TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Process: The pretreating lignocellulosic biomass material involves contacting the lignocellulosic biomass material with aqueous fluid, and swelling the lignocellulosic biomass material. In the process, contacting the lignocellulosic biomass with an aqueous fluid is carried out at elevated temperature of 35-100 (preferably greater than 100) degrees C, and carried out under autogenous pressure. The process further involves adding an inorganic catalytic material, and adding step involves mechanical action. The mechanical action results in a particle size reduction of the biomass material. The product used in an enzymatic hydrolysis process or in a thermoconversion process. The thermoconversion process is selected from pyrolysis, catalytic cracking, gasification, steam gasification and/or hydrotreatment. The thermoconversion process is carried out in a fixed bed reactor, a fluidized bed reactor, fluidized catalytic reactor (FCC), or an ebbulated bed reactor. Preferred Components: The solvent is an aqueous liquid. The mechanical action is exerted by equipment selected from high shear mixers, kneaders, colloid mills, planetary mixers, mix-mullers, extruders, pressure filters, centrifuges and/or ball mills or other comminuting equipment. The ash content of the biomass material is reduced to less than 5 (preferably less than 3) wt.%, based on dry weight of the biomass material. The Fe content of the biomass material is reduced to less than 2000 (preferably 1000) mg/kg, based on dry weight of the biomass material. The solvent comprises an inorganic acid or an inorganic base. The inorganic catalytic material is dissolved in a solvent. The catalytic material is in a particulate form. The catalytic material comprises an inorganic salt. The catalytic material comprises a cation selected from K, NH4, Na, Ba, Mn, Mg, Ca, Li and/or Zn. The catalytic material comprises an anion selected from OH, CO3, SO4, PO4, Cl and/or NO3. The catalytic material comprises an insoluble inorganic material, in a colloidal or nanoparticular form. The insoluble inorganic material is selected from refractory oxides, zeolites, cationic clays, anionic clays, layered hydroxide materials and/or hydrotalcites. EXAMPLE - No suitable example given.