Investigation of the synergistic effect of co-gasification of rice husk and cashew nut shell in a dynamic environment of nitrogen and steam in a fixed-bed reactor system
La revue Environmental Science and Pollution Research (ESPR) publie une étude sur l'effet synergique de la co-gazéification des coques de riz et de noix de cajou dans un réacteur à lit fixe, mettant en lumière les avantages de cette méthode pour la production de syngas. En utilisant des mélanges à différents ratios, les résultats montrent une amélioration significative des rendements énergétiques et une réduction des déchets, soulignant le potentiel de la biomasse comme alternative durable aux combustibles fossiles.
With the depletion of energy resources like coal, dependence on cleaner energy carriers like biomass is growing in the present century. Gasification is the most renowned and more energetically efficient technology for extracting this energy via the generation of syngas than other thermochemical conversion processes. It can produce power, liquid fuel, and valuable chemicals like methanol, upon which the present civilization relies. In contrast, other thermochemical processes can produce products (biochar or bio-oil) that do not hold value as high as syngas. Rice husk (RH) and cashew nut shells (CNS) are the two abundant biomasses predominantly found in India with extensive energy potential. RH and CNS gasification have several disadvantages that can be eliminated when gasified together, e.g., co-gasification can reduce the tar and ash content, which can cause serious operational issues during gasification. RH with significant lignin content and CNS with high volatile matter are ideal feedstocks for syngas production via gasification. The present study investigated the synergistic effect of co-gasification of the above feedstocks in a fixed-bed reactor. The mixtures of RH and CNS with blending ratios of 75:25, 50:50, and 25:75 were gasified using steam as the gasifying agent and N2 as the carrier gas at a reaction temperature of 850 °C. The N2 flow rate was kept at 20 LPM, and the steam flow rate was 0.825 mLPM in all the experiments. Syngas, with an optimum energy content (higher heating value) of 13.8 MJ/Nm3, the highest H2 concentration of 43.5% volume (without considering N2 and O2), and the highest yield of 1.24 Nm3/kg obtained with gasification of a 50:50 blend, revealed the synergistic effect simultaneously. The char and tar yields were also the lowest in the case of 50:50 blend gasification.
