Question: what is the name of the process used to separate the components of petroleum
[{'answer': 'fractional distillation', 'provenance': [{'wikipedia_id': '23195', 'title': 'Petroleum', 'start_paragraph_id': 1, 'start_character': 237, 'end_paragraph_id': 1, 'end_character': 260, 'bleu_score': 1.0, 'section': 'Section::::Abstract.'}]}, {'provenance': [{'wikipedia_id': '23195', 'title': 'Petroleum', 'start_paragraph_id': 1, 'start_character': 0, 'end_paragraph_id': 1, 'end_character': 404, 'bleu_score': 0.7999267847857171, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 16720530540341678748}, 'section': 'Section::::Abstract.'}]}]