A.I. Fernández

Short-term natural weathering of MSWI bottom ash as a function of particle size

The chemical and material composition of MSWI bottom ash depends on the particle size; this suggests that the mechanisms and kinetics of natural weathering are also a function of particle size. This paper reports the effects of short-term natural weathering on the leaching of heavy metals (mainly Pb, Cu and Zn) from MSWI bottom ash. Initial concentrations of heavy metals were higher for the smallest particle size fractions, but these levels fell dramatically during the first 50 days of weathering before levelling off. The main differences between size fractions were in the pH and the solubility of calcium and aluminium. For the initial stages of weathering and small size fractions, portlandite solubility seemed to control the pH. In contrast, for fractions bigger than 6 mm, the formation of ettringite was the reaction controlling the pH and the solubility of sulphates, aluminium and calcium.

1 – Introduction to thermal energy storage (TES) systems

Thermal energy storage (TES) systems can store heat or cold to be used later, under varying conditions such as temperature, place or power. TES systems are divided in three types: sensible heat, latent heat, and thermochemical. Clues for each TES system are presented in this chapter and requirements for each technology and application are given. An overview of system types and description of particular and novel applications are presented. The potential for energy saving and climate change mitigation using TES with a 10-year scenario is presented for specific cases. Finally, the CO2 mitigation potential of TES in different applications is presented.

19 – Thermal energy storage (TES) systems using heat from waste

Even though there are many references in the literature identifying the potential of thermal energy storage (TES) technologies for the recovery of waste heat in different industries, there are far fewer examples of the application of TES for waste heat management actually running in industry. This chapter focuses on a compilation of these cases. The first part of the chapter addresses the generation of waste process heat in different industries. The few real scenarios where the waste heat is valorized in combination with a thermal energy storage system are reported in the second part of the chapter.

Phase-change materials for reducing building cooling needs

This chapter shows how phase-change materials can be considered eco-efficient materials for mitigating building cooling demands. The chapter considers eco-efficiency from the point of view of materials and from the point of view of systems, that is, the use of eco-efficient materials and the use of materials that enable the system to be more eco-efficient. In this sense, phase-change materials are shown to contribute to the eco-efficiency of systems. The use of phase-change materials in passive and active systems is described in detail.

Study of the Thermal Properties and the Fire Performance of Flame Retardant-Organic PCM in Bulk Form

The implementation of organic phase change materials (PCMs) in several applications such as heating and cooling or building comfort is an important target in thermal energy storage (TES). However, one of the major drawbacks of organic PCMs implementation is flammability. The addition of flame retardants to PCMs or shape-stabilized PCMs is one of the approaches to address this problem and improve their final deployment in the building material sector. In this study, the most common organic PCM, Paraffin RT-21, and fatty acids mixtures of capric acid (CA), myristic acid (MA), and palmitic acid (PA) in bulk, were tested to improve their fire reaction. Several flame retardants, such as ammonium phosphate, melamine phosphate, hydromagnesite, magnesium hydroxide, and aluminum hydroxide, were tested. The properties of the improved PCM with flame retardants were characterized by thermogravimetric analyses (TGA), the dripping test, and differential scanning calorimetry (DSC). The results for the dripping test show that fire retardancy was considerably enhanced by the addition of hydromagnesite (50 wt %) and magnesium hydroxide (50 wt %) in fatty acids mixtures. This will help the final implementation of these enhanced PCMs in building sector. The influence of the addition of flame retardants on the melting enthalpy and temperatures of PCMs has been evaluated.

Materials Selection for Superheater Tubes in Municipal Solid Waste Incineration Plants

Corrosion reduces the lifetime of municipal solid waste incineration (MSWI) superheater tubes more than any other cause. It can be minimized by the careful selection of those materials that are most resistant to corrosion under operating conditions. Since thousands of different materials are already known and many more are developed every year, here the selection methodology developed by Prof. Ashby of the University of Cambridge was used to evaluate the performance of different materials to be used as MSWI superheater tubes. The proposed materials can operate at steam pressures and temperatures over 40 bars and 400xa0°C, respectively. Two case studies are presented: one makes a balanced selection between mechanical properties and cost per thermal unit; and the other focuses on increasing tube lifetime. The balanced selection showed that AISI 410 martensitic stainless steel (wrought, hard tempered) is the best candidate with a good combination of corrosion resistance, a relatively low price (0.83-0.92 €/kg) and a good thermal conductivity (23-27xa0W/mxa0K). Meanwhile, Nitronic 50/XM-19 stainless steel is the most promising candidate for long-term selection, as it presents high corrosion resistance with a relatively low price (4.86-5.14 €/kg) compared to Ni-alloys.

The State of the Art for Technologies Used to Decrease Demand in Buildings: Thermal Energy Storage

The high energy consumption in the building sector, especially for heating and cooling, has promoted new and more restrictive energy policies around the world, such as the new European Directive 2010/31/EU on the energy consumption of buildings. Apart from enforcing stringent building codes that include minimum energy consumption for new and refurbished buildings, the IEA ETP 2012 highlights the necessity of using highly efficient technologies in the envelopes, equipment, and new strategies to address the high energy consumption of the sector. In this context, the use of appropriate thermal energy storage (TES) systems has a high potential to reduce the energy demand for both heating and cooling. The use of TES in the building sector not only leads to the rational use of thermal energy, which reduces the energy demand, but allows peak load shifting strategies, as well as manages the gap between possible renewable energy production and heating/cooling demands. In this chapter, various available technologies are analyzed where sensible, latent, or thermochemical storages are implemented in either active, passive, or hybrid building systems.

Study of Fresh and Hardening Process Properties of Gypsum with Three Different PCM Inclusion Methods

Gypsum has two important states (fresh and hardened states), and the addition of phase change materials (PCM) can vary the properties of the material. Many authors have extensively studied properties in the hardened state; however, the variation of fresh state properties due to the addition of Micronal® DS 5001 X PCM into gypsum has been the object of few investigations. Properties in fresh state define the workability, setting time, adherence and shrinkage, and, therefore the possibility of implementing the material in building walls. The aim of the study is to analyze, compare and evaluate the variability of fresh state properties after the inclusion of 10% PCM. PCM are added into a common gypsum matrix by three different methods: adding microencapsulated PCM, making a suspension of PCM/water, and incorporating PCM through a vacuum impregnation method. Results demonstrate that the inclusion of PCM change completely the water required by the gypsum to achieve good workability, especially the formulation containing Micronal® DS 5001 X: the water required is higher, the retraction is lower (50% less) due to the organic nature of the PCM with high elasticity and, the adherence is reduced (up to 45%) due to the difference between the porosity of the different surfaces as well as the surface tension difference.