Mass Production Of Covalent Organic Polymers And Study On Natural Gas Storage

Natural gas,with lower carbon-to-hydrogen emissions and higher mass energy density than traditional fossil fuels,is considered as a promising substituted energy.Owning to the low critical temperature(Tc=191 K)and volume energy density in ambient temperature,three kinds of methane storage methods used in transportation have been developed,i.e.,Liquefied Natural Gas(LNG),Compressed Natural Gas(CNG)and Adsorption Natural Gas(ANG).Compared to the former two storing strategy,ANG,without demands for low storage temperature and heavy high pressure storage vessels,allows using lightweight,inexpensive,conformable fuel tanks and is regarded as the most promising natural gas storage technology for motor vehicle.Therefore,it is urgently necessary for achieving ANG technology business applications to find suitable adsorbents with excellent methane adsorption capacity and good application stability in moderate storage conditions and achieve this material rapid mass preparation with high efficiency and low cost.The main component of natural gas is methane,typically 80-95 percent,but also containing some other gases such as carbon dioxide,nitrogen,and heavier hydrocarbons,depending on the source of the gas.Moreover,methane in landfill gas is also a significant source of natural gas.However,it often contains unacceptable level of contaminants which degrade the purity and calorific value of the Natural gas.Generally,a typical industrial or municipal landfill gas contains approximately 40-60 percent of carbon dioxide.For enabling natural gas to be an alternative energy source to conventional fuels,developing efficient and stable separation materials to capture CO2 from methane is essential for the upgrading of natural gas and the treatment of landfill gas to improve purity and reduce pipeline corrosion induced by acid CO2 gas in the presence of water.In order to realize the efficient and economical preparation of porous adsorption materials with high performance and develop natural gas decarburization materials,herein,we firstly combine Higee technology with covalent organic polymers(COPs)to realize rapid production of COPs and modify COP-10 by introducing transition metal to promote COPs decarburization performance.The main innovations and contents of this work are as follows:In this work,the authors firstly used Rotating Packed Bed(RPB)reactor to realize the preparation of COPs and explored the operating conditions.The data from BET surface area tests shows that the optimum operating conditions were as follows:the rotation speed was 2500 rpm,the residence time was 15 min,and the ratio was 3:1.Compared to previous reported methods,the synthesis time was reduced from 600 to 15 minutes,the synthesis efficiency increased by 97.5%and the amount of catalyst reduced by 40%.An amplification experiment was carried out at the optimum operating conditions.Fourier transform infrared(FTIR)and nuclear magnetism(NMR)tests demonstrate the successful synthesis of COP-10 in RPB reactor.The nitrogen adsorption-desorption isotherms measurements at 77 K show that the BET surface area of COP-10 is 3068 m2 g-1 and the pore volume reach 2.74 cm3 g-1.The high pressure methane adsorption shows that the absolute methane adsorption at practical conditions(298 K,65 bar)and working capacity(between 5 bar and 65 bar)of COP-10 are reaching 483 cm3 g-1 and 415 cm3 g-1,which are much higher than many pours materials.Furthermore,we realize the rapid production of COP-1,COP-3,COP-10 and COP-13 with Higee technology and the space-time yield(STY)reaches 357 kg(m3·day)-1,299 kg(m3·day)-1,157 kg(m3·day)-1 and 327 kg(m3·day)-1 respectively.we used COP-10 coupled in amplification experiment as pours platform and derived COP-10-SO3Cu as an efficient and stable CO2/CH4 separation material by introducing copper sulfonate groups.The results from FT-IR,X-ray photoelectron spectroscopy(XPS),and elemental analysis indicate that sulfonate function and metal has been successfully introduced into COP-10.Single-component isotherms of CO2 and CH4 were experimentally measured.Ideal adsorbed solution theory(IAST)along with adsorption heat and the systematic evaluation of applicability were employed to predict CO2/CH4 adsorptive selectivity.The experiment results further demonstrate this rule and show that the selectivity of COP-10-SO3Cu reaches 13.3 at 298 K and 1 bar,which has increased almost 4 times than COP-10.Importantly,COP-10-SO3Cu exhibits dramatically high working stability,whose adsorption performance shows ignorable decrease after soaking in simulated acidic environment even for one week.Accordingly,COP-10-SO3Cu is a promising adsorbents for separation and purification of CO2 from natural gas.