what is the difference between an industrial and automotive diesel engine?

There is no difference with the actual 'power plant', pistons fuel
pump etc., but if used to power an industrial machine, the gearbox or
connection will be different. Any automotive application must have
changeable gears, through a gearbox. A marine application requires a
reduction box to slow the revs. and then through a simple
forwartd/reverse gearbox. An industrial use might have a direct drive
or a reduction box, with possibly no reverse. Hope this helps.

Diesel engines used in cars will have a shorter stroke than their
industrial counterparts.  Heavy goods vehicles have lots of gears to
cope with the narrow rev range of their engines, but this wouldn't be
practical in a car so the engines are designed to have a wider rev
range.

Ian G.