RETRACTED: Catalytic co-pyrolysis of rice straw and ulva prolifera macroalgae: Effects of process parameter on bio-oil up-gradation

Abstract

Co-pyrolysis of rice straw (RS) and ulva prolifera macroalgae (UPM) was studied over a series of nickel-iron-layered double oxides (NiFe-LDO) supported on activated bio-char catalysts. Results showed that, co-pyrolysis produced higher bio-oil yield compared to the individual pyrolysis. Maximum bio-oil yield (46.68 wt%). was found with RS/A-UPM mixture biomass at 500 °C. While RS and UPM and it mixture (RS/UPM) without acid treated UPM was showed lower bio-oil yield. The catalytic pyrolysis up-gradation decreased the bio-oil due to the coke formation. However the bio-oil quality significantly improved with using the 5%Ga/NiFe-LDO/AC catalyst. Also, improved performance with higher amount of bio-oil and lower amounts of char and gas were achieved by acid washing the macroalgae, which is due the removal of ash content or partially fragmented the macromolecule compositions. Catalytic co-pyrolysis of feedstocks also revealed that introducing NiFe-LDO nanosheets into the activated char could result in NiFe-LDO/AC catalysts of higher surface area and increased active sites to adsorb oxygenated and nitrogenated compounds. Being impregnated by 5%Ga, catalysts with improved acid sites and thereby, advanced deoxygenation and aromatization activities were achieved. This implied that the synthesized Ga/NiFe-LDO/AC could be considered as a promising catalyst for RS/A-UPM bio-oil upgrading. • High quality bio-oil by co-pyrolysis of rice straw and ulva prolifera macroalgae. • Acid washing pretreatment considered to enhance the feedstocks synergistic effects. • Highly dispersed NiFe-LDO nanosheets synthesized over obtained activated bio-char. • NiFe, AC, and Ga were used as active phase, support, and promoter. • Advanced catalysts were achieved using Ga impregnation to promote bio-oil quality.