{'fraction_non_alphanumeric': 0.01331967213114754, 'fraction_numerical': 0.0, 'mean_word_length': 5.7379310344827585, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Aviation renewable fuels: technical status and challenges for commercialisation

Abstract An overview of the major issues to be addressed for widespread commercial introduction and use of aviation biofuels is presented in this paper. These include the progress toward standards and approvals, bio-feedstock supply and sustainability, conversion routes to suitable fuel molecules, and policy and regulation considerations to create the necessary market and investment environment. It has been shown that while technical standards are now largely in place, biojet faces competition from biodiesel markets for feedstock, and existing sources of vegetable oil face sustainability challenges for greater supply. Other conversion routes exist that can use more sustainable feedstock, but they are capital intensive and will require a high fuel price to support investment. Policy approaches to cover the expected price premium above fossil fuel may also face political difficulties.