Unlike crude oil, biomass is distributed evenly over the world and its quantity is gigantic, which makes biomass a promising energy source of the future. Pyrolysis, which is a well-known method to produce energy from biomass, is a thermal conversion process producing a liquid fuel called bio-oil. The bio-oil produced from catalytic pyrolysis of biomass normally exhibit low oxygen content, high heating value, and improved miscibility with petroleum-derived liquid fuels. While lignocellulosic biomass has widely been used as a feedstock for catalytic pyrolysis, macroalgae, including various seaweeds, are recently receiving significant

attention as a new biomass material for energy production. The high photosynthetic efficiency of seaweeds, compared to that of woody land biomass, arouses an anticipation of producing bio-oil more effectively [1]. However, the pyrolysis bio-oil of seaweeds often SIS3 solubility dmso displays severe instability, requiring catalytic MG-132 datasheet reforming to improve the stability of the oil [1, 2]. The research on the catalytic pyrolysis of macroalgae is still limited, compared to that for land biomass. Application of various catalysts to the pyrolysis of macroalgae needs to

be investigated to learn more realize the potential of macroalgae as an energy source. Mesoporous catalysts can be good candidates for the catalytic pyrolysis of biomass because their large pore size is beneficial for the catalytic cracking of large-molecular-mass species during the pyrolysis process [3]. For instance, a mesoporous catalyst Al-SBA-15 was used in the catalytic pyrolysis of herb residue or miscanthus, leading to the production of valuable components such as phenolics [3, 4]. Organic waste can also be used to produce energy. For example, a substantial amount of plastics are produced, consumed, and discarded. Waste plastics can be used to produce liquid fuel through pyrolysis. The pyrolysis oil produced from plastics is composed mostly of carbon and hydrogen, with only a limited content of oxygen, because plastics are produced from fossil Pyruvate dehydrogenase lipoamide kinase isozyme 1 fuels that contain much less oxygen than normal biomass

materials. Therefore, if waste plastics are pyrolyzed together with biomass materials, they provide carbon and hydrogen and lower the oxygen content, resulting in an improvement of the oil quality [5]. This co-pyrolysis of biomass and plastics has recently been investigated actively [6–17]. However, the co-pyrolysis of macroalgae and plastics has never been studied yet. In this study, a representative mesoporous catalyst Al-SBA-15 was applied to the catalytic pyrolysis of Laminaria japonica, a kind of seaweed, for the first time. The co-pyrolysis of polypropylene (PP), which is a representative plastic material, and L. japonica was also investigated for the first time. Methods L. japonicaand PP Proximate analyses of L.