scholarly journals Dynamic Evaluation Method of Caprock Microscopic Sealing in CO2 Sequestration Project

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-12
Author(s):  
Xu Han ◽  
Fuping Feng ◽  
Ziyuan Cong

The existing statistical evaluation methods of caprock sealing ability in CO2 sequestration engineering only take into account the sealing ability of caprocks before sequestration but cannot reflect the retained sealing ability of caprock after hydrochemical reactions. A microscopic sealing evaluation method of caprock was established based on the microscopic mechanism of chemical reaction and the breakthrough pressure of caprock which, changes with the time of CO2 sequestration, was taken as the dynamic evaluation index. The results show that the change of microstructure parameters such as the average pore radius after dissolution is the essential reason that affects the variation of the caprock microscopic sealing property. Dissolution or precipitation of different caprock minerals during the chemical reaction process is the key factor that determines the decrease or increase of caprock microscopic sealing property. The evaluation method can reflect the change of microscopic sealing property of the caprocks in different areas as the sealing time goes and provides an efficient and practical quantitative evaluation method for the initial formation site selection and safety sealing in the later stage.

2013 ◽  
Vol 275-277 ◽  
pp. 429-432 ◽  
Author(s):  
Yu Qiang Cai ◽  
Na Xing

Abstract. Magnetic fluid revolving sealing is widely used in modern industry. In the process of application, it is founded that the starting friction torque is very large, particularly at lower temperature. This problem has become a key factor restricting the application of magnetic fluid rotation sealing. In this paper, the mechanism of starting torque increase is analyzed, based on the change of microstructure and its viscosity. After analysis , such conclusion is obtained , which can be described: to a certain sealing structure, the type of magnetic fluid, size distribution of magnetic particles as well as the working condition concluding temperature, magnetic field gradient and the revolving velocity of shaft is the main influence factor of starting friction torque . It is very useful to reduce the starting friction torque.


2010 ◽  
Vol 5 (3) ◽  
pp. 261-268 ◽  
Author(s):  
Rodiansono Rodiansono ◽  
Wega Trisunaryanti

Activity test and regeneration of NiMo/active natural zeolite catalyst for hydrocracking of waste plastic fraction of polyprophylene (PP) type have been carried out. The catalysts was prepared by loading Mo followed by Ni Metals onto the natural zeolite (Z) sample, then calcined at 500oC, oxidized and reduced at 400oC under nitrogen, oxygen and hydrogen stream, respectively. The characterization of catalysts including spesific surface area, average pore radius, and total pore volume were performed by gas sorption analyzer, amount of total acid sites was determined by gas sorption method, and acid site strength was confirmed by IR spectroscopy. The hydrocracking process was carried out in a semi-flow reactor system at 360 oC and catalyst:feed ratio 0.5 under hydrogen stream (150 mL/hour). The feed was vaporized from the pyrolisis reactor into the hydrocracking reactor. A liquid product was collected and analyzed by gas chromatography (GC) and gas chromatography-mass spectroscopy (GC-MS). The characterization results showed that spesific surface area, average pore radius, and total pore volume of the Z sample decreased after loading of the Ni and Mo metals. Amount of total acid sites of the NiMo/Z catalyst was higher than that of the Z sample. The activity of NiMo/Z catalyst decreased after several continously runs. Its regeneration produced the NiMo/Z reg catalyst with similar activity and selectivity to the fresh catalyst (NiMo/Z). The activity of catalysts at the optimum condition followed the order of NiMo/Z reg>NiMo/Z>Z (conversion of hydrocarbon C>12) and NiMo/Z reg>NiMo/Z>Z (total yield of gasoline fraction). The selectivity of catalysts for C7-C8 product followed the order of Z>NiMo/Z>NiMo/Z reg. Keywords: activity, polyprophylene, catalyst, gasoline fraction.


Water Policy ◽  
2018 ◽  
Vol 20 (2) ◽  
pp. 410-428 ◽  
Author(s):  
Yongnan Zhu ◽  
Lei Li ◽  
Yong Zhao ◽  
Zhongmin Liang ◽  
Haihong Li ◽  
...  

Abstract We used system theory to analyze the structure of a regional drought disaster system and separated the drought disaster risk system into three subsystems. These were drought disaster-causing factors, disaster-inducing environments, and disaster-bearing bodies. Analysis of the main factors of these subsystems allowed the establishment of a regional comprehensive drought disaster risk evaluation index system. To simultaneously evaluate the distribution and development trends of the regional comprehensive drought disaster risk, we established a dynamic evaluation model. Based on the ideas of the projection pursuit clustering method and the dynamic comprehensive evaluation method, the model can make use of multi-dimensional space–time drought disaster information. The model was applied to evaluate comprehensive drought disaster risk in the Xuzhou region, China. The evaluation results show that the method was able to illustrate the development trend and distribution of the comprehensive drought disaster risk in the Xuzhou region. The clustering zoning results show that Pizhou City is the area with the highest risk in Xuzhou, while Fengxian has the lowest. The development trend of comprehensive drought disaster risk with time is not significant.


1996 ◽  
Vol 13 (6) ◽  
pp. 469-477 ◽  
Author(s):  
A.M. Youssef ◽  
G.E. Badr ◽  
Th. El-Nabarawy

CuO/Fe2O3 (1:1) was prepared by co-precipitation. Six thermal products (I–VI) were obtained by calcination in the temperature range 300–800°C. The structures of I–VI were determined from XRD patterns and they were also identified from electrical conductivity measurements in the temperature range 313–523 K. The textural properties were determined from nitrogen adsorption at 77 K and the acidities of the thermal product were measured by pyridine chemisorption at 423 K. The decomposition of H2O2 over the catalysts I–VI was followed in the temperature range 303–323 K. Conversion of 2-propanol was investigated at 523 K. Calcination of CuO/Fe2O3 at 600°C resulted in partial transformation to CuFe2O4, this transformation predominating at 700°C and being complete at 800°C. Two mechanisms of electrical conduction are involved for catalysts calcined at 600–800°C depending on the temperature at which σ is measured. The surface area decreases and the average pore radius increases with increasing calcination temperature due to sintering and spinel formation. A mechanism is suggested for H2O2 decomposition and the activity and selectivity of the catalysts towards the conversion of 2-propanol are discussed.


2020 ◽  
Vol 10 (1) ◽  
pp. 1-6
Author(s):  
Rahma Joni ◽  
Syukri Syukri ◽  
Hermansyah Aziz

Studi karakteristik karbon aktif dari cangkang buah ketaping (Terminalia Catappa) sebagai elektroda superkapasitor telah diteliti. Karbon aktif dari cangkang buah ketaping (CBK) disiapkan dengan proses karbonisasi pada suhu 400oC dan Proses aktivasi KOH pada suhu 800oC di bawah aliran gas N2. Karbon aktif CBK memiliki kandungan karbon dengan massa atomik sebesar 97,52%. Karbon aktif CBK memiliki struktur amorf dengan dua buah puncak yang lebar pada sudut 2θ yaitu 24,93o dan 42,93o yang bersesuaian dengan bidang (002) dan (100). Karbon aktif CBK yang dihasilkan memiliki pola serapan dengan jenis ikatan OH, C-H, C=O, dan C=C. Adanya ikatan OH dan C=O menunjukkan bahwa arang aktif yang dihasilkan cenderung bersifat lebih polar. Morfologi permukaan karbon aktif CBK menunjukan distribusi ukuran pori yang merata dan luas permukaan yang besar. Luas permukaan spesifik karbon aktif dari CBK adalah 799,892 m2×g-1 dengan volume total pori 0,080 cm3×g-1 dan jari-jari pori rata-rata 1,9072 nm. Kapasitansi spesifik dari karbon aktif dari CBK adalah sebesar 125,446 F×g-1. Studies on the characteristics of activated carbon from ketaping fruit shells (Terminalia Catappa) as supercapacitor electrodes have been studied. Activated carbon from ketaping fruit shells (KFS) prepared by carbonization process at 400oC and the KOH activation process is carried out at 800oC under N2 gas flow. Activated carbon KFS has a carbon content with 97.52% of atomic mass. Activated carbon KFS has an amorphous structure with two wide peaks at an angle of 2θ 24.93ᵒ and 42.93ᵒ corresponding to the plane (002) and (100). Activated carbon KFS produced has an absorption pattern with OH, C-H, C = O, and C = C bond types. The presence of OH and C = O bonds indicates that the activated charcoal produced tends to be more polar. The surface morphology of activated carbon KFS shows an even distribution of pore size and large surface area. The specific surface area of activated carbon KFS is 799.892 m2×g-1 with a total pore volume 0.080 cm3×g-1 and an average pore radius of 1.9072 nm. The specific capacitance value of activated carbon KFS is 125.444 F×g-1.Keywords: Ketaping, Activated Carbon, Supercapacitor, Activator, Capacitance. 


2020 ◽  
Vol 9 (1) ◽  
pp. 1-8
Author(s):  
Agustino Agustino ◽  
Rakhmawati Farma ◽  
Erman Taer

Elektroda karbon aktif berbasis serat daun nanas (SDN) telah berhasil diproduksi dengan proses tiga langkah berikut ini, yaitu: (i) aktivasi kimia, (ii) karbonisasi, dan (iii) aktivasi fisika. Aktivasi kimia dilakukan dengan menggunakan agen pengaktif KOH dengan konsetrasi 0,3 M. Karbonisasi dilakukan dalam lingkungan gas N2 pada temperatur 600oC dan diikuti oleh aktivasi fisika pada temperatur 850oC menggunakan gas CO2 selama 2,5 jam. Luas permukaan spesifik elektroda 512,211 m2×g-1 dengan volume total pori sebesar 0,093 cm3×g–1, dan jari-jari pori rata-rata 1,199 nm. Morfologi permukaan elektroda karbon aktif menunjukkan adanya serat karbon dengan diameter serat dalam kisaran 101 - 185 nm dan memliki kandungan karbon dengan massa atomik sebesar 84,33%. Elektroda karbon aktif memiliki struktur amorf, yang ditunjukkan oleh dua puncak difraksi yang lebar pada sudut hamburan 24,64 dan 43,77o yang bersesuaian dengan bidang (002) dan (100). Kapasitansi spesifik, energi spesifik dan daya spesifik sel superkapasitor yang dihasilkan masing-masing sebesar 110 F×g-1, 15,28 Wh×kg-1 dan 36,69 W×kg-1. Pineapple leaf fiber (PALF) based activated carbon electrode has been successfully produced using three-step process, i.e. (i) chemical activation, (ii) carbonization, and (iii) physical activation. The chemical activation was carried out using KOH activating agent with a concentration of 0.3 M. The carbonization process is conducted out in N2 gas environment at 600oC and followed by physical activation at a temperature of 850oC by using CO2 gas for 2.5 h. The specific surface area of the electrode is 512.211 m2×g-1 with a total pore volume of 0.093 cm3×g-1, and average pore radius of 1.199 nm. The surface morphology of the electrode shown the carbon fibers with diameter in the range of 101 - 185 nm and carbon content with 84.33% of atomic mass. The activated carbon electrode has an amorphous structure, which is shown by two wide diffraction peaks at scattering angles of 24.64 and 43.77o which correspond to the plane (002) and (100), respectively. The specific capacitance, energy and power of the electrode are 110 F×g-1, 15.28 Wh×kg-1 and 36.69 W×kg-1, respectively.Keywords: Serat daun nanas, Kalium hidroksida, Elektroda karbon aktif, Kapasitansi spesifik, Superkapasitor 


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