The pursuit of alternative energy sources for the nitrogen fertilizers sector has recently earned renewed interest due to increasing concerns regarding the world dependence on non-renewable energy resources and also motivated by the more stringent environmental regulations. The decarbonization of this sector, responsible for 2% of the global energy consumption, might help not only improving its carbon footprint, but also reducing its dependence on international market prices of natural gas. In order to palliate the environmental impacts that nitrogen fertilizers production is responsible for, several efforts have been addressed to incentivize the partial or total decarbonization of the ammonia supply chain. Alternative pathways of hydrogen production, such as solar or wind energy, have been widely proposed. However, the thermochemical conversion routes of biomass have shown to be the most interesting opportunity to capitalize on the underexploited biomass potential in tropical countries. Thus, in this work, two nitric acid and urea production plants integrated to a kraft pulp mill are evaluated in light of thermodynamic and environmental aspects. Furthermore, the variations of the market prices of the feedstock and the carbon tax have been investigated to evaluate their impact on the technological and financial feasibility of integrated biorefineries. By varying the electricity cost between 0.01-0.5 EUR/kWh, the chips cost between 0.006-0.024 EUR/kWh and the carbon taxation between 0-200 EUR/tCO2, the choice of the utility system has been driven by the interrelation of the market conditions, as well as the extent of the energy integration of the chemical plants. As a result, the exergy efficiency of the integrated plants remains competitive against the conventional kraft pulp mill thanks on the optimal selection of the operating conditions of the utility system that fits the variation of the carbon taxation.