The classical Carnot analysis provides means to calculate, relative to a specified heat supply and relative to specified temperature bounds, a limit on the work that can be obtained in any cyclic process consistent with those specifications. Moreover, the Carnot analysis indicates that the calculated limit is sharp, to the extent that it can be attained by a special process ( a Carnot cycle) which cannot itself be realized but which can be approximated arbitrarily closely by actual processes. We indicate how, in the spirit of the Carnot analysis, theoretical limits to the productivity of steady-state reactor-separator systems can be calculated relative to specified commitments of resources and relative to specified constraints. We also indicate a sense in which those limits are sharp, to the extent that they might be attained by certain idealized reactor-separator systems which, like Carnot cycles, cannot be realized in practice but which might be approached by actual processes.