Toward sustainable biofuels in arid regions: Bioprospecting Qatar's flora

Biofuels offer a renewable alternative to fossil fuels and can contribute to low-carbon energy transitions in arid regions. This evidence-mapping study screened nearly 400 vascular plant species in Qatar and identified 84 species with published biofuel-relevant characteristics. Across these species, reported biomass properties showed substantial variation: higher heating values (HHV) ranged from 10 to 19 MJ/kg, and lignocellulosic fractions reached up to 78 wt% (Acacia tortilis), and seed oil contents extended to 52 wt%, and fatty acid methyl ester yield of 98.70 % through catalysis. Thermochemical studies on species occurring in Qatar documented bio-oil yields of 12–57 wt%, char yields of 10–39 wt%, and fuel-grade properties for several species, including biodiesel densities of 0.86–0.88 g/cm³, viscosities of 3.5–6.8 mm²/s, and cetane numbers exceeding 60. Ten species met the criteria for “advanced” research maturity based on the availability of quantitative feedstock, chemical, physical, and combustion data. Mapping these traits to conversion routes reveals that lignocellulosic species are most compatible with pyrolysis and gasification. At the same time, lipid-rich halophytes are best suited for biodiesel production under saline agricultural conditions. These findings highlight promising candidates for Qatar's bioenergy portfolio and identify critical evidence gaps requiring pilot-scale validation, species-specific fuel testing, and integrated policy support to advance sustainable biofuel development in arid and saline environments.