Neither rain, nor sleet, nor snow can slow down the sessions here at the 2010 AIChE Annual Meeting in Salt Lake City. At the Sustainable Fuel From Renewable Resources Session, Biomass was the name of the game.
Led off by Sumesh Sukumara of the University of Kentucky, the stage was set for the biomass discussions with hispresentation Region Specific Economic Modeling of Integrated Biorefining Using Process Simulation and Supply Chain Optimization. Sukumara analyzed the biomass potential of the Jackson Purchase area of Kentucky--specifically looking at chicken litter. His Supply Chain Optimization model looked at the transportation infrastructure of the area in order to calculate the transportation costs.
Purdue University's Dharik Mallapragada was up next with his dynamic presentation The Scope of Using Concentrated Solar Energy to Produce Liquid Fuels from Biomass. Focusing on producing hydrocarbon fuels, his research centered around finding processes that could convert the most carbon from biomass feed.
Considering biomass more as a source of carbon than a source of energy, he analyzed the carbon conversion of a standalone gasification process, solar thermal gasification process, fast-hydropyrolysis and a solar energy assisted fast-hydropyrolysis process. He found that the H2 Bioil-STG process needed less energy, but produced about the same amount of fuel and converts the same amount of carbon recovery (44+%) in the liquid fuel as the heat assisted gasification process. Mallapragada took his presentation further and speculated, based on current research, that it would be possible to achieve nearly 100% biomass carbon recovery using solar energy as part of the process.
Mary Biddy of the National Renewable Energy Laboratory continued the biomass discussion with her presentation on the Comparison of Gasification/Synthesis Processes for Converting Wood Alcohols or Gasoline. Specifically, Biddy's presentation looked at the standard Methanol-to-Gasoline process utilized by industry with uses fixed beds in a multi-step process. The industrial Fixed Bed reactors require downtime for regeneration (and in business, time is money).
Her presentation also explored a fluidized bed reaction, a non-standard in industry reaction method which would not require as many separate reaction vessels or the same amount of downtime for the fixed bed regeneration. In addition to looking at the processes, hybrid poplar wood was used as the biomass feed. The overall process used Indirect biomass gasification to produce ethanol, a separate reaction to produce methanol from the ethanol, and the fluidized bed to produce gasoline from the methanol. Ultimately, her team was able to produce a yield of 55.4 gallons of gasoline per dry U.S. ton of the hybrid poplar feedstock.
Stephen M. Ritchie
Alternative Energy through Optimization of Methane Formation by Anaerobic Digesters in Municipal Wastewater Treatment Plants presented by Stephen M. Ritchie of the University of Alabama looked at a different type of biomass than the previous presenters. Looking at municipal wastewater treatment facilities as the source of the biomass feedstock, Richie broke down the Hydrolysis, Acidogenesis and Methanogenesis reactions necessary to produce methane from the raw material waste activated sludge.
Additonal experiments consisted of adding volatile fatty acids to the samples. Working with a biomass from a water treatment facility is interesting because these facilities have a constant feed coming in and the exact makeup of samples vary.
Finishing up the session was Ramalingam Subramaniam of the University of Louisiana at Lafayette with Optimization of Medium by Response Surface Methodology for reducing Ethanol Production Cost. In this presentation, Subramaniam explored the possibility of replacing yeast extract in an ethanol fermentation process with Biotin, Inositol and Calcium Pantothenate vitamins.
Prior to performing an experiment, he created a model for predicting the ethanol yield with this vitamin mixture. His ethanol yield model with the vitamins accurately predicted the experimental ethanol yield (Experimental value: 0.53g/g starch). Also, Subramaniam calculated the cost difference between using yeast extract versus the vitamin mixture: a savings of $1.15 per gallon of ethanol.
The biomass to fuel conversion is a great option as a place to begin on our global mission to reduce our dependence on polluting energy options. Removing fossil fuels from the equation is the first step, and with many options for biomass items, each geographical area may have their own unique optimal biomass product.
In his presentation, Dharik Mallapragada referenced an NRC report stating that there are currently 498 million metric tons per year of standalone biomass potential currently available--perhaps these findings and this technology will help us on our way to truly sustainable energy production.