The necessity of limitation of carbon dioxide emissions, which also concerns the energy sector, causes that more and more effective and efficient methods of CO2 capture from the flue gas are being tested. Among these technologies are adsorption ones, which have been used for a gas separation for many years. The characteristic features of adsorption separation are: long life of the sorbents used, low energy expenditure, and minim effect on the environment; however, their application requires adequate initial preparation of the flue gas fed into the system of CO2 separation so that the flue gas temperature is as low as possible, and there is no water content in it. The study presents the concept and numerical calculations of the system for preparation of the flue gas feeding the CO2 adsorption (vacuum pressure swing adsorption (VPSA)) separation unit, using the absorption chiller (AC). In the presented concept, the AC is driven by the flue gas which is used as both: upper and lower heat source for AC; however, due to the amount of energy being carried out with the flue gas, which is larger than required by the AC, the additional heat exchangers must be implemented. The calculations presented in the study show that owing to the application of AC, flue gas may be cooled down to temperatures even about 5 °C. Moreover, the simultaneous process of flue gas cooling and drying in such system is realized at low energy expenditure which leads to improvement of the overall energy efficiency of the system of CO2 separation from flue gas and also to reduction of its dimensions.
Carbon Capture Utilization and Storage (CCUS) is a set of technologies aimed at capturing carbon dioxide (CO2) emissions from point-source emitters to either store permanently or use as a feedstock to produce chemicals and fuels. In this paper, the potential benefits of CCUS integration into the energy supply sector are evaluated from a Life Cycle Assessment (LCA) perspective by comparing two different routes for the CO2 captured from a natural gas combined cycle (NGCC). Both the complete storage of the captured CO2 and its partial utilization to produce dimethyl ether are investigated. Moreover, the assessment is performed considering the region-specific features of two of the largest CO2 emitters in Europe, namely Italy and Poland. Results shows that the complete storage of the captured CO2 reduces Global Warming Potential (GWP) by ~89% in Italy and ~97%, in Poland. On the other hand, the partial utilization of CO2 to produce dimethyl ether leads to a decrease of ~58% in Italy and ~68% in Poland with respect to a comparable reference entailing conventional dimethyl ether production. A series of environmental trade-offs was determined, with all the investigated categories apart from GWP showing an increase, mainly connected with the higher energy requirements of CCUS processes. These outcomes highlight the need for a holistic-oriented approach in the design of novel implemented configurations to avoid burden shifts throughout the value chain.
Original scientific paper https://doi.org/10.2298/TSCI19S4101ZThe very rapid growth of share of electricity generation from renewable sources is observed recent years. However, even if that share reaches about 50% in 2050, almost 50% of electricity will still be generated based on fossil fuels combustion rather than on nuclear energy. That means, energy generated from coal will still be important for the next decades. The largest sources of energy loses within the steam power plant is the steam cooling system. The energy dissipated to the atmosphere in that system is very difficult to be utilized mainly due to the relatively low temperature, and its direct utilization without additional equipment is rather impossible. The large amount of energy lost to the environment leads to low overall thermal efficiency of the plant, therefore, utilization of this energy should be of primary importance. The paper shows concept of increasing efficiency of cogeneration plant thermal cycle by utilisation of waste heat from flue gas with absorption heat pump, for the purpose of system heat generation. Calculations of combined system of power plant fuelled with biomass fuel with implemented waste heat utilisation system were performed for one heating season and different moisture content in the fuel. Results show, that owing to waste heat utilization instead of conventional heat exchanger, additional electricity generation during the heating season at even 46864 MWh may be achieved which is over 18% more for the moisture content in the biomass fuel at 0.5 kg/kg, the same ambient conditions and heat generation. combustion technologies for CO 2 capture [3,4] are highly energy consuming [5,6], and leading to significant decrease of power plant (PP) efficiency, the less costly way of emission reduction (especially of CO 2 ) from energy sector seems to be waste heat utilisation. There are two largest sources of energy loses within the conventional or cogeneration plant (CHP). One is the cooling system of steam leaving the turbine, where the low temperature heat is dissipated to the environment in cooling tower, and the second one is boiler generating hot (about 120 °C for hard coal and 170 °C for lignite) flue gas. The water in a cooling system and the flue gas are both sources of low temperature heat, however, the temperature of flue gas is much greater than of cooling water (which is less than 30 °C). The energy lost to the atmosphere with these two carriers is very difficult to be utilized mainly due to the relatively low temperature, and its direct utilization without additional equipment is rather impossible. However, the large amount of energy lost to the environment leads to low overall thermal efficiency of the plant, therefore, utilization of this energy should be of primary importance, and its lost amount should be minimized if only possible.One of possible solutions leading to significant increase of conventional steam PP efficiency is implementation of a system for useful heat generation, i. e. for district heating system (...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.