Naseer Aboodi Madlool Alkhalidi

Due the advances in the industrial processes, in which the cement industry is a major contributor, energy consumption and greenhouse gas emission has increased significantly. This paper reviews previous studies on energy saving, carbon dioxide emission reductions and the various technologies used to improve the energy efficiency in the cement industry. Energy efficiency measures for raw materials preparation, clinker production, products and feedstock changes, general energy efficiency measures, and finish grinding have been surveyed. It was found that the largest recorded amounts of thermal energy savings, electrical energy savings and emission reductions to date are 3.4 GJ/t, 35 kW h/t and 212.54 kgCO2/t, respectively.

Grate coolers are widely used in cement industries to recover heat from hot clinker, coming out from the rotary kiln. This study focuses on improving the energy, exergy and recovery efficiencies of a grate cooling system through the optimization of its operational parameters such as masses of cooling air and clinker, cooling air temperature, and grate speed. It has been found that the energy and recovery energy efficiencies of a cooling system can be increased by 1.1% and 1.9%, respectively, with every 5% mass increases of cooling air. Similarly, it has been estimated that energy and recovery energy efficiencies can be increased by 2.0% and 0.4% with every 5% increase of cooling temperature. The exergy and its recovery efficiencies found to be increased by 3.6% and 2.2%, respectively, for the same condition. Energy efficiency and energy recovery efficiencies are increased by 3.5% and 1.4% with every 9.1% increase of grate speed. Using heat recovery from the exhaust air, energy and exergy recovery efficiencies of the cooling system found to be increased by 21.5% and 9.4%, respectively. It has been found that about 38.10% and 30.86% energy cost can be saved by changing mass flow rate of clinker and mass flow rate of cooling air, respectively.

In recent years, there has been an increasing interest in waste heat recovery in the cement industry. The aim of this work is to determine the waste heat recovery by utilizing the waste exit gases from the pre-heater and grate cooler to generate electricity, furthermore estimation of cost saving. The results based on the operational data which is collected from Al-Muthanna Cement Plant. The net power output of 834.12 kJ/kg was estimated. A 6.673 ×103 MWh/yr electricity generation were achieved. The cost saving was estimated of 467,110.00 USD/yr in addition to 20 months was expected as the simple payback period.

Cement production has been one of the most energy intensive industries in the world with energy typically accounting about 30–40% of the production costs. Reduction of the production cost is very much important. Therefore, many studies on the efficient use of energy were carried out in the past. Moreover, these studies, which are based on exergy analysis, focus on industrial applications only. This paper reviewed exergy analysis, exergy balance, and exergetic efficiencies for cement industry. It is found that the exergy efficiency for cement production units ranges from 18% to 49% as well as the exergy losses due to the irreversibility from kiln are higher than other units in cement production plant.

In reality, cement industry is a highly imperative segment in the industrial field that plays a substantial role in the socio-economic evolution. Up to now, approximately 40% of the waste heat energy from cement plants is released into the atmosphere without being used effectively. This work emphasizes the ability to recover the heat losses via convection and radiation in a grate cooler using new methods by utilizing these waste heats to heat the working fluid of a cogeneration cycle directly and indirectly. On the other hand, the recovery cycle was added with different four working fluids (water, nanofluid (Al- water), oil and air) to recover the waste heat and to heat the working fluid of cogeneration cycle. The energy efficiency of the first method was approximately 26% and it represented better than the second method. On the other hand, the exergy efficiency of second method with oil as a working fluid was the highest. The first method gave the best results in terms of energy and cost savings.Finally, the emission reduction of CO2 in the first method was 5053.55t CO2/year.

Industrial development has lead to higher energy consumption, and emission of greenhouse gases. Cement industry plays an important role in energy consumption and overall greenhouse gases emissions. This paper reviews the preceding studies concentration on the provision of energy saving, carbon dioxide emission reductions correlated with implementation of a number of technologies applicable to improve the energy efficiency in the cement industry. Energy efficiency measures for clinker production. It is found the largest amounts of thermal energy saving, electrical energy saving, emission reductions are 4.1 Giga Joule per ton, 35 kilo Watt hour per ton, 112,61 kilogram CO2 per ton respectively.

The cement sub-sector consumes approximately 12–15% of total industrial energy use. Therefore, a state of art review on the energy use and savings is necessary to identify energy wastage so that necessary measures could be implemented to reduce energy consumption in this sub-sector. In this paper energy use at different sections of cement industries, specific energy consumption, types of energy use, details of cement manufacturing processes, various energy savings measures were reviewed and presented. Various energy savings measures were critically analyzed considering amount of energy that can be saved along with the implementation cost. Amount of CO2 reduction has been presented along with the payback period for different energy savings measures as well. This study complied a comprehensive literature on the cement industries in terms of Thesis (MS and PhD), peer reviewed journals papers, conference proceedings, books, reports, websites. It has been observed that China producing major share of global cement production. Coal contribute major share of fuel used in cement industries. However, along with conventional fuels, industries are moving towards the use of alternative fuels to reduce environmental pollution. It was reported that cement industries are moving from wet process to dry process as it consume less energy compared to wet process.

-Along with the enhancement of technology and alarming of global warming, various types of technologies are advanced worldwide nowadays to harness the energy from the sun such as solar thermal energy, ocean thermal energy conversion, solar ponds, solar tower and photovoltaic systems to utilize the energy in the majority of domestic applications and industrial sector to a certain extent. Subsequently, gradual increase usage of solar energy requires creating awareness among public to protect the environment in term of green campaign which is one of the hot topics among the Malaysians where there are many organizations organizing green campaign such as Environmental Protection Society Malaysia (EPSM), Malaysia Environment NGOs (MENGO) and Treat Every Environment Special Sdn. Bhd. (TRESS). Therefore, this study examines solar energy production and consumption worldwide by looking at various existing solar technologies to have the understanding of each technology. This article also intends to catch up specifically the social viability of solar energy production and use, with the availability of the resources for the full scale development.