After five years of research and development, Virgin Atlantic and one of its clean-technology partners, Illinois-based LanzaTech, developed a source of jet fuel made of waste gases from steel mills. According to the companies, this new source of jet fuel passed extensive tests that both delivered on performance and promise to result in carbon emissions savings of 65 percent compared to conventional jet fuel.This discovery comes at a time when airlines, seeking to mitigate what is a carbon-intensive business, have long dabbled with jet fuel blended with algae and other biofuels. The Dutch carrier KLM experimented with algae fuel blends, has flown transatlantic flights using blends of kerosene and cooking oil, and is still apparently committed to sourcing these fuels when available. Alaska Airlines also considered using recycled cooking oil to reduce its carbon emissions. Earlier this year, United kicked off flights between San Francisco and Los Angeles using a biofuel-conventional blend. Aviation fuel using feedstock from Brazilian sugarcane is also touted as an option.