Hydrogen production by biogas steam reforming: A technical, economic and ecological analysis

Fuel cells are electrochemical energy conversion devices that convert fuel and oxidant electrochemically into electrical energy, water and heat. Compared to traditional electricity generation technologies that use combustion processes to convert fuel into heat, and then into mechanical energy, fuel cells convert the hydrogen and oxygen chemical energy into electrical energy, without intermediate conversion processes, and with higher efficiency. In order to make the fuel cells an achievable and useful technology, it is firstly necessary to develop an economic and efficient way for hydrogen production. Molecular hydrogen is always found combined with other chemical compounds in nature, so it must be isolated. In this paper, the technical, economical and ecological aspects of hydrogen production by biogas steam reforming are presented. The economic feasibility calculation was performed to evaluate how interesting the process is by analyzing the investment, operation and maintenance costs of the biogas steam reformer and the hydrogen production cost achieved the value of 0.27 US$/kWh with a payback period of 8 years. An ecological efficiency of 94.95%, which is a good ecological value, was obtained. The results obtained by these analyses showed that this type of hydrogen production is an environmentally attractive route. © 2013 Elsevier Ltd.

The functional biogeography of species: Biogeographical species roles of birds in Wallacea and the West Indies

Biogeographical systems can be analyzed as networks of species and geographical units. Within such a biogeographical network, individual species may differ fundamentally in their linkage pattern, and therefore hold different topological roles. To advance our understanding of the relationship between species traits and large-scale species distribution patterns in archipelagos, we use a network approach to classify birds as one of four biogeographical species roles: peripherals, connectors, module hubs, and network hubs. These roles are based upon the position of species within the modular network of islands and species in Wallacea and the West Indies. We test whether species traits - including habitat requirements, altitudinal range-span, feeding guild, trophic level, and body length - correlate with species roles. In both archipelagos, habitat requirements, altitudinal range-span and body length show strong relations to species roles. In particular, species that occupy coastal- and open habitats, as well as habitat generalists, show higher proportions of connectors and network hubs and thus tend to span several biogeographical modules (i.e. subregions). Likewise, large body size and a wide altitudinal range-span are related to a wide distribution on many islands and across several biogeographical modules. On the other hand, species restricted to interior forest are mainly characterized as peripherals and, thus, have narrow and localized distributions within biogeographical modules rather than across the archipelago-wide network. These results suggest that the ecological amplitude of a species is highly related to its geographical distribution within and across bio geographical subregions and furthermore supports the idea that large-scale species distributions relate to distributions at the local community level. We finally discuss how our biogeographical species roles may correspond to the stages of the taxon cycle and other prominent theories of species assembly. © 2013 The Authors.

Application of the United States Virgin Islands for membership to the CCST

Contiene la solicitud de ingreso al CCCT de las Islas Virgenes de Estados Unidos.

The British Virgin Islands national integrated development strategy

Includes bibliography

The impact of hurricane Ivan in the Cayman Islands

Includes bibliography

Trip report vital statistics assessment and training programme British Virgin Islands, July 11-19, 1985

Informe de la mision realizada para evaluar el estado de las estadisticas vitales en las Islas Virgenes Britanicas, y estudiar la forma de mejorar los sistemas de recoleccion y entrega de datos.

The informal trade in the Leeward Islands

Includes bibliography

Ocean-borne cargo movements Turks and Caicos Islands

Includes bibliography

Review of economic evaluation of proposed new port at George Town, Cayman Islands

Includes bibliography

A study of return migration to the Organisation of Eastern Caribbean States (OECS) territories and the British Virgin Islands in the closing years of the twentieth century: implications for social policy

Includes bibliography

The impact of immigration on Caribbean microstates: Bahamas, British Virgin Islands, Saint Maarten, United States Virgin Islands

Includes bibliography

Domestic violence and the law in the Turks and Caicos Islands: directions for law reform

Includes bibliography