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It is necessary to develop a small positive pressure control system for the closed ecology experiment facility (CEEF) to protect against over-differential pressure loading. In the present study, a numerical method was developed to calculate the quantity of state of the closed module, which is fitted with rubber buffers, for the small positive pressure control system. Experiments to examine the pressure change of the closed module were carried out at CEEF. Comparison of calculated and experimental results showed that the present dynamic simulation is suited to estimating the quantity of state of the closed module.

In CEEF(Closed Ecological Experiment Facility) which is the first Japanese CELSS experiment facility, the ammonia and ammonium nitrate production system is a nitrogen fixation system as a part of nitrogen circulation system. Nitrogen and water which are input materials to the system are processed to produce ammonia water and ammonium nitrate solution as raw materials of fertilizer for plant cultivation. The design basis of the system is to convert 125g/day of nitrogen to ammonia and ammonium nitrate based on the amount of one person's metabolism. Experiment of the system has been carried out and we have studied characteristics of the system.

The Closed Ecology Experiment Facilities (CEEF) have been under construction in northern Japan since 1994. These facilities contain the Closed Plant Experiment Facility (CPEF), as well as other facilities, in all of which, Controlled Ecological Life Support Systems (CELSS) research and development can be conducted. The CPEF includes two Plant Cultivation Modules (PCMs), which contain a PCM consists of three 30m2 closed cultivation rooms illuminated solely by lamps and a 165.1m3 preparation room, and a PCM consists of a 60m2 closed cultivation room illuminated by natural light and supplemental lamps and a 88.8m3 preparation room, and a Material Circulation System (MCS). Measured rate of air exchange between a 30m2 cultivation room and the preparation room was 0.48% hour-1, and that for a 60m2 cultivation room was about 0.11% hour-1. Air leak rate of the PCM as a whole was less than 0.01% hour-1 under isothermal and equal pressure condition.

The Closed Ecology Experiment Facilities (CEEF) were installed to collect data for estimation of transfer of radionuclides from atmosphere to humans in the ecosystem. The first target among the radio-nuclides is 14C. In order to validate function of material circulation in an experimental system constructed in the CEEF, circulation of air constituents, water and materials in waste was demonstrated connecting the Closed Plant Experiment Facility (CPEF) and the Closed Animal and Human habitation Experiment Facility (CAHEF) of the CEEF, since 2005 to 2007. The CPEF has a Plant Cultivation Module (PCM), which comprises of three plant chambers illuminated solely by artificial lighting, one plant chamber illuminated by both natural and artificial lighting, a space for preparation, and an airlock, and a physical/chemical material circulation system.

Rating of daily amounts of CO2 and O2 exchange of crops, animals and humans to be involved in the long-term habitation experiments using the Closed Ecology Experiment Facilities (CEEF) were carried out. Daily amounts of the CO2-absorption and O2-generation of crops including rice, soybeans and other 27 vegetables were estimated from data obtained from a sequential crop cultivation experiment conducted from August to December of FY2001. Daily amounts of O2-consumption and CO2-expiration of two female Shiba goats to be involved were estimated based on gas exchange determination conducted in FY2002. Daily amounts of CO2-expiration and O2-consumption of two persons to be involved were estimated based on correlation between respiration rate and heart rate, heart rate data during the simulated habitation in the CEEF and a tentative work schedule.

In the Closed Ecology Experiment Facilities (CEEF), with integrating the Closed Plantation Experiment Facilities (CPEF) and the Closed Animal Breading & Habitation Facilities (CABHF), closed habitation experiments without material exchange with the outside will be conducted after the 2005 fiscal year. Cultivation experiments of about 30 crops and the integrating test of the material circulation system required for the closed habitation experiments have been performed since 2000 fiscal year. Using data reported in these experiments, material circulation in CEEF is simulated based on the recent operation strategy, and the storage capacity needed for the buffer of an air processing subsystem was estimated. In order for two humans to dwell over 120 days, the storage capacities of the carbon dioxide tank, the oxygen tank, and the waste gas tank in CPEF, and the carbon dioxide tank and the oxygen tank in CABHF are 820 g, 2830 g, 4425 g, 1780 g, and 1792 g, respectively.

A simulation of an open mode system experiment was run using the same experimental conditions as an integration test conducted from September 1999 to February 2000 using the Closed Plant Experiment Facility at the Institute for Environmental Sciences in order to evaluate the operation of closed mode system to be conducted in future. Operation of the open mode system experiment required a supply of water and carbon dioxide from the outside, and the discharge of nutrient waste water and oxygen. The present simulation verified the feasibility of using non-integrated wet-oxidation processor, nutrient synthesis unit and nutrient waste water processor connected within a closed mode system, and it was confirmed that sufficient material circulation could be achieved when rice and soybeans were divided into six beds with different growing stages to facilitate control of the nutrient solution.

A series of experiments to evaluate performance of catalysts for CELSS System Wet-oxidation process has been carried out. Data obtained from the experiments show that the noble metal selected for the catalyst gives a good performance in oxidizing Organic Carbon and Organic Nitrogen. The data also show that a catalyst with certain amount of the metal (wt%) shows maximum efficiency in the oxidation; in addition, a catalyst with a different amount of metal gives good performance in producing high quality fertilizer.

System configurations of water recycling for space use have been continued through theoretical and experimental studies. The water recycling system plays a central role in a Closed Ecological Life Support System (CELSS) which offers necessary environment and life styles in closed environment such as space stations, lunar bases, etc.. Membrane technology is a possible candidate for purifying waste water produced by crew use facility, plant cultivation facility, etc. In considerations of the system compactness realizing energy saving, membrane distillation has been revealed to be a suitable purification process. Ground experiments has been performed using membrane filtration processes and membrane distillation process. Thermopervaporation technology with hydrophobic membrane is utilized in the distillation process. The energy saving is achieved by thermal return of condensation energy.

Many research activities relating the environment control and life support systems to be used in space have been conducted and continued in Japan since 1982 in order to obtain his own manned flight technologies for future Japanese missions. Research and development activities are able to be divided in two phases according mission scheduling such as JEM development to be used in International Space Station now going on and the future Japanese space infrastructures, for examples, Japanese Space Station and Lunar Base. Temperature, humidity, total atmospheric pressure and partial pressure of oxygen and carbon dioxide, necessary for all living things, are to be controlled by the environment control function.

The front half of the nitrogen fixation system, which is one of the subsystems of Controlled Ecological Life Support System (CELSS), or NH3 synthesis loop at atmospheric pressure, was studied. The NH3 separation essential in the loop is discussed. The NH3-PSA method was newly developed, since the NH3-PSA was evaluated best among separation methods from the viewpoints of CELSS criteria. It is essential to retain the H2/N2 ratio in the outlet gas the same as that of the inlet gas to the PSA. From the experimental result of PSA a material balance of the NH3 synthesis loop was calculated. Additionally a material balance of the overall process was calculated by assuming some performances in the down stream sections of the NH3 synthesis loop.

Materials circulating in a closed ecological system are classified as metabolic ones and nonmetabolic ones. Nonmetabolic substances relate to environment constituents and cultural activities. Treatment of these materials are discussed from a view point of CELSS concept. The closed system, CEEF, will be constructed in Japan in the near future. CEEF is an experiment facility with processing capacity of two adult persons, consisting of a plant module, an animal module, a habitat module and supporting facilities for the three modules. The supporting facilities are composed of artificial processors of gases, waters and wastes. The plant module has artificial and natural lighting cultivating sections.

Developments of many subsystems, such as gas separater, water purifier, decomposition unit of waste materials and others, are necessary to construct the closed loop life support test facility for studying the material circulationin earth environment and for human habitation in space. On the other hand, in order to develop and integrate these subsystems infacility, the designing paramaters of each subsystem are to be determined based on the required material flows estimation. The required material flows are very complicated and difficult to be analyzed. Therefore the trade study method for determining the design paramaters of each subsystem is to be integrated based on the break down of system configulation Level as below. Level-0 is the material flow level between the total closed loop life support facility and outside. Level-1 is the material flow level between the plantation, habitat and animal breeding modules and their supporting systems.

Recycling human and animal excreta is an important part of the proposed Closed Ecology Experiment Facility (CEEF) in Japan. This paper introduces a conceptual design for the waste collection and transfer system. Mineral-rich wastes such as urine and wool grease must be separated from other wastes to recover the minerals. Solids and liquids also require separate handling methods. Our design uses inclined conveyer belts to separate feces and urine. A fluorocarbon polymer coating prevents wastes from sticking to the belt. In-line freezers are used to solidify liquid wastes and retard premature decomposition. A summary of available data on animal excreta is included, but there is a distinct shortage of useful information. This data is insignificant for usual biology or animal husbandry, but is essential for designing the self-contained environment.

As a CO2 removing and recovering technology, the solid amine utilized as a vacuum desorbing type was developed. The evaluation experiments to measure fundamental characteristics of this material was conducted using the dry air and as the results, the high adsorbing rate, 10 wt% for short period and 7 wt% for long period was obtained and also 7 wt% of adsorbing rate can be expected for the operation of desorption temperature of 80 °C. High accuracy thermobalance device so called thermogravimetric analyzer was utilized to measure adsorption and desorption values of CO2.

In the closed environments such as manned space station, it is necessary to remove contaminant gas to keep a suitable environment. Removal of gaseous contaminants generated from crew, animals, and plants is important function to keep the environment below the allowable level in the Closed Ecology Experiment Facilities (abbreviated as CEEF). CEEF consist of three modules for habitat, animal and plant, the supporting facilities for each module and a plant cultivation facility. CEEF are scheduled to be constructed from 1994 in Aomori Prefecture, northern part of Japan. For designing Trace Contaminant Control Assembly (TCCA) for CEEF, the following six (6) trace contaminants have been selected as major contaminant gas in CEEF; Ammonia (NH3) Methane (CH4) Ethylene (C2H4) Carbon Monoxide (CO) Nitrogen Dioxide (NO2) Sulfur Dioxide (SO2) Ethylene is well-known as an aggressive contaminant to plant growth and maturity.

The catalytic Wet-Oxidation process is the most feasible candidate for the waste management process of CELSS in comparison with other applicable technologies such as dry incineration, vapor compression distillation, etc. In this report we try and discuss the design of a Wet-Oxidation Waste Management Process which supports 1 person's life in a closed system. The proposed Wet-Oxidation Waste Management process treats the waste by a two-step reaction. Planned capacity is approximately 2.5kg- dry/day. A design concept, schematic flow and basic configuration of Wet-Oxidation apparatus are considered and discussed in this paper.

Selected vegetables for life support are continuously produced in the lunar farming module. Inedible parts of the vegetables are decomposed and provided as the fertilizer elements for the next vegetables. In this report, contained elements in their inedible mass for recyclingare discussed for each of the four vegetables. Elements and concentration of cultural liquid which are required by each vegetable are surveyed as well. Adjustment of decomposition liquid is discussed in view of transforming inedible vegetable to cultural liquid. Authors are proposing wet oxidization as one of the decomposition methods for these inedible parts. Some adjusting sub-system is necessary here, since elements and their concentration in decomposition liquid is not enough to reproduce vegetables. This report aims to clarify the composition of a vegetable production system for an eight-member

We propose a new recovery system for NaCl from human urine. The system has an electrodialysis (ED) part and a crystallization part. Separation and concentration characteristics of the system are discussed for fundamental experiments of the ED and crystallization parts. Concentrated NaCl-KCl mixed solution is obtained using the ED process from simulated oxidized urine and sweat which include Ca2+ and S042- ions. Then, the crystallization process is used to separate about 80% of the NaCl from the ED treated solution. The experimental studies indicate that the mineral recovery system we proposed can recover NaCl from waste water of a CEEF.

Nitrogen Fixation Systems(NFS) suitable for plant cultivation in a closed environment have been studied through experimental verification. The system is composed of physico-chemical processes only. Nitrogen gas and water are fed into the system as raw materials,and ammonia and ammonium nitrate solution are produced as final products, which are utilized as main fertilizers in plant cultivation. Each elemental chemical process in NFS is selected with regard to unique design criteria concerning safety, energy effectiveness, compactness and reliability. An experimental apparatus for important unit processes has been made for the purpose of verifying process data. A detail design for nitrogen fixation facilities, planned for construction as the first Japanese CELSS laboratory, was carried out.