The Effect of Excess Heat Utilization on the Production Cost of Cement (original) (raw)
Related papers
Applied Thermal Engineering, 2005
A simple model is presented to assess the thermal performance of a cement industry with an integrated view to improve the productivity of the plant. The model is developed on the basis of mass, energy and exergy balance and is applied to an existing Portland cement industry in Indonesia. The data obtained from industry show that the burning efficiency and the second law efficiency of the kiln system are 52.07% and 57.07% respectively. Cooler efficiency and heat recovery efficiency are 47.75% and 51.2% respectively. The unaccounted loss at kiln system was found to be 1.85% and that of cooler system was 19%. The high loss at cooler was mainly due to the convection and radiation losses from the uninsulated cooler. Irreversibility of the system was found to be about 20%, which is due to the conversion from chemical to thermal energy. The thermal energy conservation opportunities are identified. This study show that by replacing industrial diesel oil (IDO) with waste heat recovery from kiln and cooler exhaust for drying of raw meal and fuel, and preheating of combustion air, a cement industry in Indonesia can save about 1.264 · 10 5 US dollars per year.
Thermodynamic Analysis of Cement Production Process Plant in Nigeria
2016
Cement production industry being highly energy intensive requires a major goal of minimizing energy cost and environmental effects. This paper presents the thermodynamic analysis of a cement production process in Nigeria. The process was simulated in HYSYS. Exergy analysis is an analytical tool that evaluates the irreversibility and the exergertic performance of a process as well as provides identification of possible improvements in the process. The study indicates the system has an exergy efficiency of 38.44% and about 60% exergy loss. With the inclusion of chemical exergy, the system exergy efficiency and exergy loss are 46.85% and 53.1% respectively. The study has identified degree and sources of inefficiency in the cement production process. The method proferred can also aid in making informed decisions in improving the efficiency of the process.
Thermoeconomic and environmental analyses of a dry process cement manufacturing in Nigeria
Energy, 2017
The present paper is the continuation of Part 1 of a comprehensive study on new low water consumption combined steam power plants (SPP) and refrigeration chillers. Environmental, exergy, and thermoeconomic analyses of the steam power plant with natural draft wet cooling tower (SPP-NDWCT) as the base system, combined vapor compression refrigeration and the base system (VCR-SPP-NDWCT), and combined absorption heat pump and the base system (ABHP-SPP-NDWCT) are developed. The exergy analysis is conducted to analyze and compare the systems from an exergetic point of view and the thermoeconomic analysis is done to obtain the unit cost of the water loss in the systems' cooling towers. The environmental analysis is also carried out to obtain the annual environmental revenue of the saved water compared to the annual economic and environmental costs caused by consuming more fuel in the ABHP-SPP-NDWCT system. The results demonstrated that the NDWCT exergy loss, exergy destruction and total cost value decreased by 12%, 10.7% and 1.8% in ABHP-SPP-NDWCT system, respectively. Thus, the ABHP-SPP-NDWCT system could replace the conventional SPP-NDWCT system in regions where the environmental-economic value of water is higher than 1.
Energy Auditing and Waste Heat Recovery for Dry Type Cement Kiln System in Ethiopia: A Case Study
The aim of this study is energy audit and heat recovery of a dry type technology of cement industry in Ethiopia. The kiln has a capacity to produce 2000 ton-clinker per day. By considering 12 months data for mass and energy balance, auditing energy is performed. From the result about 35% of the total input energy was being lost through hot flue gas (19.53%) and cooler stack (16.22%). By using waste heat recovery steam generator (WHRSG) about 5 MW (6.13%) of the total input energy could be recovered. The whole electrical energy usage of the kiln system safely used from the generated power. So, the factory could keep 800,000 USD/Year by using the generated power for production of clinker.
Journal of Energy Technologies and Policy, 2019
This project entitled "Recoverable quantity of waste heat at Messebo cement factor y" has tried to quantify the amount of heat loss, the amount of energy and cost saved from the waste heat. Here both primary and secondary data collection methods were included to carry out the study. So, the projects present starts by identifying the main source of waste (which part of cement have high loss), following calculated heat lost from the identified places or machines and final calculating the possible money saved if the waste heat changed to use full form or if it recovered Successful recovery waste heat contributes to lower fuel cost, lower electricity consumption. Kiln surface zones, Preheater cyclone 4 and 5 are the main areas in which high waste was occur. From Kiln surface zones (959.13 kJ), Preheater cyclone 4 and 5(587.199 kJ) amount of heat is lost. From this lost we can recover around 62 kW power is recovered, 44155kwhr/month energy and 26492birr/month could be saved. It recommended the energy management department should invite and support others participation and to study on the heat recovery from the loosing of energy and to study on the alternative energy sources of the company.
Energy consumption and saving potential in cement factory: thermal energy auditing
AFRREV STECH: An International Journal of Science and Technology, 2018
Energy is one of the major inputs for the economic development of any country, thus lack of efficient and effective utilization of energy is a major concern in high-energy consuming industries such as the cement industries. The objective of this research is therefore to conduct energy auditing in Messobo Cement Factory to quantify the energy losses in the system and to identify potential areas for improvement. On site measurements of the material and energy flows was conducted using Infrared thermometer, Thermocouples and Pitot static probe with manometer. Based on the energy analysis performed, the most energy intensive process is found to be the pyre system (burning). The specific heat consumption has been found to be 844.5 kcal/kg-cl with around 45.83 % system efficiency. The major heat losses for the processes occurred in pre - heater exhaust gases and grate cooler vent air that accounted as 176.7 kcal /kg-cl and 199.3 kcal/kg-cl respectively. Comparison of the specific heat con...
IJERT-Waste Heat Recovery in Cement plant
International Journal of Engineering Research and Technology (IJERT), 2014
https://www.ijert.org/waste-heat-recovery-in-cement-plant https://www.ijert.org/research/waste-heat-recovery-in-cement-plant-IJERTV3IS051014.pdf Cement production has been one of the most energy intensive industries in the world. In order to produce clinker, rotary kilns are widely used in cement plants. To achieve effective and efficient energy management scheme, thermal energy audit analysis was employed in the Dalmia cement plant. Reduction of the production cost and consumption cost is very much important because of that waste heat recovery is implemented in the cement industry. The waste heat recovery reduces the Green house gas emissions and enhances the overall system performance. The aim of this work is to determine the Power Generation by utilizing the waste exit gases from the Pre-heater, Grate cooler. By using the various Energy Auditing instrument the exhaust gas temperature, Dust concentration , Surface temperature, Velocity were identified. A detailed analysis of Grate cooler, Preheater are done and the possible approaches of heat recovery from some major heat loss sources. Keywords-E n e r g y a u d i t ; H e a t l o s s ; P r e h e a t e r ; C o o l e r ; H e a t r e c o v e r y ; C l i n k e r ; S t e a m c y c l e ;
Thermodynamic and exergoeconomic analysis of a cement plant: Part I â Methodology
2013
The energy, exergy and exergoeconomic analysis of a cement factory has been studied within two parts. This paper is the first part of the study which includes the thermodynamic and exergoeconomic methodology and formulations developed for such a comprehensive and detailed analysis. The second part of this study is about the application of the developed formulation which considers an actual cement plant located in Gaziantep, Turkey. The energy consumption by the cement industry is about 5% of the total global industrial energy consumption. It is also one of the world's largest industrial sources of CO 2 emissions. In this paper, a cement plant is considered with all main manufacturing units. Mass, energy, and exergy balances are applied to each system. The first and second law efficiencies based on the energy and exergy analysis and performance assessment parameters are defined for the entire cement plant. The formulations for the cost of products, and cost formation and allocation within the system are developed based on exergoeconomic analysis. In order to obtain the optimal marketing price of cement and to decrease specific energy consumption of the whole plant, the cost analysis formulated here have substantial importance.
Assessing cement plant thermal performance
2016 IEEE-IAS/PCA Cement Industry Technical Conference, 2016
Energy consumption is one of the largest cost components in the production of Portland cement. Energy is consumed through the fuel required to make the cement, as well as the electricity consumed to operate the manufacturing equipment. This paper discusses the fuel requirements for producing cement and demonstrates some simple techniques for assessing and improving thermal performance. The basic heat requirements for driving the chemical processes are the starting point for the assessment. These are found to be rather similar throughout the industry, with only minor differences between different facilities. Higher chemical variability increases the heat requirements as more heat is required for the reactions and the reaction temperatures are higher. Thermal efficiency is primarily determined by the thermal recuperation of heat contained in the fuel combustion exhaust gases and the intermediate product, clinker. This heat is recuperated in preheaters and clinker coolers respectively. The factors that drive efficient heat recuperation are discussed and simple performance assessment indicators provided. Operators who pay close attention to their thermal performance can reduce operating costs and obtain a competitive advantage in the market. I.
International Journal of Automotive and Mechanical Engineering, 2015
This paper deals with the energy audit and heat recovery system modeling and design, taking a cement factory in Ethiopia as a case study. The system is a dry type rotary kiln equipped with a sixth stage cyclone type preheater, pre-calciner and grate cooler. The kiln has a capacity of 3,000 tons/day. The energy auditing has been performed based on the data collected from control volume of the kiln system for a ten-month period. The result shows that 25.23% of the total heat input is released to the environment through the preheater and another 15.58% through the cooler exhausts. The west heat recovery system (WHRS) can produce a gross power of 5.26 MW as long as the kiln is in operation. The generated power can cover all the electrical energy consumption of the kiln system whether there is a power supply from the grid or not. Therefore, the company can save up to 536,222.10 USD per year due to the production of clinker using their own power source and avoiding the loss sustained by the company due to power interruption from the grid.