scholarly journals Updating Carbon Storage Capacity of Spanish Cements

2018 ◽  
Vol 10 (12) ◽  
pp. 4806 ◽  
Author(s):  
Carmen Andrade ◽  
Miguel Sanjuán

The fabrication of cement clinker releases CO2 due to the calcination of the limestone used as raw material, which contributes to the greenhouse effect. The industry is involved in a process of reducing this amount liberated to the atmosphere by mainly lowering the amount of clinker in the cements. The cement-based materials, such as concrete and mortars, combine part of this CO2 by a process called “carbonation”. Carbonation has been studied lately mainly due to the fact that it induces the corrosion of steel reinforcement when bringing the CO2 front to the surface of the reinforcing bars. Thus, the “rate of carbonation” of the concrete cover is characterized by and linked to the length of service life of concrete structures. The studies on how much CO2 is fixed by the hydrated phases are scarce and even less has been studied the influence of the type of cement. In present work, 15 cements were used to fabricate paste and concrete specimens withwater/cement (w/c) ratios of 0.6 and 0.45 which reproduce typical concretes for buildings and infrastructures. The amount of carbon dioxide uptake was measured through thermal gravimetry. The degree of carbonation, (DoC) is defined as the CO2 fixed with respect to the total theoretical maximum and the carbon storage capacity (CSC) as the carbonation uptake by a concrete element, a family or the whole inventory of a region or country. The results in the pastes where analyzed with respect to the uptake by concretes and indicated that: (a) the humidity of the pores is a critical parameter that favours the carbonation reaction as higher is the humidity (within the normal atmospheric values), (b) all types of cement uptake CO2 in function of the CaO of the clinker except the binders having slags, which can uptake additional CO2 giving aDoC near or above 100%. The CSC of Spain has been updated with respect to a previous publication resulting in proportions of 10.8–11.2% of the calcination emissions, through considering a ratio of “surface exposed/volume of the element” of 3 as an average of the whole Spanish asset of building and infrastructures.

2020 ◽  
Vol 10 (1) ◽  
pp. 49
Author(s):  
Suharto Suharto ◽  
Muhammad Amin ◽  
Muhammad Al Muttaqii ◽  
Syafriadi Syafriadi ◽  
Kiki Nurwanti

Experimental study on the use of basalt stone originated from Lampung has been conducted to evaluate its potential for a partial substitute of raw material in production of cement clinker. The basalt stone contains minerals of anorthite, augite, and albite phases that are required for clinker formation. In this study, the main raw materials were 80% limestone, 10% silica sand, 9% clay and 1% iron sand. The raw material in these experiments were mixtures 90% or 80% of the main raw material and 10% or 20% of basalt stone. The effect of adding coal to raw materials was also studied to see the possibility of an increase in clinkerization temperature inside the raw material mixture, and at the same time to see the effect of coal ash on clinker composition. Clinker obtained from heating of raw materials at a temperature of 1100oC had LSF of 94.1% and 95.1% (heating time of 1 and 3 hours). If heating is carried out at 1200oC, the clinker had LSF of 97.7% and 98.0% (heating time of 2 and 3 hours, respectively). Depending on the temperature and duration of heating, the clinker mostly had SM in the range of 2.18-2.40% , and AM in the range of 0,78-1.80%. Characterization using XRD showed that the clinker consisted of larnite and gehlenite phases, and dominated by CaO.Batu basalt Lampung telah diuji potensinya sebagai pengganti sebagian bahan baku utama pembuatan klinker semen. Batu basalt tersebut memiliki mineral-mineral dalam fase anorthite, augite, dan albite yang diperlukan pada pembentukan klinker. Pada penelitian ini, bahan baku utama adalah batu kapur 80%, pasir silika 10%, tanah liat 9% dan pasir besi 1%. Campuran bahan baku klinker adalah 90% atau 80% bahan baku utama dan 10% atau 20% batu basalt. Efek penambahan batubara ke dalam bahan baku klinker juga dipelajari untuk melihat kemungkinan kenaikan temperatur klinkerisasi di dalam campuran bahan baku, dan sekaligus untuk melihat efek abu batubara terhadap komposisi klinker. Klinker hasil pemanasan bahan baku pada temperatur 1100oC memiliki LSF 94,1% dan 95,1% (lama pemanasan 1 dan 3 jam). Jika pemanasan dilakukan pada 1200oC, klinker memilik LSF 97,7% dan 98,00% (lama pemanasan 2 dan 3 jam). Tergantung pada temperatur dan lama pemanasan, klinker hasil percobaan ini umumnya memiliki SM 2,18-2,40%, dan AM antara 0,78-1,80%. Karakterisasi dengan XRD menunjukkan bahwa klinker terdiri dari fase larnite dan gehlenite, dan didominasi CaO.


2015 ◽  
Vol 31 (3) ◽  
pp. 240-243 ◽  
Author(s):  
Numa P. Pavón ◽  
Christian O. Ayala ◽  
Ana Paola Martínez-Falcón

2006 ◽  
Vol 2 (5) ◽  
pp. 711-743 ◽  
Author(s):  
L. C. Skinner

Abstract. Given the magnitude and dynamism of the deep marine carbon reservoir, it is almost certain that past glacial – interglacial fluctuations in atmospheric CO2 have relied at least in part on changes in the carbon storage capacity of the deep sea. To date, physical ocean circulation mechanisms that have been proposed as viable explanations for glacial – interglacial CO2 change have focussed almost exclusively on dynamical or kinetic processes. Here, a simple mechanism is proposed for increasing the carbon storage capacity of the deep sea that operates via changes in the volume of southern-sourced deep-water filling the ocean basins, as dictated by the hypsometry of the ocean floor. It is proposed that a water-mass that occupies more than the bottom 3 km of the ocean will essentially determine the carbon content of the marine reservoir. Hence by filling this interval with southern-sourced deep-water (enriched in dissolved CO2 due to its particular mode of formation) the amount of carbon sequestered in the deep sea may be greatly increased. A simple box-model is used to test this hypothesis, and to investigate its implications. It is suggested that up to 70% of the observed glacial – interglacial CO2 change might be explained by the replacement of northern-sourced deep-water below 2.5 km water depth by its southern counterpart. Most importantly, it is found that an increase in the volume of southern-sourced deep-water allows glacial CO2 levels to be simulated easily with only modest changes in Southern Ocean biological export or overturning. If incorporated into the list of contributing factors to marine carbon sequestration, this mechanism may help to significantly reduce the "deficit" of explained glacial – interglacial CO2 change.


Food systems ◽  
2022 ◽  
Vol 4 (4) ◽  
pp. 259-268
Author(s):  
G. M. Sviridenko ◽  
M. B. Zakharova ◽  
N. V. Ivanova

The article presents the research results of studying the influence of various groups of microorganisms — coliform bacteria, lactic acid microorganisms, yeast, and spore bacteria — on the quality and storage capacity of cream used as a raw material for buttermaking. The objects of study were the following: cream as a raw material before and after pasteurization, as well as pasteurized cream seeded with testing cultures of various types of spoilage microorganisms. The samples were stored at temperature conditions of 30 ± 1 °C, 10 ± 1 °C, and 4 ± 2 °C. To evaluate the quality and storage capacity of cream used as a raw material, its microbiological and physicochemical indicators were determined by standardized methods: bacterial number, titratable acidity, indicators of oxidative spoilage of the fat phase. Organoleptic characteristics were evaluated in terms of taste, consistency and appearance. Research results have shown that the greatest microbiological risks during storage of cream used as a raw material are associated with lactococci, coliform bacteria and yeast. Microbiological risks caused by seeding of cream with thermophilic streptococcus, spore bacteria of the genus Bacillus and spore anaerobic microorganisms of the genus Clostridium are less significant, which is associated with the lack of development and metabolism of these groups of microorganisms at storage temperatures of 10 ± 1 °C and 4 ± 2 °C. At the same time, the reason for the rejection of cream contaminated with these testing cultures, at a storage temperature of 4 ± 2 °C, is primarily a decrease in organoleptic indicators, and at a temperature of 10 ± 1 °C — an excess in bacterial number.


2016 ◽  
Vol 11 (2) ◽  
pp. 113
Author(s):  
Heldy Juliana ◽  
Naniek Utami Handayani

Gudang adalah suatu tempat penyimpanan untuk semua barang-barang hasil produksi maupun penjualan. Fungsinya sebagai tempat penyimpanan memiliki peranan yang sangat vital. Oleh sebab itu diperlukan adanya pengaturan yang tepat dan cepat dalam penggunaan ruang gudang. CV.MDP-Semarang merupakan industri kemasan karton yang berlokasi di Semarang. Tingginya tingkat penggunaan gudang di perusahaan ini membuat effisiensi waktu dan ruang menjadi penting. Dari hasil pengamatan, CV. MDP-Semarang belum memiliki tata letak penyimpanan yang baik. Hal ini terlihat dari cara penyimpanan bahan baku di gudang yang belum mengikuti kaidah tata letak gudang. Pada gudang bahan baku, karton diletakkan secara acak sehingga menyulitkan pencarian, kapasitas gudang bahan baku saat ini dikeluhkan tidak mencukupi kebutuhan. Parameter tata letak gudang bahan baku yang baik adalah dipenuhinya ruang secara maksimal dan pemenuhan terhadap permintaan bahan baku yang lebih cepat. Pada penelitian ini, metode class-based storage dan penggunaan rak, memisahkan karton berdasarkan jenis karton di gudang bahan baku mampu memberikan peningkatan kapasitas gudang. Dengan rancangan tata letak gudang bahan baku usulan dapat meningkatkan kapasitas gudang, sehingga mampu memberikan ruang kosong untuk 64.000 pieces karton. AbstractWarehouse is a storage for all the goods of production and sales. Its function as a storage has a very vital role. Therefore it is necessary to have the proper regulations in the use of warehouse space. CV.MDP-Semarang is the carton packaging industry located in Semarang. The high level of the activity in the warehouse make time and space efficiency becomes important. From the observation, CV. MDP-Semarang do not yet have good storage layout. It is shown from raw material inventory in storage that are not following the principle of good storage layout. In the raw materials storage carton are placed randomly, so it makes the operator difficult to find the goods and the storage become out of capacity to fulfill demand. The good parameters for good storage are the optimal utility and the capapbility to fulfill raw material demands faster. In this paper, class-based storage method and shelf are used to separate carton based on type of carton in raw material storage in order to improve storage capacity. By proposes the design raw material storage layout, the company should be able to increase storage capacity, thus, it will be able to give space for 640.000 pieces of carton.


2020 ◽  
Vol 12 (6) ◽  
pp. 2500 ◽  
Author(s):  
Li Ping ◽  
Gang Zhao ◽  
Xiaohu Lin ◽  
Yunhui Gu ◽  
Wei Liu ◽  
...  

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.


Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 2903 ◽  
Author(s):  
Sung-Hoon Kang ◽  
Yang-Hee Kwon ◽  
Juhyuk Moon

In the cement industry, utilization of a sustainable binder that has a lower energy consumption and carbon dioxide (CO2) emission than Portland cement is becoming increasingly important. Air lime is a binder that hardens by absorbing CO2 from the atmosphere, and its raw material, hydrated lime, is manufactured at a lower temperature (around 900 °C) than cement (around 1450 °C). In this study, the amount and rate of CO2 uptake by air lime-based materials are quantitatively evaluated under ambient curing conditions of 20 °C, 60% relative humidity, and 0.04% CO2 concentration. In addition, the effects of the water-to-binder ratio (w/b) and silica fume addition on the material properties of the air lime mortar, such as strength, weight change, carbonation depth, and pore structure, are investigated. Unlike hydraulic materials, such as Portland cement, the air lime mortar did not set and harden under a sealed curing condition, however, once exposed to dry air, the mortar began to harden by absorbing CO2. During the first week, most of the internal water evaporated, thus, the mortar weight was greatly reduced. After that, however, both the weight and the compressive strength consistently increased for at least 180 days due to the carbonation reaction. Based on the 91-day properties, replacing 10% of hydrated lime with silica fume improved the compressive and flexural strengths by 27% and 13% respectively, whereas increasing the w/b from 0.4 to 0.6 decreased both strengths by 29% due to the increased volume of the capillary pores. The addition of silica fume and the change in the w/b had no significant impact on the amount of CO2 uptake, but these two factors were effective in accelerating the CO2 uptake rate before 28 days. Lastly, the air lime-based material was evaluated to be capable of recovering half of the emitted CO2 during the manufacture of hydrated lime within 3 months.


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