In this talk, I will give an overview of our recent projects on the development of sustainable processes for the conversion of waste plastics and CO2. For the waste plastic conversion part, I will discuss the recent results obtained from our EU project, PLASTICE (https://plastice.eu/). We are developing hydrothermal liquefaction (HTL) process, in PLASTICE, to convert mixed plastic waste predominantly HDPE and LDPE, from municipal waste streams, to fresh monomers. Hydrothermal Liquefaction (HTL) is an emerging chemical recycling technique for plastics. The influence of changing different parameters on the yield and composition of the oil product and other byproducts will be discussed. Moreover, the engineering and design of a scaled-up reactor also will be described. Our results show a promising potential for HTL in processing mixed municipal plastic waste streams. The oil resulting from our HTL process satisfies the requirements for feeding into the downstream cracker unit for producing olefins such as ethylene and propylene. These olefins can then be used to synthesise fresh polymers. In the second part, the conversion of CO2 using novel catalysts being developed in our group will be discussed. Albeit in the absence of noble or any expensive metals, these catalysts exhibit good performance in the conversion of CO2 to value-added products.