This study aims to evaluate the environmental and energy effects of the reuse of 1.0 m³ of water in a cooling tower obtained from an oil refinery effluent. An arrangement comprising reverse osmosis (RO), evaporation (EV), and crystallization (CR) was created for water desalination. Six process routes were evaluated; for this purpose, each of them was converted into an specific scenario of analysis: S1: pre-treatment with Ethylenediaminetetraacetic acid (EDTA) + RO + EV (multi-effect distillation) + CR; S2: S1 with pre-treatment by BaSO4; S3: with Ca(OH)2/CaCO3/HCl; S4: S3 with waste heat to supply the thermal demand of EV; S5: S3 with steam recompression in EV; and, S6: S3 with HNO3 in place of HCl. The analysis was carried out by attributional LCA for primary energy demand (PED) and global warming (GW) impacts. The comparison was carried out for a reference flow (RF) of: add 1.0 m3 of reused water to a cooling tower with quality to proper functioning of this equipment. S4 presented the best performance among the analyzed possibilities (PED: 11.9 MJ/RF; and GW: 720 gCO2,eq/RF). However, dependence on other refinery sectors makes it inadvisable as a regular treatment option. Thus, S5 appears as the lowest impact scenario in the series (PED: 17.2 MJ/RF; and GW: 1.24 kgCO2,eq/RF), given the pre-treatment technique of RO-fed effluent, and the exclusive use of steam recompression to meet total EV energy demands. Finally, an intrinsic correlation was identified between RO water recovery efficiency and the accumulated PED and GW impacts on the arrangements that operate with heat and electricity.

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Natural gas has become a strategic source of energy, despite its technical and economic benefits, largely due to its lower environmental impacts compared with other fuels. Given this scenario, Brazil has increased the availability of this resource to meet the demand of more interior regions and increases its autonomy with respect to this fuel. The aim of this study is to evaluate the environmental impacts of current and future natural gas supply situations in Brazil. To this end, the life cycle assessment (LCA) technique is applied, with a cradle‐to‐gate approach for the climate change (CC) and primary energy demand (PED) impact categories. For the current scenario, the main contributions to CC occur in the form of CH4 emissions during gas transportation operations (crude or refined) and resource withdrawal from reserves. For future supplies, the applied analysis identifies transport distance as an important PED focus, whereas the same parameter and the distributed volume of refined gas are noteworthy as impact sources concerning CC.