Deconstruction

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GLBRC's Deconstruction Research Area

Deconstruction

GLBRC's Deconstruction Lead takes top academic slot

Located at the intersection of the U.S.’s agricultural heartland and its northern forests, the GLBRC has access to a rich diversity of raw biomass for study. The Center's Deconstruction research focuses on identifying the best combinations of enzymes, chemicals, and physical processing methods for enhancing the digestibility of specific biomass sources.

Learn about the Center's research approach

Deconstruction Leadership

Deconstruction Lead

Dale is an expert on making ethanol from cellulose, plant stalks, grass, corn cobs and other woody plant parts and has developed a patented process called ammonia fiber expansion (AFEXTM), which makes the breakdown of cellulose more efficient, thus tackling...

Deconstruction Lead

Fox's research goals are to define the structure and the reactivity of the active site diiron center, to probe the catalytic contributions of the active site protein residues and to determine the consequences of protein-protein and protein-substrate interactions on the...

Project Overview

A biofuels reactor designed to produce ethanol at Michigan State University's Biomass Conversion Research Lab (BCRL)GLBRC Deconstruction research maintains a focus on the entire biofuels production pipeline: in addition to identifying and improving natural cellulose-degrading enzymes extracted from diverse environments, researchers apply unique biomass pretreatment technologies—such as ammonia fiber expansion (AFEX™), alkaline hydrogen peroxide (AHP), and extractive ammonia (EA)—that enable conversion technologies to maximize plant biomass utilization.. Researchers also explore strategies to add value to these processes by developing co-products from materials that would otherwise be treated as waste, such as lignin. Specific deconstruction projects include:

  • Pretreatment effects on biomass, alkaline peroxide pretreatment, fuel production from alkaline-pretreated biomass
  • Optimization of enzymes for biomass conversion, discovery of natural cellulolytic microbes, identification of novel microbial enzymes, and combinatorial discovery of enzymes and proteins

Deconstruction Publications

'Cradle-to-grave' assessment of existing lignocellulose pretreatment technologies

Leonardo da Costa Sousa; Shishir P.S. Chundawat; Venkatesh Balan; Bruce E. Dale

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2009

Pretreatment is considered to be a central unit process in a biorefinery to convert lignocellulosic biomass into fuels and chemicals, affecting all other operations in the process. A variety of technologies to pretreat lignocellulosic biomass are available today, which encompass a wide range of physical, chemical, and biological based processes. Among these, chemical based pretreatments are considered to be the most promising for future biorefineries. However, several key criteria regarding technical, economical, and environmental considerations should be critically analyzed when adapting these technologies for the nascent biorefinery industry. This review will discuss the most important pretreatment methods available today and will highlight key criteria for the development of a future ideal pretreatment.

Cellulosic ethanol production from AFEX-treated corn stover using Saccharomyces cerevisiae 424A(LNH-ST)

Ming W. Lau; Bruce E. Dale

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2009

Current technology using corn stover (CS) as feedstock, Ammonia Fiber Expansion (AFEX) as the pretreatment technology, and 424A(LNH-ST) as the ethanologenic strain in Separate Hydrolysis and Fermentation was able to achieve 191.5 g EtOH/kg untreated CS, at an ethanol concentration of 40.0 g/L (5.1 vol/vol%) without washing of pretreated biomass, detoxification, or nutrient supplementation. Enzymatic hydrolysis at high solids loading was identified as the primary bottleneck affecting overall ethanol yield and titer. Degradation compounds in AFEX-pretreated biomass were shown to increase metabolic yield and specific ethanol production while decreasing the cell biomass generation. Nutrients inherently present in CS and those resulting from biomass processing are sufficient to support microbial growth during fermentation. This platform offers the potential to improve the economics of cellulosic ethanol production by reducing the costs associated with raw materials, process water, and capital equipment.

Comparative analysis of efficiency, environmental impact, and process economics for mature biomass refining scenarios

Mark Laser; Eric Larson; Bruce E. Dale; Michael Wang; Nathanael Greene; Lee R. Lynd

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2009

Abstract: Fourteen mature technology biomass refi ning scenarios – involving both biological and thermochemical processing with production of fuels, power, and/or animal feed protein – are compared with respect to process effi ciency, environmental impact – including petroleum use, greenhouse gas (GHG) emissions, and water use–and economic profi tability. The emissions analysis does not account for carbon sinks (e.g., soil carbon sequestration) or sources (e.g., forest conversion) resulting from land-use considerations. Sensitivity of the scenarios to fuel and electricity price, feedstock cost, and capital structure is also evaluated. The thermochemical scenario producing only power achieves a process effi ciency of 49% (energy out as power as a percentage of feedstock energy in), 1359 kg CO2 equivalent avoided GHG emissions per Mg feedstock (current power mix basis) and a cost of $0.0575/kWh ($16/GJ), at a scale of 4535 dry Mg feedstock/day, 12% internal rate of return, 35% debt fraction, and 7% loan rate. Thermochemical scenarios producing fuels and power realize effi ciencies between 55 and 64%, avoided GHG emissions between 1000 and 1179 kg/dry Mg, and costs between $0.36 and $0.57 per liter gasoline equivalent ($1.37 – $2.16 per gallon) at the same scale and fi nancial structure. Scenarios involving biological production of ethanol with thermochemical production of fuels and/or power result in effi ciencies ranging from 61 to 80%, avoided GHG emissions from 965 to 1,258 kg/dry Mg, and costs from $0.25 to $0.33 per liter gasoline equivalent ($0.96 to $1.24/gallon). Most of the biofuel scenarios offer comparable, if not lower, costs and much reduced GHG emissions (>90%) compared to petroleum-derived fuels. Scenarios producing biofuels result in GHG displacements that are comparable to those dedicated to power production (e.g., >825 kg CO2 equivalent/dry Mg biomass), especially when a future power mix less dependent upon fossil fuel is assumed. Scenarios integrating biological and thermochemical processing enable waste heat from the thermochemical process to power the biological process, resulting in higher overall process effi ciencies than would otherwise be realized – effi ciencies on par with petroleum-based fuels in several cases.

Cradle-to-grave assessment of existing lignocellulose pretreatment technologies

Leonardo da Costa Sousa; Shishir P.S. Chundawat; Venkatesh Balan; Bruce E. Dale

More Info

2009

Pretreatment is considered to be a central unit process in a biorefinery to convert lignocellulosic biomass into fuels and chemicals, affecting all other operations in the process. A variety of technologies to pretreat lignocellulosic biomass are available today, which encompass a wide range of physical, chemical, and biological based processes. Among these, chemical based pretreatments are considered to be the most promising for future biorefineries. However, several key criteria regarding technical, economical, and environmental considerations should be critically analyzed when adapting these technologies for the nascent biorefinery industry. This review will discuss the most important pretreatment methods available today and will highlight key criteria for the development of a future ideal pretreatment.

Enzymatic digestibility and pretreatment degradation products of AFEX-treated hardwoods (Populus nigra)

Venkatesh Balan; Leonardo da Costa Sousa; Shishir P.S. Chundawat; Derek Marshall; Lekh N. Sharma; Kevin Chambliss; Bruce E. Dale

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2009

There is a growing need to find alternatives to crude oil as the primary feed stock for the chemicals and fuel industry and ethanol has been demonstrated to be a viable alternative. Among the various feed stocks for producing ethanol, poplar (Populus nigra x Populus maximowiczii) is considered to have great potential as a biorefinery feedstock in the United States, due to their widespread availability and good productivity in several parts of the country. We have optimized AFEX pretreatment conditions (180 degrees C, 2:1 ammonia to biomass loading, 233% moisture, 30 minutes residence time) and by using various combinations of enzymes (commercical celluloses and xylanases) to achieve high glucan and xylan conversion (93 and 65%, respectively). We have also identified and quantified several important degradation products formed during AFEX using liquid chromatography followed by mass spectrometry (LC-MS/MS). As a part of degradation product analysis, we have also quantified oligosaccharides in the AFEX water wash extracts by acid hydrolysis. It is interesting to note that corn stover (C4 grass) can be pretreated effectively using mild AFEX pretreatment conditions, while on the other hand hardwood poplar requires much harsher AFEX conditions to obtain equivalent sugar yields upon enzymatic hydrolysis. Comparing corn stover and poplar, we conclude that pretreatment severity and enzymatic hydrolysis efficiency are dictated to a large extent by lignin carbohydrate complexes and arabinoxylan cross-linkages for AFEX.

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