Structure and activity of thermophilic methanogenic microbial communities exposed to quaternary ammonium sanitizer

Food processing facilities often use antimicrobial quaternary ammonium compound (QAC) sanitizers to maintain cleanliness. These QACs can end up in wastewaters used as feedstock for anaerobic digestion. The aim of this study was to measure the effect of QAC contamination on biogas production and structure of microbial communities in thermophilic digester sludge. Methane production and biogas quality data were analyzed in batch anaerobic digesters containing QAC at 0, 15, 50, 100 and 150 mg/L. Increasing sanitizer concentration in the bioreactors negatively impacted methane production rate and biogas quality. Microbial community composition data was obtained through 16S rRNA gene sequencing from the QAC-contaminated sludges. Sequencing data showed no significant restructuring of the bacterial communities. However, significant restructuring was observed within the archaeal communities as QAC concentration increased. Further studies to confirm these effects on a larger scale and with a longer retention time are necessary.     

Build it,but will they come? Evidence from consumer choice between gasoline and sugarcane ethanol

How consumers might switch from gasoline and diesel to alternative energy sources is not known, since the availability of alternatives is currently very limited. To bridge this gap, we exploit exogenous variation in ethanol prices at Brazil's pumps and uncover substantial consumer heterogeneity in the choice between long-established gasoline and an alternative that is similarly available and usable: sugarcane ethanol. We observe roughly 20% of flexible-fuel motorists choosing gasoline when gasoline is priced 20% above ethanol in energy-adjusted terms ($/mile) and, similarly, 20% of motorists choosing ethanol when ethanol is priced 20% above gasoline. We use transaction-level data to explore “non-price” characteristics which differentiate the two goods in the minds of different groups of consumers. Our findings suggest—and a counterfactual illustrates—that switching away from gasoline en masse, should this be desired, would require considerable price discounts to boost voluntary adoption, in the US and elsewhere.     

Greenwashing Consumption: The Didactic Framing of ExxonMobil's Energy Solutions

Corporate advertising campaigns increasingly use environmental frames to promote their products and processes, many of which are neither sustainable nor environmentally friendly. This study examines ExxonMobil's recent efforts at green advertising, focusing specifically on their widely aired “Energy Solutions” television advertisements. We argue that ExxonMobil's use of a didactic, greenwashed frame stifles criticism and discourages examination of ideologies of consumption by exploiting the ethos of the scientist and highlighting technological solutions to problems that are deeply tied to a culture of consumerism. The definition of green energy is controlled by those with the power to generate persuasive public messages about the sources and production of energy. Counterframes, however, can be employed to turn a questioning eye upon the solutions advanced by ExxonMobil. We issue a call for green frames that help citizens and consumers critically examine the ecological integrity of all means of energy production, and that call attention to the ways in which the greenwashing of research and development initiatives can dissuade necessary action, including reduction of US energy consumption.     

The effects of forest harvest intensity in combination with wind disturbance on carbon dynamics in Lake States Mesic Forests

Total forest carbon (C) storage is determined by succession, disturbances, climate, and the edaphic properties of a site or region. Forest harvesting substantially affects C dynamics; these effects may be amplified if forest harvesting is intensified to provide biofuel feedstock. We tested the effects of harvest intensity on landscape C using a simulation modeling approach that included C dynamics, multiple disturbances, and successional changes in composition. We developed a new extension for the LANDIS-II forest landscape disturbance and succession model that incorporates belowground soil C dynamics derived from the CENTURY soil model. The extension was parameterized and calibrated using data from an experimental forest in northeastern Wisconsin, USA. We simulated a 9800 ha forested landscape over 400 years with wind disturbance combined with no harvesting, harvesting with residual slash left on site (‘standard harvest’), and whole-tree harvesting. We also simulated landscapes without wind disturbance and without eastern hemlock (Tsuga canadensis) to examine the effects of detrital quantity and quality on C dynamics. We estimated changes in live C, detrital C, soil organic C, total C, and forest composition. Overall, the simulations without harvesting had substantially greater total C and continued to sequester C. Standard harvest simulations had more C than the whole tree harvest simulations. Under both harvest regimes, C accrual was not evident after 150 years. Without hemlock, SOC was reduced due to a decline in detritus and a shift in detrital chemistry. In conclusion, if the intensity of harvesting increases we can expect a corresponding reduction in potential C storage. Compositional changes due to historic circumstances (loss of hemlock) may also affect forest C although to a lesser degree than harvesting. The modeling approach presented enabled us to consider multiple, interacting drivers of landscape change and the subsequent changes in forest C.     

The higher price of cleaner fuels: Market power in the rail transport of fuel ethanol

This paper provides evidence of market power in the transportation of ethanol used in reformulated gasoline and alternative transportation fuels. I estimate a reduced form model for railroad route-level prices. My identification strategy instruments for railroad entry, controls for selection and explicitly models capacity constraints. A detailed understanding of this industry is important because U.S. environmental policies seek to substantially expand ethanol use. Evidence of market power may alter the types of policies pursued by lawmakers. I find that ethanol shipment prices are lower for more competitive routes. I also find evidence that railroads price discriminate based on environmental regulation at route destinations. Monopolist prices for shipments to carbon monoxide non-attainment areas are 3% higher than shipments to other destinations. This price premium falls sharply with increased competition. This suggests a perverse result where environmental regulation increases the price of a clean input.     

Burning Water: A Comparative Analysis of the Energy Return on Water Invested

While various energy-producing technologies have been analyzed to assess the amount of energy returned per unit of energy invested, this type of comprehensive and comparative approach has rarely been applied to other potentially limiting inputs such as water, land, and time. We assess the connection between water and energy production and conduct a comparative analysis for estimating the energy return on water invested (EROWI) for several renewable and non-renewable energy technologies using various Life Cycle Analyses. Our results suggest that the most water-efficient, fossil-based technologies have an EROWI one to two orders of magnitude greater than the most water-efficient biomass technologies, implying that the development of biomass energy technologies in scale sufficient to be a significant source of energy may produce or exacerbate water shortages around the globe and be limited by the availability of fresh water.     

Social trends of the people of the region of Eastern Macedonia and Thrace-Greece: about the potential of using biofuels from forest products residues

In the framework of enquiry of biomass usage possibilities in our country, a research was made through the whole Eastern Macedonia region, related to disposal possibilities from the production conveyors and usage possibilities from the region’s residents and businessmen, of biofuels that come from mechanical wood treatment residues and from the residues of agricultural production, in wooden form, known with the term wood pellets or wood briquettes. From the present study, it came to light that there is an intense interest for direct personal usage and application of biomass for the residents or occupational spaces heating. The necessary biomass quantity for the entire region’s households is estimated up to 205,520 t. From the biomass usage as a combustible material, a 680 €/year and household about, is made. The potential investments that will be made to the region seem to have a very short depreciation, but a business plan and a marketing plan syntax are considered as necessary for the result’s maximisation.     

Regulating carbon emissions from indirect land use change (ILUC): U.S. and California case studies

As lifecycle emissions accounting becomes more widely used in policy, it is important to understand how it has been applied. This paper analyses policy-making for two U.S. fuel regulations—the federal Renewable Fuel Standard (RFS) and the California Low Carbon Fuel Standard (LCFS)—that were pioneering not only in using life cycle assessment (LCA) in performance-based environmental regulations, but especially for including emissions from indirect land use change (ILUC). The case studies in this paper focus, in particular, on the decision to include ILUC in lifecycle emissions accounting. Tracing the development of these policies shows the key role of environmental policy entrepreneurs in advocating for ILUC emissions accounting during policy formulation. Moreover, it highlights a paradox in the use of science: although ILUC policy proponents were motivated by best available research, they were also politically enabled by scientific uncertainty and lack of understanding. Understanding this political dimension of decision-making is valuable for scholars as well as practitioners facing similar decisions.     

The behaviour of suppliers and consumers in mandated markets: the introduction of the ethanol–petrol blend E10 in Germany

In December 2010, the German government increased the maximum ethanol content that can be blended with petrol from 5% to 10%, which facilitated the introduction of the ethanol–petrol blend E10. The revised ethanol–petrol blend was introduced with ambitions towards decarbonizing the transport sector as well as to support energy security and rural development. While usually supportive of actions aimed to combat climate change, the great majority of German motorists have refused to buy E10. The lacking demand for E10 is the empirical phenomenon addressed by this study. How did the fuel suppliers comply with the policy provisions? Which actors made attempts to influence the motorists’ demand for the new ethanol–petrol blend? Which actor was assigned the responsibility for the problems that occurred upon the rollout of the new fuel type? These research questions guide this study, which concentrates on the behaviour of transport fuel suppliers and consumers in mandated markets, that is, markets created by policy provisions.