A pathway towards net-zero emissions in oil refineries

Rapid industrialization and urbanization have increased the demand for both energy and mobility services across the globe, with accompanying increases in greenhouse gas emissions. This short paper analyzes strategic measures for the abatement of CO2 emissions from oil refinery operations. A case study involving a large conversion refinery shows that the use of post-combustion carbon capture and storage (CCS) may only be practical for large combined emission point sources, leaving about 30% of site-wide emissions unaddressed. A combination of post-combustion CCS with a CO2 capture rate well above 90% and other mitigation measures such as fuel substitution and emission offsets is needed to transition towards carbon-neutral refinery operations. All of these technologies must be configured to minimize environmental burden shifting and scope 2 emissions, whilst doing so cost-effectively to improve energy access and affordability. In the long run, scope 3 emissions from the combustion of refinery products and flaring must also be addressed. The use of synthetic fuels and alternative feedstocks such as liquefied plastic waste, instead of crude oil, could present a growth opportunity in a circular carbon economy

Multidimensional Classical and Quantum Wormholes in Models with Cosmological Constant

A multidimensional cosmological model with space-time consisting of $n (n \ge 2)$ Einstein spaces $M_{i}$ is investigated in the presence of a cosmological constant $\Lambda$ and a homogeneous minimally coupled scalar field $\varphi(t)$ as a matter source. Classical and quantum wormhole solutions are obtained for $\Lambda < 0$ and all $M_{i}$ being Ricci-flat. Classical wormhole solutions are also found for $\Lambda < 0$ and only one of the $M_{i}$ being Ricci-flat for the case of spontaneous compactification of the internal dimensions with fine tuning of parameters.Comment: 31 pages, 5 figures available on request from [email protected], LaTeX, Potsdam University, preprint AIP 94-0

Solar Neutrinos Before and After KamLAND

We use the recently reported KamLAND measurements on oscillations of reactor anti-neutrinos, together with the data of previously reported solar neutrino experiments, to show that: (1) the total 8B neutrino flux emitted by the Sun is 1.00(1.0 \pm 0.06) of the standard solar model (BP00) predicted flux, (2) the KamLAND measurements reduce the area of the globally allowed oscillation regions that must be explored in model fitting by six orders of magnitude in the Delta m^2-tan^2 theta plane, (3) LMA is now the unique oscillation solution to a CL of 4.7sigma, (4) maximal mixing is disfavored at 3.1 sigma, (5) active-sterile admixtures are constrained to sin^2 eta<0.13 at 1 sigma, (6) the observed ^8B flux that is in the form of sterile neutrinos is 0.00^{+0.09}_{-0.00} (1 sigma), of the standard solar model (BP00) predicted flux, and (7) non-standard solar models that were invented to completely avoid solar neutrino oscillations are excluded by KamLAND plus solar at 7.9 sigma . We also refine quantitative predictions for future 7Be and p-p solar neutrino experiments.Comment: Published version, includes editorial improvement

Neutrinoless Double Beta Decay in Light of SNO Salt Data

In the SNO data from its salt run, probably the most significant result is the consistency with the previous results without assuming the 8B energy spectrum. In addition, they have excluded the maximal mixing at a very high confidence level. This has an important implication on the double beta decay experiments. For the inverted or degenerate mass spectrum, we find |_{ee}| > 0.013 eV at 95% CL, and the next generation experiments can discriminate Majorana and Dirac neutrinos if the inverted or degenerate mass spectrum will be confirmed by the improvements in cosmology, tritium data beta decay, or long-baseline oscillation experiments.Comment: REVTEX4, three figures. Now uses the updated SK atmospheric data rather than naive rescaling. Conclusion unchanged. References adde

Three-Neutrino Mixing after the First Results from K2K and KamLAND

We analyze the impact of the data on long baseline \nu_\mu disappearance from the K2K experiment and reactor \bar\nu_e disappearance from the KamLAND experiment on the determination of the leptonic three-generation mixing parameters. Performing an up-to-date global analysis of solar, atmospheric, reactor and long baseline neutrino data in the context of three-neutrino oscillations, we determine the presently allowed ranges of masses and mixing and we consistently derive the allowed magnitude of the elements of the leptonic mixing matrix. We also quantify the maximum allowed contribution of \Delta m^2_{21} oscillations to CP-odd and CP-even observables at future long baseline experiments.Comment: Some typos correcte

Solar models and solar neutrino oscillations

We provide a summary of the current knowledge, theoretical and experimental, of solar neutrino fluxes and of the masses and mixing angles that characterize solar neutrino oscillations. We also summarize the principal reasons for doing new solar neutrino experiments and what we think may be learned from the future measurements.Comment: Submitted to the Neutrino Focus Issue of New Journal of Physics at http://www.njp.or

Wear resistant CoCrFeMnNi0.8V High Entropy Alloy with Multi Length-Scale Hierarchical Microstructure

This work shows a CoCrFeMnNi0.8V high entropy alloy (HEA) with multiple length-scale hierarchical microstructure, obtained upon cooling at ∼ 62.5 K/s, consisting of a dominant globular sigma phase, FCC matrix and V-rich particles. The novel microstructure, never reported before for the CoCrFeMnNiV system, results in about a fourfold and sixfold increase of hardness and wear resistance, respectively, compared to that of CoCrFeMnNi alloy

Multi-model assessment of heat decarbonisation options in the UK using renewable hydrogen

Achieving the UK’s long-term climate targets will require a coordinated approach to decarbonising both electricity and heat supply, which will require substituting natural gas with low-carbon energy vectors, such as electricity and hydrogen that could be produced from renewable or other forms of zero-carbon energy. The objective of this paper is to use two established energy system models, RTN and WeSIM, to assess plausible heat decarbonisation pathways for the UK, while utilising their respective strengths – a technology-rich representation of hydrogen production, storage and transport options with high spatial granularity for the former, and high temporal resolution and detailed representation of the power system for the latter. The two models are linked through passing optimised capacities of hydrogen production technologies from RTN to WeSIM, and transferring an updated set of electricity prices in the opposite direction. Initial results indicate that model integration can improve the cost-effectiveness of the hydrogen technology mix by reducing the use of inefficient electrolysers during periods of high electricity prices and increasing the capacity and output of more efficient electrolysers, gas reformers and biomass gasification plants.UK Engineering and Physical Sciences Research Council (EPSRC) grant number EP/R045518/1 (IDLES Programme)