CCS Networks for the UK: Benefits, Impacts and Regulation

What benefits might be offered by developing well planned CCS networks? A review of the drivers for and barriers to the coherent development of CCS networks in the UK is used to synthesise a limited set of possible network topologies. The benefits offered by each topology for UK carbon dioxide and other atmospheric emissions are estimated. Other potential benefits are considered qualitatively, and a range of uncertainties identified. The complexity of CCS networks means that addressing these uncertainties is a challenging task, and the need for a whole systems approach is evaluated. Finally, implications for CCS regulation and policy are highlighted

Economic analysis of business models with multiple potential value streams: Application to the biochar system

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Hydrogen via reforming aqueous ammonia and biomethane co-products of wastewater treatment: environmental and economic sustainability

Green H2 is increasingly viewed as a key energy carrier for the fight against climate change. Wastewater treatment plants (WWTPs) have the unique potential to be centres of renewable H2 generation with the growing availability of two attractive feedstocks: biomethane and ammonia. An innovative and novel method of ammonia recovery from digestate liquor followed by a state-of-the-art H2 production process named NWaste2H2 is demonstrated for a case-study WWTP. The recovered ammonia is used alongside biomethane for H2 production and its diversion from conventional biological treatment has two other crucial benefits, with reductions in both associated electricity demand and emissions of nitrous oxide, an extremely potent greenhouse gas. Process modelling, supported by extensive experiments in a packed-bed reactor at bench-scale, demonstrate the prized capability of simultaneously performing steam methane reforming and ammonia decomposition to generate a H2-rich syngas with yields close to equilibrium values. Greenhouse gas emission abatement from the replacement of diesel buses and reduced N2O emissions from biological treatment could save up to 17.2 kg CO2 equivalent (CO2e) per year for each person served by the WWTP. An in-depth economic study illustrates the ability to achieve a positive net present value with a 10% discount factor as early as 5.8 years when the H2 is prepared and sold to power fuel cell electric buses

Determination of rolling element bearing condition via acoustic emission

Acoustic emission is an emerging technique for condition monitoring of rolling element bearings and potentially offers advantages for detection of incipient damage at an early stage of failure. Before such a technique can be applied with confidence for health monitoring, it is vital to understand the variation of acoustic emission generation with operating conditions in a healthy bearing. This paper investigates the effects of increased speed and load on the generation of acoustic emission within cylindrical roller bearings, and it was found that the root mean square signal level increased significantly with increasing speed whereas increasing load had a far weaker effect. The AERMS value for each experiment was compared with the trend of the Lambda value. The bearing was operating under full film lubrication regime, so it was determined that increases in AERMS were not caused by asperity contact. By consideration of trends in frequency energy amplitude, it was determined that excitation of the bearings resonant frequencies were responsible for an increase of energy in the frequency range of 20–60 kHz. The excitation energy at 330 kHz (the acoustic emission sensor’s resonant frequency) increased with load, indicating a link between high-frequency emission and stress at the contact zone. Following characterisation of the bearing under normal operating conditions, an accelerated life test was conducted in order to induce fatigue failure. The frequency response demonstrated that throughout a period of constant wear, the energy amplitude at the bearings resonant frequency increased with time. As the bearing failure became more significant, the energy of the high-frequency components above 100 kHz was spread over a broader frequency range as multiple transient bursts of energy were released simultaneously by fatigue failure of the raceways. This paper demonstrates the potential of acoustic emission to provide an insight into the bearing’s behaviour under normal operation and provide early indication of bearing failure

Soup to tree: the phylogeny of beetles inferred by mitochondrial metagenomics of a Bornean rainforest sample

In spite of the growth of molecular ecology, systematics and next-generation sequencing, the discovery and analysis of diversity is not currently integrated with building the tree-of-life. Tropical arthropod ecologists are well placed to accelerate this process if all specimens obtained via masstrapping, many of which will be new species, could be incorporated routinely in phylogeny reconstruction. Here we test a shotgun sequencing approach, whereby mitochondrial genomes are assembled from complex ecological mixtures via mitochondrial metagenomics, and demonstrate how the approach overcomes many of the taxonomic impediments to the study of biodiversity. DNA from ~500 beetle specimens, originating from a single rainforest canopy fogging sample from Borneo, was pooled and shotgun sequenced, followed by de novo assembly of complete and partial mitogenomes for 175 species. The phylogenetic tree obtained from this local sample was highly similar to that from existing mitogenomes selected for global coverage of major lineages of Coleoptera. When all sequences were combined, only minor topological changes are induced against this reference set, indicating an increasingly stable estimate of coleopteran phylogeny, whilst the ecological sample expands the tip-level representation of several lineages. Robust trees generated from ecological samples now enable an evolutionary framework for ecology. Meanwhile, the inclusion of uncharacterized samples in the tree-of-life rapidly expands taxon and biogeographic representation of lineages without morphological identification. Mitogenomes from shotgun sequencing of unsorted environmental samples and their associated metadata, placed robustly into the phylogenetic tree, constitute novel DNA ‘superbarcodes’ for testing hypotheses regarding global patterns of diversity

Developing an optimal electricity generation mix for the UK 2050 future

The UK electricity sector is undergoing a transition driven by domestic and regional climate change and environmental policies. Aging electricity generating infrastructure is set to affect capacity margins after 2015. These developments, coupled with the increased proportion of inflexible and variable generation technologies will impact on the security of electricity supply. Investment in low-carbon technologies is central to the UK meeting its energy policy objectives. The complexity of these challenges over the future development of the UK electricity generation sector has motivated this study which aims to develop a policy-informed optimal electricity generation scenario to assess the sector's transition to 2050. The study analyses the level of deployment of electricity generating technologies in line with the 80% by 2050 emission target. This is achieved by using an excel-based “Energy Optimisation Calculator” which captures the interaction of various inputs to produce a least-cost generation mix. The key results focus on the least-cost electricity generation portfolio, emission intensity, and total investment required to assemble a sustainable electricity generation mix. A carbon neutral electricity sector is feasible if low-carbon technologies are deployed on a large scale. This requires a robust policy framework that supports the development and deployment of mature and emerging technologies

Soup to tree: the phylogeny of beetles inferred by mitochondrial metagenomics of a Bornean rainforest sample

In spite of the growth of molecular ecology, systematics and next-generation sequencing, the discovery and analysis of diversity is not currently integrated with building the tree-of-life. Tropical arthropod ecologists are well placed to accelerate this process if all specimens obtained via masstrapping, many of which will be new species, could be incorporated routinely in phylogeny reconstruction. Here we test a shotgun sequencing approach, whereby mitochondrial genomes are assembled from complex ecological mixtures via mitochondrial metagenomics, and demonstrate how the approach overcomes many of the taxonomic impediments to the study of biodiversity. DNA from ~500 beetle specimens, originating from a single rainforest canopy fogging sample from Borneo, was pooled and shotgun sequenced, followed by de novo assembly of complete and partial mitogenomes for 175 species. The phylogenetic tree obtained from this local sample was highly similar to that from existing mitogenomes selected for global coverage of major lineages of Coleoptera. When all sequences were combined, only minor topological changes are induced against this reference set, indicating an increasingly stable estimate of coleopteran phylogeny, whilst the ecological sample expands the tip-level representation of several lineages. Robust trees generated from ecological samples now enable an evolutionary framework for ecology. Meanwhile, the inclusion of uncharacterized samples in the tree-of-life rapidly expands taxon and biogeographic representation of lineages without morphological identification. Mitogenomes from shotgun sequencing of unsorted environmental samples and their associated metadata, placed robustly into the phylogenetic tree, constitute novel DNA ‘superbarcodes’ for testing hypotheses regarding global patterns of diversity