A novel idea of solar driven steam-autothermal hybrid reforming system (SAHRS) is proposed with onboard carbon capturing system in the existence of carbon emissions taxes. The CO2 produced by the steam methane reforming is employed to the autothermal reforming as input and cryogenic air separation unit is integrated to provide autothermal reforming with oxygen and ammonia synthesis with nitrogen. The autothermal reforming is modified with further integration of water gas shift reactor (WGSR) which converts carbon mono-oxide into carbon dioxide by reacting with steam and this CO2 is captured in the carbon capturing system using aqueous ammonia. Some amount of hydrogen produced by the autothermal reforming is employed to the ammonia synthesis reactor to achieve onboard ammonia for CO2 capture. The system generates enough power to overcome the required power and supply power as a final commodity as well. The present system is essentially designed for cleaner production and industrial applications. The performance indicator for the designed system is defined in terms of energy and exergy efficiencies which are found to be 53.4% and 45.0% respectively. The carbon emissions produced by the system and tax saving by the aqueous ammonia based CO2 capturing are also calculated in the proposed study.

Introduction

The gradual depletion of the global fossil fuels reserves has been requiring critical research, innovation, advancement and technology developments on alternative energy sources, systems and applications. As per the forecast report from the Energy Information Administration (EIA, 2019), the world’s energy demand seems to upsurge by 50% by 2030. Wide-ranging research is being conducted on the efficient utilization of fossil fuels of the alternative energy sources because of the restricted fossil fuels nature and their effects on the environment (Jegadheesan et al., 2013; Muradov and Veziroǧlu, 2008). The renewable and clean nature of solar energy makes it a strong candidate for research, advancement and development (Ishaq et al., 2018). Numerous researchers consider solar energy as a promising replacement of fossil fuels as energy sources in the future. A number of researchers (Atif and Al-Sulaiman, 2018; Islam and Dincer, 2017) have developed and analyzed different integrations of solar energy with other systems, where they have integrated Brayton cycles recompression with solar tower and an optimized model of the solar heliostat was employed while in the other study, a solar-geothermal based integrated system was developed and analyzed. This developed system was comprised of two storage systems, a heat pump, two organic Rankine cycles (ORC), a drying system and an absorption chiller and system was developed for multigenerational purposes.