| 1. |
- Beiron, Johanna, 1992, et al.
(författare)
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A multiple system level modeling approach to coupled energy markets: Incentives for combined heat and power generation at the plant, city and regional energy system levels
- 2022
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Ingår i: Energy. - : Elsevier BV. - 0360-5442. ; 254
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Tidskriftsartikel (refereegranskat)abstract
- The energy system can be subdivided into interconnected structural levels with differing boundary conditions and objectives. For heat and power generation, these levels may be the: electricity price area (regional); heat price area (city); and production site (power plant). This work presents a multi-system modeling approach for the analysis of investments and operation of combined heat and power (CHP) plants, as optimized on a regional, city, or production site energy system level. The modeling framework, comprising three energy system optimization models at the respective levels, is applied to a case study of Sweden, electricity price area SE3. The modeling levels are optimized separately but linked through electricity and heat prices. The results show that optimized CHP plant investments and operation on the three levels can both align and differ, depending on conditions. With a low biomass price and moderate congestion in transmission capacity into the city, the results from the three levels generally align. Differences arise if the biomass price is increased, which impacts the competitiveness of CHP plants in the region, while city-level CHP investments are mainly determined by the local heat demand and less-sensitive to external changes. The differences indicate a risk for diverging expectations between system levels.
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| 2. |
- Beiron, Johanna, 1992, et al.
(författare)
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Flexibility provision by combined heat and power plants – An evaluation of benefits from a plant and system perspective
- 2022
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Ingår i: Energy Conversion and Management: X. - : Elsevier BV. - 2590-1745. ; 16
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Tidskriftsartikel (refereegranskat)abstract
- Variable renewable electricity generation is likely to constitute a large share of future electricity systems. In such electricity systems, the cost and resource efficiency can be improved by employing strategies to manage variations. This work investigates combined heat and power (CHP) plant flexibility as a variation management strategy in an energy system context, considering the operation and cost-competitiveness of CHP plants. An energy system optimization model with detailed representation of CHP plant flexibility is applied, covering the electricity and district heating sectors in one Swedish electricity price area. The results show that investments in CHP plants are dimensioned based on the demand for district heating rather than electricity. In the system studied, this implies that CHP plant capacity is small relative to electricity system variations, and variation management using CHP plants has a weak impact on the total system cost of supplying electricity and district heating. However, flexibility measures increase CHP plant competitiveness in scenarios with low system flexibility (assuming low availability of hydropower or no thermal energy storage) although investments in CHP capacity are sensitive to fuel cost. It is found that while district heating is the dominant CHP product (constituting 50%–90% of the annual CHP energy output), the dispatchable electricity supply has a high value and comprises around 60% of the annual CHP plant revenue. In all scenarios, operational flexibility of the boiler is more valuable than a flexible steam cycle power-to-heat ratio.
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| 3. |
- Aromada, Solomon Aforkoghene, et al.
(författare)
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Techno-Economic Assessment of Different Heat Exchangers for CO2 Capture
- 2020
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Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 13:23
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Tidskriftsartikel (refereegranskat)abstract
- We examined the cost implications of selecting six different types of heat exchangers as the lean/rich heat exchanger in an amine-based CO2 capture process. The difference in total capital cost between different capture plant scenarios due to the different costs of the heat exchangers used as the lean/rich heat exchanger, in each case, is in millions of Euros. The gasketed-plate heat exchanger (G-PHE) saves significant space, and it saves considerable costs. Selecting the G-PHE instead of the shell and tube heat exchangers (STHXs) will save euro33 million-euro39 million in total capital cost (CAPEX), depending on the type of STHX. About euro43 million and euro2 million in total installed costs (CAPEX) can be saved if the G-PHE is selected instead of the finned double-pipe heat exchanger (FDP-HX) or welded-plate heat exchanger, respectively. The savings in total annual cost is also in millions of Euros/year. Capture costs of euro5/tCO(2)-euro6/tCO(2) can be saved by replacing conventional STHXs with the G-PHE, and over euro6/tCO(2) in the case of the FDP-HX. This is significant, and it indicates the importance of clearly stating the exact type and not just the broad classification of heat exchanger used as lean/rich heat exchanger. This is required for cost estimates to be as accurate as possible and allow for appropriate comparisons with other studies. Therefore, the gasketed-plate heat exchanger is recommended to save substantial costs. The CO2 capture costs of all scenarios are most sensitive to the steam cost. The plate and frame heat exchangers (PHEs) scenario's capture cost can decline from about euro77/tCO(2) to euro59/tCO(2) or rise to euro95/tCO(2).
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| 4. |
- Beiron, Johanna, 1992, et al.
(författare)
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A Case Study of the Potential for CCS in Swedish Combined Heat and Power Plants
- 2021
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Ingår i: 15th Greenhouse Gas Control Technologies Conference 2021, GHGT 2021.
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Konferensbidrag (refereegranskat)abstract
- The global need to reduce anthropogenic CO2 emissions is imminent and might be facilitated by carbon capture and storage (CCS) technologies. Sweden has a goal to reach net-zero emissions by 2045, where negative emissions – and bio-CCS (BECCS) in particular - have been proposed as an important strategy to reach this target at the lowest cost. The Swedish district heating sector constitutes a large potential for BECCS since there is a large number of relatively large biogenic point sources of CO2 in the form of combined heat and power (CHP) plants burning biomass residues from the forest industry. This study provides a multi-level estimation of the impact and potential of CO2 capture and negative emissions in 110 existing Swedish biomass or waste-fired CHP plants, located in 78 local district heating systems. Process models of CHP steam cycles give the impact of absorption-based CCS integration on CHP plant heat and electricity production. The propagation of the plant-level impact to the unit commitment of CHP plants in district heating systems is modelled, and the potential for CO2 capture in each system is estimated. The results indicate that 45-70% of nominal steam cycle district heating generation is retained when integrating carbon capture, depending on the power-to-heat ratio; although the reduced heat output can be moderated by sacrificing electricity generation. In the district heating system context, CCS integration can lead to increased utilization and fuel use of CHP plants, in synergy with increased CO2 capture, but might also lead to greater need for peak heat and/or electricity generation. The total CO2 captured from the 45 CHP plants with modeled CO2 emissions exceeding 150 kton/year could be sufficient to meet a proposed target of 3-10 Mton/year of BECCS by Year 2045.
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| 5. |
- Beiron, Johanna, 1992, et al.
(författare)
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A techno-economic assessment of CO2 capture in biomass and waste-fired combined heat and power plants – A Swedish case study
- 2022
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Ingår i: International Journal of Greenhouse Gas Control. - : Elsevier BV. - 1750-5836. ; 118
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Tidskriftsartikel (refereegranskat)abstract
- The need to reduce global CO2 emissions is urgent and might be facilitated by carbon capture and storage (CCS) technologies. Sweden has a goal to reach net-zero emissions by 2045. Negative emissions and bio-CCS (BECCS) have been proposed as important strategies to reach this target at the lowest cost. The Swedish district heating sector constitutes a large potential for BECCS, with biogenic point sources of CO2 in the form of combined heat and power (CHP) plants that burn biomass residues from the forest industry. This study analyzes the potential of CO2 capture in 110 existing Swedish biomass or waste-fired CHP plants. Process models of CHP steam cycles give the impacts of absorption-based CCS on heat and electricity production, while a district heating system unit commitment model gives the impact on plant operation and the potential for CO2 capture. The results provide a cost for carbon capture and transport to the nearest harbor by truck: up to 19.3 MtCO2/year could be captured at a cost in the range of 45–125 €/tCO2, corresponding to around 40% of the total fossil fuel-based Swedish CO2 emissions. This would be sufficient to meet a proposed target of 3–10 Mt/year of BECCS by 2045.
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| 6. |
- Beiron, Johanna, 1992, et al.
(författare)
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Carbon capture from combined heat and power plants – Impact on the supply and cost of electricity and district heating in cities
- 2023
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Ingår i: International Journal of Greenhouse Gas Control. - 1750-5836. ; 129
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Tidskriftsartikel (refereegranskat)abstract
- The capture and storage of biogenic CO2 emissions from large point sources, such as biomass-combusting combined heat and power (CHP) plants, can contribute to climate change mitigation and provide carbon-negative electricity while supplying district heating in urban areas. This work investigates the impact of retrofitting CO2 capture processes to CHP plants in a city energy system context. An energy system optimization model is applied to a case study of the city Västerås, Sweden, with scenarios involving two existing CHP plants in the city, retrofitted with either a heat-driven (MEA) or an electricity-driven (HPC) carbon capture process. The results show that the CHP plants might be retrofitted with either option without significantly impacting the district heating system operation or the marginal costs of electricity and district heating in the city. The MEA process mainly causes a reduction in district heating output (up to 30% decrease on an annual basis), which can be offset by heat recovery from the capture unit. The electrified HPC process does not impact the CHP plant steam cycle but implies increased import of electricity to the city (up to 44% increase annually) compared to a reference scenario.
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| 7. |
- Beiron, Johanna, 1992, et al.
(författare)
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Combined heat and power operational modes for increased product flexibility in a waste incineration plant
- 2020
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Ingår i: Energy. - : Elsevier BV. - 0360-5442. ; 202
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Tidskriftsartikel (refereegranskat)abstract
- The expected strong expansion of wind power may cause challenges for the electricity system in terms of grid stability, power balance, and increased electricity price volatility. This paper analyses how the new market conditions impact the operational pattern and revenue of a combined heat and power (CHP) plant. The work focuses on product flexibility that enables varied ratios between products; and thermal flexibility, to shift load in time given the differing timescales of heat and power demand. Product flexibility is given by five operational modes: conventional CHP, heat-only, CHP plus frequency response, condensing, and condensing plus frequency response. Optimization and process modeling are combined to study the plant dispatch in current and future electricity market scenarios and with thermal flexibility. The results indicate that load-shifting of heat generation together with condensing operation can increase revenue up to 4.5 M€ and plant utilization up to 100% for a 50 MWel waste-fired plant; but requires a thermal energy storage to meet hourly heat demand. The electricity price profile impacts both the revenue and operational patterns, with low-price periods favoring increased heat generation and frequency response delivery. High average electricity price and price volatility results in increased profitability of product and thermal flexibility.
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| 8. |
- Beiron, Johanna, 1992, et al.
(författare)
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Flexible operation of a combined cycle cogeneration plant - A techno-economic assessment
- 2020
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Ingår i: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 278
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Tidskriftsartikel (refereegranskat)abstract
- The need for flexibility in combined heat and power (CHP) plants is expected to increase due to the strong expansion of wind power in electricity systems. Cost-effective strategies to enhance the flexibility of CHP operation are therefore needed. This paper analyzes three types of flexibility measures for a combined cycle CHP plant and their relative impact on the plant operation and revenue. The types of flexibility are: operational flexibility of the fuel conversion system, product flexibility with variable plant product ratios (heat/electricity/primary frequency response), and thermal flexibility in a district heating network. A modeling framework consisting of steady-state and dynamic process simulation models and optimization model is developed to combine static, dynamic, technical and economic perspectives on flexibility. A reference plant serves as a basis for the process model development and validation, and an energy system model provides input profiles for future electricity price scenarios. The results indicate that product flexibility and thermal flexibility have the highest value for the cogeneration plant (up to 16.5 M€ increased revenue for a 250 MWel plant), while operational flexibility (ramp rate) has a comparatively small impact (<1.4 M€). A wide load span and plant versatility, e.g. electricity and heat generating potential between 0 and 139% of nominal capacity, is beneficial in future energy system contexts, but has a marginal value in the current system. Electricity price volatility is a main driver that increases the value of flexibility and promotes operating strategies that follow the electricity price profile rather than the heat demand.
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| 9. |
- Beiron, Johanna, 1992, et al.
(författare)
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Integration of CCS in Combined Heat and Power Plants in a City Energy System
- 2022
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Ingår i: Proceedings of the 16th Greenhouse Gas Control Technologies Conference (GHGT-16) 23-24 Oct 2022. - : Elsevier BV.
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Konferensbidrag (refereegranskat)abstract
- Carbon dioxide removal (CDR) is expected to play an important role in climate change mitigation. Bio-energy carbon capture and storage (BECCS) is a form of CDR discussed in the Swedish district heating sector where large-scale point sources of biogenic CO2 emissions are found. This work investigates the retrofit of CO2 capture processes to combined heat and power (CHP) plants in a city energy system context, to examine the impact on CHP plant energy output and city energy balances, and the cost-optimal way to integrate and operate the capture processes. An energy system optimization model is applied to a case study of the city Västerås, Sweden, with scenarios involving the retrofit to two existing CHP plants in the city of either a heat-driven (MEA) or electricity-driven (HPC) carbon capture process. The results show that it is possible to retrofit the CHP plants with either of these options without significantly impacting the district heating system operation or the marginal costs of electricity and district heating. The MEA process mainly causes a reduction in district heating output (up to 30% decrease on an annual basis), which can be partly offset with heat recovery from the capture unit, or increased utilization of the CHP plants (if possible). The electrified HPC process does not impact the CHP plant steam cycle, but implies increased import of electricity to the city (up to 44% increase) compared to a reference scenario.
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| 10. |
- Beiron, Johanna, 1992, et al.
(författare)
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The role of BECCS in providing negative emissions in Sweden under competing interests for forest-based biomass
- 2022
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Negative emissions are needed to meet climate mitigation targets and can be achieved through the capture and storage of biogenic CO2 emissions (BECCS). Sweden holds a large potential for BECCS from the industry and heat and power sectors. This work provides a first assessment of how the conditions for BECCS in Sweden are impacted by competition for forest-based biomass from other sectors, in this work represented by production of transportation fuels. An optimization model is applied to study how demand levels for negative emissions and biofuels, and availability of forestry resources, influence the optimal system design considering the electricity, district heating and biomass sectors. BECCS and direct air capture technologies are available for investments in the model. The results show that biomass availability and biofuel demand have a large impact on the choice of negative emission technology, where high competition for biomass favours DACCS rather than BECCS. The available biomass is prioritized for use in fuel production and sets the upper limit for BECCS. In this work, CHP plants are more competitive for BECCS implementation than pulp mills, due to the energy penalty for CHP plants having a smaller impact on the overall energy system performance. The findings indicate that in addition to considering techno-economic assessments of individual technologies, it is important to take into account the system context in which they operate.
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