Hybrid Dual-Stage Solar Thermal Integration into the Cement Kiln Pre-Heater for Industrial Decarbonization: A Case Study in Jordan

Cement production generates approximately 7% of global CO2 emissions; Jordan’s kilns run on petroleum coke, coal, and olive residue with no demonstrated solar thermal integration for pre-heating. This paper addresses that gap and presents the first plant-data-backed techno-economic and environmental assessment of a hybrid dual-stage concentrating solar thermal system integrated into the pre-heater tower of a cement plant in Ma’an, Jordan (30.2° N, direct normal irradiance (DNI) = 2749 kWh/m2/yr). The study objectives are to (i) characterize Stage 5 and Stage 6 thermal loads from real plant operating data; (ii) size and simulate a 6000 m2 parabolic trough collector (PTC) field with molten-salt thermal energy storage (TES) targeting Stage 5 (380 °C, 3200 kW) and an 8000 m2 Linear Fresnel Reflector (LFR) field with rock/PCM TES targeting Stage 6 (300 °C, 2200 kW); (iii) quantify the combined solar fraction, fuel savings, and CO2 avoidance; (iv) conduct a Jordan-specific cost analysis benchmarked against NREL 2015 solar heat for industrial process (SHIP) data under three CAPEX scenarios; and (v) evaluate net present value (NPV) at two discount rates with and without carbon credits. The PTC field achieves a Stage 5 solar fraction of 35.5%, and the LFR field achieves 50.0% at Stage 6, yielding a combined annual solar fraction of 41.4% and displacing 59,384 GJ/yr (4163 t CO2/yr). Under Jordan base-case CAPEX of $3.89 M, 6% concessional finance, and a $50/t CO2 carbon credit, NPV reaches +$1.11 M with a breakeven carbon credit of $29/t CO2. These results confirm commercial viability under accessible green finance and carbon pricing, providing a replicable model for cement kiln pre-heater decarbonization in high-DNI Middle East and North Africa (MENA) countries.