Enhancement of biogas production from pineapple waste by acid-alkaline pretreatment

Abstract

The present study examined the effect of acid-alkaline pretreatment on pineapple waste for the performance on the anaerobic digestion. The acid-alkaline pretreatment was carried out by varying pH values from 2 to 12 using HCl and NaOH, and the mixtures were agitated at 250 rpm with the contact time of 24 hrs. The overall result showed that SCOD concentrations increased when pH values were increased. The value of biodegradability of raw waste was about 0.304. The BOD/COD ratios increased to 0.439 and 0.473 for pH 7 and pH 9, respectively. However, the BOD/COD ratios decreased for adjusted pH 12. For BMP test at pH 7, the removal efficiencies were 76.34%, 91.69% and 84.69% for TS, VS and COD, respectively, which were the higher efficiency than other conditions. It was also the optimal condition for the gas production rate because the pretreated pine apple waste was hydrolyzed much the organic matter into the soluble forms that can be immediately consumed by the anaerobic digestion process.

Influence of Subcritical Water Pretreatment Temperature on Pineapple Waste Biogas Efficiency: Experimental and Kinetic Study

“…The characterization processes that were carried out on the substrates utilized in the tests are listed in Table 2. The pineapple waste used in this experiment displays a high moisture content that is similar to the pineapple waste that was used by Wichitsathian et al [16] in their study. Furthermore, it is clear that the VS of the pineapple waste used in this study is a little higher.…”

“…Apart from being rich in organic matter, pineapple waste also contains a large amount of natural carbohydrates, with cellulose making up the majority (41.8%), followed by lignin (13.2%) and hemicellulose (35.2%). The lignin content in this study is low compared to the literatures [8,16]. Since lignin is resistant to microbial attack and hard to break down, substrates with lower lignin percentages are preferred as a digestion substrate.…”

“…Previously, Wichitsathian et al [16] stated that alkaline pretreated pineapple waste promotes microbial hydrolysis for subsequent anaerobic digestion and achieved over 91% and 84% of volatile solid and COD removals. Thermal pretreated pineapple waste achieved complete digestion with the domination of 70-73% acetic acid after pretreatment and produced high biogas production [17].…”

Recent Updates on the Conversion of Pineapple Waste (Ananas comosus) to Value-Added Products, Future Perspectives and Challenges

“…However, Dahunsi et al [181] reported that alkaline pretreatment using sodium hydroxide could increase the gas production of pineapple peels and poultry manure by 91% compared to acid pretreatment. Wichitsathian et al [182] also reported that pineapple waste's specific gas production rate increased from 132.05 L/kg of VS to 866.75 L/kg of VS after pretreatment was applied. For instance, the study by Aworanti et al [183] on the methane potential from the co-digestion of pineapple peels and manures and the optimisation of process parameters such as temperature, solid content and substrate to inoculum ratio discovered that by operating the co-digestion process at 55.2 • C, 6.25% solid content and 1:2 substrate to inoculum ratio could produce a high biogas yield with 71.10% methane content.…”

Pineapple core from the canning industrial waste for bacterial cellulose production by Komagataeibacter xylinus

“…Moreover, using these wastes would be a great opportunity to create new products while reducing the amount of waste generated by pineapple canning industrial waste [ 26 ]. The pineapple canning industrial waste was also used for the production of biogas [ 27 ], ethanol [ 28 ], lactic acid [ 29 ], vanillin and vanillic acid [ 30 ], and polyhydroxybutyrate. The use of pineapple industrial wastes such as peel, crown, and its mixture with the core has been studied for BC production [ [31] , [32] , [33] ].…”