Driving around in unfamiliar territory, searching for a gas station while your gauge hovers just above E is maddening and stressful. But imagine experiencing that same feeling while manning a giant aircraft carrier through foreign — and sometimes hostile — seas. To make fuel easier to come by, the US Navy is working on a way to produce it from ocean water.
Scientists at the Naval Research Lab are trying to extract the carbon dioxide from the salty sea, produce hydrogen gas from it, and then turn it into jet fuel using a gas-to-liquids conversion process. They say it'll be cheaper and won't hurt the environment. Plus, there's plenty of carbon dioxide in seawater — almost 140 times as much as in the air. Here's how the process works:
In the first step, an iron-based catalyst has been developed that can achieve CO2 conversion levels up to 60 per cent and decrease unwanted methane production from 97 per cent to 25 per cent in favour of longer-chain unsaturated hydrocarbons (olefins). In the second step these olefins can be oligomerized (a chemical process that converts monomers, molecules of low molecular weight, to a compound of higher molecular weight by a finite degree of polymerization) into a liquid containing hydrocarbon molecules in the carbon C9-C16 range, suitable for conversion to jet fuel by a nickel-supported catalyst reaction.
Water, water everywhere, and not a drop to drink. Plenty to convert into fuel, though. [Navy Research Lab]
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