Dr Rangabhasiyam and his postdoctoral scholar Dr Subramaniyasharma Sivaraman have published a groundbreaking research on “Electrostatic precipitator apparatus and methods”. Their patent has been published with Application Number 202541089260 . This study introduces a novel apparatus utilising electrostatic precipitation to effectively purify bio-oil, significantly reducing undesirable components while enriching the oil with valuable phenolics, ultimately paving the way for cleaner and higher-quality renewable fuels.

Abstract:
This research presents an apparatus and method utilizing electrostatic precipitation for purifying bio-oil derived from biomass pyrolysis, addressing the need for cleaner, higher-quality renewable fuels. The apparatus employs an electrostatic precipitator featuring a specific concentric cylinder design. This design comprises a grounded inner stainless-steel cylinder and an insulating outer polypropylene cylinder. A central wire electrode is subjected to a high positive potential of 13–15 kV to generate a corona discharge. Pyrolysis vapor flows through the gap between the cylinders , where the electrostatic field selectively removes heavier components. Experimental results demonstrate this treatment significantly reduces the acid and alcohol content (33.6%) while substantially enriching the bio-oil with valuable phenolics (7-fold), thereby improving its stability and suitability as a biofuel.

Explanation in Layperson’s Terms:
Pyrolysis is a thermochemical conversion method to produce gas and liquid fuels from waste materials. The liquid product, called bio-oil, exhibits properties similar to those of fuel oil or diesel. In recent years, it has gained attention as a prominent biofuel, growing in popularity as a building block for improved biofuels for transportation and a promising source for the development of biorefinery systems. However, this raw bio-oil is viscous and high in water/oxygen content, which impairs its properties. Furthermore, there is an increasing enthusiasm for enhancing the quality of bio-oil for use in heating, electricity generation, and various other purposes, which have potential applications as a fuel source or can be further processed for the synthesis of chemicals. We have devised a method that selectively cleans the bio-oil using high-voltage discharge. This creates a much cleaner, more stable, and more valuable bio-oil, which is far better suited to be used as renewable fuel. It is achieved while the bio-oil is still in the vapor phase, before it cools down into a liquid.

Practical Implementation and Social Implications:

• Waste Biomass Valorization: This technology provides a viable thermochemical conversion pathway for processing waste biomass. By converting waste materials into higher-value liquid fuels, it supports the valorization of agricultural or forestry residues.
• Enhanced Bio-oil Quality for Downstream Processing: By selectively removing heavier oligomeric species, the electrostatic precipitator enriches the relative concentration of valuable lighter compounds, specifically phenolics. The reduction of Total Acid Number (TAN) precursors like acids and alcohols directly implies improved bio-oil stability and reduced viscosity.
• Specialty chemicals production: The mechanism, which precipitates charged molecules, functions as a selective fractionation technique result in enriched in valuable phenolics and other light organics.