Browsing by Author "Patchigolla, Kumar"
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Item Open Access Analysis of integration method in multi-heat-source power generation systems based on finite-time thermodynamics(Elsevier, 2020-06-12) Liu, Hongtao; Zhai, Rongrong; Patchigolla, Kumar; Turner, Peter J.; Yang, YongpingMulti-heat-source power generation system is a promising technology to reduce fossil fuel consumption and save investment costs by integrating several heat sources and sharing power equipment components. Researchers have conducted many case studies based on specific power plants to find the preferred integration scheme. However, there is still no unified theory to guide the integration of different energy sources. To explore a common method to integrate various energy sources, this work developed a general multi-heat-source integrated system model based on finite-time thermodynamics, considering the external and internal irreversibility due to the constraint of finite-time and finite-size. The generalised expressions for optimum integration method are explored and expressed in dimensionless parameters. This study indicated the system with two heat-sources performs differently in four regions due to the variation of endothermic temperatures. The characteristics of energy flow and irreversibility reveal that by adding a second heat-source, the first heat-source energy can be substantially reduced at the cost of system efficiency slightly decreasing. Then four application cases for solar-aided coal-fired power plants are conducted to check its feasibility and potential to provide the performance bound of integrating multi-heat-sourcesItem Open Access Annual performance analysis and optimization of a solar tower aided coal-fired power plant(Elsevier, 2019-01-10) Li, Chao; Zhai, Rongrong; Yang, Yongping; Patchigolla, Kumar; Oakey, John E.; Turner, Peter J.The integration of solar energy into coal-fired power plants has been proven as a potential approach in the utilization of solar energy to reduce coal consumption. Moreover, solar augmentation offers low cost and low risk alternatives to stand-alone solar thermal power plants. In this study, the annual performance of a solar tower aided coal-fired power (STACP) system is investigated, and the influence of thermal storage system capacity on the annual solar generating power and annual solar-to-electricity efficiency is explored. The thermal storage system capacity is optimized to obtain the lowest levelized cost of electricity (LCOE). At the same time, the influence and sensitivity of several important economic factors are explored and assessed. Results demonstrate that compared to a coal-fired power system, the reduction in the annual average coal consumption rate of the STACP system with high direct normal irradiance (DNI), medium DNI, and low DNI are 5.79, 4.52, and 3.22 g/kWh, respectively. At a minimum, the annual coal consumption can be reduced by 14,000 t in a 600 MWe power generation unit. Because the same solar field is considered under different DNI conditions, the LCOE in the high DNI, medium DNI, and low DNI scenarios are all fairly similar (6.37, 6.40, and 6.41 ¢/kWh, respectively). When the solar multiple is 3.0, the optimal thermal storage capacity of the STACP system, with high, medium, and low DNIs are 6.73, 4.42, and 2.21 h, respectively. The sensitivity analysis shows that the change in economic parameters exerts more influence on the STACP system with the high DNI compared with the other two scenarios.Item Open Access Application of thermal spray coatings in electrolysers for hydrogen production: advances, challenges, and opportunities(Wiley, 2022-10-14) Faisal, Nadimul Haque; Prathuru, Anil; Ahmed, Rehan; Rajendran, Vinooth; Hossain, Mamdud; Venkatachalapathy, Viswanathan; Katiyar, Nirmal Kumar; Li, Jing; Liu, Yuheng; Cai, Qiong; Horri, Bahman Amini; Thanganadar, Dhinesh; Sodhi, Gurpreet Singh; Patchigolla, Kumar; Fernandez, Carlos; Joshi, Shrikant; Govindarajan, Sivakumar; Kurushina, Victoria; Katikaneni, Sai; Goel, SauravThermal spray coatings have the advantage of providing thick and functional coatings from a range of engineering materials. The associated coating processes provide good control of coating thickness, morphology, microstructure, pore size and porosity, and residual strain in the coatings through selection of suitable process parameters for any coating material of interest. This review consolidates scarce literature on thermally sprayed components which are critical and vital constituents (e. g., catalysts (anode/cathode), solid electrolyte, and transport layer, including corrosion-prone parts such as bipolar plates) of the water splitting electrolysis process for hydrogen production. The research shows that there is a gap in thermally sprayed feedstock material selection strategy as well as in addressing modelling needs that can be crucial to advancing applications exploiting their catalytic and corrosion-resistant properties to split water for hydrogen production. Due to readily scalable production enabled by thermal spray techniques, this manufacturing route bears potential to dominate the sustainable electrolyser technologies in the future. While the well-established thermal spray coating variants may have certain limitations in the manner they are currently practiced, deployment of both conventional and novel thermal spray approaches (suspension, solution, hybrid) is clearly promising for targeted development of electrolysers.Item Open Access Approaches to maximise the utilisation of residues from thermal conversion of oil palm waste.(Cranfield University, 2020-12) Ukanwa, Kalu Samuel; Patchigolla, Kumar; Sakrabani, RubenPalm oil processing generates enormous volume of waste, which can be used as a feedstock in thermal processing. Subsequently, these can be valuable in the production of activated carbon (AC) and soil amelioration. The production of AC often results in secondary contamination through activating agents. This prompts the necessity for a non-toxic activating agent for high quality production of high adsorptive AC. Therefore this research aims to assess and determine the optimum route for efficient utilisation of biowaste from thermal conversion process of palm oil residues in producing activated carbon and soil amelioration by evaluating the impact of the selected utilisation techniques. In the production process, energy demand and process duration have influence on the efficiency of AC; therefore, an appropriate design configurations and parameter selection are required to achieve an anticipated yield. AC was produced by microwave and conventional techniques through pyrolysis. The feedstock was also used in combustion and the thermal residues were applied in agricultural soil and crop yield relative to application rate was assessed on Habanero chili pepper. Therefore, the requisite to quantify the processes, which include appropriate assessment of the technology and economic performance. The accomplishment of the project overall aim was dependent on the design of a microwave system for efficient biomass pyrolysis. The process also evaluated the microwave interaction with reactors implemented to produce AC from mixed oil palm waste, using Trona ore as an activating agent. The AC was analysed to determine the effectiveness of Trona ore for activation using Fourier infrared spectrometry, Brunauer-Emmett-Teller (BET) analyser and scanning electron microscope. The oil palm waste ash was applied to the soil. The optimum outcome of the microwave assisted technique for combine palm waste (CPW) was obtained at 600 W, BET surface area (SBET) is 980 m²/g compared to 920 m²/g from a conventional technique; total volume (Vtotal) 0.865 cm³/g; mean pore diameter 2.2 nm and AC yield is 42%. Therefore, this study additionally identifies the need for an even distribution of electromagnetic waves within the reactor during activation to ensure uniformity of AC. It also proposes that the design of a composite reactor for an industrial production of AC is necessary to enable heterogeneous waste stream of the process. For ash application, the physiological development and crop yield were measured. The combine maximum yield for both sites were 49 t/ha/first season and 71.8 t/ha/second season, occurred at 8 t/ha treatment plot against the control plot with 1.3 t/ha/first season and 0.7 t/ha/second season. The interaction between oil palm waste ash and soil, improved agronomic efficiency of Habanero chilli pepper by 66-69% and Scoville value by 3.52%. These utilisation routes (AC production and ash to soil) were further integrated for economic and technological benefits using Aspen plus Economy. The processes have 16-17% return on investment for the 8-9 year payback period. This study therefore concluded that thermal residues of oil palm waste are useful in the production of high quality AC and also has rich effect on agricultural soil.Item Open Access Co-gasification of oil palm biomass in a pilot scale downdraft gasifier(Elsevier, 2020-07-22) Anyaoha, Kelechi E.; Sakrabani, Ruben; Patchigolla, Kumar; Mouazen, Abdul M.The present study focused on co-gasification of empty fruit bunch (EFB), mesocarp fibre (MF) and palm kernel shell (PKS) in a 75 kWth pilot scale downdraft gasifier for possible synergic reactions between the biomass. A series of experiments was carried out using equal blend of EFB, MF, and PKS (particle sizes of 14 and 6.7 mm) and equal blend of MF and PKS. Advanced infrared multi-gas analyser, and thermal conductivity gas analyser were employed to measure the produced gases. The elemental compositions of the raw biomass, ash and slag generated were determined using Scanning Field Emission Gun Scanning Electron Microscopy with accelerating voltage 20.0 kV and working distance 6 mm and the measurements processed using AztecEnergy V2.2 software. The co-gasification of blend of EFB, MF, and PKS, compared to the blend of MF and PKS led to higher gas yield (4.82 and 3.47 m3/kg_biomass), cold gas efficiency (16.2 and 13.37%), and carbon conversion efficiency (56.3 and 34.18%), respectively. When compared to particle size of 14 mm, the PKS of particle size of 6.7 mm in the EFB/MF/PKS blend increased the lower heating value and the higher heating value of the producer gas by 20% and 20.3%, respectively, and the residue yield was 18.6% less. The overall result has provided evidence on the importance of co-gasification of biomass especially EFB, MF and PKS, which will result in increased utilization of EFB.Item Open Access CO2/SO2 emission reduction in CO2 shipping infrastructure(Cranfield University, 2019-05-30 10:32) Awoyomi, Adeola; Patchigolla, Kumar; Anthony, BenSimulation 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.Item Open Access 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.Item Open Access Compact ammonia/water absorption chiller of different cycle configurations: parametric analysis based on heat transfer performance(MDPI, 2022-09-06) Tao, Xuan; Thanganadar, Dhinesh; Patchigolla, KumarAmmonia/water absorption chillers are driven by low-grade heat and cover wide refrigeration temperatures. This paper analyses single-stage ammonia/water absorption chillers. A numerical model was developed based on the heat exchanger performance. The model captures variational heat exchanger performances and describes the actual cycle with varying boundary conditions. The detrimental effects of refrigerant impurity were analysed quantitatively under different operating conditions. The model was validated with experimental data. A basic cycle and three advanced cycles were analysed for sub-zero refrigeration by comparing the thermodynamic performances. A compression-assisted cycle extended the activation temperature from 80 to 60 °C. At the heat source of 120 °C, when a counter-current desorber or bypassed rich solution was used, the COP increased from 0.51 to 0.58 or 0.57, respectively. The operating parameters included the heat source temperatures, heat sink temperatures, the mass flow rates and mass concentrations of rich solutions. Higher heat source temperatures increase cooling capacity. The increase was around 20 kW for the basic cycle of sub-zero refrigeration. There is an optimum heat source temperature maximising the COP. Higher heat source temperatures increased the refrigerant mass flow rate and reduced the mass concentration. The mass concentration can decrease from 0.999 to 0.960.Item Open Access A comprehensive review of pre-and post-treatment approaches to achieve sustainable desalination for different water streams(Elsevier, 2023-09-09) Poirier, Kristofer; Lotfi, Mohsen; Garg, Kapil; Patchigolla, Kumar; Anthony, Edward J.; Faisal, Nadimul Haque; Mulgundmath, Vinay; Sahith, Jai Krishna; Jadhawar, Prashant; Koh, Liam; Morosuk, Tatiana; Al Mhanna, NajahDesalination is an energy intensive process requiring adequate pre- and post- treatment. The novelty of this paper is that it jointly reviews the technologies for pre-treatment, desalination and post-treatment and bridges the gap between them while comparing the treatment methods needed depending on the type of feed water including seawater, brackish water, municipal and industrial wastewater. Those different streams show wide variability, sometimes containing organics, oil or scaling precursors which require adequate treatment. Nowadays, membrane pre-treatment methods have become promising alternatives to conventional pre-treatment techniques thanks to their flexibility. Hybrid desalination technologies have shown great potential in reducing energy consumption. Moreover, desalination plants produce large quantities of brines which require post-treatment to reduce environmental impacts. Current research on post-treatment is looking into recovering salts, metals and potable water from brines to achieve zero liquid discharge (ZLD). Thermal-based ZLD technologies are capable of extracting those resources while membrane-based ZLD methods are mostly limited to pre-concentration and water recovery due to fouling issues. Several studies have shown that ZLD systems can lower the cost of water and increase profitability if crystals and water are recovered and sold for additional revenue.Item Open Access Conceptual energy and water recovery system for self-sustained nano membrane toilet(Energy Conservation and Management, 2016-08-12) Hanak, Dawid P.; Kolios, Athanasios; Onabanjo, Tosin; Wagland, Stuart Thomas; Patchigolla, Kumar; Fidalgo Fernandez, Beatriz; Manovic, Vasilije; McAdam, Ewan J.; Parker, Alison; Williams, Leon; Tyrrell, Sean; Cartmell, EliseWith about 2.4 billion people worldwide without access to improved sanitation facilities, there is a strong incentive for development of novel sanitation systems to improve the quality of life and reduce mortality. The Nano Membrane Toilet is expected to provide a unique household-scale system that would produce electricity and recover water from human excrement and urine. This study was undertaken to evaluate the performance of the conceptual energy and water recovery system for the Nano Membrane Toilet designed for a household of ten people and to assess its self-sustainability. A process model of the entire system, including the thermochemical conversion island, a Stirling engine and a water recovery system was developed in Aspen Plus®. The energy and water recovery system for the Nano Membrane Toilet was characterised with the specific net power output of 23.1 Wh/kgsettledsolids and water recovery rate of 13.4 dm3/day in the nominal operating mode. Additionally, if no supernatant was processed, the specific net power output was increased to 69.2 Wh/kgsettledsolids. Such household-scale system would deliver the net power output (1.9–5.8 W). This was found to be enough to charge mobile phones or power clock radios, or provide light for the household using low-voltage LED bulbs.Item Open Access Critical evaluation of oil palm fresh fruit bunch solid wastes as soil amendments: Prospects and challenges(Elsevier, 2018-05-28) Anyaoha, Kelechi E.; Sakrabani, Ruben; Patchigolla, Kumar; Mouazen, Abdul M.Sustainable land use has been identified as one way of tackling challenges related to climate change, population expansion, food crisis and environmental pollution. Disposal of oil palm fresh fruit bunch (FFB) solid wastes is becoming a challenge with an increased demand and production of palm oil. Whilst this poses a challenge, it could be turned into an opportunity by utilising it as a resource and fully valorise it to meet soil and crop demands. This review presents the potentials of FFB solid wastes, which include empty fruit bunch (EFB), mesocarp fibre (MF), palm kernel shell (PKS), as soil ameliorants. The major findings are the following: 1) pyrolysis, gasification, combustion, and composting are processes that can enhance the value of FFB solid wastes. These processes lead to new products including biochar, ash, and compost, which are valuable resources that can be used for soil improvement. 2) The application of EFB mulch, ash from EFB, MF and PKS, biochar from EFB, and PKS, and compost of EFB, and MF led to improvement in soil physico-chemical properties, and growth and performance of sweet corn, mushroom, oil palm, sweet potato, cauliflower plant, banana, maize, cocoa, cassava, eggplants, and pepper. However, reports show that EFB compost and ash led to decrease in growth and performance of okra. Therefore, the use of appropriate conversion technology for FFB solid wastes as soil ameliorants can significantly improve crop yield and soil properties, reduce environmental pollution, and more importantly increase income of oil mill processors and savings for farmers.Item Open Access 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, BenTable showing the results obtained from the economic analysis of the capture integration. All graphs can be generated from the given streams.Item Open Access Data supporting the publication 'Energy and economic assessment of mixed palm residue utilisation for production of activated carbon and ash as fertiliser in agriculture'.(Cranfield University, 2021-09-29 09:26) Ukanwa, Kalu; Patchigolla, Kumar; Sakrabani, RubenData supporting the publication 'Energy and economic assessment of mixed palm residue utilisation for production of activated carbon and ash as fertiliser in agriculture'.Item Open Access Design and commissioning of a multi-mode prototype for thermochemical conversion of human faeces(Elsevier, 2018-03-23) Jurado Pontes, Nelia; Somorin, Tosin; Kolios, Athanasios J.; Wagland, Stuart; Patchigolla, Kumar; Fidalgo, Beatriz; Parker, Alison; McAdam, Ewan; Williams, Leon; Tyrrel, SeanThis article describes the design and commissioning of a micro-combustor for energy recovery from human faeces, which can operate both in updraft and downdraft modes. Energy recovery from faecal matter via thermochemical conversion has recently been identified as a feasible solution for sanitation problems in low income countries and locations of high income countries where access to sewage infrastructures is difficult or not possible. This technology can be applied to waterless toilets with the additional outcome of generating heat and power that can be used to pre-treat the faeces before their combustion and to ensure that the entire system is self-sustaining. The work presented here is framed within the Nano Membrane Toilet (NMT) project that is being carried out at Cranfield University, as part of the Reinvent the Toilet Challenge of the Bill and Melinda Gates Foundation. For this study, preliminary trials using simulant faeces pellets were first carried out to find out the optimum values for the main operating variables at the scale required by the process, i.e. a fuel flowrate between 0.4 and 1.2 g/min of dry faeces. Parameters such as ignition temperature, residence time, and maximum temperature reached, were determined and used for the final design of the bench-scale combustor prototype. The prototype was successfully commissioned and the first experimental results, using real human faeces, are discussed in the paper.Item Open Access Design of a novel CSP/MED desalination system(American Institute of Physics (AIP), 2022-05-12) Sansom, Christopher L.; Patchigolla, Kumar; Jonnalagadda, Kranthi; King, PeterWe describe the design of a large-scale thermal desalination demonstrator unit for use in arid locations with a medium-to-high DNI. Most of thermal energy is provided by a conventional parabolic trough field, in the case of the demonstrator this being 4MWt. The desalination sub-system comprises a 3-effect MED, the first stage of which is a large 20 m diameter glass and steel-structured geodesic and transparent dome. The thermal energy is supplemented by direct sunlight transmitted through the dome and by an arc of small heliostats which focus yet more sunlight onto the dome itself. The prototype is under construction at Neom in KSA.Item Open Access Design overview of high pressure dense phase CO2 pipeline transport in flow mode(Elsevier, 2013-08-05) Patchigolla, Kumar; Oakey, John E.In open literature, there is little information available with regards to the engineering and technological issues for material corrosion, in relation to high pressure supercritical CO2 pipeline transport from single point sources, such as the power industry. A typical CO2 pipeline is designed to operate at high pressure in the dense phase. However, it is evident that although there is considerable experience of testing materials in lower pressure gaseous CO2 in the oil and gas industry, there is little understanding of the behaviour of pipeline materials when in contact with impure CO2 captured either from power plants or the oil and gas industry. In this particular project development, a dynamic dense phase CO2 corrosion rig has been built (conditions: ∼85 bar, 40 °C and up to 5 l/min flow rate) in flow mode, to understand the effect of impurities (SO2, O2, H2, NO2 & CO) present in captured CO2 on the pipeline transport materials. This unique facility in the UK was developed via the MATTRANS project funded by the E.ON-EPSRC strategic partnership (EP/G061955/1). The test rig includes different metallic materials (X grade steel: X60, X70 and X100) to assess the corrosion of pipelines, and different geometry components (tubes, plates, charpy and tensile coupons), to assess ageing and decompression behavior of polymeric seals (Neoprene, fluorocarbon, ethylene and Buna N) under water-saturated dense phase CO2 with different impurity concentrations (0.05 mol % SO2; 4 mol % O2; 2 mol % H2; 0.05 mol % NO2; 1 mol % CO). The dynamic data generated from this dense phase CO2 corrosion rig will give vital information with regards to pipeline suitability and lifetimes, when operating with dense CO2.Item Open Access Development of safe and reliable operations in large-scale CO₂ shipping: an experimental approach.(2021-01) Al Baroudi, Hisham; Patchigolla, Kumar; Oakey, JohnA successful worldwide implementation of Carbon Capture, Utilisation and Storage largely relies on the establishment of a safe and reliable CO₂ transmission network. CO₂ shipping hereby represents a promising transport option, characterised by a high degree of flexibility in sink-source matching. This study addressed some key knowledge gaps that currently pose a limitation on large-scale commercialisation of this technology by providing information on operational and maintenance challenges in the chain. Firstly, an extensive review of technological advancements and future projections in large scale CO₂ shipping drew the attention to the fact that key technical challenges still need to be addressed in both pipeline and sea vessel systems in order to establish a worldwide network of CO₂ transport infrastructure. In particular, significant dearth concerns the adoption of appropriate safety protocols during accidental scenarios and selection of suitable materials to ensure integrity of transport infrastructure throughout real operations. Thus, an experimental lab scale rig was built and commissioned, capable of handling refrigerated carbon dioxide batches (up to 2.25 L) at conditions typical of sea vessel transport (~0.7 - 2.7 MPa, 223 - 259 K); the facility was designed to permit investigation of accidental leakage behaviour and to determine the qualification assessment of elastomer materials exposed under real shipping conditions. A technical qualification of elastomer materials for CO₂ transport systems was then performed with the aim of assessing their suitability in the intended systems and propensity for degradation. Such elastomers are used as seals in pressure- relief valves, providing elastomer-to-metal shutoff and eliminating leakage around stem during relief mode. Samples previously tested under pipeline conditions (9.5 MPa, 318 K) at exposure times of 50 – 400 h were characterised for a visual inspection, mechanical and thermo-analytical properties. Based on the suitable performance of the elastomers under such pipeline conditions, Ethylene Propylene Diene Monomer was selected for testing under operations typical of CO₂ shipping; constrained (25% compression) samples thereby underwent 20 – 100 CO₂ loading and offloading cycles at average decompression rates of 1.6 MPa/min; tested materials were then qualified through the aforementioned characterisation methodology, demonstrating a satisfactory resistance to rapid gas decompression and mechanical stability. A detailed experimental campaign was considered to assess the accidental leakage behaviour of CO₂ under shipping conditions; the main risks associated with CO₂ are asphyxiation due to displacement of oxygen to critically low levels, and exposure to concentrations of 15% or above in air are deemed life threating due to toxicological impacts on humans. The study highlighted that selection of initial fluid conditions significantly affects the propensity for solid formation in the vessel and blockages in the pipe section, thus resulting in significantly diverse leakage behaviours. Low-pressure decompression tests (0.7 – 0.94 MPa) resulted in the highest amount of inventory solidification (36 – 39 wt%) while high- pressure decompression scenarios (1.8 – 2.65 MPa) demonstrated the lowest (17 – 22 wt%). Lastly, a real-scale investigation on liquid CO₂ discharge from the coupler of an emergency release system was undertaken in order to scrutinise the applicability of such spillage containment measure to CO₂ shipping operations. The study focused on two refrigerated states, namely low- (0.87 – 0.94 MPa, 227 – 231 K) and medium-pressure conditions (1.62 – 1.65 MPa, 239 – 240 K) typical of shipping transport; findings demonstrated the presence of an abrupt outflow behaviour, characterised by full inventory discharge form the coupler in less than 1 s and achievement of peak depressurisation rates of 6 MPa/s. Moreover, the discharge behaviour showed considerable variations in relation to the selected initial conditions.Item Open Access Effect of SO2 and steam on CO2 capture performance of biomass-templated calcium aluminate pellets(Royal Society of Chemistry, 2016-03-29) Erans Moreno, Maria; Beisheim, T.; Manovic, Vasilije; Jeremias, M.; Patchigolla, Kumar; Dieter, H.; Duan, Lunbo; Anthony, Edward J.Four types of synthetic sorbents were developed for high-temperature post-combustion calcium looping CO2 capture using Longcal limestone. Pellets were prepared with: lime and cement (LC); lime and flour (LF); lime, cement and flour (LCF); and lime, cement and flour, doped with seawater (LCFSW). Flour was used as a templating material. All samples underwent 20 cycles in a TGA under two different calcination conditions. Moreover, the prepared sorbents were tested for 10 carbonation/calcination cycles in a 68-mm-internal-diameter bubbling fluidized bed (BFB) under three environments: with no sulphur and no steam; in the presence of sulfur; and with steam. When compared to limestone, all the synthetic sorbents exhibited enhanced CO2 capture performance in both a TGA and BFB, with the exception of the sample doped with seawater. In the BFB tests, the addition of cement binder during the pelletisation process resulted in the increase of CO2 capture capacity from 0.08 gCO2/gsorbent (LF) to 0.15 gCO2/gsorbent (LCF) by the 10th cycle. The CO2 uptake in the presence of SO2 dramatically declined by the 10th cycle; for example, from 0.22 gCO2/gsorbent to 0.05 gCO2/gsorbent in the case of the untemplated material (LC). However, as expected all samples showed improved performance in the presence of steam and the decay of reactivity during the cycles was less pronounced. Nevertheless, in the BFB environment, the templated pellets showed poorer CO2 capture performance. This is presumably because of material loss due to attrition under the FB conditions. Namely, by contrast, the templated materials performed better than untemplated materials under TGA conditions. This indicates that reduction in attrition is critical in the case of employment of templated materials in realistic systems with FB reactors.Item Open Access Energetic, exergetic and environmental (3E) analyses of different cooling technologies (wet, dry and hybrid) in a CSP thermal power plant(Elsevier, 2021-10-08) Cutillas, C. G.; Ruiz, J.; Asfand, Faisal; Patchigolla, Kumar; Lucas, M.This paper deals with the comparison of three condensation systems for the heat dissipation in a solar power plant: wet system, dry system and hybrid system based on the pre-cooling of the air in an adiabatic panel located in the entrance section of a dry system. Energy, exergy and environmental (3E) analyses were conducted to assess the influence of the condensation system on the power plant performance. The Andasol I plant located in Granada (Spain), with a net power capacity of 50 MWe, is used as a real reference case of a concentrated solar power station. The cycle refrigerated with a cooling tower achieves a lower pressure of condensation, followed by the hybrid and dry system. As the pressure decreases, the efficiency of the cycle increases and also the power generated, being 12.60% in the case of cooling tower and 4.65% in the hybrid system with respect the dry condenser. A 71.74% of water usage savings by the hybrid system carries a 7.06% of net power production with regard of the cooling tower configuration. The exergetic performance of the plant is 73.77% for the wet system, 69.21% for the hybrid and 68.46% for the dry system.Item Open Access Energy and economic assessment of mixed palm residue utilisation for production of activated carbon and ash as fertiliser in agriculture(Taylor and Francis, 2021-10-16) Ukanwa, Kalu Samuel; Patchigolla, Kumar; Sakrabani, Rubenhe resultant residues after thermal processes can be reused in the form of activated carbon (AC) production or used for soil amelioration. However, the economic and energy optimisation of the waste revaluation process is necessary for the prediction of technology requirements, investment boundaries and cost–benefit analysis. Mass, energy and cost estimation of the entire process were systematically executed relative to equipment sizing and type of product, as major factors in the evaluation. The economic analysis and process optimisation were quantified and evaluated with the Aspen Plus economy and an SPSS statistical tool for economic analysis. Simulation results were concomitant with economic analysis to determine the approximate annualised return on investment, profitability index and payback period, using optimised variables in the process. The four processes examined: process scenario 1–4 (pyrolysis, gasification, combustion and combined) have 16, 17, 14 and 17.2% return on investment for the 8.5, 8.2, 9.8 and 8-year payback period, respectively. The results provide a technology assessment and economic guide for investors and policymakers among others. This work is also useful for researchers in achieving the goal of efficient biomass utilisation. Palm waste ash as a potential alternative to chemical fertiliser, especially for the treatment of ultisol and acidic soils, were evaluated and it was confirmed that it is a good alternative to typical inorganic fertiliser. Finally, the results indicate that using such wastes in the AC market is a viable business option, though with high initial capital investment even though palm waste ash can be produced locally.