• Part-load performance of direct-firing and co-firing of coal and biomass in a power generation system integrated with a CO2 capture and compression system

      Ali, Usman; Akram, Muhammad; Font Palma, Carolina; Ingham, Derek B.; Pourkashanian, Mohamed; University of Sheffield; University of Chester; University of Engineering and Technology (Elsevier, 2017-09-18)
      Bioenergy with Carbon Capture and Storage (BECCS) is recognised as a key technology to mitigate CO2 emissions and achieve stringent climate targets due to its potential for negative emissions. However, the cost for its deployment is expected to be higher than for fossil-based power plants with CCS. To help in the transition to fully replace fossil fuels, co-firing of coal and biomass provide a less expensive means. Therefore, this work examines the co-firing at various levels in a pulverised supercritical power plant with post-combustion CO2 capture, using a fully integrated model developed in Aspen Plus. Co-firing offers flexibility in terms of the biomass resources needed. This work also investigates flexibility within operation. As a result, the performance of the power plant at various part-loads (40%, 60% and 80%) is studied and compared to the baseline at 100%, using a constant fuel flowrate. It was found that the net power output and net efficiency decrease when the biomass fraction increases for constant heat input and constant fuel flow rate cases. At constant heat input, more fuel is required as the biomass fraction is increased; whilst at constant fuel input, derating occurs, e.g. 30% derating of the power output capacity at firing 100% biomass compared to 100% coal. Co-firing of coal and biomass resulted in substantial power derating at each part-load operation.
    • Prenatal exposures and exposomics of asthma

      Choi, Hyunok; Mc Auley, Mark T.; Lawrence, David A.; University at Albany ; University of Chester ; Center for Medical Sciences, Albany, NY (AIMS Press, 2015-02-19)
      This review examines the causal investigation of preclinical development of childhood asthma using exposomic tools. We examine the current state of knowledge regarding early-life exposure to non-biogenic indoor air pollution and the developmental modulation of the immune system. We examine how metabolomics technologies could aid not only in the biomarker identification of a particular asthma phenotype, but also the mechanisms underlying the immunopathologic process. Within such a framework, we propose alternate components of exposomic investigation of asthma in which, the exposome represents a reiterative investigative process of targeted biomarker identification, validation through computational systems biology and physical sampling of environmental media
    • Process simulation and thermodynamic analysis of a micro turbine with post-combustion CO2 capture and exhaust gas recirculation

      Ali, Usman; Best, Thom; Finney, Karen N.; Font Palma, Carolina; Hughes, Kevin J.; Ingham, Derek B.; Pourkashanian, Mohamed; University of Leeds (Elsevier, 2014-12-31)
      With the effects of the emissions from power plants causing global climate change, the trend towards lower emission systems such as natural gas power plant is increasing. In this paper a Turbec T100 micro gas turbine is studied. The system is assessed thermodynamically using a steady-state model; model results of its alteration with exhaust gas recirculation (EGR) are presented in this paper. The process simulation with EGR offers a useful assessment when integrated with post-combustion CO2 capture. The EGR model results in the enrichment of the CO2 which decrease the energy demand of the CO2 capture system.
    • Production of Biomethane from Agricultural Waste Using a Cryogenic Carbon Capture Process

      Font Palma, Carolina; Lychnos, George; Willson, Paul; University of Chester; PMW Technology Limited (Energy Proceedings, 2019)
      This paper evaluates a novel cryogenic carbon capture process to upgrade biogas produced from agricultural waste. The A3C cryogenic process offers simplicity and compactness with lower capital and operating costs compared to many alternative processes. The work addresses potential technical issues presented by trace contaminants in the raw biogas including hydrogen sulphide, organics and siloxanes. It is found that the A3C process offers high CO2 removal with minimal biomethane losses while requiring simple raw gas treatment.
    • Promises and Challenges of Growing Microalgae in Wastewater

      Osundeko, Olumayowa; Ansolia, Preeti; Kumar Gupta, Sanjay; Bag, Pushan; Bajhaiya, Amit K.; University of Manchester (Springer, 2019-01-22)
      Microalgae have been theoretically described as a sustainable feedstock for biofuel production. However, there are still some concerns and obstacles that need to be overcome in order to translate the theoretical promise into commercial and economic success. These obstacles include a high requirement for nutrients and sustainable water source and the identification of affordable cultivation conditions. It has been suggested that growing microalgae in wastewater can potentially offset some of these obstacles. Microalgae can perform a dual role for remediation of nutrient pollutants and biomass production when grown in wastewater. However, there are huge challenges to overcome before this route can be exploited in an economically and environmentally sustainable manner. In the present chapter, the potentials and challenges of growing microalgae in wastewater and its future implications are discussed in detail.
    • Prospects for petcoke utilization with CO 2 capture in Mexico

      Font Palma, Carolina; Gonzalez Diaz, Abigail; University of Chester; Instituto Nacional de Electricidad y Energías Limpias (INEEL) (Elsevier, 2018-01-31)
      This paper evaluates the introduction of carbon capture and storage (CCS) to Mexico. The gasification technology is presented as a potential alternative to be applied into refinery plants due to high petcoke production. Although economic aspects, such as fuel price and selling CO2, are important in the selection of CCS alternatives, there are other limitations, i.e. water availability and space. In March 2014, Mexico launched its CCS technological roadmap. However, an evaluation of the installation of new CO2-capture ready power plants was not considered. For that reason, this study could be useful to create a technology roadmap that includes the design of CO2 capture plants into refineries and how they will have to operate for CO2 emissions reduction, and taking advantage that most of refineries and petrochemical plants are close to oil fields for enhanced oil recovery (EOR). Integrated gasification combined cycle (IGCC) with CCS was chosen in this paper for power generation using petcoke as feedstock. The emissions of CO2 in kg/kWh could be reduced by 68%.
    • A review of organic waste enrichment for inducing palatability of black soldier fly larvae: Wastes to valuable resources

      Raksasat, Ratchaprapa; Lim, Jun Wei; Kiatkittipong, Worapon; Kiatkittipong, Kunlanan; Ho, Yeek Chia; Lam, Man Kee; Font Palma, Carolina; Zaid, Hayyiratul Fatimah Mohd; Cheng, Chin Kui; Universiti Teknologi PETRONAS; Silpakorn University; King Mongkut's Institute of Technology Ladkrabang; University of Chester; Khalifa University
      The increase of annual organic wastes generated worldwide has become a major problem for many countries since the mismanagement could bring about negative effects on the environment besides, being costly for an innocuous disposal. Recently, insect larvae have been investigated to valorize organic wastes. This entomoremediation approach is rising from the ability of the insect larvae to convert organic wastes into its biomass via assimilation process as catapulted by the natural demand to complete its lifecycle. Among the insect species, black soldier fly or Hermetia illucens is widely researched since the larvae can grow in various environments while being saprophagous in nature. Even though black soldier fly larvae (BSFL) can ingest various decay materials, some organic wastes such as sewage sludge or lignocellulosic wastes such as waste coconut endosperm are destitute of decent nutrients that could retard the BSFL growth. Hence, blending with nutrient-rich low-cost substrates such as palm kernel expeller, soybean curd residue, etc. is employed to fortify the nutritional contents of larval feeding substrates prior to administering to the BSFL. Alternatively, microbial fermentation can be adopted to breakdown the lignocellulosic wastes, exuding essential nutrients for growing BSFL. Upon reaching maturity, the BSFL can be harvested to serve as the protein and lipid feedstock. The larval protein can be made into insect meal for farmed animals, whilst the lipid source could be extracted and transesterified into larval biodiesel to cushion the global energy demands. Henceforth, this review presents the influence of various organic wastes introduced to feed BSFL, targeting to reduce wastes and producing biochemicals from mature larvae through entomoremediation. Modification of recalcitrant organic wastes via fermentation processes is also unveiled to ameliorate the BSFL growth. Lastly, the sustainable applications of harvested BSFL biomass are as well covered together with the immediate shortcomings that entail further researches.
    • The role of DNA methylation in ageing and cancer

      Morgan, Amy; Davies, Trevor J.; Mc Auley, Mark T.; University of Chester (Cambridge University Press, 2018-04-30)
      The aim of the present review paper is to survey the literature related to DNA methylation, and its association with cancer and ageing. The review will outline the key factors, including diet, which modulate DNA methylation. Our rationale for conducting this review is that ageing and diseases, including cancer, are often accompanied by aberrant DNA methylation, a key epigenetic process, which is crucial to the regulation of gene expression. Significantly, it has been observed that with age and certain disease states, DNA methylation status can become disrupted. For instance, a broad array of cancers are associated with promoter-specific hypermethylation and concomitant gene silencing. This review highlights that hypermethylation, and gene silencing, of the EN1 gene promoter, a crucial homeobox gene, has been detected in various forms of cancer. This has led to this region being proposed as a potential biomarker for diseases such as cancer. We conclude the review by describing a recently developed novel electrochemical method that can be used to quantify the level of methylation within the EN1 promoter and emphasise the growing trend in the use of electrochemical techniques for the detection of aberrant DNA methylation.
    • The role of Mathematical Modelling in understanding Aging

      Mc Auley, Mark T.; Morgan, Amy; Mooney, Kathleen M.; University of Chester, Edgehill University (CRC Press, 2017-10-25)
      Mathematical models have played key roles in developing our understanding of aging. The first pioneering mathematical models evaluated aging from an evolutionary perspective, generating meaningful insights into why aging occurs and laid the foundations for our current understanding of aging. More recently mathematical models have been used to gain a deeper understanding of the intracellular mechanisms associated with intrinsic aging. This chapter will outline what mathematical modelling is, and the advantages it has over more conventional approaches used in biogerontology. The steps involved in assembling a model will also be described and the leading theoretical frameworks underpinning them will be outlined. Moreover, we discuss in detail a variety of aging focused mechanistic mathematical models which have been developed in recent years. The chapter concludes by challenging the community to develop a unified mechanistic mathematical model which can be used to examine aging in a more integrated fashion.
    • Scaling-up ultrasound standing wave enhanced sedimentation filters

      Prest, Jeff E.; Treves Brown, Bernard J.; Fielden, Peter R.; Wilkinson, Stephen J.; Hawkes, Jeremy J.; Lancaster University ; University of Manchester ; Lancaster University ; University of Chester ; University of Manchester (Elsevier, 2014-08-21)
      Particle concentration and filtration is a key stage in a wide range of processing industries and also one that can be present challenges for high throughput, continuous operation. Here we demonstrate some features which increase the efficiency of ultrasound enhanced sedimentation and could enable the technology the potential to be scaled up. In this work, 20 mm piezoelectric plates were used to drive 100 mm high chambers formed from single structural elements. The coherent structural resonances were able to drive particles (yeast cells) in the water to nodes throughout the chamber. Ultrasound enhanced sedimentation was used to demonstrate the efficiency of the system (>99% particle clearance). Sub-wavelength pin protrusions were used for the contacts between the resonant chamber and other elements. The pins provided support and transferred power, replacing glue which is inefficient for power transfer. Filtration energies of ∼4 J/ml of suspension were measured. A calculation of thermal convection indicates that the circulation could disrupt cell alignment in ducts >35 mm high when a 1K temperature gradient is present; we predict higher efficiencies when this maximum height is observed. For the acoustic design, although modelling was minimal before construction, the very simple construction allowed us to form 3D models of the nodal patterns in the fluid and the duct structure. The models were compared with visual observations of particle movement, Chladni figures and scanning laser vibrometer mapping. This demonstrates that nodal planes in the fluid can be controlled by the position of clamping points and that the contacts could be positioned to increase the efficiency and reliability of particle manipulations in standing waves.
    • Simultaneous determination of dopamine, uric acid and estriol in maternal urine samples based on the synergetic effect of reduced graphene oxide, silver nanowires and silver nanoparticles in their ternary 3D nanocomposite

      Zhao, Qian; Faraj, Yousef; Liu, Lu Yue; Wang, Wei; Xie, Rui; Liu, Zhuang; Ju, Xiao Jie; Wei, Jie; Chu, Liang Yin; University of Chester; Sichuan University
      A facile and efficient electrochemical biosensing platform based on screen printed carbon electrode (SPCE) modified with three-dimensional (3D) nanocomposite consists of reduced graphene oxide (RGO) with the insertion of silver nanowires (AgNWs) followed by the anchoring of silver nanoparticles (AgNPs) is constructed as RGO/AgNWs/AgNPs/SPCE for the simultaneous determination of dopamine (DA), uric acid (UA) and estriol (EST). The morphology characteristic and surface elemental composition of RGO/AgNWs/AgNPs nanocomposite are investigated by field-emission scanning electron microscope, transmission electron microscope and X-ray photoelectron spectroscope. Cyclic voltammetry, electrochemical impedance spectroscopy, linear sweep voltammetry and differential pulse voltammetry are utilized to explore the electrochemical performances of the constructed electrodes. Due to abundant active sites and excellent electrocatalytic activity of the nanocomposite, the RGO/AgNWs/AgNPs/SPCE sensor exhibits well-resolved oxidation peaks and enhanced oxidation peak currents in the ternary mixture of DA, UA and EST with respective linear response ranges of 0.6 to 50 μM, 1 to 100 μM and 1 to 90 μM and detection limits (S/N = 3) of 0.16 μM, 0.58 μM and 0.58 μM, respectively. Moreover, the constructed biosensor exhibits good selectivity, reproducibility and stability, and excellent performance in determining DA, UA and EST in synthetic urine samples with excellent recovery. The results reveal that the RGO/AgNWs/AgNPs nanocomposite is a promising candidate for advanced electrode material in electrochemical sensing field and possesses great application prospects in further sensing researches.
    • Synergistic carbon metabolism in a fast growing mixotrophic freshwater microalgal species Micractinium inermum

      Smith, Richard T.; Bangert, Krys; Wilkinson, Stephen J.; Gilmour, D. James; University of Sheffield ; University of Sheffield ; University of Sheffield/University of Chester ; University of Sheffield (Elsevier, 2015-05-11)
      In recent years microalgae have attracted significant interest as a potential source of sustainable biofuel. Mixotrophic microalgae are able to simultaneously photosynthesise while assimilating and metabolising organic carbon. By combining autotrophic and heterotrophic metabolic pathways biomass productivity can be significantly increased. In this study, acetate-fed mixotrophic Micractinium inermum cultures were found to have a specific growth rate 1.74 times the sum of autotrophic and heterotrophic growth. It was hypothesised that gas exchange between the two metabolic pathways within mixotrophic cultures may have prevented growth limitation and enhanced growth. To determine the extent of synergistic gas exchange and its influence on metabolic activity, dissolved inorganic carbon (DIC), dissolved oxygen (DO) and photosynthesis and respiration rates were measured under different trophic conditions. A 32.7 fold and 2.4 fold increase in DIC and DO concentrations, relative to autotrophic and heterotrophic cultures respectively, were coupled with significant increases in rates of photosynthesis and respiration. These data strongly support the hypothesis of mixotrophic gas exchange within M. inermum cultures. In addition to enhanced growth, this phenomenon may provide reductions in aeration and oxygen stripping costs related to microalgae production.
    • Systems Based Mechanisms of Aging

      Proctor, Carole; Morgan, Amy; Mc Auley, Mark; Newcastle University; University of Chester
      The last number of decades have witnessed an unrelenting global rise in the number of older people. This demographic shift is laudable; however, many older people are burdened by poor health. The main reason so many older people have their healthspan compromised is due to the complex biology which underpins ageing and the diseases which are associated with this intriguing phenomenon. Fortunately, however, in recent years there has been a paradigm shift within biological research which has seen the emergence of systems biology. In contrast to a reductionist approach which was commonplace in biological research for many years, systems biology seeks to understand biological systems in an integrated manner. Investigating ageing and age related disease in this way is becoming increasingly effective. In this article we discuss the methods which underpin systems and provide examples of their application to biogerontology research.
    • Systems biology and Nutrition

      Mc Auley, Mark
      Systems biology has established itself as a paradigm which has been adopted in order to integrate a wealth of omics data which has been generated in the last few decades. Nutrition research has gradually embraced the systems biology approach, and this holistic way of investigating biological systems is beginning to pay dividends for our understanding of diet and its relationship with health. This chapter presents an overview of the key strands of systems biology; these include, genomics, transcriptomics, proteomics, metabolomics, bioinformatics and computational modelling. I discuss how these techniques are being used to gain new insights into nutrition research. Moreover, I reveal how computational modelling is being used to unravel how ageing effects cholesterol and folate metabolism. The chapter concludes by providing an insight into how systems biology will be applied to nutrition research in the future.
    • Systems biology and synthetic biology: A new epoch for toxicology research

      Mc Auley, Mark T.; Choi, Hyunok; Mooney, Kathleen M.; Paul, Emily; Miller, Veronica M.; University of Chester ; SUNY Albany ; Edge Hill University ; New York State Department of Health ; New York State Department of Health (Hindawi Publishing Corporation, 2015-01-26)
      Systems biology and synthetic biology are emerging disciplines which are becoming increasingly utilised in several areas of bioscience. Toxicology is beginning to benefit from systems biology and we suggest in the future that is will also benefit from synthetic biology. Thus, a new era is on the horizon. This review illustrates how a suite of innovative techniques and tools can be applied to understanding complex health and toxicology issues. We review limitations confronted by the traditional computational approaches to toxicology and epidemiology research, using polycyclic aromatic hydrocarbons (PAHs) and their effects on adverse birth outcomes as an illustrative example. We introduce how systems toxicology (and their subdisciplines, genomic, proteomic, and metabolomic toxicology) will help to overcome such limitations. In particular, we discuss the advantages and disadvantages of mathematical frameworks that computationally represent biological systems. Finally, we discuss the nascent discipline of synthetic biology and highlight relevant toxicological centred applications of this technique, including improvements in personalised medicine. We conclude this review by presenting a number of opportunities and challenges that could shape the future of these rapidly evolving disciplines.
    • Thermodynamic Analysis and Process System Comparison of the Exhaust Gas Recirculated, Steam Injected and Humidified Micro Gas Turbine

      Ali, Usman; Font Palma, Carolina; Hughes, Kevin J.; Ingham, Derek B.; Ma, Lin; Pourkashanian, Mohamed; University of Leeds (ASME Proceedings, 2015-08-12)
      Stringent environmental emission regulations and continuing efforts to reduce carbon dioxide (CO2) from the energy sector, in the context of global warming, have promoted interest to improve the efficiency of power generation systems whilst reducing emissions. Further, this has led to the development of innovative gas turbine systems which either result in higher electrical efficiency or the reduction of CO2 emissions. Micro gas turbines are one of the secure, economical and environmentally viable options for power and heat generation. Here, a Turbec T100 micro gas turbine (MGT) is simulated using Aspen HYSYS® V8.4 and validated through experimental data. Due to the consistency and robustness of the steady state model developed, it is further extended to three different innovative cycles: (i) an exhaust gas recirculated (EGR) cycle, in which part of the exhaust gas is dried and re-circulated to the MGT inlet; (ii) a steam injected (STIG) cycle, and (iii) a humid air turbine (HAT) cycle. The steam and hot water are generated through the exhaust of the recuperator for the STIG and HAT cycle, respectively. Further, the steam is directly injected into the recuperator for power augmentation, while for the HAT cycle; the compressed air is saturated with water in the humid tower before entering the recuperator. This study evaluates the impact of the EGR ratio, steam to air ratio, and water to air ratio on the performance and efficiency of the system. The comparative potential for each innovative cycle is assessed by thermodynamic properties estimation of process parameters through the models developed to better understand the behavior of each cycle. The thermodynamic assessment indicates that CO2 enrichment occurs for the three innovative cycles. Further, the results indicate that the electrical efficiency increases for the STIG and HAT cycle while it decreases for the EGR cycle. In conclusion, the innovative cycles indicates the possibilities to improve the system performance and efficiency.
    • Towards sustainable methanol from industrial CO2 sources

      Douven, Sigrid; Benkoussas, Hana; Font Palma, Carolina; Leonard, Gregoire; University of Liege; University of Chester (Walter de Gruyter GmbH, 2019-10-21)
      This chapter discusses the opportunity of using CO2 from industrial sources to produce sustainable methanol. Some important industrial sectors that could be seen as potential sources of CO2 are reviewed: ammonia, steel, ethanol, ethylene, natural gas, cement and power industries. In most cases, despite a promising potential for CO2 re-use, only few projects have been identified and methanol production from CO2 is still marginal. A model for the CO2-to-methanol process is presented based on CO2-rich gas coming from ammonia production process. This model takes into account the different steps from the CO2 capture to the methanol purification, and heat integration is performed in order to determine the reduction of heat consumption achievable for the global process. Even if the economic relevance of the CO2 re-use into methanol still has to be qualified, it offers an estimation of the process efficiency.
    • Treating wastewater by indigenous microalgae strain in pilot platform located inside a municipal wastewater treatment plant

      Han, Jichang; Laurenz, Thomsen; Pan, Kehou; Wang, Pu; Wawilow, Tatjana; Osundeko, Olumayowa; Wang, Song; Theilen, Ulf; Thomsen, Claudia; Jacob University Bremen, Germany
      Various resources from a municipal wastewater treatment plant (MWTP) are available for microalgae cultivation plants, suggesting that a combination of these technologies can be used to produce microalgae biomass and remove contaminants at a low cost. In this study, the growth performance and nutrient removal efficiency of an indigenous Scenedesmus sp. in various wastewater media with different exchange patterns were investigated firstly, then transferred to a pilot-scale photobioreactor (located inside a MWTP) for bioremediation use. The temperature and pH of the platform were maintained at 15–30°C and 7.6, respectively. The NH+4− N, NO−3− N, and PO3−4− P of the wastewater could be reduced to below 0.05, 0.40, and 0.175 mg L–1, respectively. Our results indicate that microalgae cultivation using the resources of a MWTP can achieve high algal biomass productivity and nutrient removal rate. Our study also suggests that efficient technology for controlling zooplankton needs to be developed.
    • Trion formation in a two-dimensional hole-doped electron gas

      Spink, Graham G.; López Ríos, Pablo; Drummond, Neil D.; Needs, Richard J.; University of Cambridge; University of Chester; Lancaster University (American Physical Society, 2016-07-22)
      The interaction between a single hole and a two-dimensional, paramagnetic, homogeneous electron gas is studied using diffusion quantum Monte Carlo simulations. Electron-hole relaxation energies, pair-correlation functions, and electron-hole center-of-mass momentum densities are reported for a range of electron-hole mass ratios and electron densities. We find numerical evidence of a crossover from a collective excitonic state to a trion-dominated state in a density range in agreement with that found in recent experiments on quantum-well heterostructures.
    • Using Mathematical Modelling and Electrochemical Analysis to Investigate Age‐Associated Disease

      McAuley, Mark; Morgan, Amy (University of Chester, 2019-04-02)
      People are living longer. With this rise in life expectancy, a concomitant rise in morbidity in later life is observed; with conditions including cardiovascular disease (CVD), and cancer. However, ageing and the pathogenesis of age related disease, can be difficult to study, as the ageing process is a complex process, which affects multiple systems and mechanisms. The aim of this research was two‐fold. The first aim was to use mathematical modelling to investigate the mechanisms underpinning cholesterol metabolism, as aberrations to this system are associated with an increased risk for CVD. To better understand cholesterol from a mechanistic perspective, a curated kinetic model of whole body cholesterol metabolism, from the BioModels database, was expanded in COPASI, to produce a model with a broader range of mechanisms which underpin cholesterol metabolism. A range of time course data, and local and global parameter scans were utilised to examine the effect of cholesterol feeding, saturated fat feeding, ageing, and cholesterol ester transfer protein (CETP) genotype. These investigations revealed: the model behaved as a hypo‐responder to cholesterol feeding, the robustness of the cholesterol biosynthesis pathway, and the impact CETP can have on healthy ageing. The second aim of this work was to use electrochemical techniques to detect DNA methylation within the engrailed homeobox 1 (EN1) gene promoter, which has been implicated in cancer. Hypermethylation of this gene promoter is often observed in a diseased state. Synthetic DNA, designed to represent methylated and unmethylated variants, were adsorbed onto a gold rotating disk electrode for electrochemical analysis by 1) electrochemical impedance spectroscopy (EIS), 2) cyclic voltammetry (CV) and 3) differential pulse voltammetry (DPV). The technique was then applied to bisulphite modified and asymmetrically amplified DNA from the breast cancer cell line MCF‐7. Results indicated that electrochemical techniques could detect DNA methylation in both synthetic and cancer derived DNA, with EIS producing superiorresults. These non‐traditional techniques ofstudying age related disease were effective for the investigation of cholesterol metabolism and DNA methylation, and this work highlights how these techniques could be used to elucidate mechanisms or diagnose/monitor disease pathogenesis, to reduce morbidity in older people