Browsing by Author "Awoyomi, Adeola"

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    CO2/SO2 emission reduction in CO2 shipping infrastructure
    (Cranfield University, 2019-05-30 10:32) Awoyomi, Adeola; Patchigolla, Kumar; Anthony, Ben
    Simulation table streams for the liquefaction cycle, the capture process and the diesel engine used in Aspen Plus.All graphs can be generated from the given streams.
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    CO2/SO2 emission reduction in CO2 shipping infrastructure
    (Elsevier, 2019-06-04) Awoyomi, Adeola; Patchigolla, Kumar; Anthony, Edward J.
    There is an increased focus on the reduction of anthropogenic emissions of CO2 by means of CO2 capture processes and storage in geological formations or for enhanced oil recovery. The necessary link between the capture and storage processes is the transport system. Ship-based transport of CO2 is a better option when distances exceed 350 km compared to an offshore pipeline and offers more flexibility for transportation, unlike pipelines which require a continuous flow of compressed gas. Several feasibility studies have been undertaken to ascertain the viability of large-scale transportation of CO2 by shipping in terms of the liquefaction process, and gas conditioning, but limited work has been done on reducing emissions from the ship’s engine combustion. From 2020, ships operating worldwide will be required to use fuels with 0.5% or lower sulphur content (versus 3.5% now) or adopt adequate measures to reduce these emissions. This study explores the use of the solvent-based post-combustion carbon capture and storage (CCS) process for CO2 and SO2 capture from a typical CO2 carrier. A rate-based aqueous ammonia process model was developed, validated, then scaled up and modified to process flue gas from a Wartsila 9L46 F marine diesel engine. Different modes of operation of the carrier were analysed and the most efficient mode to operate the CCS system is during sailing. The heat recovered from the flue gas was used for solvent regeneration. A sensitivity study revealed that the 4 MWth supplied by the “waste heat recovery” system was enough to achieve a CO2 capture level of 70% at a solvent recirculation flowrate of 90–100 kg/s. The removal of SO2 by the ammonia water solution was above 95% and this led to the possibility of producing a value-added product, ammonium sulphate. The boil-off gas and captured emitted CO2 were recovered using a two-stage re-liquefaction cycle and re-injected into the cargo tanks, thereby reducing extra space requirements on the ship.
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    Data for the paper "Process and economic evaluation of an on-board capture system for LNG-fueled CO2 carriers"
    (Cranfield University, 2019-12-12 13:58) Awoyomi, Adeola; Patchigolla, Kumar; Anthony, Ben
    Table showing the results obtained from the economic analysis of the capture integration. All graphs can be generated from the given streams.
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    Process and economic evaluation of an on-board capture system for LNG-fuelled CO2 carriers
    (American Chemical Society, 2019-11-27) Awoyomi, Adeola; Patchigolla, Kumar; Anthony, Edward J.
    Marine pollution is a major problem but one that has to date been largely overlooked; thus, for example, it was not accounted for in the Paris agreement on climate change. Maritime fuel combustion currently contributes to 3% of the annual global greenhouse gas emissions. Nearly all shipping-related emissions occur within 400 km of land, and cause death and increased morbidity to millions of people. The initial greenhouse gas strategy on the reduction of carbon emissions to at least half of its 2008 levels by 2050, adopted by the International Maritime Organization, has the potential to spur on innovations and the use of alternative fuel, enabling the shipping industry to adapt to future challenges. Some zero-emission options such as the use of hydrogen and bio-fuels are considered potential strategies, but currently lack the infrastructure capacity needed to meet the world’s shipping demand. Liquefied natural gas (LNG) has gained substantial interest as a marine fuel because it can comply with the strictest environmental regulations currently in force, and it is often regarded as a future shipping fuel as most newly constructed ships are built to run on it. Although the use of LNG leads to lower CO2 emissions compared to traditional heavy fuel oils (HFOs), there is still a need for further reduction. A solution which can be implemented is that of an on-board marine capture system, also known as ship-based carbon capture. In this study, a process and economic evaluation was carried out on a solvent-based post-combustion capture process for the energy system of a CO2 carrier. A rate-based model was developed, validated and scaled up to process the flue gas from a Wartsila 9L46 DF marine diesel engine. Different modes of operation with respect to engine load and capture rate were analysed in this study and the capture cost was estimated. The cost of CO2 capture was used as an economic index for this study. It was observed via a sensitivity analysis that at 90% capture rate, the cost of capture was at least $117/t. The effect of exhaust gas recycle was also explored and this resulted in a considerable reduction in the capture cost. The exhaust gas waste heat was utilised and was adequate to supply the required energy needed by the reboiler at each capture rate examined. Also, for LNG-fueled CO2 ships, the cold energy obtained while converting the LNG to gas was utilised to liquefy the captured CO2 from the flue gas.
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    A review of large-scale CO2 shipping and marine emissions management for carbon capture, utilisation and storage
    (Elsevier, 2021-02-13) Al Baroudi, Hisham; Awoyomi, Adeola; Patchigolla, Kumar; Jonnalagadda, Kranthi; Anthony, Edward J.
    Carbon Capture, Utilisation and Storage (CCUS) can reduce greenhouse gas emissions for a range of technologies which capture CO2 from a variety of sources and transport it to permanent storage locations such as depleted oil fields or saline aquifers or supply it for use. CO2 transport is the intermediate step in the CCUS chain and can use pipeline systems or sea carriers depending on the geographical location and the size of the emitter. In this paper, CO2 shipping is critically reviewed in order to explore its techno-economic feasibility in comparison to other transportation options. This review provides an overview of CO2 shipping for CCUS and scrutinise its potential role for global CO2 transport. It also provides insights into the technological advances in marine carrier CO2 transportation for CCUS, including preparation for shipping, and in addition investigates existing experience and discusses relevant transport properties and optimum conditions. Thus far, liquefied CO2 transportation by ship has been mainly used in the food and brewery industries for capacities varying between 800 m3 and 1000 m3. However, CCUS requires much greater capacities and only limited work is available on the large-scale transportation needs for the marine environment. Despite most literature suggesting conditions near the triple-point, in-depth analysis shows optimal transport conditions to be case sensitive and related to project variables. Ship-based transport of CO2 is a better option to decarbonise dislocated emitters over long distances and for relatively smaller quantities in comparison to offshore pipeline, as pipelines require a continuous flow of compressed gas and have a high cost-dependency on distance. Finally, this work explores the potential environmental footprint of marine chains, with particular reference to the energy implications and emissions from ships and their management. A careful scrutiny of potential future developments highlights the fact, that despite some existing challenges, implementation of CO2 shipping is crucial to support CCUS both in the UK and worldwide