The people that say no to the original question often argue that the French are some other power would have exploited slavery if we hadn't. Even if this is true the British case shows that much of the money didn't go to the furtherance of industry but to private stashes of wealth, also so the British could have have instituted a paid labour system like they had in Britain and elsewhere, after all people wanted our products. Also the need for machinery to replace humans would have increased the incentive develop these things.
So my tentative conclusion is yes Britain could have had an Empire without slavery, whether it would have, who. can say? I'd say probably and probably better!