Thermochemical pretreatment of meat and bone meal and its effect on methane production

Since the solubilization of meat and bone meal (MBM) is a prerequisite in many MBM disposal approaches, enhancement of the solubilization by means of thermochemical pretreatment was investigated in this study at two temperatures (55 degrees C and 131 degrees C) and six sodium hydroxide (NaOH) concentrations (0, 1.25, 2.5, 5, 10 and 20 g L). The MBM volatile solid (VS) reduction ratio was up to 66% and 70% at 55 degrees C and 131 degrees C, respectively. At the same temperature, the VS reduction ratio increased with the increase in the dosage of NaOH. The study on the methane (CH4) production potential of pretreated MBM shows that the addition of NaOH at 55 degrees C did not cause the inhibition of the succeeding CH4 production process. However, CH4 production was inhibited by the addition of NaOH at 131 degrees C. The CH4 production potential was in the range of 389 to 503 mL CH4 g VS MBM and 464 to 555 mL CH4 g VS MBM at 55 degrees C and 131 degrees C, respectively.