Some of the activists had glued themselves to the road surface, forcing officers to use solvents to help detach and remove them.
Police redirected vehicles around the Insulate Britain protesters, who had blocked traffic on a section of road near Thurrock, east of London.
Those refusing to move of their own accord were carried away by officers.
Activists from the Insulate Britain group want the government to commit to providing insulation for 29 million homes across the country to make them more energy efficient.
In recent weeks they have blocked slip roads, glued themselves to the road and poured paint onto the M25, which runs around London.
The government previously said it would amend existing legislation to increase penalties for obstructing a highway to an unlimited fine, six months' imprisonment, or both.