Innovative in-situ Microwave-ultrasonic Reactor for Algal Biomass Harvesting and Biodiesel ProductionEPA Grant Number: SU835519
Title: Innovative in-situ Microwave-ultrasonic Reactor for Algal Biomass Harvesting and Biodiesel Production
Investigators: Gude, Veera Gnaneswar
Current Investigators: Gude, Veera Gnaneswar , Fast, Sara Ann , Kokabian, Bahareh , Martinez-Guerra, Edith
Institution: Mississippi State University - Main Campus
EPA Project Officer: Levinson, Barbara
Project Period: August 15, 2013 through August 14, 2014
Project Amount: $14,999
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2013) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Energy , P3 Awards , Sustainability
Algae have been identified as potential future energy source due to their high oil-yielding capacity, carbon neutrality and environmental-friendliness. However, major bottlenecks for current algal biodiesel production are harvesting/concentration, drying, and extraction steps due to their cost- and energy-intensive nature. For sustainable algal biodiesel production, energy-efficient technologies will need to be developed to increase the net energy gain and economic benefit.
This project develops an integrated process which includes an ultrasonic-biopolymer enhanced flocculation step for algal biomass harvesting followed by microwave/ultrasonic single-pot extractive-transesterification step to improve the energy foot print of the overall algal biodiesel process.
Ultrasonics at high frequencies flocculate suspended algal cells and ultrasonics and microwaves together improve extraction of oils/lipids by diffusive and disruptive mechanisms and simultaneously transesterify the lipids/oils due to increased mass/heat transfer phenomena and thermal/specific non-thermal effects at molecular levels. Further, use of biodegradable polymers, chitosan, as flocculation agent eliminates toxic sludge problems. Recent research on microwaves and ultrasonics in various process chemistry applications has shown the potential to reduce process time, reaction condition severities along with reduced chemical, energy and solvent consumption. The proposed process design can be considered sustainable since it utilizes high-oil yielding renewable feedstock, energy-efficient process techniques and reduces environmental pollution.
The proposed research design project addresses critical process issues of harvesting, drying, and extraction stages of algal biofuel processes. The process operates under mild conditions which eliminates the need for high pressure vessels and high processing costs. Central to this project is development of reactor design and process optimization techniques under microwave/ultrasonic mediated conditions. An in-situ microwave applicator with direct microwave and ultrasonic effect in a single process reactor will be developed. Understanding the effect of the two non-conventional technologies in flocculation, extraction and transesterification steps of algal biodiesel production will be beneficial for many other biofuel and chemical process related applications. Further, this design project is expected to produce results that promote energy independence through local algal biodiesel production (People), energy conservation by minimizing the process energy and cost requirements (Prosperity) and environmental pollution prevention by carbon-neutral algal biomass feedstock for biodiesel production (Planet).