Realistic Mitigation Options for Global Warming

Influence of the drying mode of support on the properties of Pd/Al2O3-ZrO2 materials used for methane combustion

This work constitutes a new trial to enhance the properties of palladium supported on alumina modified with zirconium used as catalysts for methane combustion. The effect of the support drying mode is studied. For this aim, Al2O3-ZrO2 binary oxides with zirconium loading of 2 and 5% in weight were prepared using sol-gel process then dried under ordinary or supercritical conditions. Palladium with a loading of 0.5% was deposited on the support by wet impregnation. Several techniques have been used to investigate differences between the two types of the derived catalysts.

Investigation into outdoor thermal comfort conditions by different seasonal field surveys in China, Guangzhou

Outdoor microclimatic conditions strongly affect the thermal comfort of pedestrians. A transversal field survey was conducted in Guangzhou, together with micrometeorological measurements. The outdoor physiological equivalent temperature (PET) varied from 3 to 59 °C. Regression lines were obtained to establish correlations of the mean thermal sensation vote (MTSV) with the PET bins with a width of 1 °C. Furthermore, the thermal comfort range of PET, neutral PET (NPET), and preferred PET was analyzed. The results indicated that, for the young people, thermal comfort range of PET spanned from 19.2 to 24.6 °C. The NPET and preferred PET significantly differed in different seasons. The NPET was higher in the summer than that in the winter and transitional seasons. However, the preferred PET of the summer was lower than that of the winter. The PET limits of different thermal stress categories were also confirmed, which differed from those in other cities. Thus, the impacts of adaptation on thermal comfort range were significant for people in outdoor environment.

Consumers' perceptions of energy use and energy savings: A literature review

Background

Policy makers and program managers need to better understand consumers' perceptions of their energy use and savings to design effective strategies for promoting energy savings.

Methods

We reviewed 14 studies from the emerging interdisciplinary literature examining consumers' perceptions electricity use by specific appliances, and potential savings.

Results

We find that: (1) electricity use is often overestimated for low-energy consuming appliances, and underestimated for high-energy consuming appliances; (2) curtailment strategies are typically preferred over energy efficiency strategies; (3) consumers lack information about how much electricity can be saved through specific strategies; (4) consumers use heuristics for assessing the electricity use of specific appliances, with some indication that more accurate judgments are made among consumers with higher numeracy and stronger pro-environmental attitudes. However, design differences between studies, such as variations in reference points, reporting units and assessed time periods, may affect consumers' reported perceptions. Moreover, studies differ with regard to whether accuracy of perceptions was evaluated through comparisons with general estimates of actual use, self-reported use, household-level meter readings, or real-time smart meter readings.

Conclusion

Although emerging findings are promising, systematic variations in the measurement of perceived and actual electricity use are potential cause for concern. We propose avenues for future research, so as to better understand, and possibly inform, consumers' perceptions of their electricity use. Ultimately, this literature will have implications for the design of effective electricity feedback for consumers, and related policies.

Layered Double Hydroxides-Based Materials as Oxidation Catalysts

This chapter is focused on the transition-metal-containing LDHs-based materials having potential applications in both catalytic selective oxidation for obtaining chemicals and intermediates, and complete oxidation as a promising valuable technology for the destruction of Volatile Organic Compounds (VOCs).

Comparative life cycle assessment of three biohydrogen pathways

A life cycle assessment was performed to quantify and compare the energetic and environmental performances of hydrogen from wheat straw (WS-H(2)), sweet sorghum stalk (SSS-H(2)), and steam potato peels (SPP-H(2)). Inventory data were derived from a pilot plant. Impacts were assessed using the impact 2002+ method. When co-product was not considered, the greenhouse gas (GHG) emissions were 5.60 kg CO(2eq) kg(-1) H(2) for WS-H(2), 5.32 kg CO(2eq) kg(-1) H(2) for SSS-H(2), and 5.18 kg CO(2eq) kg(-1) H(2) for SPP-H(2). BioH(2) pathways reduced GHG emissions by 52-56% compared to diesel and by 54-57% compared to steam methane reforming production of H(2). The energy ratios (ER) were also comparable: 1.08 for WS-H(2), 1.14 for SSS-H(2) and 1.17 for SPP-H(2). A shift from SPP-H(2) to WS-H(2) would therefore not affect the ER and GHG emissions of these BioH(2) pathways. When co-product was considered, a shift from SPP-H(2) to WS-H(2) or SSS-H(2) decreased the ER, while increasing the GHG emissions significantly. Co-product yield should be considered when selecting BioH(2) feedstocks.

CH4 Deep Oxidation on Ag Promoted Manganese Oxide Catalysts

Manganese oxide modified by various amounts of Ag was prepared and used for CH

ENGINEERING-ECONOMIC STUDIES OF ENERGY TECHNOLOGIES TO REDUCE GREENHOUSE GAS EMISSIONS: Opportunities and Challenges

▪ Abstract  This paper compares the results of four recent engineering-economic studies of the potential for energy technologies to reduce greenhouse gas emissions. The review includes a sector-by-sector assessment of specific technology opportunities and their costs, as estimated by (a) five National Laboratories, (b) the Tellus Institute, (c) the National Academy of Sciences, and (d) the Office of Technology Assessment. These studies document that numerous cost-effective, energy-efficient technologies remain underutilized in each end-use sector of the economy. Supply-side options, on the other hand, are generally found to involve some net costs. Demand- and supply-side options benefit from being pursued concurrently because of various interaction effects. In combination, large carbon reductions are possible at incremental costs that are less than the value of the energy saved. An aggressive national commitment involving some combination of targeted tax incentives, emissions trading, and non-price policies is needed to exploit these carbon reduction opportunities.

The Ecotron: a controlled environmental facility for the investigation of population and ecosystem processes

This paper reports on aspects of the design and philosophy of the Ecotron, an integrated series of 16 controlled environmental chambers at the NERC Centre for Population Biology. The Ecotron serves as an experimental means for analysing population and community dynamics and ecosystem processes under controlled physical conditions. Within the chambers, terrestrial experimental communities are assembled into foodwebs of desired complexity from a pool of species selected for their preadaptations to the physical conditions of the Ecotron. These species include decomposers (earthworms, snails, microarthropods and microbes), primary producers (16 species of plants), primary consumers (four species of herbivorous arthropods), and secondary consumers (four species of parasitoids). The design of the Ecotron is unique in several aspects with respect to its blend of biology and technology. It supports small, dynam ic communities of up to 30 plant and metazoan species, thereby making it among the more biologically complex controlled environmental systems currently in use. Its architecture permits replication and variation of spatial scale in experimental design. Its artificial climate simulates natural environmental conditions within chambers allowing experimental control over light, water, temperature, humidity, and in the near future CO2and UV-B radiation. Sensors monitor both macro- and micro-environmental conditions of a number of physical factors within the chambers. Preliminary experiments show the Ecotron to be an excellent facility for long-term population and community-level experiments. We discuss the results of one of these early experiments and briefly consider ongoing and future experiments.

Carbon Pools and Flux of Global Forest Ecosystems

Forest systems cover more than 4.1 x 10(9) hectares of the Earth's land area. Globally, forest vegetation and soils contain about 1146 petagrams of carbon, with approximately 37 percent of this carbon in low-latitude forests, 14 percent in mid-latitudes, and 49 percent at high latitudes. Over two-thirds of the carbon in forest ecosystems is contained in soils and associated peat deposits. In 1990, deforestation in the low latitudes emitted 1.6 +/- 0.4 petagrams of carbon per year, whereas forest area expansion and growth in mid- and high-latitude forest sequestered 0.7 +/- 0.2 petagrams of carbon per year, for a net flux to the atmosphere of 0.9 +/- 0.4 petagrams of carbon per year. Slowing deforestation, combined with an increase in forestation and other management measures to improve forest ecosystem productivity, could conserve or sequester significant quantities of carbon. Future forest carbon cycling trends attributable to losses and regrowth associated with global climate and land-use change are uncertain. Model projections and some results suggest that forests could be carbon sinks or sources in the future.