Bio-methane from biogas purified and stored by hydrate technology

Biogas from anaerobic digestion is one of renewable chains that is more stable and certificate by years of develop; however, to realize a biogas plant there are lot expensive costs especially concentrated on engine purchase. Biogas can’t be put onto natural gas net because the amount of CH4 (between 50% and 70%) is too low for the characteristics of the grid established by the Italian Authority for Natural Gas. Perhaps, biogas is a renewable fuel, so it's energetic-electrical conversion benefit of high economic incentives; to vectoryze biogas trough the natural gas net we had to respect this economic incentives system. By this abstract we want to describe the application of the hydrate technology both for purification, storage and transport of bio-methane obtained by this process. The heart of the process is made by a prototype of hydrate tank: we are using some particular chemical composts to modify water structure until it will be created a “micro-box”, whit atomic level structure, able to capture only methane molecules inside themselves. The process is realized by insufflating biogas, in the hydrate tank, that it runs at the same way as purifier for sulphurous compost like H2S. The storage of CH4 is obtained and maintained by low temperature, about 0 °C; if you want to re-transform hydrate into gaseous bio-methane you had only to increase temperature and the micro-box will expand its structure until CH4 molecule is able to go out. Whit this application you can purify and storage bio-methane in only one process whit a big reduction of operating costs; moreover you can transport easily bio-methane using the same hydrate containers. To transport bio-methane whit hydrate trucks reduce sensibly environmental and social risks because of bio-methane has low pressure in the storage system, not like CNG storage system whit high pressure.