Huge potential for gas storage
The surface area of one gram of MOF could equate to the surface area of up to forty tennis courts. This means that MOFs possess large gas storage capacities with the great number of locations for gas molecules to “stick” or adsorb to. Once these molecules are immobilised on the MOF material they take up less space than when they are free to move around as a gas. This means that at a given pressure, a tank filled with MOF material can usually store much more gas than an empty tank. MOFs have a fully reversible uptake and release behaviour – the gas can be released by simply opening a valve on the tank.
Holds more. Weighs less. Introducing the gas sponge for cars.
Natural gas vehicles (NGVs) are becoming increasingly popular due to a number of key advantages over conventional, gasoline-fuelled vehicles but, a significant barrier to the uptake of NGVs has been the issues of storage, refuelling and range. Typically, natural gas is stored at very high pressures – up to 300 atmospheres – requiring heavy, cylindrical steel storage tanks and special refuelling stations using large, expensive and power-hungry compressors. MOFs’ sponge-like adsorbent qualities enable greater storage capacity at lower pressure. This reduces the strength requirements of tanks which can then be lighter and conformable to fit the free space available. The lower storage pressure also means that the heavy, expensive refueling infrastructure is no longer required and presents the possibility of refuelling at home from domestic gas supplies.
Acetylene storage is now 200 times better.
Acetylene is an important raw material for various industrial chemicals used in the production of plastics, consumer products and oxy-acetylene cutting tools. The unstable nature of acetylene renders it difficult to transport as it becomes dangerously explosive at just twice normal atmospheric pressure. To store acetylene safely, cylinders have to be filled with both porous material and liquid solvents such as acetone.
MOFs have the potential to completely transform the economics of acetylene storage by significantly increasing the possible storage capacities. At the low pressures at which this gas must be stored, a cylinder filled with MOFs can safely hold over two hundred times more acetylene gas than a conventional, empty cylinder.