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As one of the highest carbon-emitting nations, South Africa is working tirelessly to swiftly transition to sustainable technologies in order to strengthen its green economy initiatives. Amongst the technologies that are explored in the scientific and industrial community, biorefineries are seen as the most efficient technologies that can be used to create economic opportunities and will contribute to the advancement of a bio-based economy as they can synthesize diverse industrially-competitive products. Despite their numerous socio-economic advantages, the establishment of large-scale biorefineries in developing nations like South Africa is very scarce. Therefore, it is imperative to address the technological gaps that hinder the growth of large-scale biorefineries and provide practical solutions that could be used to solve these bottlenecks. This work provides a comprehensive review of the development of biowaste biorefinery-based technologies in South Africa. Different biowaste valorization technologies applicable to locally available organic waste streams, and the resulting market-based compounds that can be obtained from these sustainable feedstocks, are reviewed. Finally, the work provides insights into research and development needs (knowledge gaps) that should be explored by scientists and industries, as these technological solutions might propel biorefineries toward industrialization in South Africa. • A comprehensive review of biowaste biorefineries in South Africa is presented. • The biorefinery systems that are used to create new value chains are discussed. • The hurdles that hinder the industrialization of biorefineries are explored as well. • The study provides suggestions that could help surpass the current limitations. [ABSTRACT FROM AUTHOR]

Availability of cost-competitive biomass conversion technologies plays crucial role for successful realization of biorefinery for sustainable production of fuels and organic chemicals from biomass. The present article provides an outline of opportunities and socio-techno-economic challenges of various biomass processing technologies. The biomass processing technologies were classified into three broad categories: thermochemical, chemical and biochemical. This review article presents an overview of two potential thermochemical conversion processes, gasification and fast pyrolysis, for direct conversion of lignocellulosic biomass. The article further provides a brief review of chemical conversion of triglycerides by transesterification with methanol for production of biodiesel. The highly productive microalgae as an abundant source of triglycerides for biodiesel and various other fuels products were also reviewed. The present article also provides an outline of various steps involved in biochemical conversion of carbohydrates to alcoholic bio-fuels, bio-ethanol and bio-butanols and conversion of nature׳s most abundant aromatic polymer, lignin, to value-added fuels and chemicals. Furthermore, an overview of production of hydrocarbon fuels through various biomass processing technologies such as hydrodeoxygenation of triglycerides, biosynthetic pathways and aqueous phase catalysis in hydrocarbon biorefinery were highlighted. The present article additionally provides economic comparisons of various biomass conversion technologies. [ABSTRACT FROM AUTHOR]