Simulation-based Cost Optimization tool for CO2 Absorption Processes: Iterative Detailed Factor (IDF) Scheme

A simple, fast, and accurate process simulation based cost estimation and optimization scheme was developed in Aspen HYSYS based on a detailed factorial methodology for solvent-based CO2 absorption and desorption processes. This was implemented with the aid of the spreadsheet function in the software. The aim is to drastically reduce the time to obtain cost estimates in subsequent iterations of simulation due to parametric changes, studying new solvents/blends and process modifications. All equipment costs in a reference case are obtained from Aspen In-Plant Cost Estimator V12. The equipment cost for subsequent iterations are evaluated based on cost exponents. Equipment that are not affected by any change in the process are assigned a cost exponent of 1.0 and the others 0.65, except the absorber packing height which is 1.1. The capital cost obtained for new calculations with the Iterative Detailed Factor (IDF) model are in good agreement with all the reference cases. The IDF tool was able to accurately estimate the cost optimum minimum approach temperature based on CO2 capture cost, with an error of less than 0.2%.publishedVersio

Comparative Environmental Life Cycle Assessment of Oxyfuel and Post-combustion Capture with MEA and AMP/PZ - Case Studies from the EDDiCCUT Project

This work presents the results of a comparative life cycle assessment study for three CCS technologies applied to a coal-fired power plant: post-combustion capture with MEA, post combustion capture with AMP/PZ and cryogenic oxy-fuel. This study has been performed in the context of the EDDiCCUT project, which aims to develop an environmental due diligence framework for assessing novel CCUS technologies. The research shows that there are no significant differences in climate change potential (CCP) for the technologies under study. In the three cases the reduction is about 70% (70% for the plant with MEA, 71% for the plant with AMP-PZ, and 73% for the plant with oxy-fuel technology). With regard to other impacts (e.g., acidification, toxicity, resource depletion) the results show an increase in the impacts as consequence of CCS, mostly driven by the increase amount of feedstock per kWh. Contrary to CCS, there are clear differences among the technologies with results ranging between 20 and 30%. Toxicity impacts related to the operation of the solvent-based carbon capture unit were also considered; however, it was observed that their contribution was only around 2% of the total impact for human toxicity potential. Rather, the largest contributor to human toxicity impacts in the life cycle of coal power plants with and without CCS is coal mining waste disposal

Simulation and Impact of different Optimization Parameters on CO2 Capture Cost

The influence of different process parameters/factors on CO2 capture cost, in a standard amine based CO2 capture process was studied through process simulation and cost estimation. The most influential factor was found to be the CO2 capture efficiency. This led to investigation of routes for capturing more than 85% of CO2. The routes are by merely increasing the solvent flow or by increasing the absorber packing height. The cost-efficient route was found to be by increasing the packing height of the absorber. This resulted in 20% less cost compared to capturing 90% CO2 by increasing only the solvent flow. The cost optimum absorber packing height was 12 m (12 stages). The cost optimum temperature difference in the lean/rich heat exchanger was 5 °C. A case with a combination of the two cost optimum parameters achieved a 4% decrease in capture cost compared to the base case. The results highlight the significance of performing cost optimization of CO2 capture processes.publishedVersio

Cost and Emissions Reduction in CO2 Capture Plant Dependent on Heat Exchanger Type and Different Process Configurations: Optimum Temperature Approach Analysis

The performance of a plate heat exchanger (PHE), in comparison with the conventional shell and tube types, through a trade-off analysis of energy cost and capital cost resulting from different temperature approaches in the cross-exchanger of a solvent-based CO2 capture process, was evaluated. The aim was to examine the cost reduction and CO2 emission reduction potentials of the different heat exchangers. Each specific heat exchanger type was assumed for the cross-exchanger, the lean amine cooler and the cooler to cool the direct contact cooler’s circulation water. The study was conducted for flue gases from a natural-gas combined-cycle power plant and the Brevik cement plant in Norway. The standard and the lean vapour compression CO2 absorption configurations were used for the study. The PHE outperformed the fixed tube sheet shell and tube heat exchanger (FTS-STHX) and the other STHXs economically and in emissions reduction. The optimal minimum temperature approach for the PHE cases based on CO2 avoided cost were achieved at 4 °C to 7 °C. This is where the energy consumption and indirect emissions are relatively low. The lean vapour compression CO2 capture process with optimum PHE achieved a 16% reduction in CO2 avoided cost in the cement plant process. When the available excess heat for the production of steam for 50% CO2 capture was considered together with the optimum PHE case of the lean vapour compression process, a cost reduction of about 34% was estimated. That is compared to a standard capture process with FTS-STHX without consideration of the excess heat. This highlights the importance of the waste heat at the Norcem cement plant. This study recommends the use of plate heat exchangers for the cross-heat exchanger (at 4–7 °C), lean amine cooler and the DCC unit’s circulation water cooler. To achieve the best possible CO2 capture process economically and in respect of emissions reduction, it is imperative to perform energy cost and capital cost trade-off analysis based on different minimum temperature approaches.publishedVersio

Critical Factors Influencing CO2 Capture Cost, a Case Study

AbstractThe cost of CO2 capture is a much debated question, and it is an important issue regarding development of CO2 capture plants. The gap in the estimates is so large on a global basis, and they exhibit a great variation based on the geographically location, type of capture technology and whether the plant is based on brown coal (lignite), coal or natural gas. This paper identifies some of the reasons for these gaps, and tries to suggest how capture cost estimates can be made more comparable. Comparing different cost estimates is challenging, and there exist no final answers of what should be included or where such a plant should be located. Battery limits varies from estimated to estimates, and often are the assumption not included when a “cost per ton CO2” is presented. Two cost estimates can only be compared when all the assumptions are showed. Some people and institutes try to reduce the cost as much as they can, trying to make CO2 capture look cheaper than they are, but there are also some groups that would gain on high capture costs. Both ways, the costs is still estimation, and the uncertainty will always be a large question when it comes to cost estimation. But including the assumptions for the estimations is one step forwards to make more comparable cost estimations

Capital cost estimation of CO2 capture plant using Enhanced Detailed Factor (EDF) method: Installation factors and plant construction characteristic factors

Capital cost is frequently estimated for new and retrofit carbon capture plants as new concepts for cost reduction emerge. Capital cost during initial cost estimation of chemical plants strongly depends on the installation factor(s) of the methodology employed. How these installation factors respond to the cost of each equipment determines the total plant cost and the type of capital cost (new plant or modification project) each method is suited for. The effect of equipment installation factors on capital cost of an amine-based CO2 capture plant using the Enhanced Detailed Factor (EDF) method has been studied. Plant construction characteristic factors have also been introduced to account for different plant construction characteristic situations. The impacts of the installation factors of seven methodologies on capital cost were compared. A uniform installation factor will likely lead to overestimation of very expensive equipment and underestimation of less expensive equipment. EDF method's installation factors respond based on each equipment cost. Even though all the methods estimated the optimum in the cross-exchanger to be 15°C, the cost estimated was €66/tCO2 by the EDF method, Smith's percentage of delivered-equipment factorial method and Hand's factorial method; and €69–79/tCO2 by the other methods. The results demonstrate that the EDF method is suitable for estimating capital cost for new plants and modification projects, small and large plants, and accounts for different plants’ situations.publishedVersio

Cost and Emissions Reduction in CO2 Capture Plant Dependent on Heat Exchanger Type and Different Process Configurations: Optimum Temperature Approach Analysis

The performance of a plate heat exchanger (PHE), in comparison with the conventional shell and tube types, through a trade-off analysis of energy cost and capital cost resulting from different temperature approaches in the cross-exchanger of a solvent-based CO2 capture process, was evaluated. The aim was to examine the cost reduction and CO2 emission reduction potentials of the different heat exchangers. Each specific heat exchanger type was assumed for the cross-exchanger, the lean amine cooler and the cooler to cool the direct contact cooler’s circulation water. The study was conducted for flue gases from a natural-gas combined-cycle power plant and the Brevik cement plant in Norway. The standard and the lean vapour compression CO2 absorption configurations were used for the study. The PHE outperformed the fixed tube sheet shell and tube heat exchanger (FTS-STHX) and the other STHXs economically and in emissions reduction. The optimal minimum temperature approach for the PHE cases based on CO2 avoided cost were achieved at 4 °C to 7 °C. This is where the energy consumption and indirect emissions are relatively low. The lean vapour compression CO2 capture process with optimum PHE achieved a 16% reduction in CO2 avoided cost in the cement plant process. When the available excess heat for the production of steam for 50% CO2 capture was considered together with the optimum PHE case of the lean vapour compression process, a cost reduction of about 34% was estimated. That is compared to a standard capture process with FTS-STHX without consideration of the excess heat. This highlights the importance of the waste heat at the Norcem cement plant. This study recommends the use of plate heat exchangers for the cross-heat exchanger (at 4–7 °C), lean amine cooler and the DCC unit’s circulation water cooler. To achieve the best possible CO2 capture process economically and in respect of emissions reduction, it is imperative to perform energy cost and capital cost trade-off analysis based on different minimum temperature approaches

Ship transport – a low cost and low risk CO2 transport option in the Nordic countries

This paper investigates CO2 transport options and associated costs for CO2-sources in the Nordic region. Cost for ship and pipeline transport is calculated both from specific sites and as a function of volume and distance. We also investigate the pipeline volumetric break-even point which yields the CO2 volume required from a specific site for pipeline to become a less costly transport option than ship transport. Finally, we analyze possible effects from injectivity on the choice of reservoir and transport mode. The emission volumes from the Nordic emission sources (mostly industries) are modest, typically between 0.1 to 1.0 Mt per year, while distances to feasible storage sites are relatively long, 300 km or, in many cases, considerably more. Combined, this implies both that build-up of an inland CO2 collection system by pipeline will render high cost and that it is likely to take time to establish transportation volumes large enough to make pipeline transport cost efficient (since this will require multiple sources connected to the same system). At the same time, many of the large emission sources, both fossil based and biogenic, are located along the coast line. It is shown that CO2 transport by ship is the least costly transportation option not only for most of the sources individually but also for most of the potential cluster combinations during ramp-up of the CCS transport and storage infrastructure. It is also shown that cost of ship transport only increases modestly with increasing transport distance. Analyzing the effect of injectivity it was found that poor injectivity in reservoirs in the Baltic Sea may render it less costly to transport the CO2 captured from Finnish and Swedish sources located along the Baltic Sea by ship a further 800-1300 km to the west for storage in better suited aquifers in the Skagerrak region or in the North Sea

Cost and Emissions Reduction in CO2 Capture Plant Dependent on Heat Exchanger Type and Different Process Configurations: Optimum Temperature Approach Analysis

The performance of a plate heat exchanger (PHE), in comparison with the conventional shell and tube types, through a trade-off analysis of energy cost and capital cost resulting from different temperature approaches in the cross-exchanger of a solvent-based CO2 capture process, was evaluated. The aim was to examine the cost reduction and CO2 emission reduction potentials of the different heat exchangers. Each specific heat exchanger type was assumed for the cross-exchanger, the lean amine cooler and the cooler to cool the direct contact cooler’s circulation water. The study was conducted for flue gases from a natural-gas combined-cycle power plant and the Brevik cement plant in Norway. The standard and the lean vapour compression CO2 absorption configurations were used for the study. The PHE outperformed the fixed tube sheet shell and tube heat exchanger (FTS-STHX) and the other STHXs economically and in emissions reduction. The optimal minimum temperature approach for the PHE cases based on CO2 avoided cost were achieved at 4 °C to 7 °C. This is where the energy consumption and indirect emissions are relatively low. The lean vapour compression CO2 capture process with optimum PHE achieved a 16% reduction in CO2 avoided cost in the cement plant process. When the available excess heat for the production of steam for 50% CO2 capture was considered together with the optimum PHE case of the lean vapour compression process, a cost reduction of about 34% was estimated. That is compared to a standard capture process with FTS-STHX without consideration of the excess heat. This highlights the importance of the waste heat at the Norcem cement plant. This study recommends the use of plate heat exchangers for the cross-heat exchanger (at 4–7 °C), lean amine cooler and the DCC unit’s circulation water cooler. To achieve the best possible CO2 capture process economically and in respect of emissions reduction, it is imperative to perform energy cost and capital cost trade-off analysis based on different minimum temperature approaches

Capital cost estimation of CO2 capture plant using Enhanced Detailed Factor (EDF) method: Installation factors and plant construction characteristic factors

Capital cost is frequently estimated for new and retrofit carbon capture plants as new concepts for cost reduction emerge. Capital cost during initial cost estimation of chemical plants strongly depends on the installation factor(s) of the methodology employed. How these installation factors respond to the cost of each equipment determines the total plant cost and the type of capital cost (new plant or modification project) each method is suited for. The effect of equipment installation factors on capital cost of an amine-based CO2 capture plant using the Enhanced Detailed Factor (EDF) method has been studied. Plant construction characteristic factors have also been introduced to account for different plant construction characteristic situations. The impacts of the installation factors of seven methodologies on capital cost were compared. A uniform installation factor will likely lead to overestimation of very expensive equipment and underestimation of less expensive equipment. EDF method's installation factors respond based on each equipment cost. Even though all the methods estimated the optimum in the cross-exchanger to be 15°C, the cost estimated was €66/tCO2 by the EDF method, Smith's percentage of delivered-equipment factorial method and Hand's factorial method; and €69–79/tCO2 by the other methods. The results demonstrate that the EDF method is suitable for estimating capital cost for new plants and modification projects, small and large plants, and accounts for different plants’ situations