Agricultural residues from arid regions remain an underexplored but substantial solid-biofuel feedstock. This study presents the first integrated multi-analytical characterization of ten agricultural biomasses from the Thar Desert, Rajasthan, India: Prosopis cineraria (Khejri), Arachis hypogaea (Groundnut Shell), Brassica juncea (Mustard), Acacia nilotica (Babool), Pennisetum glaucum (Bajra), Sorghum bicolor (Jowar), Gossypium hirsutum (Cotton Stalk and Cotton Flowers), Sesamum indicum, and Cyamopsis tetragonoloba (Cluster Bean) in both raw and torrefied (300 degrees C, 60 min, N2) forms. Analyses comprised proximate and ultimate analysis, bomb calorimetry, ATR-FTIR, energy-dispersive X-ray fluorescence (ED-XRF), BET, XRD, Raman spectroscopy, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). Torrefaction raised mean carbon content from 46.0 to 59.4 wt%, with fixed carbon rising from 0.07 to 2.67 wt% (raw) to 2.01-16.90 wt% (torrefied), and shifted Van Krevelen H/C and O/C ratios from the lignocellulosic zone into the sub-bituminous coal domain. ATR-FTIR confirmed complete elimination of the O-H stretching band (3285-3334 cm- 1) across all torrefied samples. XRD revealed cellulose crystallinity index reductions from 35.8 to 54.9% (raw) to 14.9-44.7% (torrefied), with Mustard showing the largest decline (Delta CrI = -31.0%). Energy densification ratios ranged from 1.12 (Jowar) to 1.30 (Cluster Bean). ED-XRF-derived Alkali Index identified torrefied Khejri (0.27 kg GJ- 1) as the lowest-fouling feedstock. Torrefied Cluster Bean, Cotton Flowers, and Mustard exceeded 3.0 kg GJ- 1, requiring gasification or fouling mitigation. A weighted multi-criteria scoring framework ranked Khejri first and Groundnut Shell second. The results provide an experimentally grounded basis for feedstock selection and combustion-system design in arid-zone bioenergy programs.