Imperial College London

DrSemraBakkaloglu

Faculty of EngineeringDepartment of Chemical Engineering

Research Associate
 
 
 
//

Contact

 

s.bakkaloglu

 
 
//

Location

 

14 Prince's GardensSouth Kensington Campus

//

Summary

 

Publications

Publication Type
Year
to

16 results found

Vogel F, Ars S, Wunch D, Lavoie J, Gillespie L, Maazallahi H, Röckmann T, Nęcki J, Bartyzel J, Jagoda P, Lowry D, France J, Fernandez J, Bakkaloglu S, Fisher R, Lanoiselle M, Chen H, Oudshoorn M, Yver-Kwok C, Defratyka S, Morgui JA, Estruch C, Curcoll R, Grossi C, Chen J, Dietrich F, Forstmaier A, Denier van der Gon HAC, Dellaert SNC, Salo J, Corbu M, Iancu SS, Tudor AS, Scarlat AI, Calcan Aet al., 2024, Ground-Based Mobile Measurements to Track Urban Methane Emissions from Natural Gas in 12 Cities across Eight Countries, Environmental Science & Technology, Vol: 58, Pages: 2271-2281, ISSN: 0013-936X

Journal article

Bakkaloglu S, Hawkes A, 2024, A comparative study of biogas and biomethane with natural gas and hydrogen alternatives, Energy & Environmental Science, Vol: 17, Pages: 1482-1496, ISSN: 1754-5692

<jats:p>Biogas and biomethane are renewable fuels that can help to reduce greenhouse gas (GHG) emissions. The upstream, midstream (gas production), and downstream segments of the biogas and biomethane supply chain are shown in the upper figure, all alternative processes are illustrated in the lower figure.</jats:p>

Journal article

Bakkaloglu S, Mersch M, Sunny N, Markides C, Shah N, Hawkes Aet al., 2023, ECOS 2023: How far should the UK go with negative emission technologies?, Pages: 2939-2949

Negative Emissions Technologies (NETs), such as Bioenergy with Carbon Capture and Storage (BECCS) and Direct Air Carbon Capture and Storage (DACCS), are potentially valuable to offset carbon emissions and therefore commonly deployed in global climate change mitigation scenarios. However, they are controversial and sometimes seen as a means of delaying or avoiding emissions reduction efforts. Nonetheless, the UK has set an ambitious target of engineering 57 Mt CO2 per year of removals by 2050 to achieve net zero emissions[1]. This study uses the UK TIMES, technology-rich bottom-up energy system model to investigate the nationwide deployment of NETs in the energy system, while varying model parameters to provide an overview of decarbonisation in line with the UK's net zero ambitions. We investigated DACCS and BECCS NETs technologies with regards to technological uncertainties and sensitivities. We revised the TIMES model structure for NETs implementation to ensure proper integration with industry. Our analysis estimates that the UK can remove 78.5 Mt CO2 by 2050 under the balanced Net Zero Scenario. However, by integrating an updated characterisation of removal technologies, and enabling tighter integration of DACCS into industrial clusters, we can achieve a removal capacity of up to 209 Mt CO2 by 2050 based on our preliminary results. Additionally, a 50% reduction in DACCS cost could further increase the removal capacity to 218 Mt CO2. This study provides valuable insights for policymakers and stakeholders in the UK and beyond, highlighting how NETs can be integrated in industrial strategy.

Conference paper

Bakkaloglu S, Cooper J, Hawkes A, 2022, Life cycle environmental impact assessment of methane emissions from the biowaste management strategy of the United Kingdom: Towards net zero emissions, JOURNAL OF CLEANER PRODUCTION, Vol: 376, ISSN: 0959-6526

Journal article

Menoud M, van der Veen C, Lowry D, Fernandez JM, Bakkaloglu S, France JL, Fisher RE, Maazallahi H, Stanisavljevic M, Necki J, Vinkovic K, Lakomiec P, Rinne J, Korben P, Schmidt M, Defratyka S, Yver-Kwok C, Andersen T, Chen H, Rockmann Tet al., 2022, New contributions of measurements in Europe to the global inventory of the stable isotopic composition of methane, EARTH SYSTEM SCIENCE DATA, Vol: 14, Pages: 4365-4386, ISSN: 1866-3508

Journal article

Cooper J, Dubey L, Bakkaloglu S, Hawkes Aet al., 2022, Hydrogen emissions from the hydrogen value chain-emissions profile and impact to global warming, Science of the Total Environment, Vol: 830, ISSN: 0048-9697

Future energy systems could rely on hydrogen (H2) to achieve decarbonisation and net-zero goals. In a similar energy landscape to natural gas, H2 emissions occur along the supply chain. It has been studied how current gas infrastructure can support H2, but there is little known about how H2 emissions affect global warming as an indirect greenhouse gas. In this work, we have estimated for the first time the potential emission profiles (g CO2eq/MJ H2,HHV) of H2 supply chains, and found that the emission rates of H2 from H2 supply chains and methane from natural gas supply are comparable, but the impact on global warming is much lower based on current estimates. This study also demonstrates the critical importance of establishing mobile H2 emission monitoring and reducing the uncertainty of short-lived H2 climate forcing so as to clearly address H2 emissions for net-zero strategies.

Journal article

Bakkaloglu S, Cooper J, Hawkes A, 2022, Methane emissions along biomethane and biogas supply chains are underestimated, One Earth, Vol: 5, Pages: 724-736, ISSN: 2590-3322

Although natural gas generates lower CO2 emissions, gas extraction, processing, and distribution all release methane, which has a greater global warming potential than CO2. Biomethane and biogas that use organic wastes as a feedstock have emerged as alternatives to natural gas, with lower carbon and methane emissions. However, the extent to which methane is still emitted at various stages along biogas and biomethane supply chains remains unclear. Here, we adopt a Monte Carlo approach to systematically synthesize the distribution of methane emissions at each key biomethane and biogas supply chain stage using data collected from the existing literature. We show that the top 5% of emitters are responsible for 62% of emissions. Methane emissions could be more than two times of greater than previously estimated, with the digestate handling stage responsible for the majority of methane released. To ensure the climate benefits of biomethane and biogas production, effective methane-mitigation strategies must be designed and deployed at each supply chain stage.

Journal article

Bakkaloglu S, Lowry D, Fisher RE, Menoud M, Lanoisellé M, Chen H, Röckmann T, Nisbet EGet al., 2022, Stable isotopic signatures of methane from waste sources through atmospheric measurements, Atmospheric Environment, Vol: 276, Pages: 119021-119021, ISSN: 1352-2310

This study aimed to characterize the carbon isotopic signatures (δ13C-CH4) of several methane waste sources, predominantly in the UK, and during field campaigns in the Netherlands and Turkey. CH4 plumes emitted from waste sources were detected during mobile surveys using a cavity ring-down spectroscopy (CRDS) analyser. Air samples were collected in the plumes for subsequent isotope analysis by gas chromatography isotope ratio mass spectrometry (GC-IRMS) to characterize δ13C-CH4. The isotopic signatures were determined through a Keeling plot approach and the bivariate correlated errors and intrinsic scatter (BCES) fitting method. The δ13C-CH4 and δ2H-CH4 signatures were identified from biogas plants (−54.6 ± 5.6‰, n = 34; −314.4 ± 23‰ n = 3), landfills (−56.8 ± 2.3‰, n = 43; −268.2 ± 2.1‰, n = 2), sewage treatment plants (−51.6 ± 2.2‰, n = 15; −303.9 ± 22‰, n = 6), composting facilities (−54.7 ± 3.9‰, n = 6), a landfill leachate treatment plant (−57.1 ± 1.8‰, n = 2), one water treatment plant (−53.7 ± 0.1‰) and a waste recycling facility (−53.2 ± 0.2‰). The overall signature of 71 waste sources ranged from −64.4 to −44.3‰, with an average of −55.1 ± 4.1‰ (n = 102) for δ13C, −341 to −267‰, with an average of −300.3 ± 25‰ (n = 11) for δ2H, which can be distinguished from other source types in the UK such as gas leaks and ruminants. The study also demonstrates that δ2H-CH4 signatures, in addition to δ13C-CH4, can aid in better waste source apportionment and increase the granularity of isotope data required to improve regional modelling.

Journal article

Bakkaloglu S, Lowry D, Fisher RE, France JL, Nisbet EGet al., 2021, Carbon isotopic characterisation and oxidation of UK landfill methane emissions by atmospheric measurements, Waste Management, Vol: 132, Pages: 162-175, ISSN: 0956-053X

Biological oxidation of methane in landfill cover material can be calculated from the carbon isotopic signature (δ13CCH4) of emitted CH4. Enhanced microbial consumption of methane in the aerobic portion of the landfill cover is indicated by a shift to heavier (less depleted) isotopic values in the residual methane emitted to air. This study was conducted at four landfill sites in southwest England. Measurement of CH4 using a mobile vehicle mounted instrument at the four sites was coupled with Flexfoil bag sampling of ambient air for high-precision isotope analysis. Gas well collection systems were sampled to estimate landfill oxidised proportion. Closed or active status, seasonal variation, cap stripping and site closure impact on landfill isotopic signature were also assessed. The δ13CCH4 values ranged from −60 to −54‰, with an average value of −57 ± 2‰. Methane emissions from active cells are more depleted in 13C than closed sites. Methane oxidation, estimated from the isotope fractionation, ranged from 2.6 to 38.2%, with mean values of 9.5% for active and 16.2% for closed landfills, indicating that oxidised proportion is highly site specific.

Journal article

Bakkaloglu S, Ersan M, Karanfil T, Apul OGet al., 2021, Effect of superfine pulverization of powdered activated carbon on adsorption of carbamazepine in natural source waters, Science of The Total Environment, ISSN: 0048-9697

The purpose of this study is to investigate adsorptive removal of carbamazepine from natural source waters by superfine pulverized powdered activated carbon. Superfine pulverization is becoming an increasingly attractive approach to decrease the diffusion path of a target adsorbate molecule and improve the overall the kinetics of activated carbon adsorption. Here we report the impact of pulverization on powdered activated carbon characteristics, and carbamazepine adsorption behavior in distilled and deionized water and natural organic matter solutions. The superfine pulverization decreased the particle size of activated carbon by 50 folds and the specific surface area by 24%. In addition, the micropore volume of the activated carbon decreased from 0.23 cm3/g to 0.14 cm3/g, while mesopore and macropore volumes increased from 0.15 cm3/g and 0.11 cm3/g to 0.18 cm3/g and 0.48 cm3/g, respectively. In terms of surface chemistry, the oxygen and iron contents of the activated carbon increased notably after pulverization. Despite the decrease in surface area and increase in surface polarity, the pulverization improved the adsorption kinetics especially for short contact times i.e., < 6-h. In general, the dissolved organic carbon concentration negatively influenced the kinetic advantage of superfine pulverized activated carbon. Isotherm results indicated that the parent adsorbent has a higher adsorption capacity than its superfine activated carbon in distilled and deionized water and in natural waters. This was attributed to the losses in specific surface area and favorable sorption sites inside micropores. Our literature analysis indicated that unlike the small molecular weight hydrophilic organic compounds, the pseudo-equilibrium adsorption capacity could be increased or at least not deteriorated for hydrophobic molecules (Kow > 3). Therefore, superfine pulverization of PAC can serve as a promising approach to remove micropollutants from natural source waters with a k

Journal article

Bakkaloglu S, Lowry D, Fisher R, France J, Brunner D, Chen H, Nisbet Eet al., 2021, Quantification of methane emissions from UK biogas plants, Waste Management, Vol: 124, Pages: 82-93, ISSN: 0956-053X

The rising number of operational biogas plants in the UK brings a new emissions category to consider for methane monitoring, quantification and reduction. Minimising methane losses from biogas plants to the atmosphere is critical not only because of their contribution of methane to global warming but also with respect to the sustainability of renewable energy production. Mobile greenhouse gas surveys were conducted to detect plumes of methane emissions from the biogas plants in southern England that varied in their size, waste feed input materials and biogas utilization. Gaussian plume modelling was used to estimate total emissions of methane from ten biogas plants based on repeat passes through the plumes. Methane emission rates ranged from 0.1 to 58.7 kg CH4 hr-1, and the percentage of losses relative to the calculated production rate varied between 0.02 and 8.1%. The average emission rate was 15.9 kg CH4 hr-1, and the average loss was 3.7%. In general, methane emission rates from smaller farm biogas plants were higher than from larger food waste biogas plants. We also suggest that biogas methane emissions may account for between 0.4 and 3.8%, with an average being 1.9% of the total methane emissions in the UK excluding the sewage sludge biogas plants.

Journal article

Bakkaloglu S, Lowry D, Fisher R, France J, Brunner D, Chen H, Nisbet Eet al., 2020, Quantification of methane emissions from UK biogas plants, American Geoscience Union

Conference paper

Bakkaloglu S, Lowry D, Fisher R, France J, Mathias L, Fernandez Jet al., 2020, Characterization and Quantification of Methane Emissions from Waste in the UK, European Geosciences Union

Conference paper

Nisbet EG, Fisher RE, Lowry D, France JL, Allen G, Bakkaloglu S, Broderick TJ, Cain M, Coleman M, Fernandez J, Forster G, Griffiths PT, Iverach CP, Kelly BFJ, Manning MR, Nisbet-Jones PBR, Pyle JA, Townsend-Small A, al-Shalaan A, Warwick N, Zazzeri Get al., 2020, Methane Mitigation: Methods to Reduce Emissions, on the Path to the Paris Agreement, REVIEWS OF GEOPHYSICS, Vol: 58, ISSN: 8755-1209

Journal article

Bakkaloglu S, Lowry D, Fisher R, France J, Lanoisellé M, Fernandez J, Vinkovic K, Chen H, Davies S, Nisbet Eet al., 2019, The Greenhouse Gas Methane Emissions from Waste Sources in the UK, American Geoscience Union

Conference paper

This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.

Request URL: http://wlsprd.imperial.ac.uk:80/respub/WEB-INF/jsp/search-html.jsp Request URI: /respub/WEB-INF/jsp/search-html.jsp Query String: respub-action=search.html&id=01062838&limit=30&person=true