Towards integrated sustainable biofuel and chemical production: An application of banana pseudostem ash in the production of biodiesel and recovery of lignin from bamboo leaves.

This study investigated an integrated approach to the biowaste transformation and valorization of byproducts. Biochar obtained from the banana pseudostem was calcined to synthesize a heterogeneous catalyst and sustainably prepare a highly alkaline solution. The ash was utilized directly as a heterogeneous catalyst in biodiesel production from waste cooking oil. At the same time, an alkaline solution prepared from the ash was used for delignification and recovery of lignin from bamboo leaves by the hydrothermal reaction. Techniques like Fourier-transform infrared spectroscopy (FTIR), Field emission scanning electron microscopy (FESEM), Brunauer-Emmett-Teller (BET), Transmission electron microscopy (TEM), and Energy dispersive X-ray (EDX) were applied to characterized the catalyst. The alkaline solution was analyzed with Atomic absorption spectroscopy (AAS). The Response surface methodology (RSM) technique was considered for the optimization of different parameters in the transesterification and hydrothermal reaction. Under the optimized condition, waste cooking oil (WCO) to Fatty acid methyl ester (FAME) conversion was 97.56 ± 0.11%, and lignin recovery was 43.20 ± 0.45%. While at the best operating pyrolysis temperature, the liquid fraction yield from the banana pseudostem (500 °C) was 38.10 ± 0.31 wt%. This integrated study approach encourages the inexpensive, sustainable, and environment-friendly pathway for synthesizing catalysts and preparing a highly alkaline solution for the valorization of biowaste into biofuel and biochemicals.

Non-fuel applications of bio-oil for sustainability in management of bioresources.

Biomass valorization by thermochemical conversion method is a promising and intriguing pathway due to the flexibility of utilizing a diverse group of biomass and biowastes, specific product delivery mechanism through manipulation of process parameters, and wide applicability of the products. Pyrolysis has been viewed as an effective valorization technique to transform biowastes into pyrolytic oil, solid char, and syngas. Syngas is generally fed to the pyrolysis process to generate heat necessary for the pyrolysis process to sustain. Pyrolysis may also be a subsidiary component in a biorefinery system where it draws feedstocks from refinery process residues or the side streams of the refinery operation. In recent times, pyrolysis products have been under intense research for their usability and diverse applicability. Bio-oil's rich chemical makeup has promising potential to be used as an advanced biofuel and is considered as a storehouse of diverse chemical species ranging from green solvents to bioactive chemicals. The current review provides a state of knowledge on non-fuel uses of bio-oil and concludes that the pyrolysis process and products could be a part of the future bioeconomy if designed in a manner that biowastes are transformed into value-added products which replace products of petroleum origin.

Bioengineering to Accelerate Biodiesel Production for a Sustainable Biorefinery.

Biodiesel is an alternative, carbon-neutral fuel compared to fossil-based diesel, which can reduce greenhouse gas (GHGs) emissions. Biodiesel is a product of microorganisms, crop plants, and animal-based oil and has the potential to prosper as a sustainable and renewable energy source and tackle growing energy problems. Biodiesel has a similar composition and combustion properties to fossil diesel and thus can be directly used in internal combustion engines as an energy source at the commercial level. Since biodiesel produced using edible/non-edible crops raises concerns about food vs. fuel, high production cost, monocropping crisis, and unintended environmental effects, such as land utilization patterns, it is essential to explore new approaches, feedstock and technologies to advance the production of biodiesel and maintain its sustainability. Adopting bioengineering methods to produce biodiesel from various sources such as crop plants, yeast, algae, and plant-based waste is one of the recent technologies, which could act as a promising alternative for creating genuinely sustainable, technically feasible, and cost-competitive biodiesel. Advancements in genetic engineering have enhanced lipid production in cellulosic crops and it can be used for biodiesel generation. Bioengineering intervention to produce lipids/fat/oil (TGA) and further their chemical or enzymatic transesterification to accelerate biodiesel production has a great future. Additionally, the valorization of waste and adoption of the biorefinery concept for biodiesel production would make it eco-friendly, cost-effective, energy positive, sustainable and fit for commercialization. A life cycle assessment will not only provide a better understanding of the various approaches for biodiesel production and waste valorization in the biorefinery model to identify the best technique for the production of sustainable biodiesel, but also show a path to draw a new policy for the adoption and commercialization of biodiesel.