Buhr K.,IVL Swedish Environmental Reserach Institute Ltd |
Buhr K.,Linköping University |
Hansson A.,Linköping University
Global Environmental Change | Year: 2011
The development and deployment of carbon capture and storage (CCS) are sensitive to public debates that socially frame the technology. This study examines the evolving CCS debates, focusing on the media's framing of firms. Corporations are central CCS actors, and we analyze them in light of the nation-state, which has been emphasized in previous research as the primary context of CCS politics. Empirically, we compare framings of Statoil and Vattenfall in the Norwegian and Swedish media, drawing on a qualitative dataset of news media articles published between 2005 and 2009. We conclude that firms make regular media statements either to foster legitimacy or to respond to criticism of CCS. We also conclude that framing is not necessarily linked to technological success or failure and that interpretations of the technology have different forms depending on whether the related activity occurs in domestic or foreign markets. Finally, we explain the media framings based on the domestic energy situation and politics. © 2011 Elsevier Ltd.
Moldan F.,IVL Swedish Environmental Reserach Institute Ltd |
Wright R.F.,Norwegian Institute for Water Research
Environmental Pollution | Year: 2011
The role of nitrogen (N) in acidification of soil and water has become relatively more important as the deposition of sulphur has decreased. Starting in 1991, we have conducted a whole-catchment experiment with N addition at Grdsjön, Sweden, to investigate the risk of N saturation. We have added 41 kg N ha-1 yr-1 as NH4NO3 to the ambient 9 kg N ha-1 yr-1 in fortnightly doses by means of sprinkling system. The fraction of input N lost to runoff has increased from 0% to 10%. Increased concentrations of NO3 in runoff partially offset the decreasing concentrations of SO4 and slowed ecosystem recovery from acid deposition. From 1990-2002, about 5% of the total N input went to runoff, 44% to biomass, and the remaining 51% to soil. The soil N pool increased by 5%. N deposition enhanced carbon (C) sequestration at a mean C/N ratio of 42-59 g g-1. © 2010 Elsevier Ltd. All rights reserved.
Zetterberg L.,IVL Swedish Environmental Reserach Institute Ltd |
Chen D.,Gothenburg University
GCB Bioenergy | Year: 2015
The climate impacts from bioenergy involve an important time aspect. Using forest residues for energy may result in high initial emissions, but net emissions are reduced over time since, if the residues were left on the ground, they would decompose and release CO2 to the atmosphere. This article investigates the climate impacts from bioenergy with special focus on the time aspects. More specifically, we analyze the climate impacts of forest residues and stumps where combustion related emissions are compensated by avoided emissions from leaving them on the ground to decompose. These biofuels are compared with fossil gas and coal. Net emissions are defined as emissions from utilizing the fuel minus emissions from a reference case of no utilization. Climate impacts are estimated using the measures radiative forcing and global average surface temperature. We find that the climate impacts from using forest residues and stumps depend on the decomposition rates and the time perspective over which the analysis is done. Over a 100 year perspective, branches and tops have lower climate impacts than stumps which in turn have lower impacts than fossil gas and coal. Over a 20 year time perspective, branches and tops have lower climate impacts than all other fuels but the relative difference is smaller. However, stumps have slightly higher climate impacts over 20 years than fossil gas but lower impacts than coal. Regarding metrics for climate impacts, over shorter time scales, approximately 30 years or less, radiative forcing overestimates the climate impacts compared with impacts expressed by global surface temperature change, which is due to the inertia of the climate system. We also find that establishing willow on earlier crop land may reduce atmospheric CO2, provided new land is available. However, these results are inconclusive since we haven't considered the effects of producing the agricultural crops elsewhere. © 2014 John Wiley & Sons Ltd.
Jonsson A.M.,IVL Swedish Environmental Reserach Institute Ltd |
Westerlund J.,Gothenburg University |
Hallquist M.,Gothenburg University
Geophysical Research Letters | Year: 2011
In these experiments size-resolved emission factors for particle number (EFPN) and mass (EFPM) have been determined for 734 individual ship passages for real-world dilution. The method used is an extractive sampling method of the passing ship plumes where particle number/mass and CO2 were measured with high time resolution (1 Hz). The measurements were conducted on a small island located in the entrance to the port of Gothenburg (N57.6849, E11.838), the largest harbor in Scandinavia. This is an emission control area (ECA) and in close vicinity to populated areas. The average EFPN and EFPM were 2.55 0.11 × 10 16 (kg fuel)-1 and 2050 110 mg (kg fuel)-1, respectively. The determined EF for ships with multiple passages showed a great reproducibility. Size-resolved EFPN were peaking at small particle sizes ∼35 nm. Smaller particle sizes and hence less mass were observed by a gas turbine equipped ship compared to diesel engine equipped ships. On average 36 to 46% of the emitted particles by number were non-volatile and 24% by mass (EFPN 1.16 0.19 × 1016 [kg fuel]-1 and EFPM 488 73 mg [kg fuel]-1, respectively). This study shows a great potential to gain large data-sets regarding ship emission determining parameters that can improve current dispersion modeling for health assessments on local and regional scales. The global contributions of total and non-volatile particle mass from shipping using this extensive data-set from an ECA were estimated to be at least 0.80 Tgy-1 and 0.19 Tgy -1. Copyright 2011 by the American Geophysical Union.
Amand L.,IVL Swedish Environmental Reserach Institute Ltd |
Olsson G.,Lund University |
Carlsson B.,Uppsala University
Water Science and Technology | Year: 2013
This review covers automatic control of continuous aeration systems in municipal wastewater treatment plants. The review focuses on published research in the 21st century and describes research into various methods to decide and control the dissolved oxygen (DO) concentration and to control the aerobic volume with special focus on plants with nitrogen removal. Important aspects of control system implementation and success are discussed, together with a critical review of published research on the topic. With respect to DO control and determination, the strategies used for control span from modifications and developments of conventional control methods which have been explored since the 1970s, to advanced control such as model-based predictive and optimal controllers. The review is supplemented with a summary of comparisons between control strategies evaluated in full-scale, pilot-scale and in simulations. © IWA Publishing 2013.
Amand L.,IVL Swedish Environmental Reserach Institute Ltd |
Amand L.,Uppsala University |
Carlsson B.,Uppsala University
Water Research | Year: 2012
An important tool to minimise energy consumption in activated sludge processes is to control the aeration system. Aeration is a costly process and the dissolved oxygen level will determine the efficiency of the operation as well as the treatment results. What aeration control should achieve is closely linked to how the effluent criteria are defined. This paper explores how the aeration process should be controlled to meet the effluent discharge limits in an energy efficient manner in countries where the effluent nitrogen criterion is defined as average values over long time frames, such as months or years. Simulations have been performed using a simplified Benchmark Simulation Model No. 1 to investigate the effect of different levels of suppressing the variations of the effluent ammonium concentration. Optimisation is performed where the manipulated variable for aeration (the oxygen transfer coefficient, K La) is minimised with the constraint that the average daily flow-proportional ammonium concentration in the effluent should reach a desired level. The optimisation results are compared with constant dissolved oxygen concentrations and supervisory ammonium control with different controller settings. The results demonstrate and explain how and why energy consumption can be optimised by tolerating the ammonium concentration to vary around a given average value. In these simulations, the optimal oxygen peak-to-peak amplitude range between 0.7 and 1.8mg/l depending on the influent variation and ammonium level in the effluent. These variations can be achieved with a slow ammonium feedback controller. The air flow requirements can be reduced by 1-4% compared to constant dissolved oxygen set-points. Optimal control of aeration requires up to 14% less energy than needed for fast feedback control of effluent ammonium. © 2012 Elsevier Ltd.
Martin M.,IVL Swedish Environmental Reserach Institute Ltd
Journal of Cleaner Production | Year: 2015
It is generally assumed that industrial symbiosis creates economic and environmental benefits for all firms involved, though few quantifications have been produced in the literature. The environmental performance of an industrial symbiosis network of biofuel producers on the island of Händelö, Sweden will be quantified using an approach from previous literature. This method allows the benefits provided by exchanges to be partitioned to firms taking part in the industrial symbiosis network, which may have implications for tax incentives, marketing, expansion and environmental awareness. The current industrial symbiosis network has been found to have benefits compared to reference scenarios produced. However, methodological choices, such as the choice of reference scenario and allocation methods may significantly influence the results of the environmental performance. © 2015 Elsevier Ltd.
Cousins A.P.,IVL Swedish Environmental Reserach Institute Ltd
Science of the Total Environment | Year: 2012
To assess the effect of the indoor environment on the urban fate of organic chemicals, an 8-compartment indoor-inclusive steady state multimedia chemical fate model was developed. The model includes typical urban compartments (air, soil, water, sediment, and urban film) and a novel module representing a generic indoor environment. The model was parameterized to the municipality of Stockholm, Sweden and applied to four organic chemicals with different physical-chemical characteristics and use patterns: formaldehyde, 2,4,6-tribromophenol, di-ethylhexylphthalate and decabromodiphenyl ether. The results show that emissions to indoor air may increase the steady state mass and residence time in the urban environment by a factor of 1.1 to 22 for the four chemicals, compared to if emissions are assigned to outdoor air. This is due to the nested nature of the indoor environment, which creates a physical barrier that prevents chemicals from leaving the urban system with outflowing air. For DEHP and BDE 209, the additional partitioning to indoor surfaces results in a greater importance of the indoor removal pathways from surfaces. The outdoor environmental concentrations of these chemicals are predicted to be lower if emitted to indoor air than if emitted to outdoor air because of the additional indoor removal pathways of dust and indoor film, leading to loss of chemical from the system. For formaldehyde and 2,4,6-TBP outdoor environmental concentrations are not affected by whether the release occurs indoors or outdoors because of the limited partitioning to indoor surfaces. A sensitivity analysis revealed that there appears to be a relationship between logKOA and the impact of the ventilation rate on the urban fate of organic chemicals. © 2012 Elsevier B.V.
Zetterberg L.,IVL Swedish Environmental Reserach Institute Ltd
Energy Economics | Year: 2014
This paper investigates abatement incentives for allowance allocation based on output and sector specific benchmarks, here called output based allocation or benchmarking. Special attention is given to updated allocation and we assume that allowances can be traded with other sectors (open cap). We confirm earlier studies that output based allocation based on ex-ante data provide the same abatement incentives as auction or grandfathering and also confirm that output based allocation with updated output and ex-ante benchmarks provides as high abatement incentives as auction, but constitutes a production subsidy. However, we also find that benchmarking with updated output and updated benchmarks reduces abatement incentives somewhat, but less so than updated grandfathering. An allocation rule where the sector cap is prescribed ex-ante, for instance based on historic emissions, and distributed to installations in proportion to their updated production preserves full abatement incentives and avoids some of the costs associated with the determination of benchmarks. However, this rule also constitutes a production subsidy, which decreases with industry concentration. If a sector is split into smaller groups each with one benchmark per sub-sector, benchmarking evolves toward grandfathering. Since benchmarking is conditioned on production, this allocation method protects production from leakage, i.e. migrating to areas where firms face no emissions cost. This may actually be the most compelling reason for choosing benchmarking. © 2014 Elsevier B.V.
Magnusson M.,Chalmers University of Technology |
Fridell E.,Chalmers University of Technology |
Fridell E.,IVL Swedish Environmental Reserach Institute Ltd |
Ingelsten H.H.,Chalmers University of Technology
Applied Catalysis B: Environmental | Year: 2012
This study investigates how sulfur affects the NO x reduction activity over a commercial vanadium based urea-SCR catalyst for marine applications, especially at low temperatures, and in combination with H 2O. The addition of SO 2 in the absence of H 2O promotes the NO x reduction at 350°C, while the addition of H 2O, in the absence of SO 2, gives rise to a decrease in the NO x reduction and also an inhibition of the N 2O formation. The same trends are observed at transient temperatures, but no promotional effect by SO 2 is seen at temperatures below 230°C. Further, long term effects of SO 2 and H 2O were investigated and the NO x reduction remains stable, also after long term exposure of SO 2. The ammonia desorption is investigated using temperature programmed desorption (TPD) experiments, both in the presence and in the absence of SO 2. In general in the presence of both H 2O and SO 2 the catalyst does not show any sign of deactivation at temperatures above 300°C and fairly low space velocities (below 12,200h -1). However, at lower temperatures (250°C) and/or higher space velocities the catalytic performance for NO x reduction decreases with time. © 2011 Elsevier B.V.