Process integration for energy and water saving,increasing efficiency and reducing environmental impact

This article provides an introduction to the current Special Issue of the journal of Applied Thermal Engineering, which contains eight carefully selected articles from the 12th Conference Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction – PRES’09. This issue builds upon the multi-year co-operation between the PRES conference planners and the journal. The articles cover important subjects of increased energy and resource efficiency in industrial production and emission reduction. The first paper is based on the conference plenary presentation and is providing an overview of the historical developments in the Process Integration (PI) area and the apparently significant contribution of the PRES series of conferences. This is followed by a second group of two papers dedicated to important PI topics – retrofit of Heat Exchanger Networks and simultaneous minimisation of water and energy consumption. The third group contains three contributions dedicated to energy savings via the application of PI in specific industrial sectors. The final fourth group of two papers is dedicated to the implementation of energy conversion technologies. Those papers are discussing environmental impact of waste-to-energy processes and heat exchanger improvements.     

Application of optimization heuristics for complex astronomical object model identification

Detection and localization of astronomical objects are two of the most fundamental topics in astronomical science where localization uses detection results. Object localization is based on modeling of point spread function and estimation of its parameters. Commonly used models as Gauss or Moffat in objects localization provide good approximation of analyzed objects but cannot be sufficient in the case of exact applications such as object energy estimation. Thus the use of sophisticated models is upon the place. One of the key roles plays also the way of the objective function estimation. The least square method is often used, but it expects data with normal distribution, thus there is a question of a maximum likelihood method application. Another important factor of presented problem is choice of the right optimization method. Classical methods for objective function minimization usually require a good initial estimate for all parameters and differentiation of the objective function with respect to model parameters. The results indicated that stochastic methods such as simulated annealing or harmony search achieved better results than the classical optimization methods.     

Diffractive-refractive optics: X-ray collimator

Diffractive-refractive optics are x-ray focusing monochromators based on the diffraction on profiled crystal surface. Diffraction on longitudinal parabolic groove machined in crystal surface forms a sagittaly focused synchrotron radiation beam. Such kind of monochromator may be realized as a crystal with parabolic hole, where the beam is diffracted on the inner wall of the hole. Two such asymmetrically cut crystals set into antiparallel position, creating a dispersive (+,-,-,+) arrangement, form a sagittaly focusing x-ray monochromator which should be practically aberration-free. The focusing properties of such kind of monochromator are discussed in detail and it is shown for the first time that it can be used not only for focusing but also for creating highly parallel monochromatic beam in the broad region of the Bragg angles. This device with parabolic hole has not been tested experimentally yet.     

Low-carbon emission development in Asia: energy sector,waste management and environmental management system

Clean Technologies and Environmental Policy - Mitigation of greenhouse gases (GHG) emissions is desirable without compromising the economic growth. This paper reviews the recent trends to mitigate...     

Drying activity of oxovanadium(IV) 2-ethylhexanoate in solvent-borne alkyd paints

Oxovanadium(IV) 2-ethylhexanoate was established as a new primary drier for alkyd-based paints. A series of experiments has demonstrated an excellent drying activity toward solvent-borne alkyd resins of different oil length at considerably lower metal concentration than optimal for commercial cobalt(II) 2-ethylhexanoate. The behavior in real paint was simulated on formulations bearing inhibitor of autooxidation. The detailed studies of the drying process have shown that the relatively slow initial step of autooxidation reaction, when compared with cobalt compounds, is compensated for by the absence of the induction times. Furthermore, the active oxovanadium(IV) species are not consumed during the drying processes as evidenced by EPR spectroscopic measurements.     

Phase properties of two-mode gaussian light fields with application to Raman scattering

Abstract

We investigate quantum phase properties of two-mode optical fields whose quasidistributions have Gaussian form. We show how to simplify the calculation of the joint phase distribution defined via radial integration of the quasidistribution related to s-ordering of the field operators. We find an analytical formula for the joint phase distribution when coherent components of both modes vanish. The general results are applied to analysis of quantum phase properties of the two-mode Stokes-anti-Stokes field generated by means of Raman scattering with a broad reservoir phonon system and strong coherent laser pumping.     

Microstructure,martensitic transformation and anomalies in c′-softening in Co–Ni–Al ferromagnetic shape memory alloys

The morphology, microstructure and elastic softening in single crystals of Co–Ni–Al ferromagnetic shape memory alloy were studied to clarify the conditions for martenstic transformation in this alloy. We used two-phase (β matrix + γ particles) samples with different heat treatments, as-cast and annealed at temperatures from 1523 to 1623 K, and a sample of pure β (B2) phase. A complete set of elastic coefficients at room temperature and the temperature dependence of the softest shear coefficient (c′) of the Co₃₈Ni₃₃Al₂₉ austenite was measured by a combination of pulse echo and resonant ultrasound spectroscopy in the range 208–398 K. All examined materials exhibit anomalous c′-softening for the whole temperature range except the interval 258– 328 K, in which a change in the slope appears. However, only annealed samples transformed to martensite. The change in the slope is ascribed to (i) magnetoelastic softening with the absence of a sharp Curie point; (ii) structural stiffening that prevents the martensitic transition in both the as-cast and single-phase alloys. No signature of the premartensite phenomenon was found.     

Integration of solar thermal energy into processes with heat demand

An integration of solar thermal energy can reduce the utility cost and the environmental impact. A proper integration of solar thermal energy is required in order to achieve it. The objective of this study is to maximise the solar thermal energy delivered to the process. It is a result of trade-off between the captured solar thermal energy and maximal energy delivered to the process (process demand). Two novel curves are introduced to present this trade-off: (i) The Captured Solar Energy Curve (CSEC), which represents the available amount of heat from solar source and (ii) The Minimal Capture Temperature Curve (MCTC), indicating the minimal temperature making the heat transfer feasible. The crossing point of these two curves presents the minimal temperature of the capture being still sufficiently high to be usable for processes. The suitability of these curves for using in combination with standard heat integration methods is analysed and evaluated. The capture potential is revealed in full when the CSEC and MCTC are used with the Grand Composite Curve. In Total Site Profiles, the heat recovery is first maximised and then the CSEC and MCTC tool is applied. The implementation of CSEC and MCTC approach is illustrated by two case studies.