## 3 Results and Discussion
### Anaerobic Digestion Process  
The percentage of total solids contained in the mixture with which the digester is loaded is an important factor to consider to ensure that the process is carried out satisfactorily. The accessibility of methanogenic bacteria within the substrate is increasingly limited as the solids content increases, and the gas efficiency and production can therefore be affected. Table 4 shows the results of the characterisation of the substrate of cow manure and corncob hydrolysate obtained in this project. Experimentally, it has been shown that the load in semicontinuous digesters should not have more than \begin{table}
\begin{tabular}{c c} \hline
**Parameters** & **Values \(\pm\) SD** \\ \hline Proteins (\%) & 0.20 \(\pm\) 2.81 \\ \hline Fats (\%) & 0.77 \(\pm\) 0.54 \\ \hline Ash (\%) & 0.47 \(\pm\) 0.96 \\ \hline Carbohydrates (\%) & 5.95 \(\pm\) 0.29 \\ \hline \end{tabular}
\end{table} 
Table 2: Bromatological analysis of corncob hydrolysate. \begin{table}
\begin{tabular}{c c c} \hline
**Parameters** & **Organosolv Hydrolysate** & **Soda Hydrolysate** \\ \hline Total Reducing Sugars (g/L) & 65.84 \(\pm\) 3.29 & 4.64 \(\pm\) 0.23 \\ \hline Total sugars (g/L) & 157.7 \(\pm\) 3.86 & 20.80 \(\pm\) 1.04 \\ \hline Non-reducing sugars (g/L) & 91.86 \(\pm\) 4.56 & 16.16 \(\pm\) 0.80 \\ \hline \multirow{4}{*}{Sugars (Monomers)} & Glucose (g/L) & 6.23 \(\pm\) 0.34 & 4.12 \(\pm\) 0.20 \\ \cline{2-3}  & Xylose (g/L) & 4.12 \(\pm\) 0.34 & 3.54 \(\pm\) 0.17 \\ \cline{1-1} \cline{2-3}  & Galactose (g/L) & 2.42 \(\pm\) 0.17 & 1.9 \(\pm\) 0.09 \\ \cline{1-1} \cline{2-3}  & Mannose (g/L) & 1.66 \(\pm\) 0.41 & 0.5 \(\pm\) 0.02 \\ \hline Chemical oxygen demand (g/L) & 690 \(\pm\) 5.67 & 195 \(\pm\) 6.56 \\ \hline \end{tabular}
\end{table} 
Table 3: Characterisation of corncob hydrolysate. 8% to 12% total solids to ensure the proper functioning of the process, unlike discontinuous digesers, which can handle between 40% and 60% total solids. In this case, the total solids value was 14.82%, which is attributed to the cow manure [29]. Figure 1 shows the maximum value of biogas production in the bottles reactor obtained with the hydrolysate corncob at 15 days compared with a control corncob without the hydrolysate organosolv pretreatment and with different pretreatments in the bottles reactor reported by other authors [9; 30; 31], [PERSON] (2016) reported the effect of microbial pretreatment on the biogas production of non-sterile, rotted silage maize straw, finding 305 NmL/gVS [30], while [PERSON] (2017) reported extrusion and enzymatic hydrolysis, finding 279 and 290 NmL/gVS, respectively [9]. [PERSON] (2018) reported 360 NmL/gVS using lime (Ca(OH)\({}_{2}\)) soaking as a pretreatment [31]. It was clearly observed that, with the use of pretreatment with organosolv, the production of biogas was superior, because 484 NmL/gVS was obtained compared to the other reported treatments. It was also observed that adding the hydrolysate organosolv increased the production because the values of the control without hydrolysate were 120 NmL/gVS. Figure 2 shows a representative evolution in cumulative biogas production in the Labfors batch-type biological reactor. In this section, the values found with and without corncob hydrolysate are compared. The biogas production was observed to be very low for the first nine days in both cases, but began from day 10. In the corncob hydrolysate test, the biogas production was higher than the non-hydrolysate test. Biogas production was monitored until day 20, but there was no production from days 15 to 20, so there was a constant line, and all the added organic substrate was consumed by day 15. The total biogas accumulated in 15 days of production was 5050 \(\pm\) 253 NmL/gVS and 1212 \(\pm\) 120 NmL/g VS with and without hydrolysate, respectively. The increase in biogas production was notable when the organosolv hydrolysate of corncob was added.