CO2 Discharge Research Articles

Scope for reductions in the cost of CO2 capture using flue gas scrubbing with amine solvents

A previous IEA GHG study of CO2 capture from a pulverized coal (PC) power plant using an amine solvent for flue gas scrubbing has been used as the basis for calculations of the reductions in electricity and CO2 avoidance costs that might be achievable through improved thermodynamic integration between the CO2 capture plant and the steam cycle, the use of a solvent with lower regeneration energy requirements and solvent storage to allow rapid load changes and electricity ‘storage’. It was predicted that the efficiency penalty for CO2 capture for PC plant with flue gas scrubbing using an amine solvent can be reduced to 20 per cent (from 28 per cent) with improved thermodynamic integration and lower-energy solvent, giving a 10 per-cent reduction in electricity costs, from $63.5/MW h to $57.4/MW h, and a 25 per cent reduction in the cost of CO2 avoid from $45/t to $34/t. These values are both lower than predictions for the gasifier-based coal power plant in the original IEA GHG study. Reductions in the average cost of electricity of 6–7 per cent were estimated using solvent storage, giving a cost of electricity of $56.73/MW h and $33/t CO2 avoided for an integrated plant with monoethanolamine (MEA) as the solvent. Also, CO2 venting would allow an additional 20-25 per cent increase in output to be maintained indefinitely when $/MW h electricity prices were 2–3 times greater than the $/t penalty for CO2 discharges.

The Optimal Cost Allocation For Urban Transport Management

Many researchers have discussed the grounds for higher priority of investment in urban mass transit systems within the context of the Downs-Thomson's paradox. The optimal cost allocation of the introduction of a new transit system between urban transit users was examined as the second best pricing problem constrained by the binary mode choice/assignment model and restriction of the CO2 discharge in the urban transport network in Gifu city, Japan. Results show that the effects of introducing a guideway bus system are limited in the city because its urban transit system is inclined to very heavy automobile use. However, charging for automobile use is possible. Furthermore, if the public transit agency operating the guideway bus system were to be subsidized by profits from automobile charges, substitutable transport modes could be made available for automobile users. This combination policy is the most effective way to transfer urban transport demand from automobiles to the public transit system.

中国のエネルギー開発戦略と研究

The current world energy resource system is changing from the petroleum age to the petroleum natural gas age. The general trend of the energy development in the world is to develop clean, high quality and efficient energy, to pay more attention to the environment issues such as ozone layer depletion, CO2 discharge and acid rain, to devote all efforts to raise the utilization efficiency, and to save energy, i.e. to reduce energy consumption. They have become important basis to formulate the policy and strategy for energy development over the world.To well coordinate the relationship among sustained development of economy and science, energy supply and environment protection in China, it has been followed with interest by all of the colleagues in the world. Based on that issue and the theory of existence, in this paper we introduce and analyse the status, progress, scientific research and developing strategy for the development and utilization of energy in China. Finally, we have discussed the prospects for the cooperation in science and technology between China and Japan.

Development of a New Polyester-Based Polymerization Toner

Synthesized superior toner with intension of protection of environment is developed aiming energy saving and environment lord decreasing. The new polymerization toner is synthesized with new manufacturing method that utilized ester elongate reaction of a pre-polymer. The new polymerization toner is superior to usual polymerization toners in low temperature fixing. It consists of polyester resins, while usual toners consist of styrene-acrylic copolymers. The futures of new polymerization toner are as follows;(1) Energy saving by low temperature fixing with polyester resins.(2) High image quality and reduction of 40% in toner consumption (the antecedent machine ratio) by super fine toner.(3) Superior characteristics in toner cleaning process.(4) Reduction of 35% in environmental load (as CO2 discharge).

Estimation of Carbon Dioxide Reduction Based on Modal Shift of Freight Transportation

The global warming due to the increase of greenhouse gases such as carbon dioxide, i. e., CO2, is the most serious and important issue in the global environmental problems. In this paper, a simple analysis is indicated in order to estimate the reduction of CO2 based on modal shift of freight transportation from motor trucks to merchant shipping or railroads with a view to protect global warming by using several statistical data on CO2 discharge in Japan. The analytical result shows that the modal shift plan proposed by the present paper is very effective for the reduction of CO2 in comparison with a few another countermeasures and it makes a great contribution for the goal of CO2 reduction following Kyoto Protocol to the United Nations Framework.

Experimental study of negative corona discharge in pure carbon dioxide and its mixtures with oxygen

The products of a negative corona discharge in both pure CO2 and mixtures of CO2 + O2 have been studied using a coaxial cylindrical electrode geometry with particular emphasis on the production of ozone. The discharge current in pure CO2 was found to be highly sensitive to the presence of trace concentrations of molecular oxygen and to changes in the flow speed through the discharge. The effect of dissociative electron attachment to ozone on the discharge current was studied by measurements of ozone and CO production. The ozone concentration increases monotonically with increasing content of oxygen in the mixture with carbon dioxide, whereas the CO concentration exhibits a flat maximum for oxygen concentrations of around 4%. A simple kinetic model of the dominant chemical processes is described and compared with the experimental results.

Past and present circulation of CO2-bearing fluids in the crystalline Gran Paradiso Massif (Orco Valley, north-western Italian Alps): tectonic and geochemical constraints

In the Orco Valley, inside the Gran Paradiso Massif, 3 main fault systems are present: (a) E–W striking faults dipping at 45–60° to the N, (b) high-angle NW–SE striking faults, and (c) high-angle NE–SW to NNE–SSW striking faults. The E–W striking faults and the interposed NW–SE-faults appear to represent a cogenetic structural association related to a larger scale transtensional shear zone, while the NE–SW faults are probably inherited by an older discontinuous deformation stage. Breccia bodies or veins, mostly consisting of carbonate (siderite–ankerite±calcite)+quartz with sulphide–Au mineralisation, recording a multistage mesothermal evolution, occur along both E–W and NW–SE fault systems. Three water types are recognised: type I, Ca2+–HCO3− waters, with minor SO42−; type II, (Ca2+/Na+)–HCO3− waters varying towards Na+–(HCO3−/Cl−) waters; and type III, Mg2+–HCO3− waters. Type I and type III groundwaters are freshly recharged waters, only slightly exchanged with rocks. Type II includes waters which come into contact with carbonate fracture fillings, and geochemical modelling indicates that dissolution of carbonates along fractures is the main process controlling the groundwater chemistry. These waters evolve in a system open to uprising CO2, and their strongly negative δ13CCO2 suggests a substantial organic component in the CO2 discharge. In the past, CO2-bearing fluids were likely responsible for the formation of Fe-bearing carbonate fracture fillings. The persistence through time of the CO2 flux in the region has important implications for the reconstruction of the Alpine tectonic evolution and deep structure.

WOODCHAR AS A SUSTAINABLE REDUCTANT FOR IRONMAKING IN THE 21ST CENTURY

Presently, 850 million tons of steel is being produced in the world, mainly through the basic oxygen furnace (BOF) and electric arc furnace (EAF) route. The iron demand is met by hot metal produced in blast furnaces and smelting reduction units, whereas the cold metal is supplied as recycled scrap and sponge iron/HBI manufactured in DRI plants. This current practice uses fossil fuels (e.g., coke, coal, oil, and natural gas) as a source for chemical and thermal energy requirements and discharges CO2 as waste gas. This amounts to nearly 6% of the total CO2 discharge in the world. Due to mass awareness regarding global warming and its ill effects, the world has agreed to minimize CO2 emission, which was the main content of the KOYOTO Protocol signed in 1997. Motivated by the world opinion, efforts are being made to develop a renewable energy source for ironmaking to mitigate the effect of CO2.In this paper, the possibility of using woodchar as a reductant and energy source for ironmaking is explored in a scientific and rational way. The need for such an approach is explained in this paper. The basic principles of wood production are outlined with merits and limitations of its use. The woodchar preparation method is given before comparing the properties of woodchar with coke for use in ironmaking. The conceptual methods of ironmaking visualized for periods up to the years 2020, 2021–2040, and beyond 2041 are mentioned in brief. The paper concludes with a remark that intensive R & D may be needed to revive the use of woodchar in the future to mitigate global warming.

Study on Distributed Generators Arrangement in Urban Area Using GIS: Case Study in Tokyo's 23 Wards, Japan

From the viewpoint of global-warming prevention, it is asked for the curtailment of the amount of CO2 discharge in the advanced countries including Japan internationally. In Kyoto COP3 (The 3rd Session of the Conference of the Parties to the United Nations Framework Convention on Climate Change) in 1997, Japan is lifting the target value which will cut down the amount of CO2 discharge 6% in 2010 compared with 1990. In this study, a planning and evaluation system for introducing distributed generators in city level was built using GIS. An arrangement planning of the distributed generators in the Tokyo's 23 wards was performed using the planning and evaluation system. Curtailment of commercial and residential sector's energy and CO2 discharge was calculated from the field of energy-saving nature, environmental-preservation nature, and enterprise nature. The result showed that when the unused energy and CGS were introduced in 500m mesh, the rate of injection primary energy curtailment and CO2 curtailment became 11.4% and 15.3% in the Tokyo's 23 wards. The amount of CO2 curtailment became the result equivalent to 76% of the amount of required curtailment of Tokyo.

An Overview of CO2 Mitigation Options for Global Warming-Emphasizing CO2 Sequestration Options

CO2 mitigation options have been overviewed from an engineering point of view. There have been proposed a number of mitigation options, which can be divided into three categories; 1. reduction of energy intensity; 2. reduction of carbon intensity; 3. carbon sequestration. In this review paper, various mitigation options are reviewed focusing on the carbon sequestration options.A reduction in energy intensity is essentially an energy saving. A reduction in carbon intensity could be achieved by switching to energy resources with lower carbon contents. Based on the 2001 IPCC report, the mitigation potential related to energy intensity is estimated at 1, 900–2, 600 Mt-C/year in 2010, and 3, 600–5, 050 Mt-C/year in 2020, including other greenhouse gas equivalents. There are additional benefits in implementing these options; they are economically beneficial, and have no associated harmful effects. The carbon sequestration options can be divided into two categories; the enhancement of the natural sinking rates of CO2, and a direct discharge of anthropogenic CO2. The relevant sequestration options in the first category include terrestrial sequestration by vegetation, ocean sequestration by fertilization, and an enhancement of the rock weathering process. In the direct discharge options, the CO2 produced from large point sources, such as thermal power stations, would be captured and separated, then transported and injected either into the ocean or underground. Although the sequestration options are less beneficial in terms of cost per unit CO2 reduction compared to other options, technical developments in sequestration options are necessary for the following reasons; 1. A huge potential capacity for carbon sequestration, 2. carbon sequestration enables a continuous use of fossil fuels, which is unavoidable at the moment, before switching to renewable energy sources. Each sequestration option has advantages and disadvantages in terms of capacity, cost, the time scale of the sequestration, the stability of sequestered CO2, and additional environmental impacts, which depend on the location, time, and amount of sequestration. Thus, reliable evaluations of the mitigation efficiency are essential for each sequestration option upon implementation.

The mutual conversion of CO2 and CO in dielectric barrier discharge (DBD)

Non-equilibrium plasma, which was engendered by dielectric barrier discharge (DBD) was used to analyze the mutual conversion between CO2 and CO. The results showed that the conversion ratio of CO increased monotonously with the increasing voltage. But CO2 was not so. Its conversion ratio reached maximum when the voltage was 3600 V in Ar system. It also showed that the existence of water molecules was more advanageous for the conversion of CO to CO2 in Air system than in oxygen system, and the conversion ratio could reach 75.8% when the relative humidity was 100%. We also discussed the energy yield and energy efficiency, and the result was that high voltage and high concentration of reactant was disadvantageous for energy utilization.

Integration of water treatment, environmental and information technologies: Amagasaki project

The Hanshin Water Supply Authority (HWSA) supplies drinking water to approximately 2.4 million consumers in the Hanshin area, including the city of Kobe. The HWSA has completed a project integrating two aging plants into a new water treatment plant (Amagasaki WTP) with a capacity of 373,000 m3 per day. The Amagasaki WTP has three significant special merits: water treatment, environmental, and information technology. The water treatment system is based on a multiple-barrier concept that estimates the value of water treatment technology not by individual processes, but by the overall performance of the system. The treatment train consists of coagulation/sedimentation, ozonation/activated carbon fluidized-bed adsorption, and coagulation/high-rate filtration, most of which fully utilize upward-flow. The key environmental technology characteristic of the new WTP is its achievement of zero-emissions. This design reduces CO2 discharge from the plant, as well as making it possible to completely recycle the sludge as an alternate material of agricultural and horticultural soils. Improvement of customer relations is a feature of the information technology. The authority provides information on the safety of the finished drinking water, watershed management, and the maintenance of source water quality. A visitors' area and emergency water supply facility for use in disasters have also been set up at the WTP. The Amagasaki WTP started commercial operation in April 2001. The completion of this renovated plant will significantly raise the quality of service to the customers.

Effect of pulsed nanosecond ionisation on the characteristics of an electric-discharge CO2 laser

The possibility of improving the electric discharge stability, increasing the efficiency, and expanding the dynamic operating range of an industrial self-sustained discharge CO2 laser using additional ionisation by high-voltage nanosecond pulses is studied.

Longitudinal disch. CO2 laser with pulsed pre-ionization

A novel pre-ionization scheme of helical transverse-pulsed pre-ionization in a longitudinal discharge CO2 laser is presented. The laser tube is made of glass with inner diameter of 7.5mm and discharge length of 50cm. The laser performance characteristics as functions of parameters, such as pressure, charging capacitance and applied voltage, are investigated. Compared with the same laser structure without pre-ionization, the maximum pulse energy improves by 23%, the optimum electro-optical efficiency increases by 31%, and the specific output energy reaches 26 J/(L·atm).

Multiphase flow dynamics during CO2 disposal into saline aquifers

Injection of CO2 into saline aquifers is described by mass conservation equations for the three components water, salt (NaCl), and CO2. The equations are discretized using an integral finite difference method, and are solved using methods developed in geothermal and petroleum reservoir engineering. Phase change processes are treated through switching of primary thermodynamic variables. A realistic treatment of PVT (fluid) properties is given which includes salinity and fugacity effects for partitioning of CO2 between gaseous and aqueous phases. Chemical reactions and mechanical stress effects are neglected. Numerical simulations are presented for injection of CO2 into a brine aquifer, and for loss of CO2 from storage through discharge along a fault zone. It is found that simulated pressures are much more sensitive to space discretization effects than are phase saturations. CO2 discharge along a fault is a self-enhancing process whose flow rates can increase over time by more than an order of magnitude, suggesting that reliable containment of CO2 will require multiple barriers.

Energy use and emissions due to the manufacture of a forwarder

The aim of the study was to assess the amount of energy input and emissions of CO2, CO, NOx, SOx, N2O, HC, CH4 and particles discharge to the environment in association to the following stages of a forwarder's life cycle; (1) material premanufacturing, (2) fabrication of individual components, (3) assembly of the vehicle, and (4) associated transports. The premanufacturing phase accounted for 65% of the total energy consumption, 70% of the CO2 emissions, 95% of CO emissions and 65% of the NOx emissions. Transports showed the smallest contribution to the environmental impact among the forwarder life cycle phases examined.

Characterization of CO2 Plasma and Interactions with Polypropylene Film

The interactions between CO2 plasma, less degrading than O2 plasma, and polymeric surfaces are studied. CO2 discharge and the relationships between the density of plasma reactive species are analyzed by optical emission spectroscopy and mass spectrometry. The optical emission spectrum was identified and five principal systems of carbon monoxide were assigned: the 4th and 3rd positive systems, Angstrom and 3A systems. Other systems dealing with ionized species CO+2 and CO+ were also found. Mass spectrometry showed that the carbon monoxide and atomic oxygen were created through CO2 dissociation by electronic impact. The detected molecular oxygen coming from the atomic oxygen recombination was associated with the power. The study of plasma/polymer interface showed the consumption of ionized species, the appearance of atomic hydrogen due to methyl groups transformation into exomethylene groups onto the polypropylene surface, and a degradation mechanism dependent on atomic oxygen density in the plasma phase.

P15-03 マイクロガスタービンのコジェネシステム

Construction of Co-generation system with Micro-gasterbine will be necessary to spread widely in the distributed power generation field. Utilization of exhaust gas by co-generation will contribute to reduction of total energy consumption and will be supposed to decrease the discharge of CO2 which is a cause of green house effects, compared to traditional commercial electric power generation system. In this paper features of developed hot water supply system combined with micro-terbine TA-80 engine are stated and single-double effect absorption chiiler/heater applied for air conditioning also. Co-generation system with developed water boiler package and chiller/heater with high energy utilization ratio is found to decrease the discharge of CO2,compared to traditional energy source system which consists of commercial electric power and city gas.

Present and past nonanthropogenic CO2 degassing from the solid earth

Global carbon cycle models suggest that CO2 degassing from the solid Earth has been a primary control of paleoatmospheric CO2 contents and through the greenhouse effect, of global paleotemperatures. Because such models utilize simplified and indirect assumptions about CO2 degassing, improved quantification is warranted. Present‐day CO2 degassing provides a baseline for modeling the global carbon cycle and provides insight into the geologic regimes of paleodegassing. Mid‐ocean ridges (MORs) discharge 1–3 × 1012 mol/yr of CO2 and consume ∼3.5 × 1012 mol/yr of CO2 by carbonate formation in MOR hydrothermal systems. Excluding MORs as a net source of CO2 to the atmosphere, the total CO2 discharge from subaerial volcanism is estimated at ∼2.0–2.5 × 1012 mol/yr. Because this flux is lower than estimates of the global consumption of atmospheric CO2 by subaerial silicate weathering, other CO2 sources are required to balance the global carbon cycle. Nonvolcanic CO2 degassing (i.e., emission not from the craters or flanks of volcanos), which is prevalent in high heat flow regimes that are primarily located at plate boundaries, could contribute the additional CO2 that is apparently necessary to balance the global carbon cycle. Oxidation of methane emitted from serpentinization of ultramafics and from thermocatalysis of organic matter provides an additional, albeit unquantified, source of CO2 to the atmosphere. Magmatic CO2 degassing was probably a major contributor to global warming during the Cretaceous. Metamorphic CO2 degassing from regimes of shallow, pluton‐related low‐pressure regional metamorphism may have significantly contributed to global warming during the Cretaceous and Paleocene/Eocene. CO2 degassing associated with continental rifting of Pangaea may have contributed to the global warming that was initiated in the Jurassic. During the Cretaceous, global warming initiated by CO2 degassing of flood basalts, and consequent rapid release of large quantities of CH4 by decomposition of gas hydrates (clathrates), could have caused widespread extinctions of organisms.

Preparation of Catalytic Filters by the Urea Method and Its Application for Benzene Cracking in H2S-Containing Biomass Gasification Gas

The urea method has been explored to introduce nickel(II) into the pores of ceramic filter substrates to develop a catalytic filter for the combined removal of tars and particles from hot biomass gasification gas. SEM-EDX characterization showed that the above method gave a fairly uniform spatial distribution of nickel throughout the modified filter substrate. It was observed that urea decomposition products such as NH3 and CO2 limited the incorporation of nickel in the filter substrate due to the complexation of NH3 with Ni(II) and loss of impregnation solution by the discharge of CO2. It was demonstrated that the release of CO2 could be suppressed by increasing the starting pH of the impregnation solution. In addition, the urea method was explored to add calcium(II) to the catalyst formulation but it remained unclear if the calcium precursor coprecipitated with the nickel precursor during the urea decomposition or precipitated in the posttreatment of drying. The resulting catalytic filter substrates wer...