Tons Of Oxygen Research Articles

A novel pathway for achieving efficient integration of SOFC/SOEC and addressing photovoltaic duck curve challenge

This study presents a novel method that directly integrates SOFC oxy-fuel combustion and SOEC co-electrolysis to tackle the challenges of high-energy consumption of SOFC/SOEC integration and photovoltaic duck curve. To explore the viability of this method, a biomass-solar complementary scenario is pioneered and its performance is assessed from thermodynamic and economic standpoints. The results show that the studied scenario achieves CHP and exergy efficiencies of 50.67% and 43.68% with the corresponding total product cost rate (Ċtot) of 45.44 $/h and the levelized cost of products (cp) of 14.61 $/GJ under the design conditions. The system annually produces 17485 tons of freshwater and 1432 tons of oxygen. Exergy analysis identifies the afterburner (AB-II) and supercritical CO2 recompression power cycle (SCRPC) as the primary contributors to exergy destruction with 381.74 kW and 343.62 kW, which alone account for over half of the total irreversibility. Increasing the isentropic efficiency of gas turbine (ηGT) and SOFC operating pressure (Pop) improves the overall thermodynamic performance, but enhancing SOFC current density and gasification temperature has adverse effects. Across varying Pop andηGT, there exist optimal Ċtot (44.83 $/h) and cp (14.47 $/GJ), which are obtained at ηGT of 80% and Pop of 600 kPa, as well as at ηGT of 87.14% and Pop of 800 kPa, respectively. This research can provide a reference for the development of cyclic energy storage technologies and the low-carbon transition in the energy fields.

An Assessment of Urban Forest Landscape Services for Green Space Management Improvement in Bandung City, West Java, Indonesia

In the Bandung metropolitan area, urban forests (UFs) play a crucial role in providing landscape services, especially within the Babakan Siliwangi Urban Forest (BSUF). The BSUF is currently facing multiple development challenges, necessitating scientific evidence to elucidate its role in Bandung's urban landscape. This research analyzes the BSUF’s function in carbon storage, carbon sequestration, and oxygen production and to formulate management recommendations to provide optimal future benefits. Data collection was carried out in 14 sample plots and i-Tree Eco was used to analyze landscape services and predict future vegetation structure based on planned plantings. The findings reveal that (1) BSUF has a high tree diversity, with a 3.3 Shannon index and 41 tree species identified; (2) it stores 381 tons of carbon, sequesters 25.17 tons of carbon annually, and produces 65.07 tons of oxygen per year; (3) to enhance landscape services value for the next 30 years, a minimum 300 trees must be planted per year. These results demonstrate the BSUF’s significance and the importance of tree diversity in sustaining landscape services provided by UF. Additionally, this research introduces i-Tree Eco as a valuable tool for conducting vegetation analysis, aiding stakeholders in monitoring and formulating improved landscape management strategies.

The establishment of the national key ecological functional zone and the county’s ecological green development

Ecological green development is the development of conforming to nature and promoting the harmonious coexistence of man and nature. As the most basic and supportive grassroots political unit, the county level occupies a special key position in the overall national green development strategy. How to evaluate the ecological green development of the county, protect the green earth, and respond to climate change, have become a new problem facing various countries around the world. To this end, China is determined to implement the establishment of a national key ecological functional zone pilot policy to study its ecological green development from the perspective of the county. Based on the literature review and theoretical mechanism, this paper selects 1997 county-level data indicators in mainland China from 2007 to 2019 to explore the role of the establishment of national key ecological function areas on the ecological green development of counties. The implementation of the national key ecological function zone policy can significantly increase the vegetation normalization index by about 0.035–0.037 units. The implementation of the policy has greatly expanded the capacity and range of above-ground and below-ground biomass. The reduction of large-scale investment by the government, the improvement of quality and efficiency of enterprises in the region, and the increase artificial afforestation are important transmission mechanisms for the implementation of policies to affect the green development of counties. The implementation of the policy has a positive green spillover effect on adjacent areas, which can realize regional coordinated ecological governance. Each additional hectare of artificial afforestation can absorb about 134,800 tons of carbon emissions each year, bringing additional benefits of 730 million yuan. It releases about 98,000 tons of oxygen a year, which can be used for 1.312 billion people for oxygen respiration consumption every year.

Mars Oxygen ISRU Experiment (MOXIE)-Preparing for human Mars exploration.

MOXIE [Mars Oxygen In Situ Resource Utilization (ISRU) Experiment] is the first demonstration of ISRU on another planet, producing oxygen by solid oxide electrolysis of carbon dioxide in the martian atmosphere. A scaled-up MOXIE would contribute to sustainable human exploration of Mars by producing on-site the tens of tons of oxygen required for a rocket to transport astronauts off the surface of Mars, instead of having to launch hundreds of tons of material from Earth’s surface to transport the required oxygen to Mars. MOXIE has produced oxygen seven times between landing in February 2021 and the end of 2021 and will continue to demonstrate oxygen production during night and day throughout all martian seasons. This paper reviews what MOXIE has accomplished and the implications for larger-scale oxygen-producing systems.

Peculiarities of formation of oxygen productivity of broadleaved stands in kyiv region under diverse forest growth conditions

The research presents the results of assessment of oxygen productivity of deciduous stands in Kyiv city and Kyiv region as one of the basic ecosystem functions of forest plant communities in urban conditions. Quantitative assessment of oxygen productivity is based on the use of a "semi-empirical" method of evaluation of net primary production, which considers it as an analogy to the annual increase in total productivity of live biomass (or total live biomass growth). In total, the assessment of oxygen productivity of forests in Kyiv region covers the forested area of over 75 thousand hectares in twenty-one type of forest growth conditions. We have established that deciduous forests in Kyiv region produce more than 4 million tons of oxygen annually, at the same time the mean oxygen productivity in the studied stands is more than 17 t·ha-1·year-1. Almost 75% of these oxygen volumes are produced by hardwood stands. Peculiarities of formation of forests’ oxygen productivity in different types of forest growth conditions have been determined within this research. In particular, forest plant communities in fairly infertile conditions (1.98 million tons) account for almost 50% of oxygen produced, including more than 1 million tons of oxygen produced by stands in fresh fairly infertile conditions (C2). A significant influence of forest growth conditions type on the indices of intensity of oxygen productivity in the studied stands was established. The highest values of mean oxygen productivity are typical for plantations in fresh fertile and fairly fertile conditions – 26.9 and 23.2 t·ha-1·year-1, respectively. Net oxygen productivity in these types of forest growth conditions is 10.8 and 8.9 t·ha-1·year-1, respectively. The obtained results serve as an information basis for ecological monitoring of the impact of forest ecosystems of the region on the state of recreational potential in Kyiv region.

Kentsel yeşil alanlardaki ekosistem servislerinin hesaplanması: Eugene Pioneer Mezarlığı, Eugene, Oregon (ABD)

Objective: The objective of this study was to quantify four regulating ecosystem services; carbon sequestration and storage, avoided run-off, air pollution removal by trees and oxygen production in the Eugene Pioneer Cemetery, OR (USA).
 Material and Methods: For data preparation the field data of trees was collected on paper data sheets. Collected data in the field were land-use type, tree species, diameters of breast height-DBH (cm), total tree height (m), live crown height (m), crown base height (m), and crown percent missing. In data analysis I-Tree Eco model version 6 developed by the U.S. Forest Service, Northern Research Station was used.
 Results: The gross sequestration of the cemetery trees is about 7,136 metric tons of carbon per year. Trees in the cemetery were estimated to store 1,610 metric tons of carbon. The trees and shrubs of the cemetery help to avoid run-off by an estimated 452 cubic meters a year. It was estimated that trees remove 143,9 kilograms of air pollutions. Trees in the cemetery were estimated to produce 19,03 metric tons of oxygen per year.
 Conclusion: This study recommends large green areas (large permeable surfaces) and trees with large crowns in the planting design as a better solution for regulating ecosystem services.

(Invited) Electrolysis at a Distance: Challenges to Autonomous Operation of MOXIE on Mars

Currently on Mars aboard the Perseverance rover, the Mars Oxygen ISRU Experiment (MOXIE) is a prototype of a system that will someday provide many tons of oxygen as the major component of the propellant for a Mars Ascent Vehicle that will return astronauts from the Red Planet.MOXIE (Figure 1) first collects, filters, and compresses the thin Martian air, which consists of 95% CO2 and small amounts of nitrogen and argon at a pressure of <10 mbar, using a custom scroll pump developed by Air Squared, Inc. It then pre-heats the gas to ~800˚C and injects it into a stack of 10 solid oxide electrolysis cells (SOXE) developed by Ceramatec, Inc. (now OxEon Energy). CO2 is thermally and catalytically decomposed according to the reaction CO2 → CO + O2- at the cathode of the electrolysis cells, then the oxygen ions are selectively drawn through the yttriumstabilized zirconia electrolyte where they recombine at the anode into O2 molecules. The transfer of 4 electrons from anode to cathode completes the circuit and provides the motive force for the reaction. The pure oxygen product is characterized, then released through a precision aperture, while CO fuel and unused CO2 are similarly characterized and discharged through an exhaust port.MOXIE expects to produce 6-10 grams of 98% pure O2 per hour, a factor of ~200 less than will eventually be needed on a full-scale system.Planning of MOXIE operations is dominated by the need to maintain safe conditions while at the same time exploring the limits of performance and characterizing the state of the system. As shown in Figure 2, the voltage across the MOXIE cells, the flow rates, and the SOXE temperature need to be carefully balanced to avoid crossing Boudouard boundaries. MOXIE is typically operated in a constant-current mode, introducing uncertainties into the operating voltage. To compound these uncertainties, there are significant voltage drops elsewhere in the system across series resistances that are dominated by the Inconel electrical leads. Determining the variation of performance with SOXE temperature is a one method used to distinguish the resistance across the membrane, which is a strong function of temperature, from those series resistances.Subsequent runs will evaluate operation at different inlet flows and SOXE temperature, and will test alternative control configurations such as voltage-feedback control instead of current-feedback control or cathode pressure feedback control of compressor speed. Development of a “smart” control system is a high priority for future work and will be explored in a laboratory setting during the MOXIE campaign. Acknowledgement: MOXIE is supported by a collaboration between NASA’s Human Exploration and Operations Mission Directorate and the Space Technology Mission Directorate. The Mars 2020 mission is supported by the Science Mission Directorate.

Peculiarities of growth, development and climate-stabilizing significance of pine plantations of the Ukrainian Carpathians

Peculiarities of growth and development of pine forest plantations in the Ukrainian Carpathians by forestry districts: Precarpathian, Mountain Carpathian and Transcarpathian plains and foothills are determined. Mathematical dependences of pine growth and development on age, height and diameter are offered. According to the obtained mathematical empirical dependences, it was established that Scots pine (Pinus sylvestris L.) grows and develops better in the Mountain Carpathian forest district. In the Mountain Carpathian Forestry County, the growth of pine is dominated by 2% for the Precarpathian forest district, and in Transcarpathian plains and foothills by 1%. By completeness in the Gorge of Cocarpathian forestry County, the diameter of the pine is higher than the Carpathian forest county on the 3%, and the Transcarpathian plains and the foothills — 1%. Using the Microsoft Excel data analysis package, correlation matrices were constructed and regression and variance analysis of such indicators as: age, height, diameter, phytomass — wood, bark, and crown was performed. Mathematical equations were obtained, which made it possible to establish the biological productivity of Pinus sylvestris L. Using the obtained empirical equations according to the methods of IPCC (Intergovernmental Panelon Climate Change, 2015), G. Matthews (1993) and I.Ya. Liepa (1980) established the carbon-absorbing and oxygen-forming capacity of pine tree plantations at the age of 70 on an area of 1 ha. It is determined that on the area of 1 ha pine plantations absorb the most carbon — 88.9 tons, and produce oxygen — 262.2 tons in the Mountain Carpathian Forestry District, in the Precarpathian Forestry District 76.0 tons of carbon and 224.1 tons of oxygen, in the Transcarpathian plains and foothills Scots pine absorbs 69.5 tons of carbon and produces 204.9 tons of oxygen. The amount of CO2 emissions into the environment in the conditions of the Ukrainian Carpathians is analyzed, it was established that pine forests reduce carbon dioxide emissions by 32%.

Peculiarities of growth, development and climate-stabilizing significance of fir plantations of the Ukrainian Carpathians

Peculiarities of growth and development by diameter of fir forest plantations in the Ukrainian Carpathians by forestry districts: Precarpathian, Mountain Carpathian and Transcarpathian plains and foothills are determined. Mathematical dependences of completeness and growth of white fir (Abies alba Mill.) On age and height and on age and diameter are offered. According to the obtained mathematical empirical dependences, it is established that white fir grows better in the forest-growing districts of the Mountain Carpathian and Transcarpathian plains and foothills. In these forest districts the growth of Abies alba Mill. prevails by 5% in the Pre-Carpathian forest district. In the district of the Transcarpathian plains and foothills, the diameter of the fir is higher than the Mountain Carpathian district by 12%, and the Precarpathian region by 17%. The Microsoft Excel data analysis package builds correlation matrices and establishes close relationships between age, height, diameter and phytomass by individual fractions. Regression and disperse analysis were performed and mathematical dependences were obtained. The biological productivity of Abies alba Mill in the Ukrainian Carpathians was established with the help of equations. According to the methods of IPCC (Intergovernmental Panelon Climate Change, 2015), G. Matthews (1993) and I.Ya. Liepa (1980) established the carbon-absorbing and oxygen-forming capacity of white fir at the age of 70 on an area of 1 ha in the forest vegetation districts of the Carpathians. It has been determined that on the area of 1 ha fir plantations absorb the most carbon — 117.6 tons, and produce oxygen — 346.6 tons in the Transcarpathian plains and foothills, and in the forestry districts of the Carpathian and Precarpathian Abies alba Mill. absorbs 89.2 tons of carbon and produces 262.9 tons of oxygen. Analyzing the annual emissions of carbon dioxide into the environment of the Ukrainian Carpathians for the period 2010–2020, it was found that the average emissions were 18.6 million tons. It was determined that fir forests reduce carbon dioxide emissions by 30%.

A Review of Southeast Asian Oil Palm and Its CO2 Fluxes

Palm oil production is a key industry in tropical regions, driven by the demand for affordable vegetable oil. Palm oil production has been increasing by 9% every year, mostly due to expanding biofuel markets. However, the oil palm industry has been associated with key environmental issues, such as deforestation, peatland exploitation and biomass burning that release carbon dioxide (CO2) into the atmosphere, leading to climate change. This review therefore aims to discuss the characteristics of oil palm plantations and their impacts, especially CO2 emissions in the Southeast Asian region. The tropical climate and soil in Southeast Asian countries, such as Malaysia and Indonesia, are very suitable for growing oil palm trees. However, due to the scarcity of available plantation areas deforestation occurs, especially in peat swamp areas. Total carbon losses from both biomass and peat due to the conversion of tropical virgin peat swamp forest into oil palm plantations are estimated to be around 427.2 ± 90.7 t C ha−1 and 17.1 ± 3.6 t C ha−1 year−1, respectively. Even though measured CO2 fluxes have shown that overall, oil palm plantation CO2 emissions are about one to two times higher than other major crops, the ability of oil palms to absorb CO2 (a net of 64 tons of CO2 per hectare each year) and produce around 18 tons of oxygen per hectare per year is one of the main advantages of this crop. Since the oil palm industry plays a crucial role in the socio-economic development of Southeast Asian countries, sustainable and environmentally friendly practices would provide economic benefits while minimizing environmental impacts. A comprehensive review of all existing oil plantation procedures is needed to ensure that this high yielding crop has highly competitive environmental benefits.

Ecological functions of forest stands in urbanized environment of Moscow

In urban forests, stock production is not the main function of stands. Carbon sequestration, the release of oxygen and phytoncides, dust precipitation, and changing wind conditions et al. are the main environmental functions. Phyto-organic substances emitted by trees help to reduce the number of microorganisms in air make the air cleaner and fresher. The purpose of the study is to evaluate the ecological functions of forest stands based on long-term observations of the forest stands of the Forest Experimental District of the Russian State Agrarian University - Moscow Timiryazev Agricultural Academy. The study used data about 7 permanent trial plots in natural pine stands, 7 - in pine plantations (planting density - 32 000 trees per 1 ha), 13 - in larch plantations (planting density - 700-4000 trees per 1 ha), 8 - in oak stands (natural stands and plantations) and 9 - in birch stands (natural stands and plantations). For a year, 1 ha of forest covered area produces 10 tons of oxygen, and the entire territory of the Forest Experimental District produces about 2.5 thousand tons of oxygen. In the year, the stands of the Forest Experimental District absorb about 3 thousand tons of carbon dioxide. The forest stands of the Forest Experimental District are capable of precipitating 135 tons of dust and they emit about 130 tons of phytoncides into the air during the growing season. Under urban conditions, forest stands are subject to the influence of negative factors: emissions from industrial enterprises and transport, recreational loads, disruption of natural conditions, and many others. Negative factors lead to a decrease in the performance of ecological functions. Therefore, in urban forests it is necessary to carry out silvicultural measures to increase the sustainability and productivity of stands.

Modeling air pollutant removal, carbon storage, and CO2 sequestration potential of urban forests in Scotlandville, Louisiana, USA

Abstract: Understanding an urban forest’s structure, function, and value can promote management decisions that will improve environmental quality and human health. Using i-Tree Eco software and its sampling and data collection protocol, an assessment of the baseline condition, ecological function, and value of the urban forests in Scotlandville (Louisiana, USA) was conducted during 2014. A stratified (by land use type) random sample plot map of the town was generated. Data from 170 field plots located throughout Scotlandville were collected, including tree species, diameter at breast height, total tree height, height to live top, height to crown base, crown width, crown dieback, crown light exposure, percent impervious surface under the tree, and direction and distance to building. Data were then entered into i-Tree Eco v5.0 and analyzed. Modeling results indicated that there are a total of 31 species and an estimated 239.000 trees in Scotlandville with a tree canopy cover of 23.7 percent; the three most common species are Black willow (Salix nigra), Water oak (Quercus nigra), and American elm (Ulmus americana); the overall tree density is 77 trees per hectare and trees with diameters of more than 15 cm (6 inches) constitute 56.5% of the population. The model estimated that annually, the urban forests in Scotlandville remove 96 tons of air pollutants; gross sequestration is about 3.880 tons of carbon and net carbon sequestration is about 3.650 tons. Each year, trees in Scotlandville are estimated to store 88.700 tons of carbon, produce 9.720 tons of oxygen, reduce runoff by 121.200 m3, reduce energy-related costs by $324.000 USD, and provide an additional $52.595 in value by reducing the amount of carbon released by power plants (a reduction of 739 tons of carbon emissions). The structural value for Scotlandville community forest is estimated at $185 million and the annual ecological functional value is estimated at 9 million USD. These results provide baseline information for management recommendations to maximize the ecological benefits provided by trees.

Comparative Analysis of Oxygen Production for Oxy-combustion Application

Oxy-combustion is presently considered as the most promising technology to enable the capture of CO2 from fossil fuel based power plants. The concept of oxy-combustion is to use oxygen instead of air for the combustion process and to achieve a high concentration of CO2 in the flue gas. In this technology an exemplary 1 GWe thermal power plant will require daily about 18 000 tons of oxygen. A potential implementation of oxy-combustion on significant for power generation scale, would create the necessity of the oxygen production capacity increase by at least an order of magnitude in comparison to the present production rate. The paper categorizes the oxygen production methods and validates them with respect to oxy-combustion requirements. Present development in cryogenic air separation installations will be presented. A special attention is paid to sorption methods (TSA, PTSA) making use of heat cogenerated in thermal power plants. A novel use of high capacity heat pumps in air separation systems is proposed.

A captured asteroid : Our David's stone for shielding earth and providing the cheapest extraterrestrial material

The issue of protecting the Earth against an asteroid impact is very popular and many concepts have been proposed to fulfil this objective. In this paper, we develop the idea of capturing a small size asteroid from an orbit close to Earth's in terms of energy and placing it into a loose Earth-bound orbit in order to use it as a shield by engineering its collision with any incoming, threatening body prior to its impact with the Earth. The operations for turning the captured asteroid into an efficient shield appear to be quicker, easier, cheaper and safer than an mission aimed at landing on an incoming impact-bound asteroid either for altering its trajectory or attempting to destroy it. The aim is an asteroid typically 20–40 m in diameter, too small to cause damage on Earth if an improper management leads to its crash, but big enough to destroy and deviate any incoming body if a collision is engineered with it preferably at more than one million km from Earth. Such a collision could be implemented within a 8 month time frame. Such an asteroid would also be a source of material such as liquid oxygen for exploratory missions. We show that the production of this material is much more efficient from an asteroid's surface than from the Moon's. As the celestial surface most accessible from Earth, a captured asteroid is also easier to engineer. Several thousands of tons of oxygen might become available sitting on the outer rim of Earth's gravity field. We examine the advantages and drawbacks of this concept and we propose a stepped approach for making it a reality within a foreseeable future. Key factors are first the detection of a candidate, whose small size make it difficult to spot, among a population of asteroids easy to reach from the Earth. We have identified such a potential candidate in 2000SG344 and describe the parameters of its capture. The second key point is how to deviate the candidate into an loose Earth bound orbit. Our preferred concept is to deposit a small robotic instrument aimed at throwing up matter gathered on the surface of the body with typical velocities of tens of meters per second. The robot would require a year and a few hundreds of watts continuously to alter the velocity of the asteroid in such a way as to inject it through an Earth–Sun Lagrange point, and then to control a Lagrangian quasi-periodic orbit with a typical 6-month period. We conclude that such an enterprise is far from being unfeasible and that it can probably be conducted using today's systems and exploratory tools in a few years time frame.

Industry gets tons of oxygen...with no capital investment

Industry gets tons of oxygen...with no capital investment

Industry gets tons of oxygen...with no capital investment

Industry gets tons of oxygen...with no capital investment