Compact, Lightweight Adsorber and Sabatier Reactor for CO2 Capture and Reduction for Consumable and Propellant Production
The utilization of CO2 to produce (or recycle) life support consumables, such as O2 and H2O, and to generate propellant fuels is an important aspect of NASA’s concept for future, long duration planetary exploration. One potential approach is to capture and use CO2 from the Martian atmosphere to generate the consumables and propellant fuels. Precision Combustion, Inc. (PCI), with support from NASA, continues to develop its regenerable adsorber technology for capturing CO2 from gaseous atmospheres (for cabin atmosphere revitalization and in-situ resource utilization applications) and its Sabatier reactor for converting CO2 to methane and water. Both technologies are based on PCI’s Microlith ® substrates and have been demonstrated to reduce size, weight, and power consumption during CO2 capture and methanation process. For adsorber applications, the Microlith substrates offer a unique resistive heating capability that shows potential for short regeneration time and reduced power requirements compared to conventional systems. For the Sabatier applications, the combination of the Microlith substrates and durable catalyst coating permits efficient CO2 methanation that favors high reactant conversion, high selectivity, and durability. Results from performance testing at various operating conditions will be presented. An effort to optimize the Sabatier reactor and to develop a bench-top Sabatier Development Unit (SDU) will be discussed. Nomenclature
CO2 Recycling into CH4 and H2O over Ru/CeO2 Catalyst Prepared by one-pot Synthesis
CO2 collected from the outdoor atmosphere or produced in an aerospace cabin, may be recycled to produce methane and water by the Sabatier reaction. This reaction is carried out over a catalyst to decrease the reaction temperature and increase the selectivity towards CH4 avoiding CO production. The practice of "in-situ resource utilization" needs a catalyst highly active at low temperatures, highly selective, and stable towards deactivation throughout the duration of the mission. This paper reports the catalytic activity of CeO2 supporting ruthenium (3 wt%), synthesized by the one-pot hydrothermal method followed by a reduction in H2 at 500 °C. Catalyst morphology, and Ru reducibility and dispersion were investigated by XRD, FE-SEMEDS microscopy, BET, H2-TPR and H2-TPD. The catalytic properties for the CO2 methanation were tested at atmospheric pressure with a stoichiometric ratio of the reagents (CO2: H2 = 1: 4). The one-pot synthesis of Ru(3 wt%)/CeO2 produced an unexpected nanocube morphology with a high surface area, favoring a very high Ru dispersion (50%) corresponding to an average particle dimension < 2 nm. The catalyst shows good catalytic performances reaching 70% of CO2 conversion at 350 °C, with 98% of selectivity towards CH4. Carrying out the reaction for 12 hours at 500 °C, the catalyst shows no activity nor selectivity loss, appearing as a reliable catalyst for in-situ resource utilization and atmosphere revitalization processes.
Automatic classification of TV news articles based on telop character recognition
The purpose of this study is to develop a multimedia database system for TV news video data. TV news video data consist of speech, characters and images. In this study, telop characters are recognized and given to the news articles as indices for classification. At first, telop frames which include telop characters are detected and then the telop characters are extracted and recognized. Through morphological analysis of the recognized telop characters, keywords are extracted which consist of more than two characters. Their keywords are used as indices to classify the TV news articles. We carried out experiments for 30 days of NHK 5 minutes news and obtained 95.4% telop character extraction rate, 81.4% character recognition rate and 83.8% article classification rate. We improved the article classification rate by 43.4% through character recognition improvement from 44.1% to 81.4%.