Potassium sulfate as a byproduct of manganese heptoxide synthesis? Manganese heptoxide may be  formed by the action of concentrated sulfuric acid on potassium permanganate (ref):

$$ \ce{2KMnO4 + 2H2SO4 -&gt; Mn2O7 + H2O + 2KHSO4} $$

Could the amount of potassium permaganate as a reactant in the reaction be increased to yield potassium sulfate as a product instead of potassium bisulfate as shown?
The reaction you mentioned shows the formation of manganese heptoxide and potassium bisulfate. But if you alter the stoichiometry of the reaction, i.e. change the moles of the reactant, you will obviously get different products like manganese(II or III)sulfate, manganese oxide, potasium sulfate etc. For this, the reaction conditions should be changed.


$$\ce{2KMnO4 + 2H2SO4 ⟶ Mn2O7 + H2O + 2KHSO4}$$



  Potassium permanganate react with sulfuric acid to produce
  manganese(VII) oxide, potassium bisulfate and water. Potassium
  permanganate - solid. Sulfuric acid - 98% solution. The reaction
  proceeds at room temperature. Impurities: manganese(IV) oxide
  $\ce{MnO2}$(source)



$$\ce{2KMnO4 + H2SO4 → Mn2O7 + K2SO4 + H2O}$$



  Potassium permanganate react with sulfuric acid to produce
  manganese(VII) oxide, potassium sulfate and water.(source)



$$\ce{4KMnO4 + 6H2SO4 → 4MnSO4 + 2K2SO4 + 5O2 + 6H2O}$$



  Potassium permanganate react with sulfuric acid to produce
  manganese(II) sulfate, potassium sulfate, oxygen and water. Sulfuric
  acid - 60% solution. Impurities: ozone $\ce{O3}$.(source)



$$\ce{2KMnO4 + 4H2SO4 -&gt;[70-75°C] Mn2(SO4)3 + K2SO4 + 4H2O + 2O2}$$



  Potassium permanganate react with sulfuric acid to produce
  manganese(III) sulfate, potassium sulfate, water and oxygen. Sulfuric
  acid - 98% solution. This reaction takes place at a temperature of
  70-75°C.(source)