Diani Indrachapa Muhandiram

• Roy, Shetal; Rudra, Souman; Indrachapa, Muhandiram Diani & Roshid, M. M. (2025). Numerical modelling and experimental validation of an orifice plate-based hydrodynamic cavitation process for improving the biomass pretreatment. Biotechnology Reports. 48. doi: 10.1016/j.btre.2025.e00925. Fulltekst i vitenarkiv Vis sammendrag

  Hydrodynamic cavitation can be used to pretreat biomass by utilizing the energy released during the collapse of cavitation bubbles. Delignification as pretreatment enhances the biodegradation of lignocellulosic composition. The present study employed a CFD model and experimental validation of the numerical analysis of hydrodynamic cavitation (HC) in multi-hole orifice (MHO) designs under various operating conditions. The total 14 geometry of the orifice plate depends on the plate thickness, the number of holes, and the hole orientation used to analyze and optimize geometry for the biomass pretreatment process. Three phases are used in numerical analysis and experimentation to investigate the effect of particles on cavitation. The simulated results regarding velocity and pressure gradients, turbulence quantities, and vapor volume fractions are critically analyzed and discussed. The cavitation number changes to 0.22 in the experiment and 0.16 in the simulation due to the presence of biomass particles. Orifice plate thickness was found to significantly influence cavitation inception and evolution. 4 mm thickness and nine holes with specific orientations were found to be an optimized geometry with the lowest cavitation number, maximum pressure drop, and highest throat velocity. In the experimentation, 0.8 mm biomass particles were used in the mixture (2 % w/w) to determine the effect of biomass particles on the flow. This result helps identify the critical operating and design parameters and the impact on the cavitation of particles to achieve the desired cavitation phenomena.

• Indrachapa, Muhandiram Diani & Rudra, Souman (2025). TECHNO-ECONOMIC ANALYSIS OF HYDRODYNAMIC CAVITATION-ASSISTED HYDROTHERMAL SEPARATION FOR WHEAT STRAW, CORNCOB AND SUGARCANE BAGASSE. European biomass conference and exhibition proceedings. s. 695–708. Fulltekst i vitenarkiv
• Indrachapa, Muhandiram Diani & Rudra, Souman (2025). Coupled hydrodynamic cavitation–hydrothermal separation for biomass valorization: Simulation and experimental validation, and techno-economic assessment. Bioresource Technology Reports. 32. doi: 10.1016/j.biteb.2025.102450. Fulltekst i vitenarkiv Vis sammendrag

  Hydrodynamic cavitation (HC) is an emerging effective pretreatment for biomass, enhancing the bio-product separation. This study simulated and analysed a coupled HC-hydrothermal separation (HTS) process in Aspen Plus and compared its efficiency and economic performance with an HTS-only setup. The HC pretreatment was conducted at 30 °C and 4 bar, and HTS was optimized at 130 °C, 15 bar, 6-min residence time, and a 10 % solid-to-liquid ratio. The integrated HC-HTS approach showed higher energy and exergy efficiencies, with a 38–57 % separation in lignin yield and a 63–88 % improvement in extractive removal over HTS alone. For oak-based sawdust, lignin and extractive removal after HC were estimated using thermogravimetric analysis (TGA), whereas other feedstocks utilised literature data. The techno-economic analysis projected an initial investment of approximately ∼€10 million, with HC-HTS generating positive annual cash flows (€1–€14 million), short payback periods of 0.7–1 year, and positive net present value (NPV) for favorable feedstocks. Sensitivity analysis showed that profitability is primarily influenced by product sales and prices. Overall, the HC-HTS process demonstrated superior technical and economic performance, offering an energy-efficient and economically viable route for biomass volarization through improved recovery and separation of lignocellulosic bioproducts.

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