Browsing by Author "Wilson, Ian"

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    Carbon Brainprint Case Study: optimising defouling schedules for oil- refinerypreheat trains
    (2011-07-31T00:00:00Z) Parsons, David J.; Chatterton, Julia C.; Wilson, Ian; Ishiyama, Edward
    In an oil refinery, crude oil is heated to 360-370°C before entering a distillation columnoperating at atmospheric pressure where the gas fraction and several liquid fractions withdifferent boiling points (e.g. gasoline, kerosene, diesel, gas oil, heavy gas oil) are separated off.The crude oil is heated in two stages. The preheat train - a series of heat exchangers - heats itfrom ambient temperature to about 270°C when it enters the furnace, known as the coil inlettemperature. The furnace then heats the oil to the temperature required for distillation.The purpose of the preheat train is to recover heat from the liquid products extracted in thedistillation column. Without this, 2-3% of the crude oil throughput would be used for heating thefurnace; with the preheat train up to 70% of the required heat is recovered. It also serves tocool the refined products: further cooling normally uses air or water. Over time, fouling reduces the performance of the heat exchangers, increasing the amount ofenergy that has to be supplied. It is possible to bypass units to allow them to be cleaned, withan associated cost and temporary loss of performance. The cleaning schedule thus has animpact on the overall efficiency, cost of operation and emissions. The group at the Department of Chemical Engineering and Biotechnology at Cambridgedeveloped a scheduling algorithm for this non-linear optimisation problem. It yields a good,though not-necessarily optimal, schedule and can handle additional constraints, such as thepresence of desalters with specific temperature requirements within the preheat train. This isnow being developed into a commercial software product. Data from two refineries - one operated by Repsol YPF in Argentina and the Esso FawleyRefinery in the UK - were used to model the systems and test the algorithm. For the Repsol YPF refinery, when compared with current practice and including a constrainton the desalter inlet temperature, the most conservative estimate of the emissions reductionwas 773 t CO2/year. This assumed a furnace efficiency of 90%. The emissions reductionincreased to 927 t CO2/year at 75% efficiency and 1730 t CO2/year at 40%. These were basedon a stoichiometric estimate of the emissions from the furnace. Using a standard emissionfactor increased them by 7.4%. For Esso Fawley, the estimated emission reduction compared to no maintenance was1435 t CO2/year at 90% furnace efficiency. This increased to 1725 t CO2/year at 75% and3225 t CO2/year at 40% efficienc
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    Carbon brainprint – An estimate of the intellectual contribution of research institutions to reducing greenhouse gas emissions
    (Elsevier, 2015-05-07) Chatteron, Julia C.; Parsons, David J.; Nicholls, John R.; Longhurst, Philip J.; Bernon, Mike; Palmer, Andrew; Brennan, Feargal P.; Kolios, Athanasios; Wilson, Ian; Ishiyama, Edward; Clements-Croome, Derek; Elmualim, Abbas; Darby, Howard; Yearly, Tom; Davies, Gareth J.
    Research and innovation have considerable, currently unquantified potential to reduce greenhouse gas emissions by, for example, increasing energy efficiency. Furthermore, the process of knowledge transfer in itself can have a significant impact on reducing emissions, by promoting awareness and behavioural change. The concept of the ‘carbon brainprint’ was proposed to convey the intellectual contribution of higher education institutions to the reduction of greenhouse gas emissions by other parties through research and teaching/training activities. This paper describes an investigation of the feasibility of quantifying the carbon brainprint, through six case studies. The potential brainprint of higher education institutes is shown to be significant: up to 500 kt CO2e/year for one project. The most difficult aspect is attributing the brainprint among multiple participants in joint projects.
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    Carbon Brainprint: quantifying the impact of universities on carbon footprint reduction
    (Cranfield University, 2019-02-13 11:37) Parsons, David; Chatterton, Julia; Clements-Croome, Derek; Elmualim, Abbas; Darby, Howard; Yearly, Tom; Davies, Gareth; Wilson, Ian; Ishiyama, Edward
    Universities make tremendous intellectual and technical advances that help other organisations and individuals reduce their own carbon footprints. This is the universities€™ carbon brainprint, and measuring this allows universities to quantify the impact of their research, innovation and knowledge transfer activities on cutting global GHG emissions. It provides further endorsement of the value of investing in universities such as Cranfield to address the challenge of global warming. The initial project developed a set of approaches to estimating the carbon brainprint of an activity, such as research, development, consultancy or training. These were applied to six case studies from Cranfield, Cambridge and Reading Universities, which demonstrated the large impact that higher education institutions can have. A summary of the final report is attached, as well as a summary of each of the six case studies: 1. Ceramic coatings for jet engine turbine blades, Cranfield University and Rolls-Royce. Summary pdf attached; read full case study. 2. Novel offshore vertical axis wind turbines, Cranfield University and Energy Technologies Institute. Summary pdf attached; read full case study. 3. Improved delivery vehicle logistics, Cranfield University and Defra. Summary pdf attached; read full case study. 4. Training for landfill gas inspectors, Cranfield University and Environment Agency. Summary pdf attached; read full case study. 5. Intelligent buildings, University of Reading and HEFCE. Summary pdf attached; read full case study. 6. Optimising defouling schedules for oil-refinery preheat trains, University of Cambridge and EPSRC. Summary pdf attached; read full case study. Additional project outputs are: - The final report at http://dspace.lib.cranfield.ac.uk/handle/1826/6805. - The guidance on calculating brainprints at http://dspace.lib.cranfield.ac.uk/handle/1826/8236. - The 2015 paper €˜Carbon brainprint €“ An estimate of the intellectual contribution of research institutions to reducing greenhouse gas emissions€™ published in Process Safety and Environmental Protection 96, 74€“81. Available at https://doi.org/10.1016/j.psep.2015.04.008. - The 5min35 summary video of the project at https://youtu.be/9GSjDaWO9dQ. The Carbon Brainprint project was highly commended at the 2011 Green Gown Awards in the research category.
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    Detonation performance of urea hydrogen peroxide
    (Unknown, 2022-04-06) Halleux, Francis; Pons, Jean-François; Wilson, Ian; Van Riet, Romuald; Simoens, Bart; Lefebvre, Michel
    Carbamide Peroxide is commonly used in the cosmetic and pharmaceutical industries as a solid source of hydrogen peroxide. This adduct of Urea and Hydrogen Peroxide (UHP) has explosive properties, which have been only recently studied, highlighting its behaviour of non-ideal tertiary explosive and detonability at large scale. Our work focussed on investigating UHP detonability in the 100 g-scale. A maximum of experimental data, collected from combining laboratory and underwater measurement campaigns, is required to evaluate the detonation performance of non-ideal explosives. Our lab results confirmed self-sustained detonation under heavy confinement, with observed detonation velocities consistent with literature values from large-scale field experiments. We further fired UHP charges underwater and quantified brisance and explosive power respectively from underwater shock pressure and bubble period. By comparing experimental results and numerical simulations, we could assess the level of agreement between lab and underwater detonation performance parameters.
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    Detonation performance of Urea-Hydrogen Peroxide (UHP)
    (Wiley, 2023-02-23) Halleux, Francis; Pons, Jean-François; Wilson, Ian; Simoens, Bart; Van Riet, Romuald; Lefebvre, Michel
    Carbamide Peroxide, an adduct of Urea and Hydrogen Peroxide, is commonly used in the cosmetic and pharmaceutical industries as a solid source of hydrogen peroxide. However, it exhibits explosive properties and can be easily manufactured from readily available household chemicals, making it a potential emerging threat. We carried out a detailed performance assessment, combining experiments, thermochemical calculations and numerical simulations and highlighted a good level of agreement between experimental data from lab, field and underwater firings. A maximum detonation velocity of 3.65 km/s was recorded for unconfined 25 kg UHP charges at 0.85 g/cm 3 (200 mm charge diameter). We determined in these conditions an infinite diameter detonation velocity of 3.94 km/s. These results are also consistent with previous results obtained at small scale under heavy confinement. Airblast measurements highlighted an average 40% TNT equivalence for impulse and 55% for peak overpressure at short distance, which are in good agreement with the 57% (Power Index) calculated from Explo5, while 50% for bubble energy (explosive power) and 20% for shock pressure (brisance) were obtained from underwater experiments. The use of different experimental approaches has proven useful to characterise the performances parameters of a non-ideal explosive for risk assessment purposes.
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    Development of metal-organic framework (MOF) sensors for landmine detection
    (AMA Service GmbH, 2019-07-19) Humphreys, Lisa; Wilson, Ian; McAteer, Daniel; Pons, Jeff
    Rural populations in Colombia are significantly affected by anti-personnel mines used by revolutionary armed forces. These mines typically contain ammonium nitrate (AN) based explosive compositions. The international community is committed to tackling the danger posed by landmines and other improvised explosive devices (IEDs). This involves the removal of explosive materials installed in areas of conflict. Current technologies used for humanitarian demining can be separated into three distinct categories; metal detection, mechanical clearance, and detection using trained animals [1]. Metal detection is deemed to be most effective but as plastic-bodied IEDs are now also in use other detection approaches must be sought after. Cranfield University, Universidad Nacional de Colombia and Oxford University have proposed the development of a device capable of detecting AN based IEDs using an optoelectronic sensor. The goal of the project is to establish the scientific validity of the new sensing method for the detection of explosive materials found in landmines and IEDs, and to demonstrate its usefulness in locating buried explosive devices. This will entail optimising the sensitivity and selectivity of the sensor. A systematic series of MOFs comprising transition metal acetates/chlorides and terephthalic acid derivatives as linkers has been synthesised and structurally characterised. Cobalt and copper based salts have been paired with numerous organic ligands to create MOFs which have been responsive to concentrations of ~100 ppm ammonia in aqueous conditions. The developed MOFs have also been assessed for their response to ammonia in the gas phase and at representative concentrations throughout the project.
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    Further insights into the discoloration of TATB under ionizing radiation
    (Taylor and Francis, 2020-02-26) Lewis, Dan; Padfield, James; Connors, Scott; Wilson, Ian; Akhavan, Jacqueline
    To determine degradation products formed by exposure of TATB to ionizing radiation, a computational and experimental study is presented. Thermochemical and spectral data have been calculated using DFT at the MH06-HF/aug-cc-pVTZ level which suggest the formation of the cation radical derivative of TATB. Irradiated TATB samples showed the widely reported yellow-to-green discoloration, with measured CIE L*, a*, b* and RGB values correlating with total dose. Trace quantities of a mono-furazan derivative were detected by HPLC-MS; the discoloration is not attributed to this, but rather to the presence of a paramagnetic species (i.e., the cation), as detected by ESR measurements. Recrystallized irradiated TATB samples reverted to their original color, further suggesting it is the cation radical that is responsible for color change.
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    Small-scale characterisation of urea hydrogen peroxide explosive performance using heterodyne velocimetry
    (Royal Society of Chemistry, 2022-06-24) Halleux, Francis; Stennett, Christopher; Pons, Jean-François; Wilson, Ian; Lefebvre, Michel
    Urea Hydrogen Peroxide (UHP) is widely available in the cosmetic and pharmaceutical industries. UHP exhibits the behaviour of a tertiary explosive and previous research from the same authors has highlighted its detonability at small-scale under heavy confinement. In this work, UHP performance parameters are further investigated by heterodyne velocimetry. An average detonation pressure of 3.7 GPa for UHP at a mean density of 0.75 g/cm3 has been determined using the impedance window method, corresponding to a 20% TNT equivalence for brisance. This result is consistent with calculation from empirical correlations. An average 3200 m/s detonation velocity was recorded using contact probes, in excellent agreement with measurements from passive optical probes. This small-scale experimental campaign, which was complementary to and consistent with previous research, has proven useful to characterise the performances of non-ideal explosives for risk assessment purposes.
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    Small-scale detonation of industrial Urea-Hydrogen Peroxide (UHP)
    (Wiley, 2021-12-03) Halleux, Francis; Pons, Jean-François; Wilson, Ian; Van Riet, Romuald; Lefebvre, Michel
    The adduct of Urea and Hydrogen Peroxide (UHP), also called Carbamide Peroxide, is industrially produced as a solid source of hydrogen peroxide for bleaching, disinfection, and oxidation reactions. As a chemical combination of fuel and oxidiser, UHP has explosive potential but it is unclear whether it could sustain a detonation at small scale. In the configuration we tested, we succeeded in recording self-sustained detonation at relatively small scale under heavy confinement, measuring a maximum experimental velocity of detonation of 3860 m/s at an optimum 1.1 g/cm3 loading density. UHP can sustain a detonation, even at the 100 g scale, but this is strongly dependant on booster size, confinement material, loading density, charge length and diameter. According to our performance assessment, pure UHP exhibits the behaviour of a non-ideal tertiary explosive. Maximum calculated detonation pressures are below 10 GPa, the order of magnitude for commercial blasting explosives. Small-scale results are consistent with literature values from large-scale experiments, although literature on the matter is quite limited. The proposed experimental method can be used to quantify the detonability and performance of other industrial materials that may have energetic properties, or small samples of homemade explosive compositions, avoiding time-consuming, expensive and potentially hazardous large-scale experiments.
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    Stability and hazard properties of improvised nitrocellulose
    (Taylor & Francis, 2023-02-12) Moniruzzaman, Mohammed; Houlihan, Emma; Parker, Matthew; Wilson, Ian
    Nitrocellulose is a vulnerable and sensitive energetic material that can easily be manufactured from ordinary household chemicals and used for illicit purposes. Hazards of this material can lead to incidents resulting from unplanned initiation in manufacturing, storage or handling. Thermal stability and hazard data for so-called improvised nitrocellulose (IN) are crucial to formulate guidance for storage and handling of such materials recovered from illegal possession. This study focused on the energy content, stability and safety properties of IN. The energy contents increase linearly with nitrogen contents of IN. Improvised nitrocellulose showed a similar sensitivity to impact and electrostatic discharge, but vacuum stability testing demonstrated more gas release (2.8–3.4 cm3 g−1) compared to commercial NC (1.7 cm3 g−1). Chemiluminescence analysis established activation energies for hydrolytic and thermolytic decomposition to be 36 and ~93 kJ mol-1, respectively. Results suggest that NC samples recovered from improvised devices or illegal possession should be handled with special care.
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    Urea-Hydrogen Peroxide (UHP): comparative study on the experimental detonation pressure of a non-ideal explosive
    (Wiley, 2023-08-28) Halleux, Francis; Pons, Jean-François; Wilson, Ian; Stennett, Christopher; Van Riet, Romuald; Lefebvre, Michel
    Carbamide Peroxide, an adduct of Urea and Hydrogen Peroxide (UHP) industrially used as a solid source of hydrogen peroxide, exhibits the behaviour of a tertiary explosive but a detailed performance characterisation is still lacking in the literature. In this work, we calculated a 20% experimental TNT equivalence for brisance, i.e. the shattering effect from the shock wave transmitted from the detonating high explosive into adjacent materials, by experimental indirect measurement of UHP detonation pressure. We determined a 3.5 GPa detonation pressure for 5 kg unconfined UHP charges (0.87 g/cm3, 120 mm charge diameter) by measuring the attenuated shock wave velocity (ASV) in adjacent inert materials using passive optical probes. Particle velocity measurements at the interface of a PMMA impedance window carried out with Photonic Doppler Velocimetry on scaled-down charges of 90 g UHP under heavy confinement (0.85 g/cm3, 30 mm charge diameter, 4 mm thick steel) are consistent with ASV results in the PMMA acceptors but further investigations are required to determine the detonation pressure, using a small-scale experimental set-up. The ASV method has proven reliable to assess the brisance of a non-ideal explosive for risk assessment purposes.