Kirtika Kohli and BK Sharma have been busy in the lab creating a greener delignification method for biofuels refinery processes. Many see biofuels as a viable alternative to fossil fuels because they are renewable and can reduce carbon emissions through plant growth. However, biomass needs to be processed before it can be converted to biofuels.
Lignin is a substance found in plants that makes them rigid and woody. Lignin helps plants resist rotting, so biomass harvested for biofuels must undergo a pre-treatment process to break down the lignin. Once lignin is removed, the remaining biomass could be easily converted to monomeric sugars, which can be converted biochemically into biofuels and other components in a biorefinery. With some additional refinement, the extracted lignin has the potential to be used in other applications in biofuels, biolubricants, polymers, binders, and biochemicals.
Current delignification processes have limited industrial applications because of their high costs, toxicity, and inability to recycle/reuse the chemicals used in the process. The team’s new method is more efficient, economic, and less toxic than current processes. It should ease operation/maintenance requirements and the need for special equipment as well as increase cost-effectiveness and recyclability. Their process is able to extract 85-88% of the lignin from Birchwood and Miscanthus (the two biomasses tested).
The team also developed a new lignin quantification method. The delignification process developed dissolves lignin into a green solvent that can be directly used for the quantification using a UV-Vis spectrophotometer. This new method is easier and more accurate than older lignin quantification methods, which were based on weight of the lignin yields that resulted in rough estimates.
In this research study, funded by ISTC’s Sponsored Research Program, Lance Schideman and his team partnered with Abbott Power Plant and the Urbana & Champaign Sanitary District to address critical challenges to practical demonstrations of biological CO2 capture systems and subsequent thermochemical conversion of biomass to biofuels.
The researchers developed the capability to harvest and store actual power plant flue gas samples in pressurized cylinders, then used these samples to study acclimation in algae cultivation systems dosed with flue gas. The project also demonstrated the use of anaerobic digestion to recover residual energy from the aqueous byproduct of hydrothermal liquefaction (HTLaq), which is generated during the conversion of algae or other organic feedstocks to biofuels.
This study showed that mixed culture algae are capable of using CO2 in flue gas, and the impact of the flue gas on algal growth rates was positive. Because higher flue gas injection rates resulted in higher productivity and lower CO2 removal efficiency, higher flue gas injection rates are preferable when the CO2 source is cheap and algae are considered the main product. Low flue gas injection rates would be preferable when the CO2 source is expensive or the CO2 removal efficiency is important. Heavy metal analysis showed that algal biomass will accumulate Zn, Pb, and Cu from flue gas, which can exceed certain animal feed regulatory limits.
This work also demonstrated that anaerobic treatment of HTLaq in combination with sewage sludge is feasible in both lab- and full-scale applications, which highlights the potential for enhancing energy recovery from sewage sludge through integration of hydrothermal liquefaction (HTL) technology with municipal wastewater treatment. Overall, this study highlights that integrating HTL technology with existing municipal sludge anaerobic digesters could significantly improve the bioenergy production of municipal wastewater treatment systems by 50 to 70% at a cost that is favorable compared to other alternatives.
Pairing of Waste Processing and Algae Farming Offers ‘Clean’ Energy
CHAMPAIGN, Ill. — “Mr. Sewer” is a multi-stage waste-to-biofuel production system under development by ISTC which can extract 100 percent of energy from a wide variety of wastes.
No, it’s not the fabled perpetual motion machine, it combines hydrothermal liquefaction of wastes with algae farming, which captures additional energy from the sun.
The best news is it can use a variety of energy-rich materials that are now landfilled. According to Lance Schideman, research scientist at the Illinois Sustainable Technology Center, the optimal location for the Mr. Sewer system is close to a sanitary landfill, a wastewater treatment plant, or both. A video on the energy research is available here.
Sewage solids, food wastes, even waste paper are all rich in energy content. This system can remove both organics and nutrients in these sources and turn them into renewable energy resources. Processing of wastewaters is combined with algae farming in a way that amplifies the energy production while cleaning the water for potential reuse applications. The nutrients support algal growth and the algae are then harvested for use in biofuels.
Amplified by the sun’s energy and multi-cycle nutrient reuse, an optimized system can harvest three to ten times the energy contained in the wastewater.
Calculations based on a commercial-scale demonstration plant on the University of Illinois campus indicate the technology is well-suited to generate fuel/revenue from wastes at the scale of a small city, a military installation, or a large animal feeding operation.
Theoretically Mr. Sewer, applied to all U.S. wastewater treatment plants and livestock operations, could produce enough bio-energy to replace all current petroleum imports, according to Schideman.
Today the commercial-scale plant is being optimized and a mobile version of the system is being developed.
Happy Back to the Future Day! ISTC Senior Research Engineer B.K. Sharma is one of the University of Illinois researchers featured in a fun roundup of predictions made for this day by the feature film 26 years ago.
The movies predictions about alternative fuels from garbage were somewhat prescient. Sharma hasn’t come up with Mr. Fusion, but he makes gasoline from all types of wastes (grocery bags, prescription medicine bottles, milk cartons, straws, bottle caps, tires, old coffee grounds, algae, sewage sludge, manure and food waste).
This fall the Illinois Sustainable Technology Center (ISTC) at the University of Illinois will be presenting information about several of its research and outreach projects at Urbana’s Market at the Square. Topics include:
• September 22 – Waste Biomass Projects: Turning waste into energy. Come learn how ISTC researchers, Dr. Junhua Jiang (Senior Research Engineer), uses biochar – a black carbon-rich solid made from biomass – in supercapacitors. Dr. B.K. Sharma (Senior Research Engineer) and Joe Pickowitz (Environmental Engineer) will also present how they turn everyday household and restaurant waste into bio-oils/bio-lubricants and biodiesel.
• September 29 – PPCPs in the Environment: More and more we hear of various chemicals being found in our streams and rivers. ISTC researcher, Dr. Wei Zheng (Senior Research Chemist), will discuss his research on fate and transport Pharmaceuticals and Personal Care Products (PPCPs) in the environment.
• October 6 – Sustainable Electronics Initiative (SEI) and the Indoor Climate Research & Training: Have you ever wondered where your discarded electronics go or just how much electronic waste the US produces each year? Visit with Joy Scrogum (Emerging Technologies Resource Specialist) who can answer these questions and others about SEI, e-waste, and responsible recycling.
Your home is your sanctuary; a place where all the worries of the world go away. Learn with Bill Rose (Senior Research Architect) and the ICRT program about way to improve your sanctuary’s performance in the areas of indoor air quality, roofing materials and attic ventilation, freezing pipe conditions, thermal performance at wall-ceiling junctions, and more.
• October 20 – Mud to Parks: Have you ever seen abandoned industrial areas that are eye sores in communities? Come learn how ISTC’s John Marlin (Research Affiliate) helped to discover how river sediments can be used to turn old industrial sites into parks.
• October 27 – Water Use and Reuse: Ever wondered how your drinking water gets cleaned? Learn how a couple of ISTC researchers, Dr. Kishore Rajagopalan (Associate Director for Applied Research) and Eric Duitsman (Chemist), clean a variety of liquid wastes with reverse osmosis membrane technology.
• November 3 – Waste to Oil: Dr. B.K. Sharma is back to demonstrate how he turns those pesky plastic grocery bags and other discarded plastic items into oil.
For more information on ISTC and/or these topics, please visit www.istc.illinois.edu or contact Elizabeth Luber at 217-333-7403 or firstname.lastname@example.org or Nancy Holm at 217-244-3330 or email@example.com.