Sept 18 (Reuters) - Keyera Corp KEY.TO :
* KEYERA SCHEDULES MAINTENANCE AT ALBERTA ENVIROFUELS
* KEYERA CORP - SIX WEEK OUTAGE IS NOT EXPECTED TO HAVE A MATERIAL FINANCIAL IMPACT AS DEMAND FOR ISO-OCTANE IS TYPICALLY LOWER IN Q4
* KEYERA CORP - MAINTAINS ITS 2020 GUIDANCE FOR MARKETING SEGMENT