Organic loading rate may affect biogas production rate and methane concentration in a positive manner, where
an increasing of OLR provides a better production either concentration or rate of biogas. However, there is a
synergistic effect between OLR with the function of NaOH to degrade lignin in the content of co-substrate, can
reduce the residence time and improve the quality of the biogas. The result of the process optimization shows that
the increased production of biogas yield at 67.6 mL · min
–1
with 63.4 % methane concentration require 43.6 g
VS · L · d
–1
of OLR and the 33.1 % of NaOH (w/w). The requirement for the production rate and concentration was
to set the OLR and NaOH at the minimum utilization. However, the given solution needs to be evaluated thoroughly
to meet the best option, in terms of cost, efficiency, and practicality.