31 resultados para Allegheny Coal Company.
em Cambridge University Engineering Department Publications Database
Resumo:
A chemical looping process using the redox reactions of iron oxide has been used to produce separate streams of pure H2 and CO2 from a solid fuel. An iron oxide carrier prepared using a mechanical mixing technique and comprised of 100wt.% Fe2O3 was used. It was demonstrated that hydrogen can be produced from three representative coals - a Russian bituminous, a German lignite and a UK sub-bituminous coal. Depending on the fuel, pure H2 with [CO] ≲50vol.ppm can be obtained from the proposed process. The cyclic stability of the iron oxide carrier was not adversely affected by contaminants found in syngas which are gaseous above 273K. Stable quantities of H2 were produced over five cycles for all three coals investigated. Independent of the fuel, SO2 was not formed during the oxidation with steam, i.e. the produced H2 was not contaminated with SO2. Since oxidation with air removes contaminants and generates useful heat and pure N2 for purging, it should be included in the operating cycle. Overall, it was demonstrated that the proposed process may be an attractive approach to upgrade crude syngas produced by the gasification of low-rank coals to pure H2, representing a substantial increase in calorific value, whilst simultaneous capturing CO2, a greenhouse gas. © 2010 Elsevier B.V.
Resumo:
Purpose: The purpose of this paper is to present an exception to the common belief "If you can't measure it, you can't manage it". It aims to show how in certain situations particular practices, attitudes and cultures can remove the need for individual performance measurement. Design/methodology/approach: First, the paper identifies the usual roles of performance measurement in managing individual employees as described by control and motivation theorists. Second, it identifies a market-leading organisation where managers deliberately refuse to use their top-level performance measurement system to manage the performance of individual employees. A case study is carried out to test what non-measurement mechanisms fulfil the roles of individual performance measurement in this organisation. Findings: Building on situations observed at this company, a set of possible characteristics of companies that do not require formalised individual performance measurement systems in order to achieve high performance standards is put forward. Practical implications: Managers should not always assume that individual performance measurement is the only way to achieve excellent performance. This study shows that, by granting responsibilities and providing appropriate support, managers can channel workers' enhanced motivation towards meeting wider organisational goals. Originality/value: This work broadens the understanding of how excellent performance can be achieved. It shows that excellence can be achieved through practices based on shared values linked to motivation, trust, and a common sense of mission, without the need to install individual performance measurement systems based on cybernetic principles. © Emerald Group Publishing Limited.