1,721,027 research outputs found
The 3-D Supply Chain Management
No full textIncreasing in market competitiveness for the worldwide energetic demand and the raw materials supply, in primis natural gas and crude oil, even more constrained by contract clauses and trade agreements, is pushing main enterprises and both National and European energetic corporations to be interested in the supply chain management as a valid support for decision-making processes and strategic optimization.
This paper remarks the importance of a strategic coordinator, which can decide when and especially what to produce. It is placed on the top of the widespread tactical coordinators (model predictive controls, dynamic optimizations ...), which can decide how to produce. The strategic coordinator has the aim to (i) reduce the energetic consumption; (ii) fulfil final users’ market demand; and (iii) transform process transients, demand volatilities, and market price fluctuations into interesting opportunities to improve enterprise-wide benefits.
Specifically, the paper wants to introduce the commercial hierarchy in the multifaceted problem of the enterprise-wide optimization of decentralized-production societies, going beyond horizontal (process flow) and vertical (process control) hierarchies, which characterizes the traditional supply chain. It strictly deals with the business supply chain, by discussing the business strategies adopted by large-scale societies and main energy-intensive production sites as well as contract clauses defined by National organizations, including the National (Italian) electric energy suppliers (TERNA, GRTN)
Kinetic Modeling and Hydrocarbon Mixture Properties Characterisation in Coking Operations
No full textRefinery thermal processes are diffused all over the world, because of their relatively simple configuration and operating flexibility compared to catalytic processes. In particular Delayed Coking is coherent with the growing demand for transportation fuels, more stringent legislation and the opportunity for significant improvement in refinery profit margins. The coking capacity has in fact increased by about 50 million tons from 1999 to 2005 (Valyavin et al., 2007). The development of extended kinetic models can help to accurately describe these processes (characterised by liquid phase pyrolysis) and can be useful for their better description. Such modeling tools are also convenient supports for the production planning, the optimisation of the process and the operator training. This paper present a detailed, mechanistic model of Delayed Coking process and some results compared with experimental data. Moreover a first approach to fluid- and flexicoking modeling is presented
Estimation of the thermodynamic properties of several oxygenated compounds involved in biomasses pyrolysis
No full textAs already well established, the products of biomasses pyrolysis can be important in the exploration of alternatives to the use of fossil fuels. The study of the kinetic mechanism of thermal degradation of biomasses requires the knowledge of thermodynamic properties of the species, molecules and radicals, involved in the reaction path. These properties have been estimated by using the group contributions method and the program THERM. Particularly in the case of radicals the use of THERM can be difficult and, as an alternative, here is proposed a criterion based on analogy rules (isodesmic method). The obtained properties have been tabulated and compared with the experimental data where available. Moreover a comparison among the methods has been performed. A useful databank for several oxygenated compounds involved in biomasses pyrolysis has been obtaine
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