An integrated experimental and quantum-chemical investigation on the vibrational spectra of chlorofluoromethane

The vibrational analysis of the gas-phase infrared spectra of chlorofluoromethane (CH2ClF, HCFC-31) was carried out in the range 200-6200 cm(-1). The assignment of the absorption features in terms of fundamental, overtone, combination, and hot bands was performed on the medium-resolution (up to 0.2 cm(-1)) Fourier transform infrared spectra. From the absorption cross section spectra accurate values of the integrated band intensities were derived and the global warming potential of this compound was estimated, thus obtaining values of 323, 83, and 42 on a 20-, 100-, and 500-year horizon, respectively. The set of spectroscopic parameters here presented provides the basic data to model the atmospheric behavior of this greenhouse gas. In addition, the obtained vibrational properties were used to benchmark the predictions of state-of-the-art quantum-chemical computational strategies. Extrapolated complete basis set limit values for the equilibrium geometry and harmonic force field were obtained at the coupled-cluster singles and doubles level of theory augmented by a perturbative treatment of triple excitations, CCSD(T), in conjunction with a hierarchical series of correlation-consistent basis sets (cc-pVnZ, with n = T, Q, and 5), taking also into account the core-valence correlation effects and the corrections due to diffuse (aug) functions. To obtain the cubic and quartic semi-diagonal force constants, calculations employing second-order Moller-Plesset perturbation (MP2) theory, the double-hybrid density functional B2PLYP as well as CCSD(T) were performed. For all anharmonic force fields the performances of two different perturbative approaches in computing the vibrational energy levels (i.e., the generalized second order vibrational treatment, GVPT2, and the recently proposed hybrid degeneracy corrected model, HDCPT2) were evaluated and the obtained results allowed us to validate the spectroscopic predictions yielded by the HDCPT2 approach. The predictions of the deperturbed second-order perturbation approach, DVPT2, applied to the computation of infrared intensities beyond the double-harmonic approximation were compared to the accurate experimental values here determined. Anharmonic DFT and MP2 corrections to CCSD(T) intensities led to a very good agreement with the absorption cross section measurements over the whole spectral range here analysed. (C) 2013 AIP Publishing LLC

Mobility justice in low carbon energy transitions

Mobility systems raise multiple questions of justice. Work on mobility justice and policy often treats different elements of the debate separately, for example focussing on environmental justice or accessibility. This is problematic as it can privilege policy solutions without a full view of the winners and losers and the values implicit in that. Using analysis of current policy, we investigate how mobility justice can reconcile its different components, and find two major consequences. First, is doubt about the justice of the existing policy approach which tries to tackle transport pollution primarily through a shift to low emission vehicles. This approach privileges those with access to private vehicles and further privileges certain sets of activities. Second is a need to reassess which basic normative ideas should be applied in mobility justice. Work on mobility justice has tended to appeal to conceptions of justice concerned with access to resources including resources enabling mobility. These conceptions say little about how resources should be used. We show that avoiding stark inequalities means collectively thinking about how resources are used, about how we value activities involving mobility, and about what sorts of goods and services we create

Coal in the 21st Century: a climate of change and uncertainty

Coal presents a particular set of challenges when balancing energy policy goals. Despite presenting viable solutions to the problems of energy security and global energy poverty, coal struggles, given its greenhouse-gas drawbacks, in a world of increasingly harmful climate change. Notwithstanding the harm caused to the environment, coal remains an expanding low-price route to meeting local energy needs. It is forecasted to remain a major global resource for the foreseeable future. In the short term it is predicted to have a 26% share of the global energy mix. Recent years have witnessed severe deviations from previously stable trends in coal markets and policy dynamics. According to the predictions by the International Energy Agency (IEA), a variety of factors ranging from the planned phase-out of coal in countries such as Denmark, France and the UK, to changes in policy in China and import-dependency in India, and demand drop in the US have together resulted in the largest decline in coal production in 2015 since 1971 (IEA, Coal Information, 2016). This paper seeks to outline basic coal facts, recent market trends and directions globally and provides an overview of issues shaping the future of coal in the twenty-first century. This paper seeks to outline basic coal facts, recent market trends and directions globally and provide an overview of issues shaping the future of coal in the 21st century

Barriers of solar energy uptake and the potential for mitigation solutions in Barbados

Understanding the barriers that inhibit the deployment of renewable energy technologies to achieve long-term reductions in carbon emissions from the use of fossil fuels is paramount to Barbados. Although there are targets towards renewable energy (solar, wind, biomass, geothermal) uptake, the share of these technologies in the energy mix does not exist in Barbados due to the total dependence on fossil fuels. In this paper, a review of potential challenges and the main problems for deployment of alternative energy sources is presented. Through interviews, questionnaires with a focus group of key personnel’s, the paper documents the lack of renewable energy sources (with emphasis on solar energy) as one of the main alternatives to meet the carbon emission targets set by the country. The barriers and challenges facing the implementation of solar energy deployment have been clarified. From the results, it is evident that significant policy barriers still exist at the country level, which has reduced the effectiveness of a concerted national effort to deploy renewables. The current policy landscape which benefits from fossil fuel imports, the lack of technical know-how and the lack of research and development in the renewable energy space are amongst the key barriers identified. The paper also outlines the key policy’s frameworks, regulatory environment and the lack of incentives, which encompasses the renewable energy sector, and presents a critical analysis of the barriers faced by the industry. A mitigation framework is proposed to bridge the gap of solar energy (renewable energy) deployment

Challenges towards renewable energy : an exploratory study from the Arabian Gulf region

Considering the importance of energy for social and economic development, access to clean, affordable and reliable energy has been adopted as one of the United Nations sustainable development goals that all countries aim to achieve by 2030. However, much of the world's energy is still produced from fossil fuels and thus the progress towards clean and renewable energy is slow. This paper explores the key challenges towards renewable energy in Gulf Cooperation Council countries blessed with plenty of oil and gas reserves. The key challenges identified through literature review were ranked using a quantitative approach through the data collected from a selective sample across the six countries. These challenges in order of importance were found to be policies and regulations, manpower experience and competencies, renewable energy education, public awareness, costs and incentives for renewable energy and government commitment. The findings could be helpful to decision makers and government organisations in the region to develop strategies to overcome these identified challenges

Reducing energy demand through low carbon innovation: a sociotechnical transitions perspective and thirteen research debates

Improvements in energy efficiency and reductions in energy demand are expected to contribute more than half of the reduction in global carbon emissions over the next few decades. These unprecedented reductions require transformations in the systems that provide energy services. However, the dominant analytical perspectives, grounded in neoclassical economics and social psychology, focus upon marginal changes and provide only limited guidance on how such transformations may occur and how they can be shaped. We argue that a socio-technical transitions perspective is more suited to address the complexity of the challenges involved. This perspective understands energy services as being provided through large-scale, capital intensive and long-lived infrastructures that co-evolve with technologies, institutions, skills, knowledge and behaviours to create broader ‘sociotechnical systems’. To provide guidance for research in this area, this paper identifies and describes thirteen debates in socio-technical transitions research, organized under the headings of emergence, diffusion and impact, as well as more synthetic cross-cutting issues