Promoter Preparation And Mechanism Study Of Hydrate Based Gas Separation Method For IGCC Gas

In recent years,with the rapid development of China’s economy,energy and environmental issues have also emerged.Hydrogen energy not only has high energy density but also does not cause pollution during use,and is known as the"ultimate energy of the 21st century".Therefore,the development and application of hydrogen energy is an excellent solution to solve energy,environmental and other problems.Hydrogen production technology is the foundation of hydrogen energy application,and the use of nuclear energy or other renewable energy to produce"green hydrogen"is the future development direction of hydrogen energy;In the early stages of the development of the hydrogen energy industry,the use of carbon capture,utilization,and storage technology to produce"blue hydrogen"can effectively solve current energy and environmental problems,and on the other hand,promote the development of the hydrogen energy industry,helping China lead the energy revolution represented by hydrogen energy.The integrated Coal gasification combined cycle（IGCC）power generation system is a typical"blue hydrogen"production and utilization system.The problem with using the IGCC system to produce hydrogen lies in the separation of IGCC gas（CO₂/H₂）.Many scholars believe that the low cost and safety of the hydrate method are the best methods for IGCC gas separation.The key to gas separation by hydrate method lies in the selection of promoter.Different promoter have different promoting effects on the formation of hydrate.In this paper,promoter with different promoting mechanisms are organically combined to study the separation effects of nanospheres and emulsion systems on IGCC gas.The main research content and results are as follows:（1）The sulfonic acid radical in SDS（sodium dodecyl sulfate）was fixed on the surface of PSNS（nanospheres）through lotion polymerization.The gas separation experiment was carried out by adding PSNS in TBAB（tetra-n-butylammonium bromide）solution.The results showed that the gas selectivity in the hydrate formation process was greatly improved after adding PSNS,and the separation factor of 2 mmol/L PSNS was the highest,106%higher than before;Adding different concentrations of PSNS significantly increased the gas consumption of hydrates,with 2mmol/L nanospheres having the highest gas consumption.By utilizing the principles of electrostatic adsorption and in-situ reduction,silver nanoparticles can be loaded onto the surface of nanospheres.Gas separation experiments were conducted based on the different ratios of silver particles to sulfonic acid ions.The results showed that silver loaded nanospheres can further increase the gas consumption of hydrates.The gas consumption is highest when the ratio of silver to sulfonic acid ions is 1:10,and when the ratio of silver to sulfonic acid ions is 3:10,The gas selectivity to carbon dioxide is the strongest during the process of hydrate formation.（2）By observing the formation process of hydrates in the stirred tank,it was found that compared to pure TBAB solution,the induction period of hydrates was significantly shortened after the addition of nanospheres.The formation process of TBAB hydrates in the stirred tank was as follows:after the induction period ended,hydrates were rapidly generated,and under the action of stirring,they quickly spread to the entire stirred tank.Due to the formation of hydrates,the reaction tank gradually became turbid,and finally a white hydrate slurry was generated.The droplet experiment can observe the nucleation site and growth direction of hydrates:TBAB droplet nucleation site is at the bottom of the droplet,and hydrates grow from bottom to top;The nucleation site of PSNS is located inside the droplet,growing from the inside out,and the final droplet remains in the shape of the droplet after becoming a hydrate;Silver loaded nanospheres are most likely to generate hydrates,which rapidly grow outward after nucleation on the surface of droplets.During the process of hydrate generation,multiple gas analyses were conducted and it was found that in gas separation experiments,the hydrogen gas in the mixed gas was more likely to enter the cage of the hydrate when it was first generated.As the hydrate continued to grow,the hydrogen gas in the cage was replaced by more stable carbon dioxide.（3）A small size water in oil lotion（TBAB solution/decane）was prepared at a high rotational speed（30000 r/min）.Different emulsifier content had different effects on the results of gas separation experiments.When the emulsifier content was 10%of the solution mass,the gas storage capacity,separation factor and separation efficiency of the lotion were higher than those of the other lotion.Adding a small amount of MOF material to lotion can enhance the absorption of carbon dioxide in lotion system.The experiment shows that adding 0.09g MOF to 30ml lotion can increase the gas consumption by 5.6%;Increase the separation factor by 14.4%;Increase separation efficiency by 1.4%.This section compares the lotion system with the nanospheres solution system.Under the same reaction conditions as 30ml of the reaction solution,although the water in the lotion system is only 30%,the gas consumption of the lotion system is 19%higher than that of the solution system,and the reaction rate is also far greater than that of the solution system,indicating that the amount of hydrates generated in the lotion system and the formation rate are more and faster than that of the solution system,It is proved that the lotion system has great potential in gas hydrate separation.