From private to social cost-benefit analysis: life cycle environmental impact cost internalization in cement production fuel switching

Cement production is linked to heavy environmental load with exigences for reduction and substitution of raw materials and energy demands/sources. Recently, with the potential commercial discovery of natural gas (NG) reserves in Lebanon, discussions on the viability of fuel-switching, from petcoke (kiln processes) and heavy fuel oil (HFO) (reciprocating engines) to NG in the cement sector emerged. To that aim three alternative scenarios (SCx) were suggested: shifting petcoke to NG in kiln processes (SC1); shifting reciprocating engines from HFO to NG (SC2); shifting kiln processes and reciprocating engines to NG (SC3). An economic analysis indicated that SC2 is the only viable option. This paper presents a new combination of life cycle impact assessment (LCA) and monetization to quantify environmental impacts for the decision-making processes, within the Lebanese context. The LCA was conducted using primary data and SimaPro v8.5.2.0. The functional unit (FU) was 1 kg of cement. IPCC 2013 GWP 100a V1.03, Cumulative Energy Demand (CED) V1.10 ReCiPe 2016 E v1.02 impact assessment and Stepwise2006 (V1.05.3) monetary valuation methods were used. Results indicated that all scenarios lead to a reduced carbon footprint: 0.016 kgCO2eq., 0.0008 kgCO2eq. and 0.0168 kgCO2eq. for SC1, SC2 and SC3, respectively, from the baseline 1.0327 kgCO2eq.. The baseline CED was 5.06 MJ, and 4.5 MJ, 4.91 MJ and 4.35 MJ for SC1, SC2, and SC3, respectively. SC3 had the lowest environmental burden, followed by SC1 and SC2. Damage assessment results indicated that all alternative scenarios reduce environmental damage, while SC3 brought the highest benefit followed by SC1 and SC2, respectively. Monetization results/ FU indicated a cost burden of 25.54 US¢, 24,64 US¢, 25.5 US¢ and 24.6 US¢ for baseline, SC1, SC2 and SC3, respectively. Finally, the best fit option, after internalizing the environmental cost, shifted from SC2 to SC3 indicating the merits of combining LCA and monetization into decision-making processes.