Wheat Straw Pretreatment With KOH For Enhanced Biomethane Production And Fertilizer Value Via Anaerobic Digestion

Anaerobic digestion provide pivotal environmental advantages in positive terms for example, diminishing greenhouse gas emissions, replacing in organic fertilizer, yielding renewable energy and reducing waste. However, there are drawbacks in anaerobic digestion such as less biomethane production, process instability, system failure and lack availability of biomass have reduced the complete utilization of the anaerobic digestion process.This study was undertaken to deal with the analysis of the possible impacts on wheat straw in terms of positive or negative characteristics on the productivity of anaerobic digestion. Furthermore, it determines ways of improving the biomethane yield of prctreatcd wheat straw along with accruing a quality digestate residual element.The digested residual was also analyzed for chemical analysis in terms of nutrients. In order to improve the biogas production and biomethane yield, wheat straw shredded and milled to 2 to 3 cm size was pretreated with potassium hydroxide (KOH) at ambient temperature for 3 days in this research. Ambient temperature was implied as treatment temperature to be able to analyzed its effectiveness economically prospects for treatment process in the future.The efficacy of the different doses of KOH pretreatment were then evaluated by running batch anaerobic digestion test for 40 days at mesophilic temperature to enhance biomethane and accrued valued digestate which was enriched in elemental profile.In second batch test with varied organic loading rate OLR, the best result was achieved after 6% KOH pretreatment, leading to 331 mLNCH4/gVS of biomethane yield, corresponding to an increase by 52% compared to biomethane yield obtained for the untreated straw. It was found that KOH pretreatment of wheat straw at ambient temperature improved the biodegradability of the wheat straw by reducing the main components such as total solids, volatile solids, lignin, cellulose and hemicellulose. Furthermore, degradability was determined by crystallinity index analysis by supporting the amorphous region of lignocellulose pretreated substrate. Those results transpired by improved total biogas production and cumulative biomethane yield. The profile of digestate residue also suggested that primary nutrients of fertilizer nitrogen, phosphorus and potassium were enriched along with cationic substances which make this digestate as a value added biofertilizer for sustainable agricultural land which are deficient in potassium.Applied KOH pretreatment to wheat straw improved the solution of substrate analyzed i.e. degradation of organic matter and disruption hemicellulose and open the surface area of cellulose via pretreatment, were observed to be as effective means of improving biogas and biomethane production from pretreated wheat straw with enriched fertilizer value thereby improving the overall anaerobic digestion process.