Preparation And Performance Of High Efficiency Desulfurization Adsorbent

At present,natural gas and oil still occupy the leading position in the world energy,among which the sulfur content in fossil fuels has always been concerned.When fossil fuels are burned,SOx is released into the atmosphere,causing environmental pollution and endangering human health.With the pressure of increasingly stringent environmental regulations,the ultra-deep removal of thiophene sulfide in transportation fuel by adsorption has become the focus of research,and the development of efficient desulfurization adsorbent is the key to the production of clean transportation fuel.In this work,the metal-organic framework HKUST-1 was used as the research object,and hydroxyl functionalized micro-mesoporous metal organic framework（OH-HKUST-1）adsorbents were rapidly prepared by microwave-assisted synthesis and mixed-ligand strategy.The characterization results show that OH-BDC as a mixed linker can adjust the number of defects in HKUST-1.The OH-HKUST-1 prepared by adding the mixed linker OH-BDC in the synthesis process has mesoporous pore sizes of 3.4 and 3.8 nm.When the molar ratio of OH-BDC:H₃BTC was 0.2,the adsorption capacity of OH-HKUST-1-0.2 was the highest.In the static adsorption test,the maximum adsorption capacity of OH-HKUST-1-0.2 at 25℃ and 4 h was 26.30 mg S/g.In the fixed bed adsorption breakthrough experiments,the breakthrough sulfur capacity was 0.0490 mmol S/g.The fixed bed adsorption regeneration experiment of OH-HKUST-1-0.2 was carried out,and the adsorption capacity was still 90%of the fresh adsorbent after three times of regeneration.The adsorption mechanism was also discussed.The results show that micro mesoporous OH-HKUST-1 can be used as an excellent and efficient adsorbent for desulfurization due to its rapid synthesis and remarkable ability of BT adsorption.Amino functionalized micro mesoporous HKUST-1（NH₂-HKUST-1）was synthesized by replacing 5-hydroxyisophthalic acid with 5-aminoisophthalic acid.The adsorbents were characterized by X-ray powder diffraction（PXRD）,BET,FT-IR and TGA.The characterization results show that the mole ratio of NH₂-BDC and H₃BTC is adjusted during the synthesis process,so that the prepared NH₂-HKUST-1 has mesopores of 2.1 nm.The effects of the amount of mixed ligand 5-aminoisophthalic acid（NH₂-BDC）,adsorption temperature,adsorption contact time and oil/solvent ratio on the desulfurization performance of HKUST-1 were systematically studied.And the desulfurization performance of sorbents benzophenthiophene is tested by static and fixed bed adsorption respectively.The results showed that the maximum adsorption capacity of NH₂-HKUST-1-0.1 was 21.62 mg S/g at 25℃ for 4 h,and the adsorption capacity reached93%of the initial adsorption capacity after three times of regeneration.KIT-6 was studied by changing the hydrothermal crystallization temperature（80,100,120℃）.KIT-6 with different mesoporous pore sizes was successfully prepared and characterized by small angle X-ray scattering（SAXS）,Specific surface area and pore size analyzer（BET）.The characterization results show that the mesoporous pore size increases from 5.0 nm to 7.0nm with the increase of hydrothermal synthesis temperature.The desulfurization performance of the adsorbent was tested by static adsorption and fixed bed adsorption.The results showed that the desulfurization performance of the adsorbent was KIT-6-100>KIT-6-80>KIT-6-120with the change of synthesis temperature.Finally,four kinds of mesoporous silica SBA-15,MCM-41,FDU-12 and KIT-6-100 were tested for desulfurization by fixed bed adsorption at500 ppmw.The results showed that the desulfurization performance of KIT-6-100 was in the order of KIT-6-100>SBA-15>MCM-41>FDU-12,which indicated that KIT-6-100 was an excellent and efficient adsorbent for desulfurization.