• Evaluation of a Micro Gas Turbine With Post-Combustion CO2 Capture for Exhaust Gas Recirculation Potential With Two Experimentally Validated Models

      Nikpey Somehsaraei, Homam; Ali, Usman; Font-Palma, Carolina; Mansouri Majoumerd, Mohammad; Akram, Muhammad; Pourkashanian, Mohamed; Assadi, Mohsen (American Society of Mechanical Engineers, 2017-08-17)
      The growing global energy demand is facing concerns raised by increasing greenhouse gas emissions, predominantly CO2. Despite substantial progress in the field of renewable energy in recent years, quick balancing responses and back-up services are still necessary to maintain the grid load and stability, due to increased penetration of intermittent renewable energy sources, such as solar and wind. In a scenario of natural gas availability, gas turbine power may be a substitute for back-up/balancing load. Rapid start-up and shut down, high ramp rate, and low emissions and maintenance have been achieved in commercial gas turbine cycles. This industry still needs innovative cycle configurations, e.g. exhaust gas recirculation (EGR), to achieve higher system performance and lower emissions in the current competitive power generation market. Together with reduced NOx emissions, EGR cycle provides an exhaust gas with higher CO2 concentration compared to the simple gas turbine/combined cycle, favorable for post-combustion carbon capture. This paper presents an evaluation of EGR potential for improved gas turbine cycle performance and integration with a post-combustion CO2 capture process. It also highlights features of two software tools with different capabilities for performance analysis of gas turbine cycles, integrated with post-combustion capture. The study is based on a combined heat and power micro gas turbine (MGT), Turbec T100, of 100kWe output. Detailed models for the baseline MGT and amine capture plant were developed in two software tools, IPSEpro and Aspen Hysys. These models were validated against experimental work conducted at the UK PACT National Core Facilities. Characteristics maps for the compressor and the turbine were used for the MGT modeling. The performance indicators of systems with and without EGR, and when varying the EGR ratio and ambient temperature, were calculated and are presented in this paper.
    • Evaluation of the Performance and Economic Viability of a Novel Low Temperature Carbon Capture Process

      Lychnos, George; Clements, Alastair; Willson, Paul; Font Palma, Carolina; Diego, Maria E.; Pourkashanian, Mohamed; Howe, Joseph; PMW Technology Limited; University of Sheffield; University of Chester (SSRN, 2018-10)
      A novel Advanced Cryogenic Carbon Capture (A3C) process is being developed due to its potential to achieve high CO2 capture efficiencies using low cost but high intensity heat transfer to deliver a much reduced energy consumption and process equipment size. These characteristics, along with the absence of process chemicals, offer the potential for application across a range of sectors. This work presents a techno-economic evaluation for applications ranging from 3% to 30% CO2 content.
    • Evaluation of the performance and economic viability of a novel low temperature carbon capture process

      Wilson, Paul; Lychnos, George; Clements, Alastair; Michailos, Stavros; Font Palma, Carolina; Diego, Maria E.; Pourkashanian, Mohamed; Howe, Joseph; PMW Technology Ltd; University of Sheffield; University of Chester (Elsevier, 2019-04-22)
      A novel Advanced Cryogenic Carbon Capture (A3C) process is being developed using low cost but high intensity heat transfer to achieve high CO2 capture efficiencies with a much reduced energy consumption and process equipment size. These characteristics, along with the purity of CO2 product and absence of process chemicals, offer the potential for application across a range of sectors. This work presents a techno-economic evaluation for applications ranging from 3% to 35%vol. CO2 content. The A3C process is evaluated against an amine-based CO2 capture process for three applications; an oil-fired boiler, a combined cycle gas turbine (CCGT) and a biogas upgrading plant. The A3C process has shown a modest life cost advantage over the mature MEA technology for the larger selected applications, and substantially lower costs in the smaller biogas application. Enhanced energy recovery and optimization offer significant opportunities for further reductions in cost.
    • Experimental and process modelling study of integration of a micro-turbine with an amine plant

      Agbonghae, Elvis O.; Best, Thom; Finney, Karen N.; Font Palma, Carolina; Hughes, Kevin J.; Pourkashanian, Mohamed; University of Leeds (Elsevier, 2014-12-31)
      An integrated model of a micro-turbine coupled to a CO2 capture plant has been developed with Aspen Plus, and validated with experimental data obtained from a Turbec T100 microturbine at the PACT facilities in the UKCCS Research Centre, Beighton, UK. Monoethanolamine (MEA) was used as solvent and experimental measurements from the CO2 capture plant have been used to validate the steady-state model developed with Aspen Plus®. The optimum liquid/gas ratio and the lean CO2 loading for 90% CO2 capture has been quantified for flue gases with CO2 concentrations ranging from 3 to 8 mol%.
    • Experimental Exploration of CO2 Capture Using a Cryogenic Moving Packed Bed

      Cann, David; Willson, Paul; Font Palma, Carolina; University of Chester; PMW Technology Ltd; University of Chester (SSRN, 2018-10)
      This study examines a novel cryogenic post-combustion capture process, based on a moving bed of cold beads to freeze CO2 out of a flue gas, and this paper presents the first steps in experimental work. The preliminary experiments included the test of fluidization of bed material, if the flow rate of bed material can be kept constant in and out of the column and the estimation of heat transfer coefficient. The obtained results are encouraging for the running of the rig at cryogenic conditions.
    • Impact of the operating conditions and position of exhaust gas recirculation on the performance of a micro gas turbine

      Ali, Usman; Font Palma, Carolina; Hughes, Kevin J.; Ingham, Derek B.; Ma, Lin; Pourkashanian, Mohamed; University of Chester/University of Leeds (Elsevier, 2015-06-10)
      Gas turbines are a viable and secure option both economically and environmentally for power and heat generation. The process simulation of the micro gas turbine with exhaust gas recirculation (EGR) and its impact on performance is evaluated. This study is further extended to evaluate the effect of the operating conditions and position of the EGR on the performance of the micro gas turbine. The performance analysis for different configurations of the EGR cycle, as well as flue gas condensation temperature, results in the optimized position of EGR at the compressor inlet with partial condensation resulting in the CO2 enhancement to 3.7 mol%.
    • Integrated Oxyfuel Power Plant with Improved CO2 Separation and Compression Technology for EOR application

      Font Palma, Carolina; Errey, Olivia; Corden, Caroline; Chalmers, Hannah; Lucquiaud, Mathieu; Sanchez del Rio, Maria; Jackson, Steve; Medcalf, Daniel; Livesey, Bryony; Gibbins, Jon; et al. (Elsevier, 2016-06-25)
      An integrated advanced supercritical coal-fired oxyfuel power plant with a novel cryogenic CO2 separation and compression technology for high purity CO2 to suit injection for enhanced oil recovery purposes is investigated. The full process is modelled in Aspen Plus® consisting of: an Air Separation Unit (ASU), an Advanced Supercritical Pulverised Fuel (ASC PF) power plant with a bituminous coal as feedstock, a steam cycle, and a Carbon dioxide Purification Unit (CPU). The proposed CPU process accommodates a distillation column with an integrated reboiler duty to achieve a very high purity CO2 product (99.9%) with constrained oxygen levels (100 ppm). This work presents a detailed analysis of the CO2 separation and compression process within the full power plant, including effective heat integration to reduce the electricity output penalty associated with oxyfuel CO2 capture. The results of this analysis are compared with previous studies and indicate that the combined application of process optimisation in the CPU and advanced heat integration with the power plant offer promising results: In this work a high purity CO2 product was achieved while maintaining 90% capture for a net plant efficiency of 38.02% (LHV), compared with a thermal efficiency of 37.76% (LHV) for a reference simulation of an ASC PF oxy-fired plant with advanced heat integration, providing a lower purity CO2 product.
    • Intermediate pyrolysis of biomass energy pellets for producing sustainable liquid, gaseous and solid fuels

      Yang, Y.; Brammer, John G.; Mahmood, A. S. N.; Hornung, A.; Aston University; Institute Branch Sulzbach-Rosenberg (Elsevier, 2014-07-16)
      This work describes the use of intermediate pyrolysis system to produce liquid, gaseous and solid fuels from pelletised wood and barley straw feedstock. Experiments were conducted in a pilot-scale system and all products were collected and analysed. The liquid products were separated into an aqueous phase and an organic phase (pyrolysis oil) under gravity. The oil yields were 34.1 wt.% and 12.0 wt.% for wood and barley straw, respectively. Analysis found that both oils were rich in heterocyclic and phenolic compounds and have heating values over 24 MJ/kg. The yields of char for both feedstocks were found to be about 30 wt.%, with heating values similar to that of typical sub-bituminous class coal. Gas yields were calculated to be approximately 20 wt.%. Studies showed that both gases had heating values similar to that of downdraft gasification producer gas. Analysis on product energy yields indicated the process efficiency was about 75%.
    • The Interplay Between Cholesterol Metabolism and Intrinsic Ageing

      Mc Auley, Mark T.; University of Chester (SpringerLink, 2018-12-31)
      The last few decades have witnessed remarkable progress in our understanding of ageing. From an evolutionary standpoint it is generally accepted that ageing is a non-adaptive process which is underscored by a decrease in the force of natural selection with time. From a mechanistic perspective ageing is characterized by a wide variety of cellular mechanisms, including processes such as cellular senescence, telomere attrition, oxidative damage, molecular chaperone activity, and the regulation of biochemical pathways by sirtuins. These biological findings have been accompanied by an unrelenting rise in both life expectancy and the number of older people globally. However, despite age being recognized demographically as a risk factor for healthspan, the processes associated with ageing are routinely overlooked in disease mechanisms. Thus, a central goal of biogerontology is to understand how diseases such as cardiovascular disease (CVD) are shaped by ageing. This challenge cannot be ignored because CVD is the main cause of morbidity in older people. A worthwhile way to examine how ageing intersects with CVD is to consider the effects ageing has on cholesterol metabolism, because dysregualted cholesterol metabolism is the key factor which underpins the pathology of CVD. The aim of this chapter is to outline a hypothesis which accounts for how ageing intersects with intracellular cholesterol metabolism. Moreover, we discuss the implications of this relationship for the onset of disease in the 'oldest old' (individuals ≥85 years of age). We conclude the chapter by discussing the important role mathematical modelling has to play in improving our understanding of cholesterol metabolism and ageing.
    • Investigating Cholesterol Metabolism and Ageing Using a Systems Biology Approach

      Morgan, Amy; Mooney, Kathleen M.; Wilkinson, Stephen J.; Pickles, Neil; Mc Auley, Mark T.; University of Chester (Cambridge University Press, 2016-11-02)
      CVD accounted for 27 % of all deaths in the UK in 2014, and was responsible for 1·7 million hospital admissions in 2013/2014. This condition becomes increasingly prevalent with age, affecting 34·1 and 29·8 % of males and females over 75 years of age respectively in 2011. The dysregulation of cholesterol metabolism with age, often observed as a rise in LDL-cholesterol, has been associated with the pathogenesis of CVD. To compound this problem, it is estimated by 2050, 22 % of the world's population will be over 60 years of age, in culmination with a growing resistance and intolerance to pre-existing cholesterol regulating drugs such as statins. Therefore, it is apparent research into additional therapies for hypercholesterolaemia and CVD prevention is a growing necessity. However, it is also imperative to recognise this complex biological system cannot be studied using a reductionist approach; rather its biological uniqueness necessitates a more integrated methodology, such as that offered by systems biology. In this review, we firstly discuss cholesterol metabolism and how it is affected by diet and the ageing process. Next, we describe therapeutic strategies for hypercholesterolaemia, and finally how the systems biology paradigm can be utilised to investigate how ageing interacts with complex systems such as cholesterol metabolism. We conclude by emphasising the need for nutritionists to work in parallel with the systems biology community, to develop novel approaches to studying cholesterol metabolism and its interaction with ageing.
    • LDL-C levels in older people: Cholesterol Homeostasis and the Free Radical Theory of Ageing Converge

      Mc Auley, Mark T.; Mooney, Kathleen M.; Univeristy of Chester; Edge Hill University (Elsevier, 2017-05-17)
      The cardiovascular disease (CVD) risk factor, low density lipoprotein cholesterol (LDL-C) increases with age, up until the midpoint of life in males and females. However, LDL-C can decrease with age in older men and women. Intriguingly, a recent systematic review also revealed an inverse association between LDL-C levels and cardiovascular mortality in older people; low levels of LDL-C were associated with reduced risk of mortality. Such findings are puzzling and require a biological explanation. In this paper a hypothesis is proposed to explain these observations. We hypothesize that the free radical theory of ageing (FRTA) together with disrupted cholesterol homeostasis can account for these observations. Based on this hypothesis, dysregulated hepatic cholesterol homeostasis in older people is characterised by two distinct metabolic states. The first state accounts for an older person who has elevated plasma LDL-C. This state is underpinned by the FRTA which suggests there is a decrease in cellular antioxidant capacity with age. This deficiency enables hepatic reactive oxidative species (ROS) to induce the total activation of HMG-CoA reductase, the key rate limiting enzyme in cholesterol biosynthesis. An increase in cholesterol synthesis elicits a corresponding rise in LDL-C, due to the downregulation of LDL receptor synthesis, and increased production of very low density lipoprotein cholesterol (VLDL-C). In the second state of dysregulation, ROS also trigger the total activation of HMG-CoA reductase. However, due to an age associated decrease in the activity of cholesterol-esterifying enzyme, acyl CoA: cholesterol acyltransferase, there is restricted conversion of excess free cholesterol (FC) to cholesterol esters. Consequently, the secretion of VLDL-C drops, and there is a corresponding decrease in LDL-C. As intracellular levels of FC accumulate, this state progresses to a pathophysiological condition akin to nonalcoholic fatty liver disease. It is our conjecture this deleterious state has the potential to account for the inverse association between LDL-C level and CVD risk observed in older people.
    • Lipid metabolism and hormonal interactions: Impact on cardiovascular disease and healthy aging

      Mc Auley, Mark T.; Mooney, Kathleen M.; University of Chester ; Edge Hill University (informa health care, 2014-07)
      Populations in developed nations are aging gradually; it is predicted that by 2050 almost a quarter of the world’s population will be over 60 years old, more than twice the figure at the turn of the 20th century. Although we are living longer, this does not mean the extra years will be spent in good health. Cardiovascular diseases are the primary cause of ill health and their prevalence increases with age. Traditionally, lipid biomarkers have been utilized to stratify disease risk and predict the onset of cardiovascular events. However, recent evidence suggests that hormonal interplay with lipid metabolism could have a significant role to play in modulating cardiovascular disease risk. This review will explore recent findings which have investigated the role hormones have on the dynamics of lipid metabolism. The aim is to offer an insight into potential avenues for therapeutic intervention.
    • A mathematical model of microbial folate biosynthesis and utilisation: implications for antifolate development

      Salcedo-Sora, J. Enrique; Mc Auley, Mark T.; Liverpool Hope University, University of Chester (Royal Society of Chemistry, 2016-01-15)
      The metabolic biochemistry of folate biosynthesis and utilisation has evolved into a complex network of reactions. Although this complexity represents challenges to the field of folate research it has also provided a renewed source for antimetabolite targets. A range of improved folate chemotherapy continues to be developed and applied particularly to cancer and chronic inflammatory diseases. However, new or better antifolates against infectious diseases remain much more elusive. In this paper we describe the assembly of a generic deterministic mathematical model of microbial folate metabolism. Our aim is to explore how a mathematical model could be used to explore the dynamics of this inherently complex set of biochemical reactions. Using the model it was found that: (1) a particular small set of folate intermediates are overrepresented, (2) inhibitory profiles can be quantified by the level of key folate products, (3) using the model to scan for the most effective combinatorial inhibitions of folate enzymes we identified specific targets which could complement current antifolates, and (4) the model substantiates the case for a substrate cycle in the folinic acid biosynthesis reaction. Our model is coded in the systems biology markup language and has been deposited in the BioModels Database (MODEL1511020000), this makes it accessible to the community as a whole.
    • Mathematical modelling of metabolic regulation in aging

      Mc Auley, Mark T.; Mooney, Kathleen M.; Angell, Peter J.; Wilkinson, Stephen J.; University of Chester ; Liverpool Hope University ; Edge Hill University ; University of Chester (MDPI, 2015-04-27)
      The underlying cellular mechanisms that characterize aging are complex and multifaceted. However, it is emerging that aging could be regulated by two distinct metabolic hubs. These hubs are the pathway defined by the mammalian target of rapamycin (mTOR) and that defined by the NAD+-dependent deacetylase enzyme, SIRT1. Recent experimental evidence suggests that there is crosstalk between these two important pathways; however, the mechanisms underpinning their interaction(s) remains poorly understood. In this review, we propose using computational modelling in tandem with experimentation to delineate the mechanism(s). We briefly discuss the main modelling frameworks that could be used to disentangle this relationship and present a reduced reaction pathway that could be modelled. We conclude by outlining the limitations of computational modelling and by discussing opportunities for future progress in this area.
    • Mathematically modelling the dynamics of cholesterol metabolism and ageing

      Morgan, Amy; Mooney, Kathleen M.; Wilkinson, Stephen J.; Pickles, Neil; Mc Auley, Mark T.; University of Chester, Edgehill University (Elsevier, 2016-07-30)
      Cardiovascular disease (CVD) is the leading cause of morbidity and mortality in the UK. This conditionbecomes increasingly prevalent during ageing; 34.1% and 29.8% of males and females respectively, over 75years of age have an underlying cardiovascular problem. The dysregulation of cholesterol metabolism isinextricably correlated with cardiovascular health and for this reason low density lipoprotein cholesterol(LDL-C) and high density lipoprotein cholesterol (HDL-C) are routinely used as biomarkers of CVD risk. Theaim of this work was to use mathematical modelling to explore how cholesterol metabolism is affectedby the ageing process. To do this we updated a previously published whole-body mathematical model ofcholesterol metabolism to include an additional 96 mechanisms that are fundamental to this biologicalsystem. Additional mechanisms were added to cholesterol absorption, cholesterol synthesis, reversecholesterol transport (RCT), bile acid synthesis, and their enterohepatic circulation. The sensitivity of themodel was explored by the use of both local and global parameter scans. In addition, acute cholesterolfeeding was used to explore the effectiveness of the regulatory mechanisms which are responsible formaintaining whole-body cholesterol balance. It was found that our model behaves as a hypo-responderto cholesterol feeding, while both the hepatic and intestinal pools of cholesterol increased significantly.The model was also used to explore the effects of ageing in tandem with three different cholesterolester transfer protein (CETP) genotypes. Ageing in the presence of an atheroprotective CETP genotype,conferring low CETP activity, resulted in a 0.6% increase in LDL-C. In comparison, ageing with a genotypereflective of high CETP activity, resulted in a 1.6% increase in LDL-C. Thus, the model has illustrated theimportance of CETP genotypes such as I405V, and their potential role in healthy ageing.
    • Methods for the Treatment of Cattle Manure—A Review

      Font Palma, Carolina (MDPI, 2019-05-15)
      Environmental concerns, caused by greenhouse gases released to the atmosphere and overrunning of nutrients and pathogens to water bodies, have led to reducing direct spread onto the land of cattle manure. In addition, this practice can be a source of water and air pollution and toxicity to life by the release of undesirable heavy metals. Looking at the current practices, it is evident that most farms separate solids for recycling purposes, store slurries in large lagoons or use anaerobic digestion to produce biogas. The review explores the potential for cattle manure as an energy source due to its relatively large calorific value (HHV of 8.7–18.7 MJ/kg dry basis). This property is beneficial for thermochemical conversion processes, such as gasification and pyrolysis. This study also reviews the potential for upgrading biogas for transportation and heating use. This review discusses current cattle manure management technologies—biological treatment and thermochemical conversion processes—and the diverse physical and chemical properties due to the differences in farm practices.
    • Model-directed engineering of “difficult-to-express” monoclonal antibody production by Chinese hamster ovary cells

      Pybus, Leon P.; Dean, Greg; West, Nathan R.; Smith, Andrew; Daramola, Olalekan; Field, Ray; Wilkinson, Stephen J.; James, David C.; University of Sheffield ; BioPharmaceutical Development ; University of Sheffield ; BioPharmaceutical Development ; BioPharmaceutical Development ; BioPharmaceutical Development ; University of Sheffield ; University of Sheffield; ChELSI Institute; Department of Chemical and Biological Engineering; University of Sheffield; Mappin Street Sheffield S1 3JD UK; et al. (Wiley, 2013-11-14)
      Despite improvements in volumetric titer for monoclonal antibody (MAb) production processes using Chinese hamster ovary (CHO) cells, some “difficult-to-express” (DTE) MAbs inexplicably reach much lower process titers.
    • Modelling the molecular mechanisms of ageing

      Mc Auley, Mark T.; Martinez Guimera, Alvaro; Hodgson, David; McDonald, Neil; Mooney, Kathleen M.; Morgan, Amy; Proctor, Carole; University of Chester; Edgehill University; Newcastle University (Portland Press, 2017-02-23)
      The ageing process is driven at the cellular level by random molecular damage which slowly accumulates with age. Although cells possess mechanisms to repair or remove damage, they are not 100% efficient and their efficiency declines with age. There are many molecular mechanisms involved and exogenous factors such as stress also contribute to the ageing process. The complexity of the ageing process has stimulated the use of computational modelling in order to increase our understanding of the system, test hypotheses and make testable predictions. As many different mechanisms are involved, a wide range of models have been developed. This paper gives an overview of the types of models that have been developed, the range of tools used, modelling standards, and discusses many specific examples of models which have been grouped according to the main mechanisms that they address. We conclude by discussing the opportunities and challenges for future modelling in this field.
    • Obesity and the Dysregulation of Fatty Acid Metabolism: Implications for Healthy Aging

      Morgan, Amy; Mooney, Kathleen M.; Mc Auley, Mark T.; University of Chester; Edge Hill University (Taylor & Francis, 2016-10-17)
      The population of the world is aging. In 2010, an estimated 524 million people were aged 65 years or older presenting eight percent of the global population. By 2050, this number is expected to nearly triple to approximately 1.5 billion, 16 percent of the world’s population. Although people are living longer, the quality of their lives are often compromised due to ill-health. Areas covered. Of the conditions which compromise health as we age, obesity is at the forefront. Over half of the global older population were overweight or obese in 2010, significantly increasing the risk of a range of metabolic diseases. Although, it is well recognised excessive calorie intake is a fundamental driver of adipose tissue dysfunction, the relationship between obesity; intrinsic aging; and fat metabolism is less understood. In this review we discuss the intersection between obesity, aging and the factors which contribute to the dysregulation of whole-body fat metabolism. Expert Commentary. Being obese disrupts an array of physiological systems and there is significant crosstalk among these. Moreover it is imperative to acknowledge the contribution intrinsic aging makes to the dysregulation of these systems and the onset of disease.
    • Oxyfuel power plant with novel CO2 separation and compression technology

      Font Palma, Carolina; University of Leeds (2014-04-03)