Graphene is arguably the most tuneable material in the modern era with virtually endless number of applications. Current production methods such as chemical exfoliation and chemical vapour deposition are energy-intensive and environmentally unsustainable. Though fluid exfoliation is a scalable alternative to these methods of graphene synthesis, its low yield, long processing times and need for surfactants prevent its widespread use. Furthermore, the need for high-quality natural graphite resources as feed raises concerns due to the rapid increase in demands for batteries, with future market trends predicting a global graphite supply chain risk, making current graphene synthesis methods unsustainable and limiting the potential for graphene to be utilised in many industrial fields. In this study, nanocellulose and pine wood biomass, low-cost sustainable lignocellulosic biomass-derived materials were used as the precursor for graphene production. The biomass were pyrolysed to form biochar and then converted to graphene in the vortex fluidic device (VFD) using a combination of in situ grinding media and shear fluid exfoliation in water. The high shear spinning top flows in the VFD were responsible for the exfoliation and subsequent transformation of the biochar to graphene. The biochar properties such as the specific surface area and defect degree impacted the exfoliation degree, and 600°C was deemed the optimal pyrolysis temperature. The VFD processing parameters such as the Earth’s magnetic field and rotation direction, speed, residence time and use of grinding media also affected the exfoliation process. AFM and TEM showed that the graphene material was composed of <6 layered graphene with Raman spectroscopy revealing a low defect degree (ID/IG ratio of 0.40-0.60). XPS also revealed that the oxidation level of the graphene was dependent on the VFD processing time. In summary, this study achieved a high yield conversion of biomass to graphene using a sustainable and scalable approach.