements for algae cultivation, and (3) environmental concerns about the large amount of water and nutrient inputs needed for growing algae. This project has taken direct aim at resolving these key limitations and demonstrated several viable approaches to improve the economic and environmental feasibility of algal carbon capture. In particular, this project demonstrated a significant increase in average annual algal productivity from baseline values of 8 g/m 2 -day to above 20 g/m 2 -day. This supports a much lower projected cost of algae production (<$\$500$/ton) and reduces land requirements by more than 50%. Additionally, this project confirmed the ability to grow multiple algae species with wastewater nutrients, which facilitates the potential for substantial new revenue streams for algae cultivation based on tipping fees for nutrient laden wastewater. This study highlighted that there is more potential value in wastewater nutrient treatment credits than in the primary commodity products made from algae. The use of wastewater inputs also mitigates the concerns associated with the large amount of water needed for growing algae. The algal biomass grown for this project using wastewater and simulated flue gas inputs were characterized for potential use as an animal feed ingredient. The algae had a protein content in the range of 35-40%, which is between some common commodity animal feed products— distiller’s grains (~25-30% protein) and soybean meal (45-50% protein). In-vitro digestion tests using cattle rumen fluids, showed that this algae biomass was best suited for use as “bypass protein”, which is digested in the animal intestine. Based on the protein content and amino acid profile of the algae grown in this study, it was estimated to have market value in the range of $\$190$-$\$280$/ton. There is potential for higher value feed products if the algae content of omega-3 fatty acids or antioxidants is accounted for. This project also did small scale demonstration of forward osmosis algae dewatering and nanofiltration of hydrothermal liquefaction aqueous products, which were shown to improve the cost and energy balance for producing algal products. When all the improvements demonstrated in this study were included in techno-economic analysis, it showed there was a viable pathway to profitable algal CO 2 utilization with a payback period in the range of six to ten years.

01 COAL, LIGNITE, AND PEAT↗
NASA NTRS2011

Trajectory Guidance for Mars Robotic Precursors: Aerocapture, Entry, Descent, and Landing

Future crewed missions to Mars require improvements in landed mass capability beyond that which is possible using state-of-the-art Mars Entry, Descent, and Landing (EDL) systems. Current systems are capable of an estimated maximum landed mass of 1-1.5 metric tons (MT), while human Mars studies require 20-40 MT. A set of technologies were investigated by the EDL Systems Analysis (SA) project to assess the performance of candidate EDL architectures. A single architecture was selected for the design of a robotic precursor mission, entitled Exploration Feed Forward (EFF), whose objective is to demonstrate these technologies. In particular, inflatable aerodynamic decelerators (IADs) and supersonic retro-propulsion (SRP) have been shown to have the greatest mass benefit and extensibility to future exploration missions. In order to evaluate these technologies and develop the mission, candidate guidance algorithms have been coded into the simulation for the purposes of studying system performance. These guidance algorithms include aerocapture, entry, and powered descent. The performance of the algorithms for each of these phases in the presence of dispersions has been assessed using a Monte Carlo technique.

Sostaric, Ronald R.↗
NASA NTRS2010

Design and Testing of an Active Heat Rejection Radiator with Digital Turn-Down Capability

NASA's proposed lunar lander, Altair, will be exposed to vastly different external environment temperatures. The challenges to the active thermal control system (ATCS) are compounded by unfavorable transients in the internal waste heat dissipation profile: the lowest heat load occurs in the coldest environment while peak loads coincide with the warmest environment. The current baseline for this fluid is a 50/50 inhibited propylene glycol/water mixture with a freeze temperature around -35 C. While the overall size of the radiator's heat rejection area is dictated by the worst case hot scenario, a turn-down feature is necessary to tolerate the worst case cold scenario. A radiator with digital turn-down capability is being designed as a robust means to maintain cabin environment and equipment temperatures while minimizing mass and power consumption. It utilizes active valving to isolate and render ineffective any number of parallel flow tubes which span across the ATCS radiator. Several options were assessed in a trade-study to accommodate flow tube isolation and how to deal with the stagnant fluid that would otherwise remain in the tube. Bread-board environmental tests were conducted for options to drain the fluid from a turned-down leg as well an option to allow a leg to freeze/thaw. Each drain option involved a positive displacement gear pump with different methods of providing a pressure head to feed it. Test results showed that a start-up heater used to generate vapor at the tube inlet held the most promise for tube evacuation. Based on these test results and conclusions drawn from the trade-study, a full-scale radiator design is being worked for the Altair mission profile.

Sunada, Eric↗
NASA NTRS2005

Feed-Back Moisture Sensor Control for the Delivery of Water to Plants Cultivated in Space

The development of a spaceflight-rated Porous Tube Insert Module (PTIM) nutrient delivery tray has facilitated a series of studies evaluating various aspects of water and nutrient delivery to plants as they would be cultivated in space. We report here on our first experiment using the PTIM with a software-driven feedback moisture sensor control strategy for maintaining root zone wetness level set-points. One-day-old wheat seedlings (Tritium aestivum cv Apogee; N=15) were inserted into each of three Substrate Compartments (SCs) pre-packed with 0.25-1 . mm Profile(TradeMark) substrate and maintained at root zone relative water content levels of 70, 80 and 90%. The SCs contained a bottom-situated porous tube around which a capillary mat was wrapped. Three Porous Tubes. were planted using similar protocols (but without the substrate) and also maintained at these three moisture level set-points. Half-strength modified Hoagland's nutrient solution was used to supply water and nutrients. Results on hardware performance, water usage rates and wheat developmental differences between the different experimental treatments are presented.

Levine, Howard G.↗
DOE OSTI2025

Mechanistic insights into N 2 O formation as a side product in NH 3 -SCR over small pore Cu-zeolites

Here, the present contribution provides clarity to N 2 O formation mechanisms and key influencing factors during low temperature NH 3 -SCR, with the goal of enabling the rational design of advanced SCR catalysts with low greenhouse gas impact. By studying more than 50 small pore Cu-exchanged zeolite SCR catalyst samples, including model catalysts synthesized in our laboratories and state-of-the-art industrial catalysts, we explored a wide range of factors affecting N 2 O formation. These factors included Cu loading, support Si/Al ratio, support topology, catalyst aging, reaction temperature and reactant feed composition effects. We probed N 2 O formation under both steady-state SCR, and during NH 4 NO 3 decomposition via temperature programmed desorption (TPD). Finally, we used DFT to probe energetics of possible N 2 O formation pathways. Based on these studies, we confirm that low temperature N 2 O formation occurs via multiple reaction pathways that all involve NH 4 NO 3 and are supported by Cu moieties that facilitate in-situ NO oxidation to NO 2 .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS2021

Importance of Trade Dependencies for Agricultural Inputs: A Case Study of Finland

Approximately 80% of the world's population lives in countries that are dependent on food imports to sustain an adequate food supply. Besides these food imports, further dependencies also arise due to the requirements for agricultural inputs, including energy, fertilisers, feed and agricultural machinery. While the trade of agricultural inputs is relatively well represented in economic analysis, the quantification is often in terms of monetary values, and thus the assessments of the actual input quantities are very limited. In this paper, we develop a framework for analysis of the traded input quantities at the country-level and demonstrate its utility through an in-depth analysis of Finland's dependency on agricultural inputs. Further, we assess the importance of these inputs for domestic food production from a resilience perspective. We find that Finland, a country with relatively high food self-sufficiency but also a great dependency on imported agricultural inputs, experienced an increase in its dependency over the period 1996-2016. In case of trading partners, the story is more mixed: while trading partners for soybeans increased, those decreased in case of electricity while no significant change was observed in other commodities. In Finland, the rapeseed dependency on imports (ratio of net imports and consumption) grew from around 0% to almost 50% between the years 1987-2013. Changes for electricity remained substantially smaller, with dependency only slightly growing during the study period. Crude oil and soybean supplies are totally dependent on imports as neither is produced in Finland. Interestingly, the highest dependencies for agricultural inputs were on different countries than that for foodstuff imports. Thus, when identifying and assessing approaches to increase resilience to trade-related shocks, it is essential to understand both foodstuff and agricultural input dependencies within the global food system.

trade dependencies↗
DOE OSTI2023

Acquisition of Rickettsia rickettsii (Rickettsiales: Rickettsiaceae) by Haemaphysalis longicornis (Acari: Ixodidae) through co-feeding with infected Dermacentor variabilis (Acari: Ixodidae) in the laboratory

Abstract Haemaphysalis longicornis (Neumann) is an invasive ixodid tick originating from eastern Asia which recently has become established in the United States. In its native range, this tick can transmit several pathogens to animals and humans, but little is known about its ability to acquire and transmit pathogens native to the United States. Geographic overlap with ticks such as Dermacentor variabilis (Say), a known vector of Rickettsia rickettsii, makes investigation into the interactions between H. longicornis and D. variabilis of interest to the public health community. Previous studies have shown that H. longicornis can serve as a competent vector of R. rickettsii under laboratory settings, but there is little information on its ability to acquire this pathogen via other biologically relevant routes, such as co-feeding. Here, we assess the ability of H. longicornis nymphs to acquire R. rickettsii through co-feeding with infected D. variabilis adults on a vertebrate animal model under laboratory conditions. The median infection prevalence in engorged H. longicornis nymphs across 8 cohorts was 0% with an interquartile range (IQR) of 4.13%. Following transstadial transmission, the median infection prevalence in flat females was 0.7% (IQR = 2.4%). Our results show that co-feeding transmission occurs at low levels in the laboratory between these 2 species. However, based on the relatively low transmission rates, this may not be a likely mechanism of R. rickettsii introduction to H. longicornis.

Entomology↗
NASA NTRS1980

Solar power satellite offshore rectenna study

It was found that an offshore rectenna is feasible and cost competitive with land rectennas but that the type of rectenna which is suitable for offshore use is quite different from that specified in the present reference system. The result is a nonground plane design which minimizes the weight and greatly reduces the number of costly support towers. This preferred design is an antenna array consisting of individually encapsulated dipoles with reflectors supported on feed wires. Such a 5 GW rectenna could be built at a 50 m water depth site to withstand hurricane and icing conditions for a one time cost of 5.7 billion dollars. Subsequent units would be about 1/3 less expensive. The east coast site chosen for this study represents an extreme case of severe environmental conditions. More benign and more shallow water sites would result in lower costs. Secondary uses such as mariculture appear practical with only minor impact on the rectenna design. The potential advantages of an offshore rectenna, such as no land requirements, removal of microwave radiation from populated areas and minimal impact on the local geopolitics argue strongly that further investigation of the offshore rectenna should be vigorously pursued.

Source record↗
NASA NTRS1989

Hybrid propulsion technology program. Volume 1: Conceptional design package

A concept design study was performed to configure two sizes of hybrid boosters; one which duplicates the advanced shuttle rocket motor vacuum thrust time curve and a smaller, quarter thrust level booster. Two sizes of hybrid boosters were configured for either pump-fed or pressure-fed oxygen feed systems. Performance analyses show improved payload capability relative to a solid propellant booster. Size optimization and fuel safety considerations resulted in a 4.57 m (180 inch) diameter large booster with an inert hydrocarbon fuel. The preferred diameter for the quarter thrust level booster is 2.53 m (96 inches). As part of the design study critical technology issues were identified and a technology acquisition and demonstration plan was formulated.

Jensen, Gordon E.↗
NASA NTRS2017

Estrous Cyclicity of Mice During Simulated Weightlessness

Hindlimb unloading (HU) is a rodent model system used to simulate weightlessness experienced in space. However, some effects of this approach on rodent physiology are under-studied, specifically the effects on ovarian estrogen production which drives the estrous cycle. To resolve this deficiency, we conducted a ground-based validation study using the HU model, while monitoring estrous cycles in 16-weeks-old female C57BL6 mice. Animals were exposed to HU for 12 days following a 3 day HU cage acclimation period, and estrous cycling was analyzed in HU animals (n22), normally loaded HU Cage Pair-Fed controls (CPF; n22), and Vivarium controls fed ad libitum (VIV; n10). Pair feeding was used to control for potential nutritional deficits on ovarian function. Vaginal cells were sampled daily in all mice via saline lavage. Cells were dried and stained with crystal violet, and the smears evaluated using established vaginal cytology techniques by two individuals blinded to the animal treatment group. Estrous cyclicity was disrupted in nearly all HU and CPF mice, while those maintained in VIV had an average normal cycle length of 4.8 0.5 days, with all stages in the cycle visibly observed. CPF and HU animals arrested in the diestrous phase, which precedes the pre-ovulatory estrogen surge. Additionally, infection-like symptoms characterized by vaginal discharge and swelling arose in several HU animals, which we suspect was due to an inability of these mice to properly groom themselves, andor due to the change in the gravity vector relative to the vaginal opening, which prevented drainage of the lavage solution. Pair-feeding resulted in similar weight gains of HU and CPF (1.5 vs 3.0, respectively). The current results indicate that pair-feeding controlled weight gain and that the HU cage alone influenced estrous cyclicity. Thus, longer acclimation needs to be tested to determine if and when normal estrous cycling resumes in non-loaded mice in HU cages prior to HU testing. Future studies might also examine whether modifications to the vaginal lavage procedure might prevent the onset of the infection-like symptoms, and allow estrous cyclicity to be measured in this model system.

fertilit↗
DOE OSTI2022

Adapting isotopic tracer and metabolic flux analysis approaches to study C1 metabolism

Single-carbon (C1, or one-carbon) substrates are promising feedstocks for sustainable biofuel and biochemical production. Crucial to the goal of engineering C1-utilizing strains for improved production is a quantitative understanding of the organization, regulation and rates of the reactions that underpin C1 metabolism. 13 C Metabolic flux analysis (MFA) is a well-established platform for interrogating these questions with multi-carbon substrates, and uses the differential labeling of metabolites that results from feeding a substrate with position-specific incorporation of 13 C in order to infer quantitative fluxes and pathway topology. Furthermore, adapting isotopic tracer approaches to C1 metabolism, where position-specific substrate labeling is impossible, requires additional experimental considerations. Here we review recent studies that have developed isotopic tracer approaches to overcome the challenge of uniform metabolite labeling and provide quantitative insight into C1 metabolism.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Separation of volatile organic contaminants from water using a direct-contact dehumidifier: An experimental study and modeling

A packed-bed, direct-contact dehumidifier (PB-DCD) has been developed to selectively condense water from a gaseous mixture of organic contaminants. In this process, hot air is humidified by mixing with wastewater vapor in a static mixer and is dehumidified by subcooled fresh water passing through the PB-DCD in a counter-current configuration. The goal of this study is to understand the relationship between various operating parameters and how they affect separation of isopropyl alcohol (IPA) from the gaseous mixture with the purpose of expanding the investigation to other contaminants in the future. The process has been successfully used to separate IPA from wastewater. Different parameters including the concentration of IPA in water, feed temperature, air-to-vapor ratio, and cooling-water-to-vapor mass ratio, as well as residence time were examined to determine their influence on contaminant separation and clean water recovery rate. The Buckingham Pi theorem was applied to reduce the number of studying variables by generating non-dimensional groups. Experiments were performed to determine the relationship between the non-dimensional parameters and model mass transfer in the system. Mass transfer coefficients for multicomponent gaseous mixture condensation in a packed-bed direct contact condenser column are calculated and a modified correlation of mass transfer is developed. The parameters of the mass transfer model are obtained from operating conditions of the PB-DCD, stream conditions and thermodynamic properties. A modified Sherwood correlation is developed to predict IPA separation from a gaseous mixture consisting of air, water, and IPA. The modified Sherwood correlation is applied to successfully predict the Sherwood number with a mean absolute error equal to 6.6 %. According to the experimental results, the maximum IPA separation achieved was 76.3 %, which corresponds to a water recovery rate of 58.7 %.

42 ENGINEERING↗