Analysis of sorption enhanced reforming for the valorization of biorefinery and industrial fuel gases

In recent years, the development of sustainable energy solutions has become increasingly important as we strive towards a net zero carbon future. As a result, there has been growing interest in hydrogen production as a potential vector for the complete decarbonization of the energy, industry, and transport sectors. Sorption Enhanced Reforming (SER) is one such technology that has been extensively studied in the literature, with a focus on producing pure streams of H2 and CO2 from not only methane but also several bio-feeds. The integration of SER within biorefinery schemes has also been proposed as a means of producing hydrogen from waste and side streams, but significant challenges remain due to the complex nature of such side streams besides the potential impact of hydrogen content in these streams on the reforming process. In this regard, the aim of this thesis work is to evaluate the technical viability of integrating the sorption enhanced reforming process within existing refinery and biorefinery processes, with a focus on its potential to valorize side streams and minimize carbon emissions. The initial part of the work is focused on studying the thermal behavior of an adiabatic fixed bed SER reactor; where, a 1-D dynamic heterogeneous model was developed. A set of key performance indices such as CH4 conversion, H2 yield, and purity as well as carbon capture ratio were calculated by integrating over the reforming step to evaluate the impacts of feed gas temperature, initial bed temperature, and bed thermal capacity. Then, SER technology was investigated as a potential solution for treating gaseous side streams obtained from refinery and biorefinery hydrocracking, hydrotreating, and hydrogenation processes. These streams have limited hydrocarbon conversion due to thermodynamic and kinetic constraints resulting from the high H2 content. The developed model was thus applied to evaluate the effect of H2 dilution on the performance indicators. Finally, the reactor level analysis was upgraded to the plant scale evaluating the performance of a H2 production plant based on the SER of both methane and the biorefinery side streams. The assessment of the plant's performance included the reforming and regeneration stages, steam generation and feed preheating, hydrogen purification, as well as CO2 sequestration and pressurizing.

Negli ultimi anni lo sviluppo di soluzioni energetiche sostenibili è diventato sempre più importante mentre ci impegniamo verso un futuro a zero emissioni nette di carbonio. Di conseguenza, c'è stato un crescente interesse nella produzione di idrogeno come possibile vettore per la decarbonizzazione completa dei settori dell'energia, dell'industria e dei trasporti. La Sorption Enhanced Reforming (SER) è una di queste tecnologie che è stata ampiamente studiata in letteratura, con un focus sulla produzione di flussi puri di H2 e CO2 non solo da metano ma anche da diversi bio-feeds. È stata anche proposta l'integrazione di SER all'interno di schemi di bioraffineria come modo per produrre idrogeno da rifiuti e sottoprodotti, ma rimangono sfide significative a causa della natura complessa di tali sottoprodotti e dell'eventuale impatto del contenuto di idrogeno su tali processi di riformazione. In questo contesto, l'obiettivo di questa tesi è valutare la fattibilità tecnica dell'integrazione del processo SER all'interno dei processi di raffineria e bioraffineria esistenti, con particolare attenzione al suo potenziale per valorizzare sottoprodotti e ridurre le emissioni di carbonio.