scholarly journals Feasibility and Carbon Footprint Analysis of Lime-Dried Sludge for Cement Production

2020 ◽  
Vol 12 (6) ◽  
pp. 2500 ◽  
Author(s):  
Li Ping ◽  
Gang Zhao ◽  
Xiaohu Lin ◽  
Yunhui Gu ◽  
Wei Liu ◽  
...  
Keyword(s):  
Carbon Footprint ◽  
Raw Material ◽  
Cement Clinker ◽  
Cement Kiln ◽  
Drying Process ◽  
Cement Production ◽  
Footprint Analysis ◽  
Cement Kilns ◽  
Cement Manufacturing ◽  
Dried Sludge

Cement manufacturing and the treatment of sludge are considered both energy-intensive industries and major greenhouse gas (GHG) emitters. However, there are still few studies on comprehensive carbon footprint analysis for adding municipal sludge in the cement production. In this study, the lime-dried sludge blended with calcium oxide at the mass mixing ratio of 10% was utilized as raw material for the preparation of Portland cement. The chemical and physical properties of sludge were analyzed. A set of carbon footprint calculation methods of lime-drying treatment of sludge and reuse in cement kilns was then established to explore the feasibility of coprocessing lime-dried sludge in cement kilns. The results showed lime-dried sludge containing CaO, SiO2, Al2O3, and Fe2O3 was ideal for cement production as raw material. However, the water content of lime-dried sludge should be strictly limited. The lime-drying process presented the biggest carbon emission (962.1 kg CO2-eq/t sludge), accounting for 89.0% of total emissions. In the clinker-production phase, the lime-dried sludge as raw material substitute and energy source gained carbon credit of 578.8 and 214.2 kg CO2-eq/t sludge, respectively. The sludge used for producing cement clinker could reduce carbon emissions by 38.5% to 51.7%. The addition ratio of lime and stacking time in the sludge lime-drying process could greatly affect the carbon footprint of coprocessing lime-dried sludge in cement kiln.

scholarly journals Utilization of lime-dried sludge for eco-cement clinker production: effects of different feeding points

2017 ◽  
Vol 77 (4) ◽  
pp. 960-970 ◽  
Author(s):  
Haihua Cao ◽  
Wei Liu ◽  
Jingcheng Xu ◽  
Jia Liu ◽  
Juwen Huang ◽  
...  
Keyword(s):  
Heterocyclic Compounds ◽  
Cement Industry ◽  
Cement Clinker ◽  
Cement Kiln ◽  
The Sustainable Development ◽  
Alternative Materials ◽  
Cement Manufacturing ◽  
Dried Sludge ◽  
Production Effects ◽  
Clinker Production

Abstract Co-processing lime-dried sludge (LDS) in cement kilns is an appropriate technique to solve the problem of LDS disposal and promote the sustainable development for cement industry. However, there were limited studies that investigated the effects of feeding points on product quality and cement kiln emissions. In this study, simulated experiments were conducted by dividing the feeding points into high-temperature zones (HTZs) and raw mill (RM). Cement quality and major cement kiln emission characteristics were comprehensively investigated. The results showed that in terms of burnability, compressive strength and microstructure, the optimum co-processing amount of LDS were 9 wt% when feeding at RM, while 6% when feeding at HTZs. Meanwhile, the organic emissions of RM samples were mainly low environmental risk compounds of amides and nitrogenous heterocyclic compounds. Inorganic gaseous pollutions of NOX and SO2, respectively, were 8.11 mg/g DS and 12.89 mg/g DS, compared with 7.61 mg/g DS and 4.44 mg/g DS for HTZs. However, all the cement kiln emissions concentration were still much lower than standard requirements. Overall, RM had a bigger LDS co-processing capacity and higher, but acceptable, cement kiln emissions. Feeding LDS via RM could dispose larger amounts of sludge and provide more alternative materials for cement manufacturing.

Study on the Calcinations of Recycled Cement Clinker Using Waste Concrete and Waste Clay Brick

2014 ◽  
Vol 629-630 ◽  
pp. 337-342
Author(s):  
Hong Mei Ai ◽  
Su Feng Zhu
Keyword(s):  
Hydration Product ◽  
Raw Material ◽  
Cement Clinker ◽  
Sintering Process ◽  
Clay Brick ◽  
Cement Production ◽  
Construction Waste ◽  
Industry Waste ◽  
Waste Concrete ◽  
Hydration Characteristics

Utilizing construction waste, mainly waste concrete, to produce recycled cement, provides possibility for realizing the closed circulation between concrete and cement, which is an effective way for sustainable development of cement and concrete industry. Waste clay brick (WCB) and its surface-coated waste mortar are inevitably introduced into the raw meals while waste concrete is used in cement production. So on the basis of the composition characteristics of construction waste, considering of optimizing the performance of recycled cement and improving the adaptability of recycled cement to complex raw material, it's necessary to study the effect of raw meal mixing waste concrete and WCB on sintering process and property of recycled cement clinker. Mixing waste concrete and WCB in three different proportions, the burnability of raw meal, clinker mineral composition, clinker mineral morphology and hydration characteristics of recycled cement have been studied in this paper. The results indicate, the presence of WCB is beneficial for the generation and development of silicate minerals; with increasing proportion of WCB, the content of f-CaO in recycled cement clinker rises, the structure of C-S-H gel from hydration product presents higher densification and the compression strength of 3d and 28d curing period are enhanced.

Evaluation of Green Cement Manufacturing Seeking Joint Treatment for Urban Refuse

2013 ◽  
Vol 567 ◽  
pp. 143-148 ◽  
Author(s):  
Yue Qin Tang
Keyword(s):  
Waste Treatment ◽  
Raw Materials ◽  
Carbon Dioxide Emission ◽  
Waste Incineration ◽  
National Standards ◽  
Cement Kiln ◽  
Domestic Waste ◽  
Cement Production ◽  
Cement Manufacturing ◽  
Cement Factories

Sanitary landfill, Burning, Compost are the main method to dispose gabage in China.If urben refuse is put into the cement kiln, processing it, producing cement, it will benefit all. This mature method has no influence on neither the cement production nor the quality of cement products,however the indexes of all emissions in the manufacturing meet the national standards. Statistics show the heat generated by every ton of waste is equal to that of 183kg standard coals; the cinders are mixed in cement during the treatment process, thus 107kilograms substitute raw materials can be generated by every ton of waste, and 6 to 7 percent are added. Moreever, it reduces carbon dioxide emission 8000 tons for every 10,000 tons waste. This paper concludes: the utilization of cement kiln to incinerate domestic waste has obvious advantages in environmental protection and total investment does not cost much. The municipal engineering construction has the priority to use the products from domestic treatment cement factories, and domestic waste incineration cement factories should be under self-management. Also supportive policies as well as the readjustment of waste treatment management and interest pattern can promote the development of treating urban domestic waste by cement production.

Economic and Environmental Assessment of Redmud as Aggregate in Cement Clinker Production

2011 ◽  
Vol 90-93 ◽  
pp. 3254-3257
Author(s):  
Jing Min Hong ◽  
Ling Wang ◽  
Jing Lan Hong
Keyword(s):  
Raw Materials ◽  
Raw Material ◽  
Cement Clinker ◽  
Coal Production ◽  
Dominant Contribution ◽  
Environment Impact ◽  
Cement Production ◽  
Material Efficiency ◽  
Transport Distance ◽  
Clinker Production

A cost combined life cycle assessment was carried out to estimate the economic and environmental impact of redmud as aggregate in cement production. Results showed that the raw materials, transport, electricity and coal had the highest contribution to overall cost, while coal production and direct emissions represented the dominant contribution to overall environment impact. Improving energy and raw material efficiency and minimizing raw materials transport distance are the efficient way to minimize overall environmental and economic impacts.

scholarly journals Toward electrochemical synthesis of cement—An electrolyzer-based process for decarbonating CaCO3while producing useful gas streams

2019 ◽  
Vol 117 (23) ◽  
pp. 12584-12591 ◽  
Author(s):  
Leah D. Ellis ◽  
Andres F. Badel ◽  
Miki L. Chiang ◽  
Richard J.-Y. Park ◽  
Yet-Ming Chiang
Keyword(s):  
Fossil Fuels ◽  
Value Added ◽  
Water Electrolysis ◽  
Electrochemical Process ◽  
Molar Ratio ◽  
Cement Kiln ◽  
Fuel Production ◽  
Cement Production ◽  
Gas Streams ◽  
Cement Manufacturing

Cement production is currently the largest single industrial emitter of CO2, accounting for ∼8% (2.8 Gtons/y) of global CO2emissions. Deep decarbonization of cement manufacturing will require remediation of both the CO2emissions due to the decomposition of CaCO3to CaO and that due to combustion of fossil fuels (primarily coal) in calcining (∼900 °C) and sintering (∼1,450 °C). Here, we demonstrate an electrochemical process that uses neutral water electrolysis to produce a pH gradient in which CaCO3is decarbonated at low pH and Ca(OH)2is precipitated at high pH, concurrently producing a high-purity O2/CO2gas mixture (1:2 molar ratio at stoichiometric operation) at the anode and H2at the cathode. We show that the solid Ca(OH)2product readily decomposes and reacts with SiO2to form alite, the majority cementitious phase in Portland cement. Electrochemical calcination produces concentrated gas streams from which CO2may be readily separated and sequestered, H2and/or O2may be used to generate electric power via fuel cells or combustors, O2may be used as a component of oxyfuel in the cement kiln to improve efficiency and lower CO2emissions, or the output gases may be used for other value-added processes such as liquid fuel production. Analysis shows that if the hydrogen produced by the reactor were combusted to heat the high-temperature kiln, the electrochemical cement process could be powered solely by renewable electricity.

Life Cycle Assessment of Comprehensive Utilization of Calcium Carbide Slag in Cement Kiln

2020 ◽  
Vol 993 ◽  
pp. 1487-1495
Author(s):  
Xin Ping Lin ◽  
Ai Wei Liu ◽  
Yun Fa Feng ◽  
Qi Ling Chen ◽  
Tao Chen ◽  
...  
Keyword(s):  
Life Cycle Assessment ◽  
Emission Reduction ◽  
Calcium Carbide ◽  
Cement Industry ◽  
Cement Clinker ◽  
Cement Kiln ◽  
Cement Production ◽  
Comprehensive Utilization ◽  
Carbide Slag ◽  
Portland Cement Clinker

The recycling utilization of solid waste is an important technical means for the sustainable development of the cement industry in China. Calcium carbide slag is a special solid waste in China, which can be used for cement production with a great advantage on CO2 emission reduction. With an view to providing methodological and data support for the development of policies in the cement industry, this paper quantitatively analyzes the environmental effects/environmental benefits of the comprehensive utilization of calcium carbide slag in cement kiln by comparing the traditional system of Portland cement clinker completely produced by natural resources with the system of cement clinker produced by calcium carbide slag based on the life cycle assessment (LCA) method given in standards and specifications of ISO 14040 series. The results show that the latter system has a better effect in material saving and carbon emission reduction, will increase the energy consumption in cement production process, and also slightly increase other pollutants (e.g. SOx, NOx, etc.) emission. The GWP, AP and EP indicators of the calcium carbide slag cement clinker system decrease compared with those of the Portland cement clinker system, while other indicators do not differ much or even slightly increase.

scholarly journals Recycling of Cement Kiln Dust as a Raw Material for Cement

Environments ◽  
2019 ◽  
Vol 6 (10) ◽  
pp. 113 ◽  
Author(s):  
Minhye Seo ◽  
Soo-Young Lee ◽  
Chul Lee ◽  
Sung-Su Cho
Keyword(s):  
Removal Efficiency ◽  
Raw Material ◽  
Cement Kiln Dust ◽  
Cement Kiln ◽  
Distilled Water ◽  
Leaching Solution ◽  
High Concentrations ◽  
Cement Manufacturing ◽  
Exchange Resins ◽  
Kiln Dust

Cement kiln dust (CKD) is a major by-product of cement manufacturing and has the potential to be recycled as a raw material if the high concentrations of chlorine and potassium are removed. This study tested four leaching solutions (distilled water and three organic acids) and determined the optimum reaction conditions. At a liquid/solid (L/S ratio) of 10, the removal efficiency of formic, citric, and oxalic acid was higher than that of distilled water, but at L/S 20, distilled water also achieved a high removal efficiency of Cl (≥90%) and K (≥70%). In addition, to minimize the discharge of wastewater after leaching, the efficiency of ion-exchange resins for the recovery of leaching solution was tested. When the cation- and anion-exchange resins were arranged together, more than 95% of both Cl and K contained in the leaching solution could be removed. Leaching solution without Cl and K was found to have a high leaching efficiency even after being recycled three times, resulting in a significant reduction in wastewater emissions.

scholarly journals Carbon Footprint Evaluation of Hazardous Waste Based Solid Fuel: Application in a Cement Kiln

2021 ◽  
Author(s):  
Balasubramaniam Karpan ◽  
Abdul Aziz Abdul Raman ◽  
Razuana Rahim ◽  
Kheireddine Taieb Aroua ◽  
Archina Buthiyappan
Keyword(s):  
Carbon Dioxide ◽  
Life Cycle ◽  
Hazardous Waste ◽  
Carbon Footprint ◽  
Solid Fuel ◽  
Industrial Wastes ◽  
Total Carbon ◽  
Cement Kiln ◽  
Manufacturing Plant ◽  
Cement Manufacturing

Abstract This study aimed to evaluate industrial wastes-based solid fuel (IWSF) carbon footprint from the boundary of the cradle-to-grave life cycle. It includes emissions released from the transportation, manufacturing of IWSF, waste disposal, utilization of IWSF in the cement manufacturing plant, and end of life of IWSF. The quantification of total IWSF carbon footprint measures greenhouse gas emissions, carbon dioxide, nitrous oxide, and methane and is expressed as carbon dioxide equivalent (CO2-eq). The CO2-eq emission factors are calculated based on Intergovernmental Panel on Climate Change (IPCC) guideline, and the information used in this study is obtained from the actual operation. The study confirmed that the total carbon footprint of IWSF is approximately 0.17 kg CO2-Eq. MJ-1 energy generated. The results show that the utilization of IWSF at a cement manufacturing plant is the key contributor to carbon footprint, contributing to 94.3% of the total percentage, with a quantitative value of 27,000.7 MT CO2-eq per year IWSF manufacturing stage with 2.6 %. Subsequently, CO2-eq emission reduction initiatives have been implemented by the IWSF manufacturer, able to reduce approximately 333 MT of CO2-eq emission and total cost saving of USD50 000 annually. This study proves that industrial hazardous waste can be a source of fuel with positive economic and environmental returns. Besides, it was noted from the study that while direct combustion of solid-derived fuels can efficiently produce heat, it can also lead to the generation of greenhouse gases during the production and use phases. In summary, to estimate GHG emissions from IWSF production, a Life Cycle Assessment- Carbon Footprint (LCA-CF) should be considered.

Thermal Transformations of the Technogenic Component of the Cement Raw Material Mixture

2020 ◽  
Vol 24 (4) ◽  
pp. 36-41
Author(s):  
O.A. Miryuk
Keyword(s):  
Raw Materials ◽  
Research Result ◽  
Integrated Approach ◽  
Raw Material ◽  
Cement Clinker ◽  
Thermal Transformations ◽  
Cement Production ◽  
Mineral Characteristics ◽  
Technogenic Raw Materials ◽  
Cement Clinkers

There are presented the results of physicochemical studies of the composition and thermal transformations og large-tonnage wastes of beneficiation of scarnified-magnetite ores from Kazakhstan. To determine the composition of materials and thermal transformations, the following methods were used: X-ray phase analysis, differential-thermal analysis, Mцssbauer and infrared spectroscopy. There was revealed the stepwise nature of the transformation of anthropogenic material during roasting, due to polymineral composition of ore beneficiation. It has been established that the chemical-mineral characteristics of natural silicates determine the formation processes and properties of clinker phases. An integrated approach to the study of technogenic raw materials allowed not only to substantiate the possibility and expedience of using scarnified-magnetite ore beneficiation wastes in cement production, but also to determine the preference for the phase composition of cement clinker. Research result from the basis for the development of low-energy cement clinkers with a high content of belite phase.

Kinetic Consideration of Clinker Formation in Portland Cement Production Using Demolition Rubbles (Concrete,mortar and plaster) Part I : Burning Ability of Raw Mixes

2005 ◽  
Vol 5 (2) ◽  
pp. 169
Author(s):  
Sumardi P ◽  
I. B. Agra ◽  
I. M. Bendiyasa ◽  
Wahyudi B. S.
Keyword(s):  
Portland Cement ◽  
Raw Materials ◽  
Weight Ratio ◽  
Raw Material ◽  
Silica Sand ◽  
Cement Clinker ◽  
Cement Production ◽  
Operating Condition ◽  
Saturation Factor ◽  
Specific Operating Condition

Wahyudi B.S.Wahyudi B.S.In general, the main raw materials in Portland cement production are limestone, clay, and corrective materials such as iron sand and silica sand. These raw material come from natural deposits, which are very hard to find in some countries. In this research, Portland cement was made by utilizing the demolition rubble of office and housing buildings. The rubble consists of concrete wastes (mixtures of hydrated Portland cement minerals and some aggregates) and some building bricks as well as mortar/plaster of Portland cement. To meet the cement modulus, which is generally used in Portland cement industries, corrective materials such as limestone (source of CaO) and disposed building bricks are used. The term burning ability is used for Portland cement to measure the CaO free content in the cement clinker produced from specified raw material mixes at a specific operating 'condition of clinkering. The cement modulus used is Ume Saturation Factor (LSF) and Silica Modulus (SM). The minimum Cao free content was found by using LSF: 0.86, SM: 2.14, and clinkering temperature 14000C for 30 minutes. The cement modulus was made from concrete waste, limestone, and disposed red brick with a weight ratio of 1: 3.489: 0.677. Keywords: Burning ability,demolition rubble of buildings, Portland cement, and raw mixes.

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