Got the same problem. After trying multiple libraries such as [Hidealo's][1], [IamCal's][2] or [Urakoz's][3], this is the only way I have found to make sure all emojis are gone:

$CleanString = iconv('ISO-8859-1', 'UTF-8', str_replace('?', '', iconv('UTF-8', 'ISO-8859-1//TRANSLIT', $EmojiedString)));

Works like a charm! [1]: https://github.com/hidehalo/emoji [2]: https://github.com/iamcal/php-emoji [3]: https://github.com/urakozz/php-emoji-regex