Browsing by Author "Jeremias, Michal"

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    COVID-19 pandemic and global carbon dioxide emissions: A first assessment
    (Elsevier, 2021-07-01) Sikarwar, Vineet Singh; Reichert, Annika; Jeremias, Michal; Manovic, Vasilije
    Anthropogenic carbon dioxide emissions are the main cause of global climate change. The COVID-19 pandemic has been one of the worst of its kind in the last century with regard to global deaths and, in the absence of any effective treatment, it led to governments worldwide mandating lock-down measures, as well as citizens voluntarily reducing non-essential trips and activities. In this study, the influence of decreased activity on CO2 emissions and on the economy was assessed. The US, EU-28, China and India, representing almost 60% of anthropogenic carbon emissions, were considered as reference entities and the trends were extrapolated to estimate the global impact. This study aimed to deduce initial estimates of anthropogenic CO2 emissions based on the available economic and industrial outputs and activity data, as they could not be directly measured. Sector-wise variations in emissions were modeled by assuming proportionality of the outputs/activities and the resulting emissions. A decline in road traffic was seen up to March 2020 and then a steady growth was observed, with the exception of China where road traffic started to recover by the end of January. The vast majority of passenger flights were grounded and, therefore, global air traffic plummeted by 43.7% from January to May 2020. A considerable drop in coal power production and the annual industrial growth rate was also observed. The overall economic decline led to a drop of 4.9% in annual global gross domestic product (GDP) for Q2 2020. The total global CO2 emissions reduction for January through April 2020 compared to the year before was estimated to be 1749 Mt. CO2 (14.3%) with a maximum contribution from the transportation sector (58.3% among total emissions by sector). Like other previous crises, if the economy rebounds as expected the reductions will be temporary. Long-term impacts can be minimized considering the business as well as lifestyle changes for travel, utilizing virtual structures created during this crisis, and switching to sustainable transportation.
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    Pilot testing of enhanced sorbents for calcium looping with cement production
    (Cranfield University, 2018-06-12 12:59) Erans moreno, María; Jeremias, Michal; lyzheng@alum.imr.ac.cn; G. Yao, Joseph; Blamey, John; Manovic, Vasilije; S. Fennell, Paul; Anthony, Ben
    Raw data from pilot plant experiments depicted in "Pilot testing of enhanced sorbents for calcium looping with cement production"
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    Pilot testing of enhanced sorbents for calcium looping with cement production
    (Elsevier, 2018-05-26) Erans, María; Jeremias, Michal; Zheng, Liya; Yao, Joseph G.; Blamey, John; Manovic, Vasilije; Fennell, Paul S.; Anthony, Edward J.
    One of the main challenges for commercialising calcium looping (CaL) as a CO2 capture technology is maintaining a high level of sorbent reactivity during long-term cycling. In order to mitigate the decay in carrying capacity, research has moved towards producing enhanced sorbents. However, this creates potential problems related to ease of scaling up production techniques and production costs, and raises the question as to whether such approaches can be used at large scale. On the other hand, a key advantage of CaL over other carbon capture technologies is synergy with the cement industry, i.e., use of spent sorbent as a feedstock for clinker production. In this work two enhanced materials: (i) limestone doped with HBr through a particle surface impregnation technique; and (ii) pellets prepared from limestone and calcium aluminate cement, were tested in a 25 kWth dual fluidised bed pilot-scale reactor in order to investigate their capture performance and mechanical stability under realistic CaL conditions. Moreover, the spent sorbent was then used as a raw material to make cement, which was characterised for phase and chemical composition as well as compressive strength. The HBr-doped limestone showed better performance in terms of both mechanical strength and stability of the CO2 uptake when compared to that of pellets. Furthermore, it was shown that the cement produced has similar characteristics and performance as those of commercial CEM 1 cement. This indicates the advantages of using the spent sorbent as feedstock for cement manufacture and shows the benefits of synthetic sorbents in CaL and suitability of end-use of spent sorbents for the cement industry, validating their synergy at pilot scale. Finally, this study demonstrates the possibility of using several practical techniques to improve the performance of CaL at the pilot scale, and more importantly demonstrates that commercial-grade cement can be made from the lime product from this technology.
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    SO3 formation and the effect of fly ash in a bubbling fluidised bed under oxy-fuel combustion conditions
    (Elsevier, 2017-07-18) Sarbassov, Yerbol; Duan, Lunbo; Jeremias, Michal; Manovic, Vasilije; Anthony, Edward J.
    This study investigates the formation of SO3 under air and oxy-fuel combustion environments in a bench-scale bubbling fluidized bed. Flue gas compositions typical of air and oxy-fuel environments were simulated by bottle gases. Parameters such as bed temperature, SO2, O2 and H2O concentrations were varied to determine their effect on the formation of SO3 in both tests with fly ash acting as a catalyst catalyzed and uncatalyzed tests. Catalytic tests were conducted by adding three different fly ashes generated from three different coals. Experimental results support the expectation of show increased SO3 concentration for oxy-fuel combustion environments compared to typical air-fired environments. SO3 concentrations increased with combustion temperature, O2 and H2O concentrations. Catalytic tests have shownshowed that the formation of SO3 depends on the chemical composition of the fly ash, while unburnt carbons in the ash tend to reduce SO3 concentrations.
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    Technical and economic feasibility evaulation of calcium looping with no CO2 recirculation
    (Elsevier, 2017-11-04) Hanak, Dawid P.; Erans, María; Nabavi, Seyed Ali; Jeremias, Michal; Romeo, Luis M.; Manovic, Vasilije
    Carbon capture and storage is expected to play a key role in decarbonisation of the power and industrial sectors, with calcium looping (CaL) being regarded as a well-developed technology that can reduce energy and economic penalties associated with mature technologies. Nevertheless, retrofits of CaL to coal-fired power plants result in net efficiency penalties of 5–8% points. The state-of-the-art CaL configurations assume that, similarly to oxy-fuel combustion systems, CO2 needs to be recycled to moderate the temperatures in the calciner. This study aims to assess the feasibility of CaL with no CO2 recirculation to the calciner via pilot plant testing and techno-economic analysis. The results collected during the experimental trials indicated that the temperatures inside of the calciner were within 930–950 °C, which were within the commonly reported operating temperature range of that reactor. Furthermore, the techno-economic analysis of the CaL retrofit to a conventional 580 MWel coal-fired power plant indicated that operation of CaL without CO2 recirculation will have a negligible effect on the net thermal efficiency of the entire system. Nevertheless, reduction in the size of the system resulted in a 21.7% reduction in the specific capital cost, and thus a 14.3% and 27.4% reduction in the levelised cost of electricity and cost of CO2 avoided, respectively. Therefore, CaL with no CO2 recirculation can be considered as a technically and economically feasible option to reduce the economic penalty associated with this emerging technology.