Solidified natural gas (SNG) allows for safe and cost-effective long-term storage of natural gas (NG). Natural gas is stored in the form of ice-like compounds, gas hydrates. SNG can store these hydrates at standard pressure and 0 oC. It eliminates the risks associated with cryogenic handling of liquefied natural gas (LNG at -163oC) or high-pressure hazards of compressed natural gas (CNG at > 200 atm). The company is targeting for SNG’s capital cost to be less than 50 % of the cost of comparable LNG storage tanks, current industrial benchmarks. The customers are natural gas producers, power generation companies (Gencos), distributors, industrial users and energy hub companies
The technology comprises of an integrated system for long term natural gas storage, in the form of hydrates at 0 oC and 1 atm. It comprises of innovative hydrate formation reactor and process design with high hydrate yield (> 80%) (patent pending), which can directly produce natural gas hydrate pellets. Currently, production capacity of up to 15 kg/day has been demonstrated. The formation of hydrates occurs at 5-20 oC at a pressure range of 30-70 bar by utilising this process. Coupled with a hydrate storage unit, the hydrates can be stored as long as desired. Stable storage of up to 8 months has been demonstrated at laboratory scale. Additionally, the hydrates can be dissociated to deliver the natural gas when required. The system enables safe natural gas storage at ambient pressure eliminating the high pressure risks of CNG. SNG can store as high as 160 times natural gas compared at up to 0 oC and normal pressure.
Potential end-users include power plants, industrial users and natural gas producers. In Singapore, power plants need to store backup fuel for at least 45-60 days and currently resort to storing diesel primarily due to lack of viable options. Energy security is another key application for various industries highly reliant on natural gas with less than 1-2 weeks of storage. Industrial benchmark, LNG storage tanks, at best still cost US$ 600-700 per m3/LNG storage. This number becomes further unattractive when considering smaller scale applications.
Natural gas is the cleanest and the fastest growing fossil fuel. With the growing natural gas needs, storage requirements also grow rapidly especially as natural gas supply chain is spread across the globe. With the market moving towards small scale LNG (SSLNG), LNG becomes less economically attractive. This provides a unique opportunity for SNG to enter into the market and deliver value to the customers.
1) Safe natural gas storage: If the hydrates are produced at a central location and delivered to remote location, the consumer would not need to deal with any high pressure like CNG or cryogenic handling of LNG. There is no need for high pressure and the inherent safety of storing natural gas as hydrates delivers a safe solution to the market for natural gas delivery.
2) Lower Costs: With significant milder conditions for storage, the company targets for SNG storage cost to be less than 50% of comparable volume natural gas storage. With lower boil-off issues than LNG, operating cost would be lower than LNG as well.
3) Superior process (Patent Pending): The innovative process enables formation of the hydrates up to 20oC, with up to 80% hydrate yield in 1 hour. The system is optimised for rapid hydrate formation and storing these hydrates require low energy consumption, thereby reducing the overall cost to customers. Estimated cost of SNG pelletization is around 1 US$/MMBTU compared to 2-2.5 US$/MMBTU of liquefaction of LNG.