My general impressions of those words are:
An intellectual is someone who is curious about the world, asks lots of questions, and seeks out answers. They are philosophers and knowledge-seekers. People who thrive on a good debate are intellectual, but intellectuals don't necessarily like to debate...
An academician is goal-oriented and focused on formal education. Achievement of some goal (degree, job, research grant, money) is a primary motivator.
I suspect most, but not all, academicians are intellectuals but there are many intellectuals that are not academicians. Benjamin Franklin was an intellectual but not an academician. Albert Einstein was both (eventually). Many gifted people with lots of formal schooling are academic but not intellectual.
Just my general impressions.... not dictionary definitions!
