For parallel reactions with two reactants (A and B), the critical factor in obtaining favorable product distribution is the contacting pattern. If both A and B are to be kept low Use a single backmix reactor with A and B added simultaneously to the reactor. Use a plugflow reactor with a flowing continuously into the reactor and B added gradually. Use a series of backmix reactor with A and B added simultaneously to the reactor. Use a plugflow reactor where A and B flow simultaneously to the reactor