Evaluating CO2 sources for power-to-gas applications – A case study for Austria

Role of CCS for Emission Reduction from Fertiliser and Cement Industry

CO2 capture and recycle using microalgae was demonstrated at a coal-fired power plant (Duke Energy’s East Bend Station, Kentucky). Using an in-house designed closed loop, vertical tube photobioreactor, Scenedesmus acutus was cultured using flue gas as the CO2 source. Algae productivity of 39 g/(m2 day) in June–July was achieved at significant scale (18,000 L), while average daily productivity slightly in excess of 10 g/(m2 day) was demonstrated in the month of December. A protocol for low-cost algae harvesting and dewatering was developed, and the conversion of algal lipids—extracted from the harvested biomass—to diesel-range hydrocarbons via catalytic deoxygenation was demonstrated. Assuming an amortization period of 10 years, calculations suggest that the current cost of capturing and recycling CO2 using this approach will fall close to $1,600/ton CO2, the main expense corresponding to the capital cost of the photobioreactor system and the associated installation cost. From this it follows that future cost reduction measures should focus on the design of a culturing system which is less expensive to build and install. In even the most optimistic scenario, the cost of algae-based CO2 capture is unlikely to fall below $225/ton, corresponding to a production cost of ~$400/ton biomass. Hence, the value of the algal biomass produced will be critical in determining the overall economics of CO2 capture and recycle.

A multi-rotor medium-voltage wind turbine system and its control strategy

How storage uncertainty will drive CCS infrastructure

With the rapid development of new energy industries, the development of energy storage technology is becoming the focus of attention. Energy storage technology as a process operation of the grid in mining, generation, transmission, distribution, use, storage of six links, plays an important role in grid and distributed generation based on micro-grid system; These technology applications will also bring major changes in the traditional power system design, planning, scheduling, control and so on. Current research is mainly used for energy storage technology of distributed photovoltaic power generation, wind power systems; Energy storage converter played an energy storage system, an important part, between the photovoltaic panels, wind turbines and grid played interface role in achieving the two-way exchange of energy. Firstly, this paper describes the development and the classification of the bidirectional energy storage converter, and analyzes the structure and working principle of the bi-directional DC/DC converter and AC/DC converter topology. Then establish the mathematical model of single-phase PWM rectifier circuit is established, which is based on the rotating coordinate transformation, This paper - investigates the bidirectional flow of energy between network side and energy storage battery through selecting different control strategy to operate the system. According to the current inner loop and voltage outer loop control, the system of energy storage can run steadily.

It is said that 1 i and Mo have good high temperature corrosion resistarlce against impurities in helium gas.Thus, in order to investigate the possibility that corrosion resistance rif alloys might be improved by coating these metals on them, oxidation behavior of superalloys with spray coating of i and Mo was studied at 1 OOOCfor duration up to 600 h in impure helium gas.The principal results are as follows.(I) Mo-coated alloys show not on!yhigh corrosion resistance but also good long term stability because rif absence of dif/ilsion of alloying elements from matrices to coatings.H owever, it is observed that adequate thin coating should be selected to avoid cracking in coating.(2) Ni-coated alloys show lower corrosion resistance than Mo-coated alloys because considerable diffusion of alloying elements takes place from matrices to coatings, though they have higher resistance against cracking than Mo-coated alloys.(3) The jJossibility that superalloys with large quantity of Co would be used as materials Q[ high tem/Jerature parts except reactor core was shown.

Over 20 exocometary belts host detectable circumstellar gas, mostly in the form of CO. Two competing theories for its origin have emerged, positing that the gas is either primordial or secondary. Primordial gas survives from the belt's parent protoplanetary disc and is therefore H_2-rich. Secondary gas is outgassed in situ by exocomets and is relatively H_2-poor. Discriminating between these scenarios has not been possible for belts that host unexpectedly large quantities of CO. We aim to break this gas origin dichotomy through direct measurement of H_2 column densities in two edge-on, CO-rich exocometary belts around ∼15 Myr-old A-type stars, constraining the frac CO H _2 ratio and CO gas lifetimes. Observing edge-on belts enables rovibrational absorption spectroscopy against the stellar background. We present near-IR CRIRES+ spectra of HD 110058 and HD 131488, which provide the first direct probe of H_2 gas in CO-rich exocometary belts. We targeted the H_2 (v=1-0 S(0)) line at 2223.3 nm and the 12 CO v=2̊ightarrow0 rovibrational lines in the range 2333.8-2335.5 nm and derived constraints on column densities along the line of sight to the stars. We detect 12 CO strongly, but not H_2$, in the CRIRES+ spectra. This allows us to place 3σ lower limits on the frac CO H _2 ratios of $> 1.35 $ and $> 3.09 $ for HD 110058 and HD 131488, respectively. These constraints demonstrate that, at least for HD 110058, the exocometary gas is compositionally distinct and significantly H_2-poor compared to the <10^-4 frac 10^ -3 10^ -5 CO H _2 ratios typical of protoplanetary discs. For HD 131488, we further compared the CO photodissociation timescale to the age of the system through simple shielding arguments, and find that we cannot formally rule out a primordial origin; however, we suggest that a more realistic model of CO survival likely supports a secondary origin for this system as well. Overall, a high $ ratio for HD 110058 indicates that the gas in this CO-rich belt is most likely not primordial in composition, supporting the presence of exocometary gas. CO H _2

The photooxidation of glyoxylate by envelope-free spinach chloroplasts and its relation to photorespiration

FTIR analysis of storage behavior and sulfur tolerance in barium-based NOx storage and reduction (NSR) catalysts

Evidence at the Cretaceous/Tertiary boundary suggests that the proposed 'extinction' bolide struck a continental or shallow marine terrane. This evidence includes: shocked quartz and feldspar grains found in the boundary layer inherited from a range of rock types; a high ^(87)Sr/^(86)Sr ratio in some planktonic fossils which could reflect continental-derived Sr(ref.5); and evidence that the platinum-group-element-rich clay layer is underlain (at some localities) by a deposit of possible tsunamic origin. These observations and data demonstrate that sea level at the end of the Cretaceous was ~150-200 m higher than at present, suggesting the possibility that the extinction bolide struck a shallow marine carbonate-rich sedimentary section. Here we show that the impact of such a bolide (~5km in radius) onto a carbonate-rich terrane would increase the CO_2 content of the atmosphere by a factor of two to ten. Additional dissolution of CO_2 from the ocean's photic zone could release much larger quantities of CO_2. The impact induced release of CO_2, by itself, would enhance atmospheric greenhouse heating and give rise to a worldwide increase in temperature from 2 K to 10 K for periods of 10^4 to 10^5 years.

<div class="htmlview paragraph">Hydrogen is one of the better fuels for use in fuel cells. In the production of hydrogen by reacting hydrocarbons with steam, large quantities of CO must be converted to hydrogen by the classical water-gas shift reaction. Newer catalysts operating at low temperatures offer certain advantages over “conventional” catalysts. Several applications, are discussed, illustrating the advantages of the low-temperature CO conversion catalyst (400 F and higher).</div>

Cost-effective reductions in greenhouse gas (GHG) emissions are best achieved when all low-carbon energy resources are fully utilized. This includes base-load power: nuclear energy (NE) and fossil energy (FE), integrated with CO₂ capture, use, and storage (CCUS), and variable renewable energy (VRE) (wind and solar); but, current CCUS options don’t justify CO₂-capture costs and existing energy-storage approaches lack the capacity and storage duration needed to fully utilize all forms of low-carbon energy without curtailment. The Earth Battery is designed to meet these challenges by synergistically integrating conventional- and renewable-energy resources, allowing each to contribute more efficiently to the grid than if operated independently. The Earth Battery stores energy underground as pressure and heat, using compressed air and/or CO₂, together with heated brine. These fluids are stored in either saline aquifers used for CO₂or natural gas (NG) storage or in oil and gas reservoirs, making deployment possible over much of the U.S. We can provide enormous energy-storage capacity and duration. The main goal of this study was to assess the techno-economic feasibility of the versions of the Earth Battery that use compressed air energy storage (CAES). Current CAES systems use NG turbines and store air in salt caverns, which limits geographic deployment. Conventional CAES wastes much of the heat of air compression, comprising half of the compression energy. Our technology addresses these deficiencies by using permeable sedimentary rock to store air and the heat of compression as heated brine. When electricity is needed, air and hot brine are produced, with hot brine used to pre-heat air before it is fed into the expanders. Key factors affecting round-trip efficiency are (1) pressure loss in the air-storage reservoir, which depends on permeability (> 100 mD being needed for efficient operations) and (2) temperature loss in the hot-brine storage reservoir, which decreases with time as the storage formation heats up. The original scope of this project was to conduct a techno-economic assessment of diurnal storage with the CAES Earth Battery, including (1) Adiabatic CAES, which requires no fossil fuel and (2) NG/CAES, where one or more of the expansion stages are NG fueled. During its assessment, we found NG/CAES, generates excess heat of compression that can be put into long-term (seasonal) storage and be utilized in a combined-cycle fashion with the addition of steam turbines. This resulted in our developing a new Earth Battery technology, which we call the Thermal Earth Battery. We conducted energy-system analyses for the Thermal Earth Battery for various combinations of heat sources: (1) heat of FE combustion, (2) excess heat of compression from NG/CAES, and (3) solar thermal energy (STE). The other Earth Battery class we developed compresses CO₂, rather than air; hence, it is called Compressed CO₂Energy Storage (CCES). Finally, we developed an improved, more efficient, more versatile version of the Allam cycle, which uses pressurized CO₂, and developed various options for integrating renewable energy and energy storage. Our improved Allam-cycle technology minimizes cooling-water consumption, while enabling reliable, dispatchable renewable energy. Although not anticipated in our original scope of work, our Topic 1 project evolved into a highly productive discovery process wherein we developed a portfolio of Earth Battery configuration options and use cases. Our ultimate objective was to evaluate those options and use cases and determine the most optimal first best use options for our Earth Battery technology. That process resulted in identifying seasonal energy storage as a niche where no other energy storage technology could compete with us. As a result, we have identified the Thermal Earth Battery, which uses conventional steam-turbine components, and our improved Allam-cycle integrated with renewable energy and energy storage as the most promising technologies to commercialize in our Topic 2 proposal. Finally, our scope included finding a commercialization team for a Topic 2 continuation of this project, which we have successfully completed.

To comply with recent international trends and initiatives, and in order to help achieve sustainable development, Korea has established a greenhouse gas (GHG) emission reduction target of 37% (851 million tons) of the business as usual (BAU) rate by 2030. Regarding environmentally-oriented standards such as the IGCC (International Green Construction Code), there are also rising demands for the assessment on CO2 emissions during the life cycle in accordance with ISO (International Standardization Organization’s Standard) 14040. At present, precast concrete (PC) engineering-related studies primarily cover structural and construction aspects, including improvement of structural performance in the joint, introduction of pre-stressed concrete and development of half PC. In the manufacture of PC, steam curing is mostly used for the early-strength development of concrete. In steam curing, a large amount of CO2 is produced, causing an environmental problem. Therefore, this study proposes a method to assess CO2 emissions (including absorption) throughout the PC life cycle by using a life cycle assessment (LCA) method. Using the proposed assessment method, CO2 emissions during the life cycle of a precast concrete girder (PCG) were assessed. In addition, CO2 absorption was assessed against a PCG using conventional carbonation and CO2 absorption-related models. As a result, the CO2 emissions throughout the life cycle of the PCG were 1365.6 (kg-CO2/1 PCG). The CO2 emissions during the production of raw materials among the CO2 emissions throughout the life cycle of the PCG were 1390 (kg-CO2/1 PCG), accounting for a high portion to total CO2 emissions (nearly 90%). In contrast, the transportation and manufacture stages were 1% and 10%, respectively, having little effect on total CO2 emissions. Among the use of the PCG, CO2 absorption was mostly decided by the CO2 diffusion coefficient and the amount of CO2 absorption by cement paste. The CO2 absorption by carbonation throughout the service life of the PC was about 11% of the total CO2 emissions, which is about 16% of CO2 emissions from ordinary Portland cement (OPC) concrete.

Integrated environmental influences quantification of pilot-scale constructed wetlands based on modified ecological footprint assessment

In urban public spaces, maintaining high power quality is very much needed for reliable and efficient energy consumption. This study aims to develop and validate an effective design method focused on improving urban power quality through the integration of renewable wind energy. This research proposes a novel and unique design method for enhancing and improving power quality in urban areas by connecting the wind energy through the utilization of vertical‐axis wind turbines (VAWTs). The whole concept of the proposed methods involves a structured methodology comprising system modeling, integration of VAWTs with a Unified Power Quality Conditioner (UPQC), and experimental validation to measure voltage stability, total harmonic distortion (THD) and reactive power performance. The UPQC, an advanced power electronic device, operates by combining series and shunt compensators to address a wide range of power quality disturbances simultaneously. The series compensator handles the whole voltage‐related problem and the shunt compensators fully manage and coordinate the current‐related issue. This dual compensation approach ensures synchronized mitigation of both voltage and current disturbances, thereby maintaining consistent grid performance. By utilizing wind energy harnessed from VAWTs, the recommended system provides an alternative and renewable source of power, minimizing dependencies on the conventional grids and improving the overall energy efficiencies. The vertical turbines are chosen due to their excellent adaptability and suitability for all urban environments, where space limitations and varying wind directions at all positions face significant challenges. The research contains a detailed analysis of the performance enhancement brought about by the UPQC in parallel with VAWTs, leading on key power quality metrics. Experimental results show a significant minimization in voltage sags and swells, with the normalized sag values improving by up to 75% and swell values by up to 65%. The method improves power stability and promotes sustainability by combining renewable energy with advanced power electronic solutions in urban areas.