In general, higher value of OLR gave higher production rate of biogas. A production rate above 45.00 mL ·
min–1 of biogas was observed when the OLR given was above 35 g VS · L–1 · d–1. In the same way, NaOH tend to
increase the rate when the application was in the range of (30.0 to 37.5) % of NaOH with constraint of OLR
application more than 30.0 g VS · L–1 · d–1 . Below than the mentioned OLR value, the production rate would be
lower than 34.00 mL biogas · min–