A methodology for evaluating and selecting processes for natural gas conditioning

The aim of this work was to develop a generic methodology for evaluating and selecting, at the conceptual design phase of a project, the best process technology for Natural Gas conditioning. A generic approach would be simple and require less time and would give a better understanding of why one process is to be preferred over another. This will lead to a better understanding of the problem. Such a methodology would be useful in evaluating existing, novel and hybrid technologies. However, to date no information is available in the published literature on such a generic approach to gas processing. It is believed that the generic methodology presented here is the first available for choosing the best or cheapest method of separation for natural gas dew-point control. Process cost data are derived from evaluations carried out by the vendors. These evaluations are then modelled using a steady-state simulation package. From the results of the modelling the cost data received are correlated and defined with respect to the design or sizing parameters. This allows comparisons between different process systems to be made in terms of the overall process. The generic methodology is based on the concept of a Comparative Separation Cost. This takes into account the efficiency of each process, the value of its products, and the associated costs. To illustrate the general applicability of the methodology, three different cases suggested by BP Exploration are evaluated. This work has shown that it is possible to identify the most competitive process operations at the conceptual design phase and illustrate why one process has an advantage over another. Furthermore, the same methodology has been used to identify and evaluate hybrid processes. It has been determined here that in some cases they offer substantial advantages over the separate process techniques.

Justice and morality:human suffering, natural law and international politics

Bridging the contending theories of natural law and international relations, this book proposes a 'relational ontology' as the basis for rethinking our approach to international politics. The book contains a number of challenging and controversial ideas on the study of international political thought which should provoke constructive debate within international relations theory, political theory, and philosophical ethics. © Amanda Russell Beattie 2010. All rights reserved.

'Only in the leap from the lion's head will he prove his worth':natural law and international relations

This article argues the benefits of including a theological interpretation of natural law morality within the normative discourses of international politics. It challenges the assumption of a Grotian secular natural law arguing that practical reason, in a Thomist interpretation, is better suited to the demands of international political theory. It engages with themes of agency, practical reason, and community in order to enhance the content of the post-territorial community evidenced in ethical cosmopolitan debates. Likewise, it envisions a simultaneously enhancing a rapprochement among cosmopolitan and communitarian discourses of international politics facilitated through an institutional design guided by the morality of natural law.

An assessment of the performance of high density polyethylene copolymers for natural gas distribution pipes

The total thermoplastics pipe market in west Europe is estimated at 900,000 metric tonnes for 1977 and is projected to grow to some 1.3 million tonnes of predominantly PVC and polyolefins pipe by 1985. By that time, polyethylene for gas distribution pipe and fittings will represent some 30% of the total polyethylene pipe market. The performance characteristics of a high density polyethylene are significantly influenced by both molecular weight and type of comonomer; the major influences being in the long-term hoop stress resistance and the environmental stress cracking resistance. Minor amounts of hexene-1 are more effective than comonomers lower in the homologous series, although there is some sacrifice of density related properties. A synergistic improvement is obtained by combining molecular weight increase with copolymerisation. The Long-term design strength of polyethylene copolymers can be determined from hoop stress measurement at elevated temperatures and by means of a separation factor of approximate value 22, extrapolation can be made to room temperature performance for a water environment. A polyethylene of black composition has a sufficiently improved performance over yellow pigmented pipe to cast doubts on the validity of internationally specifying yellow coded pipe for gas distribution service. The chemical environment (condensate formation) that can exist in natural gas distribution networks has a deleterious effect on the pipe performance the reduction amounting to at least two decades in log time. Desorption of such condensate is very slow and the influence of the more aggressive aromatic components is to lead to premature stress cracking. For natural gas distribution purposes, the design stress rating should be 39 Kg/cm2 for polyethylenes in the molecular weight range of 150 - 200,000 and 55 Kg/cm2 for higher molecular weight materials.

Adjusting to institutional realities: the 2006 NGO law and its effects on civil society in Russia

Key findings: The paper investigates the impact that the legislative changes of 2006 had on civil society in Russia. This legislation has change the regulatory environment in which civil society actors such as Third Sector Organisations operate. Using the past development of civil society organisations as well as insights about how the institutional environment influences this article illustrates: - the undemocratic nature and motivation of the law and how it exploits the structural weaknesses of civil society - how Third Sector Organisations rationalise and translate the legislative changes into their organisational realities and how this changed or did not change their behaviour - the shift in state-civil society relations away from liberal co-existence into more hierarchical arrangements were Third Sector Organisations are subordinated to the state. These trends have far reaching implications for civil society. The empirical evidence shows that state now manages civil society to meet its own political ends. It also shows that organisations in the field welcome the more engage and directive nature of the Russian state. Why is this important? What does it mean for business or other users? Are there policy implications? The research is important as it shows how Third Sector Organisations have reacted to the legislative changes. Further it provides a basis for interpretation of the potential future development of civil society. Additional it highlights how the continuous process of democratisation in transition economies sometimes might come unstuck. In particular donor agencies will need to consider these trends when disturbing funding to Third Sector Organisations.