Techno-economic Analysis of MEA CO2Capture from a Cement Kiln - Impact of Steam Supply Scenario

This paper present the techno-economic assessment of an MEA-based CO2capture from a cement plant and the importance of the steam supply on the costs. The evaluations present the energy performances of the CO2capture process based on a cement plant with a clinker capacity of 3,000 t/d. The cost evaluation lead to a cost of cement of 45 â¬/tcementwithout capture, while the cost of cement with CO2capture is estimated to 81 â¬/tcement, resulting in a CO2avoided cost of 83 â¬/tCO2,avoided. As the steam consumption accounts for close to half of the CO2avoided cost, the impact of six alternative steam supply scenarios are considered. The evaluations show that the CO2avoided cost can decrease by up to 35% depending on the steam supply and electricity price. However the possibility of these steam supply alternatives are specific to the considered cement plant, emphasizing therefore that CO2avoided cost from cement shall rather be given as a range depending on the steam supply than as a unique value as often illustrated in the literature

Design and off-design analyses of a pre-combustion CO2 capture process in a natural gas combined cycle power plant

In this study, a cycle designed for capturing the greenhouse gas CO2 in a natural gas combined cycle power plant has been analyzed. The process is a pre-combustion CO2 capture cycle utilizing reforming of natural gas and removal of the carbon in the fuel prior to combustion in the gas turbine. The power cycle consists of a H2-fired gas turbine and a triple pressure steam cycle. Nitrogen is used as fuel diluent and steam is injected into the flame for additional NOx control. The heat recovery steam generator includes pre-heating for the various process streams. The pre-combustion cycle consists of an air-blown auto-thermal reformer, water–gas shift reactors, an amine absorption system to separate out the CO2, as well as a CO2 compression block. Included in the thermodynamic analysis are design calculations, as well as steady-state off-design calculations. Even though the aim is to operate a plant, as the one in this study, at full load there is also a need to be able to operate at part load, meaning off-design analysis is important. A reference case which excludes the pre-combustion cycle and only consists of the power cycle without CO2 capture was analyzed at both design and off-design conditions for comparison. A high degree of process integration is present in the cycle studied. This can be advantageous from an efficiency stand-point but the complexity of the plant increases. The part load calculations is one way of investigating how flexible the plant is to off-design conditions. In the analysis performed, part load behavior is rather good with efficiency reductions from base load operation comparable to the reference combined cycle plant.© 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0

Thermal efficiency of coal-fired power plants: From theoretical to practical assessments

The improvement in thermal efficiency for coal to power processes is increasingly important due to concerns on CO2 emissions. This paper presents a systematic study on direct combustion coal to power processes with respect to thermodynamic, technical and economic factors. Traditional exergy analysis focuses on irreversibilities in existing processes, while the new methodology investigates the thermal efficiency from its theoretical maximum to practical values by adding irreversibilities one by one. As a result of the study presented in this paper, various measures for increasing the thermal efficiency are investigated and the corresponding improvement potential is presented. For a reference power plant, the exergy of the coal feed is calculated to be 1.08 times the lower heating value. The actual thermal efficiency is 45.5%. The irreversibilities are caused by the combustion reaction, heat transfer between flue gas and water/steam, low temperature heat losses, the steam cycle, and other factors. Different measures to increase the thermal efficiency of the reference plant by 0.1% points are presented. The minimum thermal efficiency penalty related to CO2 capture is 2.92–3.49% points within an air factor range of 1.0–1.4 when the CO2 is 100% recovered.acceptedVersion© 2015. This is the authors’ accepted and refereed manuscript to the article. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0

The role of process synthesis in the systematic design of energy efficient fossil fuel power plants with CO2 capture

CO2 capture and storage has a potential of reducing CO2 emissions from large point sources such as fossil fuel power plants. CO2 capture is associated with substantial capital expenditures, operational expenditures dominated by high energy use and potential operational restrictions on the underlying industrial processes. The main focus of significant research efforts worldwide is thus to reduce investment costs and improve efficiency of capture technologies. The systematic methodologies developed in our group at SINTEF/NTNU for design of energy efficient fossil fuel power plants with CO2 capture are presented and show the importance of utilizing process synthesis in the design of such plants. These methods range from targeting minimum capture work for different CO2 capture processes, optimization methods for process design of pre- and post-combustion capture processes, developing surrogate models for optimization.publishedVersion© 2013 AIDIC Servizi S.r.l. This is an open access article

Process design of onboard membrane carbon capture and liquefaction systems for LNG-fueled ships

This study proposes an onboard membrane carbon capture and liquefaction system for LNG-fueled ships to satisfy the IMO’s 2050 greenhouse gas reduction targets. The exhaust gas from a natural gas ship has a low CO2 fraction (∼3%) and high O2 fraction (∼16%) compared to the flue gas from power plants. Herein, considering the above distinguishing features, a membrane carbon capture and liquefaction system has been proposed that is energy efficient and compact for the application of ships. To ascertain the performance of the proposed membrane-based system, it is compared to an amine-based onboard system in terms of energy consumption and major equipment size. This work evaluates four process configurations by varying the number of membrane stages and associated liquefaction processes at different CO2/N2 selectivity and CO2 permeance. The results show that energy consumption (3.98 GJe/tLCO2) is higher than the amine-based system (3.07 GJe/tLCO2) at the CO2/N2 selectivity of 50, but it can be decreased to 3.14 and 2.82 (GJe/tLCO2) with an improved selectivity of 100 and 150, respectively. The major equipment size decreases to 54%, 28%, and 20% of the amine-based system when the permeance is 1000, 2000, and 3000 GPU, respectively. The results indicate that the new onboard membrane carbon capture and liquefaction system can be a competitive solution for the IMO’s greenhouse gas reduction targets for 2050.Process design of onboard membrane carbon capture and liquefaction systems for LNG-fueled shipsacceptedVersio

Integrating direct air capture with small modular nuclear reactors:understanding performance, cost, and potential

Direct air capture (DAC) is a key component in the transition to net-zero society. However, its giga-tonne deployment faces daunting challenges in terms of availability of both financial resources and, most of all, large quantities of low-carbon energy. Within this context, small modular nuclear reactors (SMRs) might potentially facilitate the deployment of DAC. In the present study, we present a detailed thermodynamic analysis of integrating an SMR with solid sorbent DAC. We propose different integration designs and find that coupling the SMR with DAC significantly increases the use of thermal energy produced in the nuclear reactor: from 32% in a stand-alone SMR to 76%-85% in the SMR-DAC system. Moreover, we find that a 50-MW SMR module equipped with DAC could remove around 0.3 MtCO2 every year, while still producing electricity at 24%-42% of the rated power output. Performing a techno-economic analysis of the system, we estimate a net removal cost of around 250 €/tCO2. When benchmarking it to other low-carbon energy supply solutions, we find that the SMR-DAC system is potentially more cost-effective than a DAC powered by high-temperature heat pumps or dedicated geothermal systems. Finally, we evaluate the potential of future deployment of SMR-DAC in China, Europe, India, South Africa and the USA, finding that it could enable up to around 96 MtCO2/year by 2035 if SMRs prove to be cost-competitive. The impact of regional differences on the removal cost is also assessed.</p

Techno-economic Assessment of Optimised Vacuum Swing Adsorption for Post-Combustion CO2 capture from Steam-Methane Reformer Flue Gas

This study focuses on the techno-economic assessment integrated with detailed optimisation of a four step vacuum swing adsorption (VSA) process for post-combustion CO2 capture and storage (CCS) from steam-methane reformer dried flue gas containing 20 mol% CO2. The comprehensive techno-economic optimisation model developed herein takes into account VSA process model, peripheral component models, vacuum pump performance, scale-up, process scheduling and a thorough cost model. Three adsorbents, namely, Zeolite 13X (current benchmark material for CO2 capture) and two metal–organic frameworks, UTSA-16 (widely studied metal–organic framework for CO2 capture) and IISERP MOF2 (good performer in recent findings) are optimised to minimise the CO2 capture cost. Monoethanolamine (MEA)-based absorption technology serves as a baseline case to assess and compare optimal techno-economic performances of VSA technology for three adsorbents. The results show that the four step VSA process with IISERP MOF2 outperforms other two adsorbents with a lowest CO2 capture cost (including flue gas pre-treatment) of 33.6 € per tonne of CO2 avoided and an associated CO2 avoided cost of 73.0 € per tonne of CO2 avoided. Zeolite 13X and UTSA-16 resulted in CO2 avoided costs of 90.9 and 104.9 € per tonne of CO2 avoided, respectively. The CO2 avoided costs obtained for the VSA technology remain higher than that of the baseline MEA-based absorption process which was found to be 66.6 € per tonne of CO2 avoided. The study also demonstrates the importance of using cost as means of evaluating the separation technique compared to the use of process performance indicators. Accounting for the efficiency of vacuum pumps and the cost of novel materials such as metal–organic frameworks is highlighted. © 2020 Elsevier B.V.acceptedVersio

Optimal capacity design of amine-based onboard CO2 capture systems under variable marine engine loads

The International Maritime Organization has adopted a strategy aiming for net-zero greenhouse gas emissions from international shipping, prompting various mitigation technologies to comply with this strengthened strategy. Carbon capture technologies are increasingly being considered to satisfy the IMO strategy. In particular, amine-based carbon capture technologies, which are emerging as the most mature option, have been proposed for onboard application. However, the conventional design approach for onboard carbon capture systems, which assumes a fixed high engine load (75–100%), does not reflect ship operations in a low engine load range, consequently leading to oversizing and unnecessary capital investment. This study designs five MEA-based onboard carbon capture systems with different capacities (sizes) based on the exhaust gas conditions. The study investigates the off-design performance over the entire engine load range while maintaining the capacity of the capture systems at their design values. To identify the optimal capacity of the onboard carbon capture system, the off-design performance is applied to an actual sailing profile in order to quantify the energy requirement, potential CO2 reduction rate, and capture cost. The results show that smaller systems can reach a similar level of CO2 reduction as other larger systems while reducing capture costs. This means that it is possible to reduce capture costs by decreasing the capture capacity while maintaining the carbon reduction potential. The small capacity capture system also achieves a more competitive CO2 avoidance cost (236 € per tonne) compared to biofuel (304 € per tonne) for a similar CO2 avoidance rate (59%). Thus, this study demonstrates a new approach to the design of amine-based onboard carbon capture systems under variable engine loads and presents the potential of the decarbonization technology for shipping industry.Optimal capacity design of amine-based onboard CO2 capture systems under variable marine engine loadspublishedVersio

D5.3 Studies on CLC-CCS deployment and infrastructure development

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