The Research On Hydrate Desalination Enhanced Via Graphite/Graphene

The lack of global freshwater resources has caused humanity to face a water shortage crisis.How to extract fresh water from seawater efficiently and economically becomes the key to solving the problem.Hydrate technology seawater desalination is a new kind of energy saving seawater desalination technology,but the problems such as the long induction time,slow growth of hydrate,the limitation of mass and heat transfer and the difficulty of solid-liquid separation hinder the large-scale application of hydrate technology seawater desalination.It has been reported that carbon materials can promote the formation of hydrate to varying degrees.Therefore,this paper studies the nucleation of hydrate in the emulsion system under the action of graphene and graphite to promote the mass transfer and heat transfer during the growth process of hydrate,thereby improving the nucleation rate and growth rate of hydrate.Changing the state of hydrate growth and regulating the degree of hydrate crystal aggregation,to reduce the entrainment of concentrated liquid during solid-liquid separation,and achieve high-purity conversion of seawater to freshwater resources.At the same time,the enrichment process of high value-added lithium ions is carried out in the process of hydrate seawater desalination to maximize the utilization of products.It was found that the water and cyclopentane emulsion system under the action of graphene and graphite can promote and enhance the nucleation of hydrate and ice,greatly reducing the induction time and making it have a faster nucleation rate.The graphite particle size has different effects on desalting efficiency and conversion rate under static or constant stirring.Under the action of graphite particles,the desalting efficiency of hydrate in static state and stirring is improved compared with the blank experiment,and the maximum desalination efficiency can reach 86%.Moreover,as the hydrate reaction time increases,the desalting efficiency and conversion rate of hydrates tend to increase.This hydrate desalination process has been proven to be desalination for real seawater,and the use of natural low temperatures can reduce the energy consumption of the hydrate process.The hydrate process under the action of graphite does not depend on the volume of the treatment,so the process has great potential for scaling up in desalination.The purity of fresh water can be significantly improved by using a multi-stage desalination process of cyclopentane hydrate,and graphite exhibits excellent cycle performance in experiments.The results show that the formation of cyclopentane hydrate can be simultaneously desalted and enriched with high value-added metal lithium ions.The hydrated process assisted by graphite particles is a promising method for desalination and enrichment.It has the advantages of fast nucleation,high conversion rate,high desalination efficiency,natural low temperature and independent processing volume.This technique can be a good alternative or complementary method to the desalination process,which is highly efficient and economical.The theoretical results obtained in this study will help to develop energy-efficient seawater desalination processes to produce high purity water and to obtain high value-added products through the hydrate formation process.