Substituting renewable energy sources for fossil fuels is a viable option for mitigating environmental damage caused by the energy sector. Another strategy for better utilization of primary resources is integrating multigeneration energy plants. To that end, this study proposes the construction of a biomass-fired power, water, and hydrogen facility. A gasifier integrated gas turbine (for electricity generation), vanadium-chlorine thermochemical cycle (for hydrogen synthesis), and MED-TVC unit (for water desalination) make up this system. Compared to previous similar researches, the waste heat-driven hydrogen and freshwater production units is the most favorable feature of the proposed tri-generation plant in this research. Exergy, economic, and ecological impacts of the engineered plant are examined. The results of a thorough parametric analysis reveal that, each design variable uniquely impacts the values of three goods and three performance indicators (exergy efficiency, emission index, and levelized cost of product). Therefore, the proposed tri-generation plant's optimal operating conditions can only be determined by the use of a triple-criteria optimization. The best operation was found to have a levelized product cost of 0.0441 $/kWh, a CO2 emission of 0.530 kg/kWh, and an exergy efficiency of 56.64%. The parametric analysis also suggested that a lower pressure ratio and gasification temperature would be optimal for increasing hydrogen production.