Bioplastics derived from polyhydroxyalkanoates (PHAs) are among the promising substitutes for unsustainable petroleum-based polymers. PHA-based polymers demonstrate superior chemical and physical properties, such as hydrophobicity, insolubility in water, iso-tacticity, UV resistance, hydrolysis resistance, and absolute biodegradability. Compared with conventional plastics, bioplastics are more beneficial due to their reduced carbon footprint, energy efficiency, biodegradability, and biocompatibility, and have hence revolutionized the polymer industry. However, further research is needed to explore novel strategies to overcome their limitations, such as decreasing water absorption and brittleness, while increasing the crystallization ability and increasing the thermal degradation temperature. These constraints can be addressed by supplementing the bioplastic synthesis process with reinforcements and plasticizers. The development and adoption of biopolymers as an environmentally friendly and economically viable substitutes for synthetic plastics is imperative, considering the degree of the subsequent exhaustion of petrochemical supplies and the worldwide environmental contamination instigated by the industrial production of synthetic plastics. The goal of this appraisal is to provide an in-depth account of the most recent advancements in the generation of bioplastics derived from various wastewater streams via the use of microalgae, and subsequent harvesting technologies. Bioplastics from microalgae are of higher quality and are made of polymeric biomolecules and include polymers based on cellulose, starch, proteins, PHA, polyhydroxybutyrate (PHB), polyethylene (PE), polylactic acid (PLA), and poly vinyl chloride (PVC). Various types of bioplastic manufacturing methodologies have also been highlighted for researchers and capitalists alike to investigate ways to harness these renewable resources for the development of sustainable bioplastics. Additionally, various innovations, challenges, potential possibilities for the future, and life cycle evaluations of bioplastics are addressed.

Continuous urbanization and modernization have increased the burning of fossil fuels to meet energy needs across the globe, emanating environmental pollution and depleting fossil fuels. Therefore, a shift towards sustainable and renewable energy is necessary. Several techniques to exploit biomass to yield energy are trending, with pyrolysis one of them. Usually, a single feedstock is employed in pyrolysis for anoxygenic generation of biochar together with bio-oil at elevated temperatures (350–600 °C). Bio-oil produced through pyrolysis can be upgraded to crude oil after some modification. However, these modifications of bio-oil are one of the major drawbacks for its large-scale adoption, as upgradation increases the overall cost. Therefore, in recent years the scientific community has been researching co-pyrolysis technology that involves the pyrolysis of lignocellulosic biomass waste with non-biodegradable waste. Co-pyrolysis reduces the need for post-modification of bio-oil, unlike pyrolysis of a single feedstock. This review article discusses the recent advancements and technological challenges in waste biomass co-pyrolysis, the mechanism of co-pyrolysis, and factors that affect co-pyrolysis. The current study critically analyzes different recent research articles presented in databases such as PubMed, MDPI, ScienceDirect, Springer, etc. Hence, this review is one-of-a-kind in that it attempts to explain each and every aspect of the co-pyrolysis process and its current progress in the scientific field. Consequently, this review also compiles the remarkable achievements in co-pyrolysis and recommendations for the future.