London to Seoul layover in Shanghai

Hi, We will travel from London to Seoul with a connecting flight / few hours layover in Shanghai PVG airport. The flight to Seoul is on a separate itinerary (so I assume we will need to collect our luggage and recheck on the flight to Seoul). Can we use the 24 Hr free transit for this? We both have limited entry visas and would rather use them on the return trip via PVG when we will actually leave the airport for a day. Also, does it matter that we are attending a business meeting?

Thanks!