Recent developments in phase change materials for energy storage applications: A review

In recent years, energy conservation and environmental protection have become most important issues for humanity. Phase change materials (PCMs) for thermal energy storage can solve the issues of energy and environment to a certain extent, as PCMs can increase the efficiency and sustainability of energy. PCMs possess large latent heat, and they store and release energy at a constant temperature during the phase change process. Thereby PCMs have gained a wide range of applications in various fields, such as buildings, solar energy systems, power systems and military industry. However, low thermal conductivity of PCMs leads to low heat transfer rate, thus, numerous studies have been carried out to improve thermal conductivity of PCMs. The main purpose of this paper is to review the methods for enhancing thermal conductivity of PCMs, which include adding additives with high thermal conductivity and encapsulating phase change materials. It is found that addition of thermal conductivity enhancement fillers is a more effective method to improve thermal conductivity of PCMs, where carbon-based material additives possess a more promising application prospect. Finally, the applications of PCMs in solar energy system, buildings, cooling system, textiles and heat recovery system are also analyzed.

Review on thermal conductivity enhancement, thermal properties and applications of phase change materials in thermal energy storage

Recent advances on thermal conductivity enhancement of phase change materials for energy storage system: A review

Thermal conductivity enhancement on phase change materials for thermal energy storage: A review

The global use of petroleum hydrocarbons for energy and raw materials in various applications has increased with extensive release of a wide variety of contaminants into the environment, affecting soil, surface water and groundwater. The effect results to numerous health, ecological and environmental issues. However, treatment of contamination and pollution caused by petroleum hydrocarbons is a huge and laborious work. It involves several in situ or ex situ treatments comprising containment, separation and destruction which include biological, chemical, physico-chemical, thermal and heat, electric and electromagnetic, acoustic and ultrasonic treatment methods. These treatment methods involve several other techniques and strategies as listed in this review. The health risks pose by petroleum hydrocarbon pollution have driven scientists to research, develop and implement risk-based remediation strategies for restoration and reclamation of affected environments. To select the best treatment option for remediation, it is important to comprehend the nature, composition, properties, sources of pollution, type of environment, fate, transport and distribution of the pollutants, mechanism of degradation, interaction and relationships with microorganisms, the intrinsic and extrinsic factors affecting remediation. It helps to evaluate and predict the chemical behaviour of the pollutants with the short and long-term effects and mitigate the effects of pollution and limit exposure to the pollutants. Despite the available remediation options for petroleum hydrocarbon management and removal, sufficient and complete remediation can be implemented by adoption of proper approach derived from risk-based management procedure that can be practical, scientifically defensible, widely adapted, sustainable, non-invasive, eco-friendly and cost-efficient. This paper provides an overview of the various remediation and treatment technologies derived from risk-based approaches that are used for isolation, containment, separation, restoration reclamation and remediation of soil, sediments, surface water and groundwater contaminated by petroleum hydrocarbons and organic compounds.

Remediation of soil and water contaminated with petroleum hydrocarbon: A review

Phytoremediation of soils polluted with crude petroleum oil using Bassia scoparia and its associated rhizosphere microorganisms

This work reported that waxes are a big source for the latent heat storage as phase change materials but they suffer from the weakness in their thermal conductivity so different types of additives are needed to enhance their thermal conductivity. A sort of Paraffin Wax (PW) and Microcrystalline Wax (MW) composites with different loading levels (0.5, 1 and 2 wt%) of α Nano Alumina were successfully synthesized as Phase Change Materials (PCM). The resultant composite samples were characterized by Polarized Optical Microscope (POM), Deferential Scanning Calorimetric (DSC), X-ray diffraction (XRD) besides studying the Thermal Conductivity to investigate their homogeneity and heat storage capability. Data revealed that PW composites, with increasing the loading levels, have better thermal conductivity and latent heat than MW composites.

Thermal conductivity enhancement of treated petroleum waxes, as phase change material, by α nano alumina: Energy storage

New hydrophobic silica nanoparticles capped with petroleum paraffin wax embedded in epoxy networks as multifunctional steel epoxy coatings

In order to separate and characterize the high melting point macro- and micro-crystalline waxes from two different waste crudes (El-Ameria heavy slack wax and Alexandria crude petrolatum, respectively), one stage fractional crystallization has been done to separate these waxes by using different solvents at different fractionating solvent ratios ranging from 4:1 to 10:1 by weight and at constant washing solvent ratio of 2:1. The solvents used are butyl acetate, tertiary butyl acetate and cyclohexane at ambient temperature of 20 °C. Also, the fractionating temperature was studied in the range of 20–40 °C. The resulting products were subjected to bauxite adsorption treatment technique to bleach and purify the waxes. Also, different tools of analysis such as GC, XRD, DSC & TGA, H NMR, and SEM were used to characterize and compare the produced waxes. Data revealed that, butyl acetate solvent at solvent ratios of 6:1 and 8:1 by weight at fractionating temperature of 40 °C were selected as the most suitable conditions for obtaining the highest melting point macro- and micro-crystalline waxes having different n-paraffin contents, crystallinities, thermal characteristics, and degrees of branching and owning different crystal sizes. These waxes are considered as ceresins and can be used in different industrial applications.

Nermen H. Mohamed

Papers

Phytoremediation of soils polluted with crude petroleum oil using Bassia scoparia and its associated rhizosphere microorganisms

Thermal conductivity enhancement of treated petroleum waxes, as phase change material, by α nano alumina: Energy storage

New hydrophobic silica nanoparticles capped with petroleum paraffin wax embedded in epoxy networks as multifunctional steel epoxy coatings

Comparative study on separation and characterization of high melting point macro- and micro-crystalline waxes

Separation of different paraffin wax grades using two comparative deoiling techniques