Traditional, state-of-the-art and renewable thermal building insulation materials: An overview

A review of recent developments in hydrogen production via biogas dry reforming

Building envelope insulation is crucial for an energy-efficient and comfortable indoor environment because the envelope accounts for 50–60% of total heat gain/loss in a building. Previous studies mostly used lifecycle cost as the criteria to select the optimum insulation materials with little or no consideration of embodied energy, emission, and summer overheating potential. This study presents a comparative analysis of building insulation materials properties (thermal, hygroscopic, acoustic, reaction to fire, environmental, and cost) and their performance in different climate zones and proposed an optimization framework. Insulation materials can be primarily categorized as conventional, state-of-the-art and sustainable. State-of-the-art insulation materials have the lowest thermal conductivity value amongst the three insulation types. However, their life cycle cost is higher compared to the other types. Sustainable insulation materials could be useful to delay and minimize indoor peak temperature and reduce overheating risk during the hot summer period. The analysis also showed that building walls with comparatively lower thermal resistance are more cost-effective for the cooling dominated region, but walls with higher thermal resistance are more cost-effective in heating-dominated regions. However, highly insulated and airtight houses may also lead to increased overheating risk and peak cooling demand during a hot summer period. In addition, hygroscopic, acoustic, and fire retardancy properties of insulation materials are critical to control indoor relative humidity in a humid region, to maintain a minimum noise level in a zone, and to reduce fire destruction. Hence, the optimization should include four criteria 1) Energy, 2) Environment, 3) Economic, and 4) Comfort.

Comparative analysis of building insulation material properties and performance

Solving the matter of traditional energy consumption and finding the proper alternative resources are vital keys to a sustainable development policy. In recent years, many different thermal insulation materials have been developed for better energy efficiency and less environment damage. These products have confirmed their usefulness in buildings due to their benefits such as low density, high thermal resistance , and cost effectiveness. The efficiency of thermal insulation depends on their thermal conductivity and their ability to maintain their thermal characteristics over a period of time. This study presents factors influencing the thermal conductivity coefficient of three main groups including conventional, alternative, and new advanced materials. The most common factors are moisture content, temperature difference, and bulk density. Other factors are explained in some dependent studies such as airflow velocity , thickness, pressure, and material aging. The relationship between the thermal conductivity values with the mean temperature, moisture content, and density which were obtained from experimental investigation has also been summarized. Finally, uncertainty about the thermal conductivity value of some common insulation materials is also reviewed as the basis of selecting or designing the products used in building envelopes.

An overview of factors influencing thermal conductivity of building insulation materials

The aim of the present research work is to enhance the thermal and dynamic mechanical properties of Kevlar/Cocos nucifera sheath (CS)/epoxy composites with graphene nano platelets (GNP). Laminates were fabricated through the hand lay-up method followed by hot pressing. GNP at different wt.% (0.25, 0.5, and 0.75) were incorporated with epoxy resin through ultra-sonication. Kevlar/CS composites with different weight ratios (100/0, 75/25, 50/50, 25/75, 0/100) were fabricated while maintaining a fiber/matrix weight ratio at 45/55. Thermal degradation and viscoelastic properties were evaluated using thermogravimetric analysys (TGA), differential scanning calorimetric (DSC) analysis, and a dynamic mechanical analyser (DMA). The obtained results revealed that Kevlar/CS (25/75) hybrid composites at 0.75 wt.% of GNP exhibited similar thermal stability compared to Kevlar/epoxy (100/0) composites at 0 wt.% of GNP. It has been corroborated with DSC observation that GNP act as a thermal barrier. However, DMA results showed that the Kevlar/CS (50/50) hybrid composites at 0.75 wt.% of GNP exhibited almost equal viscoelastic properties compared to Kevlar/epoxy (100/0) composites at 0 wt.% GNP due to effective crosslinking, which improves the stress transfer rate. Hence, this research proved that Kevlar can be efficiently (50%) replaced with CS at an optimal GNP loading for structural applications.

/pdf/enhanced-thermal-and-dynamic-mechanical-properties-of-1agk08j5hp.pdf

Enhanced Thermal and Dynamic Mechanical Properties of Synthetic/Natural Hybrid Composites with Graphene Nanoplateletes

Development of polymeric heat insulators based on emirati red shale filler: Thermal and physical properties

Current perspectives, future challenges and key technologies of biohydrogen production for building a carbon-neutral future: A review.

Catalyst survey for oxidative coupling of methane (OCM) under supercritical water (SCW) environment at 658 K and 26 MPa using an 8.8-mL batch reactor and H2O2 as a molecular oxygen source was performed at a feed concentration molar ratios of 0.10 CH4/H2O and 0.15 O2/CH4. First and second transition metal oxides (V, Cr, Co, Cu, Zr and Mo) and some lanthanide oxides (La and Ce) showed relatively high OCM activities of ca. 0.5–1 % C yield at a very low catalyst loading of 0.05 g. Exploration of catalyst formulations found that oxides of transition metals combined with ZrO2 were effective, with MnO2–ZrO2 showing a high synergy effect giving almost twice as much methane coupling yield. The OCM activity was correlated with the surface amount of a low 1s binding energy (O1s, 526–527 eV) oxygen species on the catalyst, as well as its energy separation from the lattice oxygen. In terms of this oxygen species, SCW-OCM activity of Mn/Na2WO4/SiO2, known as a good gas phase OCM catalyst and also showed a high turnover efficiency for SCW-OCM was further improved by supporting Mn/Na2WO4 on ZrO2 instead of SiO2.

Catalytic oxidative coupling of methane in supercritical water: Investigations on a catalytically active species

Herein, we focus on the formulation of polymer-based heat insulators using natural local shale as a filler. The polymer composite was fabricated by blending unsaturated polyester resin with local natural Emirati shale of filler of different filler sizes and solidifying the obtained thermosetting blends. The prepared samples are subjected to compressive strength, flexural strength, and tensile strength tests. The obtained results indicate that these composites exhibit mechanical properties superior to those of commercial heat insulators and comparable with those of other building materials. Specially, the prepared composite features a much higher tensile strength (20–40 MPa) than conventional heat insulators (< 1 MPa).

/pdf/mechanical-behavior-of-emirati-red-shale-fillers-unsaturated-4d3bkm1rp3.pdf

Muzamil A. Hassan

Papers

Traditional, state-of-the-art and renewable thermal building insulation materials: An overview

Development of polymeric heat insulators based on emirati red shale filler: Thermal and physical properties

Current perspectives, future challenges and key technologies of biohydrogen production for building a carbon-neutral future: A review.

Catalytic oxidative coupling of methane in supercritical water: Investigations on a catalytically active species

Mechanical behavior of Emirati red shale fillers/unsaturated polyester composite