No module named celery using python 3.6 and apache2
As a sanity check, make sure the celery is actually installed in the virtual environment you use.
If you are using virtual environment with mod_wsgi, you may need to setup python-home=<path_to_your_virtual_env> in the WSGIDaemonProcess directive. 

Example:

WSGIDaemonProcess django python-path=/opt/portal/src/ python-home=/opt/venv/django home=/opt/portal/ 

You can use the comma-separated list if more than one directory is required in python-path
On my dev machine I installed and configured celery within a django app and it works without issues using python3.5 and the django dev webserver.
When I deploy that app to my production server I get an error "no module named celery". On the production server runs python3.6 with apache2 and mod_wsgi.
On both machines I use django-1.11 and celery-4.1.0 within a virtualenv. I suspect that it's either an issue with python3.6 or with mod_wsgi.
I haven't found any real solution to my issue so I'm trying my luck here :)
Cheers
Michael