Estimated photochemical ozone creation potentials (POCPs) of CF3CFCH2 (HFO-1234yf) and related hydrofluoroolefins (HFOs)

The photochemical ozone creation potentials (POCPs) for CF₃CFCH₂ and other commercially significant hydrofluoroolefins have been estimated for the first time. CF₃CFCH₂ (HFO-1234yf) has a POCP of 7.0 which is less than that for ethane (12.3) and greater than for methane (0.6). Methane and ethane have sufficiently low POCPs that they are usually considered unreactive with respect to ozone formation in urban areas and accordingly are exempt from volatile organic compound (VOC) emission regulations. Estimated POCPs for other hydrofluoroolefins are: CH₂CF₂, 18.0; CF₂CF₂, 12.5; CH₂CHCF₃, 10.7; CF₂CFCF₃, 5.4; Z-CHFCFCF₃, 5.6; E-CHFCFCF₃, 7.3; CH₂CHCF₂CF₃, 6.6; and t-CHFCHCF₃, 6.4.     

The Impact of Scientific Information on Ecosystem Management: Making Sense of the Contextual Gap Between Information Providers and Decision Makers

Scientific information is not always effectively incorporated into decision-making processes. This phenomenon seems to hold even when the information is aligned with an articulated need, is generated according to sound scientific procedures, and is packaged with end-user preferences in mind. We propose that contextual or cultural differences contribute significantly to the misalignment in communication between those who generate information and those who seek information for improved management of natural resources. The solution is to cultivate shared understanding, which in turn relies on acknowledgment and sharing of diverse values and attitudes. This constitutes a difficult challenge in a culturally diverse environment. Whereas cultural diversity represents wealth in experiences, knowledge and perspectives it can constrain the potential to develop the shared understandings necessary for effective integration of new information. This article illustrates how a lack of shared understanding among participants engaged in a resource-management process can produce and perpetuate divergent views of the world, to the extent that information and knowledge flows are ineffective and scientific information, even when requested, cannot be used effectively. Four themes were distilled from interviews with management and scientific staff of a natural resource–management agency in South Africa. The themes are used to illustrate how divergent views embedded in different cultures can discourage alignment of effort toward a common purpose. The article then presents a sense-making framework to illustrate the potential for developing shared understandings in a culturally diverse world.     

Micromechanical Tensile Testing of Cellulose-Reinforced Electrospun Fibers Using a Template Transfer Method (TTM)

A template transfer method (TTM) and a fiber fixation technique were established for fiber handling and micro tensile stage mounting of aligned and non-aligned electrospun fiber mats. The custom-made template had been precut to be mounted on a variety of collectors, including a rapidly rotating collector used to align the fibers. The method eliminated need for direct physical interaction with the fiber mats before or during the tensile testing since the fiber mats were never directly clamped or removed from the original substrate. By using the TTM it was possible to measure the tensile properties of aligned poly(methyl methacrylate) (PMMA) fiber mats, which showed a 250?% increase in strength and 450?% increase in modulus as compared to a non-aligned system. The method was further evaluated for aligned PMMA fibers reinforced with cellulose (4 wt%) prepared as enzymatically derived nanofibrillated cellulose (NFC). These fibers showed an additional increase of 30?% in both tensile strength and modulus, resulting in a toughness increase of 25?%. The fracture interfaces of the PMMA?CNFC fibers showed a low amount of NFC pull-outs, indicating favorable phase compatibility. The presented fiber handling technique is universal and may be applied where conservative estimates of mechanical properties need to be assessed for very thin fibers.     

Risk and mitigation of self-heating and spontaneous combustion in underground coal storage

While the self-heating and spontaneous combustion of coal is a known challenge at coal mines and storage sites, there are known methods for mitigating this challenge for typical open stockpile storage. However, closing the storage will reduce access for corrective action, and it is then important to manage the storage and its transport system with added attention without unduly adding cost or hindering availability. This paper aims to discuss the risk, prevention and extinguishing of fires in closed coal storage facilities, particularly in light of the experience with the Salmisaari underground rock storage facility in Finland. The observed autoignition events have indicated an array of contributing factors, some of which are unique to underground silo storage facilities. On the other hand, many features of the storage facilities can be compared with other extant closed storage systems. The factors affecting fire risk are described and the associated fault and event trees are outlined for autoignition at underground storage. Drawing upon the experiences with past events of self-heating and spontaneous combustion, recommendations are given on cost-effective preventive, corrective and other mitigating action for minimising fire risk and promoting storage availability.     

Conceptual design of an integrated heating system at LKAB Malmberget with consideration of social-environmental damage costs

LKAB Malmberget is a Swedish mining site located at Malmberget, Sweden. Seven boiler centers are located in the north part of Malmberget. There are no connections in between these boiler centers, meaning that it is a decentralized heating system. The heat generated is used to heat up buildings and for mine ventilation air mainly during the cold periods. The heat is mainly provided from electric and oil boilers. However, most boilers under use are over 20 years old, and it is time to retrofit the boiler system and infrastructure. The purpose of this work is to design and optimize the heating system by introducing an integrated concept to minimize the heat production cost.An optimization model based on the mixed integer linear programming (MILP) has been developed. Several technical options have been considered in a new centralized heating system. The optimization principle is based on two kinds of perspectives: current price and external costs. With consideration of environmental and health damage from society concerns point of view, instead of environmental taxes in the current price perspective, the monetary values of externalities due to pollutants such as CO₂, NO_x, SO₂ and particulates emitted from the heating system are included. On the basis of data input and assumptions, modeling results indicate that a lower cost could be achieved when a waste heat recovery boiler is installed at the older pelletization plant to recover sensible heat from flue gas. This technical option is the best solution or at least contributes to the best solution in all optimization results. Including the externality cost is useful for making fair evaluation of the social-environmental impacts of the alternatives.     

The politics of carbon taxation: how varieties of policy style matter

ABSTRACT

The momentum achieved for unilateral carbon taxes in seven European countries is examined. Why is it that small countries, despite being vulnerable to forces of international competition, have been able to implement carbon taxes? A review of national experiences does not suggest that the share of fossil fuels in the energy mix defines the room for such taxes, or point to a strong role for traditional left-right ideology. Rather, it is deep-seated patterns of national policy styles with neo-corporatist traits, providing a protective device for the open economies of small countries, which condition the introduction of carbon taxes. The associated routines of decision-making offer coordination mechanisms for proactive macroeconomic policies in which carbon taxation can find a place. Parliamentary democracies with proportional representation, as is common in the smaller countries, provide access to government for political parties that pursue carbon taxation. These in turn sensitise larger political parties to climate concerns, as they benefit from institutionalised practices and routines for problem-solving and consensus-seeking.     

IMPROVED ENERGY AND MATERIAL EFFICIENCY USING NEW TOOLS FOR GLOBAL OPTIMISATION OF RESIDUE MATERIAL FLOWS

Residue materials generated in the metallurgical industry have gained an increasing importance, both from the points of view of energy and material supply. A joint process integration model for the integrated steel plant system is developed and used in this paper. It takes into account both residue materials and energy recirculation for the system. The potential for increased recirculation and the effect on the system from an environmental point of view is presented, and implementations and practical experiences are discussed. The model developed can serve as a benchmark for different steelmaking operations and constitute a basis for the continuous work involved in material, energy, environment or economic analyses for the steel production system.     

In Search of Stability – Investigating Flexible and Stable Production Strategies for an Optimised Steel Plant

It is crucial for a steel making production system to operate at the lowest possible production cost, while satisfying stability and reliability conditions. To plan future production strategies, it is therefore important to be able to model the system behaviour when internal and external parameters are changed. In this study the sensitivity and stability of an optimised solution, of an integrated steel plant, have been investigated. The solution’s sensitivity has been analysed taking both internal process changes and external price variations into account, through applying both simulation and optimisation. The analysis also includes both costs and environmental issues such as carbon dioxide and sulphur emissions. Based on the methodology suggested, it is possible to determine the stability of the system solution, including both economic and environmental performance.