Historical clue formulations

• C2H6 compound — 2023-05-12
• Compound that becomes a man's name when its last letter is removed — 2022-09-17
• C2H6 — 2021-07-01
• Odorless hydrocarbon — 2021-05-15
• Flammable compound with two carbons — 2020-09-26
• Gas that's a man's name + E — 2019-11-20
• Simple hydrocarbon — 2019-09-29
• Component of natural gas — 2019-08-19
• Natural gas component — 2018-10-14
• Gas in fuel — 2018-06-26
• Component of natural gas — 2018-05-27
• C2H6, familiarly — 2017-11-23
• Byproduct of petroleum refining — 2014-11-09
• Gas with or without an "m" — 2013-12-12
• Second-simplest hydrocarbon — 2013-03-29
• Petroleum component — 2012-12-09
• Crude component — 2012-10-13
• Natural gas component — 2012-04-22
• Gaseous hydrocarbon — 2011-09-13
• Flammable fuel — 2010-10-17
• Hydrocarbon with two carbons — 2010-10-16
• Crude component — 2010-05-14
• Flammable gas — 2009-01-26
• Cryogenic refrigerant — 2008-06-13
• Flammable gas — 2007-11-11
• Colorless gas — 2007-02-28
• Simple hydrocarbon — 2006-08-16
• C2H6 — 2002-12-29
• Crude petroleum component — 2002-03-24
• Odorless gas — 2001-06-26
• Constituent of natural gas — 2001-03-18
• Fuel gas — 2000-04-28
• Flammable fuel — 1999-12-27
• Natural gas ingredient — 1999-09-21
• Natural gas component — 1998-06-06
• Component of natural gas — 1998-04-06
• Fuel gas — 1998-02-18
• Natural gas component — 1998-01-25
• C2H6 — 1997-03-10
• Odorless gas — 1997-01-22
• Gas fuel — 1994-08-28