173 research outputs found
A methodology for the generation and evaluation of biorefinery process chains, in order to identify the most promising biorefineries for the EU
The topic of bioenergy, biofuels and bioproducts remains at the top of the current political and research agenda. Identification of the optimum processing routes for biomass, in terms of efficiency, cost, environment and socio-economics is vital as concern grows over the remaining fossil fuel resources, climate change and energy security. It is known that the only renewable way of producing conventional hydrocarbon fuels and organic chemicals is from biomass, but the problem remains of identifying the best product mix and the most efficient way of processing biomass to products. The aim is to move Europe towards a biobased economy and it is widely accepted that biorefineries are key to this development. A methodology was required for the generation and evaluation of biorefinery process chains for converting biomass into one or more valuable products that properly considers performance, cost, environment, socio-economics and other factors that influence the commercial viability of a process. In this thesis a methodology to achieve this objective is described. The completed methodology includes process chain generation, process modelling and subsequent analysis and comparison of results in order to evaluate alternative process routes. A modular structure was chosen to allow greater flexibility and allowing the user to generate a large number of different biorefinery configurations The significance of the approach is that the methodology is defined and is thus rigorous and consistent and may be readily re-examined if circumstances change. There was the requirement for consistency in structure and use, particularly for multiple analyses. It was important that analyses could be quickly and easily carried out to consider, for example, different scales, configurations and product portfolios and so that previous outcomes could be readily reconsidered. The result of the completed methodology is the identification of the most promising biorefinery chains from those considered as part of the European Biosynergy Project
A methodology for the generation and evaluation of biorefinery process chains, in order to identify the most promising biorefineries for the EU
The topic of bioenergy, biofuels and bioproducts remains at the top of the current political and research agenda. Identification of the optimum processing routes for biomass, in terms of efficiency, cost, environment and socio-economics is vital as concern grows over the remaining fossil fuel resources, climate change and energy security. It is known that the only renewable way of producing conventional hydrocarbon fuels and organic chemicals is from biomass, but the problem remains of identifying the best product mix and the most efficient way of processing biomass to products. The aim is to move Europe towards a biobased economy and it is widely accepted that biorefineries are key to this development. A methodology was required for the generation and evaluation of biorefinery process chains for converting biomass into one or more valuable products that properly considers performance, cost, environment, socio-economics and other factors that influence the commercial viability of a process. In this thesis a methodology to achieve this objective is described. The completed methodology includes process chain generation, process modelling and subsequent analysis and comparison of results in order to evaluate alternative process routes. A modular structure was chosen to allow greater flexibility and allowing the user to generate a large number of different biorefinery configurations The significance of the approach is that the methodology is defined and is thus rigorous and consistent and may be readily re-examined if circumstances change. There was the requirement for consistency in structure and use, particularly for multiple analyses. It was important that analyses could be quickly and easily carried out to consider, for example, different scales, configurations and product portfolios and so that previous outcomes could be readily reconsidered. The result of the completed methodology is the identification of the most promising biorefinery chains from those considered as part of the European Biosynergy Project.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Feedstock Characterisation and Slow Pyrolysis Kinetic Study for the Production of Char - Greencarbon
Bioenergy Mass-Energy Balance Model
The Mass-Energy Balance model was developed by Aston University and has been designed to be used as a scoping tool and not a detailed process simulation. The model allows to investigate commercially viable opportunities for the development of modern bioenergy technologies for electricity and/or heat generation in the output range 10 kWe to 5 MWe from regional feedstocks with known properties. Typical plant configurations suited to the feedstock and energy demand can be modelled. The model as part of the ‘Bioenergy for Sustainable Local Energy Services and Energy Access in Africa - Phase 2’ (BSE-AA2) project, funded with UK aid from the UK government as part of the TEA programme. The model forms a part of a suite of research tools and products developed under BSEAA2 to enable project developers, practitioners, investors and other stakeholders to make decisions regarding the technical and commercial viability of investing in bioenergy technology within seven shortlisted industries, referred to as ‘demand sectors’
Optically-Induced Magnetic Response in All-Dielectric Nanodisk Composite Structures
Optical technologies developed throughout history have been
exploiting the electric response in matters in order to control
light. However, little has been explored for the magnetic
response in matter at optical frequencies due to the lack of
magnetic materials in this spectral region. Recently, specially
engineered materials, namely metamaterials, have been developed
to exploit the magnetic responses in matter for light
manipulation. In particular, researchers have made use of the
optically-induced magnetic responses (OIMRs) generated in
metallic nanostructures to achieve optical effects not seen in
nature. Such magnetic responses serve as a second channel to
control light, providing an alternative and an addition to the
electric responses and leading to novel observations and
innovative ideas for light manipulation. This creates many
opportunities for the development of the next generation
nano-optics and nanophotonic devices.
Dielectric nanostructures have recently been discovered to also
support OIMR, which is useful for applications requiring low loss
and simpler fabrication procedures, such as wavefront control and
robust nanoscale sensing. In this thesis, I present the study of
OIMR in several all-dielectric systems based on silicon
nanodisks, namely single, clusters and regular arrays of
nanodisks. The study of these systems provides knowledge for and
insight into harnessing the OIMRs in dielectric nanostructures
for future applications.
Chapter 1 provides a comprehensive introduction to OIMR by
presenting a historic overview of the topic and the basic
concepts involved for high-index dielectric particles. This is
followed by a description of the pioneer works on OIMR in
dielectric spherical nanoparticles, including the Mie theory and
its recent experimental verification. The similarities and
differences between the properties of plasmonic and dielectric
nanostructures in the context of metamaterials are also described
and explained. Finally, the motivation and scope of the thesis
is summarized.
Chapter 2 describes the experimental methods used that are common
to all works presented in this thesis, including the fabrication
of silicon nanodisk structures and the linear optical
characterization techniques.
Chapter 3 presents the fundamental of OIMR in single silicon
nanodisk structures, including a theoretical analysis and
experimental observation of various resonant modes of single
silicon nanodisks, as well as the numerical and experimental
results of the Fano resonances observed in the more complex
structures of single heptamer oligomers.
Chapter 4 focuses on manipulating the OIMR in combination with
the electric response to create Huygens' metasurfaces based on
silicon nanodisk arrays. Two highly-efficient functional
metadevices with polarization independence based on the Huygens'
metasurface system are presented, namely a Gaussian-to-vortex
beam shaper and a holographic phase plate.
Chapter 5 explores the cross-disciplinary area of sensing using
silicon nanodisk arrays with OIMRs, including refractive index
sensing using Fano resonances and biosensing using the dipolar
magnetic resonances where a new detection limit for the
Streptavidin protein was achieved.
Chatper 6 concludes the thesis and provides an outlook to the
research works that can be extended from the results in this
thesis
Slice-selective NMR:a non-invasive method for the analysis of separated pyrolysis fuel samples
Pyrolysis oil has been identified as a possible alternative fuel source, however widespread use is hindered by high acidity and water content. These negative characteristics can be mitigated by blending with, for example, biodiesel, marine gas oil and butanol. These blended samples can be unstable and often separate into two distinct phases. NMR spectroscopy is a well-established spectroscopic technique that is finding increasing application in the analysis of pyrolysis oil and blended fuels derived from it. Here, slice-selective NMR, where the NMR spectrum of only a thin slice of the total sample is acquired, is used to study, non-invasively, how the constituent components of blended biofuel samples are partitioned between the two layers. Understanding the outcome of the phase separation is an important step towards understanding why the blended oil samples separate, and may provide answers to mitigating and eventually solving the problem. The NMR method was successfully used to analyse a number of separated biofuel samples - typically separated into an oil layer, containing marine gas oil and biodiesel, above a bio-oil layer with a high water and butanol content
A techno-economic analysis of energy recovery from organic fraction of municipal solid waste (MSW) by an integrated intermediate pyrolysis and combined heat and power (CHP) plant
The increasing environmental concerns and the significant growth of the waste to energy market calls for innovative and flexible technology that can effectively process and convert municipal solid waste into fuels and power at high efficiencies. To ensure the technical and economic feasibility of new technology, a sound understanding of the characteristics of the integrated energy system is essential. In this work, a comprehensive techno-economic analysis of a waste to power and heat plant based on integrated intermediate pyrolysis and CHP (Pyro-CHP) system was performed. The overall plant CHP efficiency was found to be nearly 60% defined as heat and power output compared to feedstock fuel input. By using an established economic evaluation model, the capital investment of a 5 tonne per hour plant was calculated to be £27.64 million and the Levelised Cost of Electricity was £0.063/kWh. This agrees the range of cost given by the UK government. To maximise project viability, technology developers should endeavour to seek ways to reduce the energy production cost. Particular attention should be given to the factors with the greatest influence on the profitability, such as feedstock cost (or gate fee for waste), maintaining plant availability, improving energy productivity and reducing capital cost
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