| 1. |
- Beiron, Johanna, 1992, et al.
(författare)
-
Enhancement of CO2 Absorption in Water through pH Control and Carbonic Anhydrase - A Technical Assessment
- 2019
-
Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 1520-5045 .- 0888-5885. ; 58:31, s. 14275-14283
-
Tidskriftsartikel (refereegranskat)abstract
- This paper provides an industrial-scale technical assessment of absorption of CO2 in water to react into bicarbonate (HCO3−), with the goal of storing HCO3− in the oceans as a carbon sequestration technology. A potential advantage of the process is that it will not require a CO2 transport and storage infrastructure that will be expensive for small-scale and remote emission sources. Process simulations are utilized to estimate absorber column length and for mass flow estimations of water and base required for a target capture rate of 90%. The results indicate that the process is technically feasible under specific conditions, with pH regulation being highly important, although the demand for base represents a limiting factor. Yet, a potential niche for the process is CO2 capture at smaller plants emitting small amounts of CO2.
|
|
| 2. |
- Biermann, Max, 1989, et al.
(författare)
-
Lessons learned from the Preem-CCS project – a pioneering Swedish-Norwegian collaboration showcasing the full CCS chain
- 2022
-
Ingår i: 16th Greenhouse Gas Control Technologies Conference 2022 (GHGT-16).
-
Konferensbidrag (refereegranskat)abstract
- This paper presents the key findings of the Preem-CCS project, a co-funded Swedish-Norwegian R&D collaboration that investigated CO2 capture from the Preem refineries in Sweden, and subsequent ship transport of captured CO2 for permanent storage on the Norwegian Continental Shelf. The project was conducted 2019-2022 and accomplished: 1) the on-site pilot scale demonstration of amine-based CO2 absorption using Aker Carbon Capture’s mobile test unit (MTU), 2) an in-depth investigation of energy-efficient heat supply for CO2 capture, 3) a detailed techno-economic evaluation of a feasible carbon capture and storage (CCS) chain (from CO2 capture in Sweden to ship transport to Norway), and 4) an investigation of relevant legal and regulatory aspects of trans-border CO2 transport between Sweden and Norway.
|
|
| 3. |
- Mocholí Montañés, Rubén, 1990, et al.
(författare)
-
Demonstrating load-change transient performance of a commercial-scale natural gas combined cycle power plant with post-combustion CO2 capture
- 2017
-
Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 63, s. 158-174
-
Tidskriftsartikel (refereegranskat)abstract
- The present work aims to study the transient performance of a commercial-scale natural gas combined cycle (NGCC) power plant with post-combustion CO2 capture (PCC) system via linked dynamic process simulation models. The simulations represent real-like operation of the integrated plant during load change transient events with closed-loop controllers. The focus of the study was the dynamic interaction between the power plant and the PCC unit, and the performance evaluation of decentralized control structures. A 613 MW three-pressure reheat NGCC with PCC using aqueous MEA was designed, including PCC process scale-up. Detailed dynamic process models of the power plant and the post-combustion unit were developed, and their validity was deemed sufficient for the purpose of application. Dynamic simulations of three gas turbine load-change ramp rates (2%/min, 5%/min and 10%/min) showed that the total stabilization times of the power plant's main process variables are shorter (10–30 min) than for the PCC unit (1–4 h). A dynamic interaction between the NGCC and the PCC unit is found in the steam extraction to feed the reboiler duty of the PCC unit. The transient performance of five decentralized PCC plant control structures under load change was analyzed. When controlling the CO2 capture rate, the power plant performs in a more efficient manner at steady-state part load; however, the PCC unit experiences longer stabilization times of the main process variables during load changes, compared with control structures without CO2 capture rate being controlled. Control of L/G ratio of the absorber columns leads to similar part load steady-state performance and significantly faster stabilization times of the power plant and PCC unit's main process variables. It is concluded that adding the PCC unit to the NGCC does not significantly affect the practical load-following capability of the integrated plant in a day-ahead power market, but selection of a suitable control structure is required for efficient operation of the process under steady-state and transient conditions.
|
|
| 4. |
|
|
| 5. |
- Normann, Fredrik, 1982, et al.
(författare)
-
Partial Capture of Carbon Dioxide from Industrial Sources - A Discussion on Cost Optimization and the CO2 Capture Rate
- 2017
-
Ingår i: Energy Procedia. - : Elsevier BV. - 1876-6102. ; 114, s. 113-121
-
Konferensbidrag (refereegranskat)abstract
- This work discusses the cost optimal capture rate of absorption based carbon capture processes by a combination of process simulations and cost-estimation. The influence of the quality of the CO2 source (quantity, continuity and CO2 concentration) and the availability of low cost heat on the absolute and specific capture cost are highlighted. The results stress that partial capture of CO2 could lower the specific capture cost (€/ton CO2) and that the relation between capital expenditure and lowered energy demand should be reconsidered for cases with access to low-cost heat.
|
|
| 6. |
- Òsk Gardarsdòttir, Stefanìa, 1987, et al.
(författare)
-
Challenges for coal based electricity generation in energy systems with high capacity of variable renewable energy sources
- 2016
-
Ingår i: Proceedings of the 41st International Technical Conference on Clean Coal & Fuel Systems.
-
Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- The market conditions for thermal power plants in Europe are changing rapidly with ever increasing share of the supply provided by variable renewable energy sources. Operators are struggling to keep up with the new conditions in a system where power plant flexibility has historically been of less importance. This is however starting to change and in line with this development, the power industry is increasingly interested in R&D work on improving plant flexibility. Based on interviews with several experts within the power industry, a literature review and dynamic power plant modelling this work highlight and discusses important areas of development for flexible coal-based power generation. Four flexibility aspects were specifically emphasized by the experts interviewed; turn-down, part-load efficiency, start-up times and ramp rates. All experts interviewed regarded retrofits of existing plants to be a more likely development than building of new flexible plants and at present, it seems as the focus is mainly to use all low-cost options for increasing plant flexibility. The extent of beneficial effects from increased plant flexibility for both the plant operator, and the electricity system is still unclear. A techno-economic modeling study of power systems combined with dynamic power plant modeling, taking into account the possible development in plant flexibility as highlighted in this work, could further provide valuable insight and underline which flexibility aspects are of most importance to develop.
|
|
| 7. |
- Òsk Gardarsdòttir, Stefanìa, 1987, et al.
(författare)
-
Effects of CO2-absorption control strategies on the dynamic performance of a supercritical pulverized-coal-fired power plant
- 2017
-
Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 1520-5045 .- 0888-5885. ; 56:15, s. 4415-4430
-
Tidskriftsartikel (refereegranskat)abstract
- This work investigates the interactions that occur between a supercritical pulverized-coal-fired power plant and a downstream CO2-absorption process during load changes in the power plant, by linking the dynamic models of the two systems. The derived dynamic model for this integrated system is implemented in the dynamic modeling and simulation software Dymola. The operation of the integrated system is investigated in two modes of operation, considering various power plant loads and levels of steam availability for the CO2-absorption process. Several schemes for control of the CO2-absorption process, which have been suggested in the literature, are implemented for the integrated system and their effects on power plant operation are evaluated. Comparison of the simulation results obtained through varying the power plant load with and without CO2 absorption reveal that the CO2-absorption process has slower process dynamics than the power plant cycle, with the CO2 absorption stabilizing in more than 1 hour, while the power generation generally stabilizes in 6–9 minutes, in the power plant both with and without CO2 absorption. The control scheme used for the CO2-absorption process is important, as pairing of the control variables in relatively slow control loops increases the settling time of the power plant by up to 30 minutes with respect to power output. The results suggest that the investigated CO2-absorption process does not affect significantly the load-following capabilities of the power plant. Redirecting steam from the CO2-absorption process to the low-pressure turbine section in order to increase power generation (during a hypothetical peak-load demand) results in fluctuations of process variables in the power plant during the 2 hours of reduced steam availability to the CO2-absorption process. This is observed for both control schemes applied to the CO2-absorption process, and the power generation is not stabilized until the operation is restored to full load.
|
|
| 8. |
- Òsk Gardarsdòttir, Stefanìa, 1987, et al.
(författare)
-
Improving the flexibility of coal-fired power generators: Impact on the composition of a cost-optimal electricity system
- 2018
-
Ingår i: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 209, s. 277-289
-
Tidskriftsartikel (refereegranskat)abstract
- A transformation of the electricity generation system is required to drastically reduce the associated CO2 emissions. In future systems, variable renewable energy sources (wind and solar) are expected to provide a significant fraction of the electricity supply, increasing the requirement for variation management compared with today´s situation. This paper investigates the impacts of measures designed to increase the competitiveness of coal-fired power plants in future energy systems, which are facing restrictions related to CO2 emissions and variable operation as a consequence of high penetration levels of wind and solar power. We investigate the cost-optimal compositions of three regional electricity generation systems with different conditions for generation using renewables with a linear cost-minimizing investment model. The model is applied in two energy policy scenarios: one with a tight cap on CO2 emissions, and one with a stringent requirement for generation from renewables. In a system with a stringent requirement for electricity generation from renewables but without a CO2 cap, coal-based technologies with improved cycling properties provide variation management, given that the development of measures for ensuring improved flexibility continues and reaches full-scale implementation at moderate cost. The effects of improved cycling properties on the system composition are especially relevant for regions with moderate potential for wind and solar generation, in that they reduce wind curtailment and improve the underlying conditions for investments in solar power. In the system with a tight CO2 cap, only coal-based technologies with Carbon Capture and Storage (CCS) and co-firing of biomass are feasible. Increasing the share of biomass in co-firing technologies to achieve negative CO2 emissions increases the competitiveness of these technologies to a greater extent than if simply the cycling properties are improved. A larger co-firing fraction reduces the total system costs, since it facilitates the provision of low-cost flexibility by Natural Gas Combined Cycle (NGCC) plants, and it is especially important in regions where nuclear power is otherwise cost-competitive, as low-cost flexibility stimulates investments in wind and solar power at the expense of nuclear power.
|
|
| 9. |
- Òsk Gardarsdòttir, Stefanìa, 1987, et al.
(författare)
-
Investment costs and CO2 reduction potential of carbon capture from industrial plants – A Swedish case study
- 2018
-
Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 76, s. 111-124
-
Tidskriftsartikel (refereegranskat)abstract
- In this work, the investment required to apply CO2capture to large-scale industrial sources is assessed and discussed in a case study of Sweden - a highly industrialized region with relative proximity to large and well-documented storage sites in the Norwegian North Sea. The Swedish process industry is characterized by a large share of biogenic emissions, and therefore has a considerable Bio-Energy with Carbon Capture and Storage (BECCS) potential. The capital cost for CO2capture is estimated for a standard MEA-based CO2absorption process. The CO2absorption process is applied to several industries – pulp and paper, oil and gas, steel, cement and chemical production – and dimensioned using process modeling. The equipment cost is subsequently estimated using a detailed individual factor estimation method. The capture costs are compared to estimates of the cost for transport and storage.
|
|
| 10. |
- Òsk Gardarsdòttir, Stefanìa, 1987, et al.
(författare)
-
Post combustion CO2 capture applied to a state-of-the-art coal-fired power plant - the influence of dynamic process conditions
- 2015
-
Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 33, s. 51-62
-
Tidskriftsartikel (refereegranskat)abstract
- A dynamic model of the amine-based CO2-capture process is presented and applied to investigate the transient behavior of the absorption system during and after load changes in Nordjyllandsværket, a state-of-the-art coal-fired power plant with a thermal efficiency of 47.5%. Two scenarios of flexible operation in the power plant are investigated: part-load and peak load operation. Simulations of the load-variation scenarios show that implementation of active control strategies improves capture system performance with respect to capture efficiency and the heat requirement. The reboiler duty can be decreased considerably during part load operation compared to a case where no control strategy is applied. Integration of the capture process with the power plant results in an efficiency decrease of around 9 percentage points at full load and in the range of 8–12 percentage points during 60% part load operation, depending on if a process controller is used or not. Energy requirement for CO2 compression is not included in these numbers. In addition, the response time of the absorption system is significantly decreased in the cases where a process control strategy is implemented, both for part load and peak load operation
|
|
