Natural Gas Hydrate (NGH) is a solid material in icy state which is called clathrate compound where natural gas molecule is trapped within a cage composed of water molecule. NGH is able to be stabilized at minus 20 degree Celsius under atmospheric pressure, and this unique characteristic allows for natural gas transportation in bulk solid form and this method leads to reducing the total investment cost for a transportation chain. For this reason, NGH is expected to become a solution for monetizing small to medium gas fields which are considered difficult to be economically developed by liquefied natural gas (LNG). Higher security and eco-friendliness are also the advantage of NGH.
Mitsui Engineering & Shipbuilding Co., Ltd. (MES) has been proceeding with research and development on NGH technology for a decade and completed, this year, a project to demonstrate NGH land transportation jointly implemented with The Chugoku Electric Power CO., Inc. (CEP) under the assistance of a Japanese national institution, New Energy and Industrial Technology Development Organization (NEDO).
In this project, NGH production plant with 5 ton-per-day (as NGH) capacity was built in LNG-based Power Station of CEP in Yanai City and vaporized LNG was used as feed gas for NGH production. Produced NGH was transported by purpose-built tank trucks to two users' sites located approximately 100km away from Yanai. One is gas engine power generator as simulated industrial user and the other is the facility equipped with home appliances as simulated household user. Through this project, MES has succeeded in demonstrating the world's first operation of the entire land transportation chain including users' consumption in a certain scale, and acquired actual process data necessary for developing process design of the pilot plant with 100 ton-per-day capacity, which is an indispensable step for realizing commercial project based on the plant with 6,000 ton-per-day capacity per train.
In this paper, an overview of MES's NGH technology as well as an outline of this world's first demonstration project for the entire land transportation chain is provided and MES's development status towards its commercialization of NGH marine transportation is also shared.