22 research outputs found
Phase Equilibrium and Spectroscopic Characterization of CO and C3H8 Binary Clathrate Hydrates
무μ, 무미(ε³)μ΄λ©° μ λ
κ°μ€μΈ μΌμ°ννμ(CO)λ νλ‘ν(C3H8) λ° μ²μ°κ°μ€μ λΆμμ μ°μμ μν΄ μμ±λ μ μλ€. νν곡μ μ κ΄μ μμ λ³Ό λ, μΌμ°ννμλ ν©μ±κ°μ€μ μ£Όμ μ±λΆμΌλ‘, κ°μλ¦°, μλͺ¨λμ λ° λ©νμ¬κ³Ό κ°μ λ€μν ννλ¬Όμ§μ μμ°νλ λ° μ€μν μ€κ°μ°λ¬Όμ΄λ€. λ³Έ μ°κ΅¬μμλ ν΄λΌμ€λ μ΄νΈ νν λ° κ³΅ν λΆμΌμμ μμ§κΉμ§ μ°κ΅¬λμ§ μμ μΌμ°ννμμ νλ‘ν νΌν©κ°μ€ νμ΄λλ μ΄νΈμ μ΄μνμ κ±°λκ³Ό λΆκ΄νμ νΉμ±μ λν΄ μ‘°μ¬νμλ€. μΌμ°ννμ/νλ‘ν νΌν©κ°μ€ νμ΄λλ μ΄νΈλ κ°κ° 80/20, 60/40, 40/60, 20/80 mol%μ μΌμ°ννμ/νλ‘ν νΌν©κ°μ€λ‘ νμ±μμΌ°λ€. μΌμ°ννμ/νλ‘ν νΌν©κ°μ€ νμ΄λλ μ΄νΈμ 3μ νν κ²½κ³λ κ΄λ²μν μ¨λ λ° μλ ₯ (200-300 K, 20-30 MPa)μμ κ³ μ λ°μμ
μ μ¬μ©νμ¬ μΈ‘μ λμλ€. μμν μΌμ°ννμ νμ΄λλ μ΄νΈλ νμ± μ‘°κ±΄μ λ°λΌ μμ ν structure II (sII) λλ μ€μμ ν sturcture I (sI)λ₯Ό νμ±νλ λ°λ©΄, μμν νλ‘ν νμ΄λλ μ΄νΈλ sIIλ§μ νμ±νλ κ²μΌλ‘ μλ €μ Έ μλ€. Synchrotron X-ray diffraction (XRD)λ₯Ό μ¬μ©νμ¬ μΌμ°ννμ/νλ‘ν νΌν©κ°μ€ νμ΄λλ μ΄νΈμ κ²°μ ꡬ쑰λ₯Ό νμΈνμλ€. XRD κ²°κ³Όλ μΌμ°ννμ/νλ‘ν νΌν©κ°μ€ νμ΄λλ μ΄νΈκ° λͺ¨λ λΉμ¨μ κ°μ€μ λν΄ sII κ²°μ ꡬ쑰λ₯Ό νμ±νλ κ²μ 보μ¬μ£Όμλ€. Raman spectroscopyλ₯Ό μ΄μ©νμ¬ sII νμ΄λλ μ΄νΈ λ곡 λ΄μ μΌμ°ννμμ νλ‘ν κ°μ²΄ λΆμμ ν¬μ μ¬λΆλ₯Ό νμΈνμλ€. μΌμ°ννμ/νλ‘ν νΌν©κ°μ€ νμ΄λλ μ΄νΈμ ν¬μ λ κ°μ€ λΉμ¨ μΈ‘μ κ²°κ³Όλ νλ‘ν λΆμκ° μΌμ°ννμ λΆμλ³΄λ€ sII νμ΄λλ μ΄νΈμ λ곡μ μ°μ μ μΌλ‘ μ μ νλ€λ κ²μ λνλ΄μλ€. μ΄ κ²°κ³Όλ€μ νμ΄λλ μ΄νΈ κΈ°λ° κ°μ€ λΆλ¦¬ 곡μ μμ μΌμ°ννμμ νλ‘νμ μ νμ λΆλ¦¬μ μ’μ μ 보λ₯Ό μ 곡νλ€.Carbon monoxide (CO), which is a colorless, tasteless and poisonous gas, can be produced by the incomplete combustion of propane (C3H8) and natural gases. From a point of view of chemical process, CO is a primary component of syngas, which is a crucial intermediate resource in producing a variety of chemicals such as gasoline, ammonia, and methanol. In this study, we investigate thermodynamic behavior and spectroscopic characterization of CO and C3H8 binary clathrate hydrates, which has not yet been studied in the clathrate chemistry and engineering fields. The CO/C3H8 clathrate hydrates were formed from CO/C3H8 gas mixtures of 80/20,60/40,40/60, and 20/80 mol%, respectively. Three-phase equilibrium boundaries of CO/C3H8 clathrate hydrates were measured using a high-pressure cell in a wide range of temperature and pressure (200β300 K and 20β30 MPa). It is known that pure CO hydrate forms stable structure II (sII) or metastable structure I (sI) depending on the formation condition, whereas pure C3H8 hydrate forms only sII. Synchrotron X-ray diffraction (XRD) was used to identify the crystal structure of CO/C3H8 clathrate hydrates. The XRD results reveal that the CO/C3H8 clathrate hydrates show the sII crystalline product for all binary gas mixtures. Raman spectroscopic methods confirm the enclathration of both CO and C3H8 guests in the cages of sII clathrate hydrates. Direct-release measurements of CO/C3H8 clathrate hydrates indicate that C3H8 molecules preferentially occupy the cages of sII clathrate hydrate rather than CO molecules. These results provide good information for selectively separating CO and C3H8 from CO/C3H8 gas mixtures via a hydrate-based gas separation process.1. μ λ‘ 1
1.1 μ°κ΅¬λ°°κ²½ λ° λͺ©μ 1
1.2 κ°μ€νμ΄λλ μ΄νΈ 3
1.3 μ°κ΅¬λ΄μ© 5
2. κ°μ€νμ΄λλ μ΄νΈ ν©μ± λ° μ°κ΅¬λ°©λ² 6
2.1 κ°μ€νμ΄λλ μ΄νΈ ν©μ± 6
2.2 μνν곑μ μΈ‘μ 7
2.3 Raman spectroscopy 12
2.4 Synchrotron X-ray diffraction 15
2.5 Gas chromatography analysis 17
3. μ°κ΅¬κ²°κ³Ό 20
3.1 μνν곑μ μΈ‘μ 20
3.2 Raman spectroscopy 23
3.3 Synchrotron X-ray diffraction 27
3.4 Gas chromatography analysis 29
4. κ²° λ‘ 34
κ°μ¬μ κΈ 35
μ°Έκ³ λ¬Έν 36Maste