Improved utilization of biomass-derived carbon by co-processing with hydrogen-rich feedstocks in millisecond reactors

Colby, Joshua L.; Dauenhauer, Paul J.; Michael, Brian C.; Bhan, Aditya; Schmidt, L.D.

doi:10.1039/b920387g

Cited by 15 publications

(14 citation statements)

References 16 publications

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“…Powder samples were pyrolyzed at 500 C. 44 (conduction or radiation) or chemically (chemical exchange and catalysis). 68,69 Secondary catalysts (vapor): catalysts added to pyrolysis reactors that exist outside of the particle wherein vapor products could diffuse, adsorb and react to produce value-added products (also volatile). Secondary catalysts do not influence condensedphase chemistry.…”

Section: Challenge #5: How Do Inorganic Catalysts Influence Condensed...mentioning

confidence: 99%

“…Over the past three decades, it has been conclusively shown that slow heating leads predominately to char, while higher heating rates (0.1-1.0 MW m À2 ) produce higher yields of volatile organics (i.e., bio oil). 18,39,40,68,69,78 This knowledge has led to a number of reactor designs where different heating methods are employed. Examples of pyrolysis vessels include fluidized bed reactors, 70,72,79 ablative reactors, 68,69 and focused radiation reactors.…”

Section: Challenge #6: How Does Char Form In Pyrolysis?mentioning

confidence: 99%

“…18,39,40,68,69,78 This knowledge has led to a number of reactor designs where different heating methods are employed. Examples of pyrolysis vessels include fluidized bed reactors, 70,72,79 ablative reactors, 68,69 and focused radiation reactors. 32,42 Predicting thermal profiles within a pyrolyzing lignocellulosic particle is a challenge since there is little experimental data available.…”

Section: Challenge #6: How Does Char Form In Pyrolysis?mentioning

confidence: 99%

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Top ten fundamental challenges of biomass pyrolysis for biofuels

Mettler

Vlachos

Dauenhauer

2012

Energy Environ. Sci.

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502

402

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Pyrolytic biofuels have technical advantages over conventional biological conversion processes since the entire plant can be used as the feedstock (rather than only simple sugars) and the conversion process occurs in only a few seconds (rather than hours or days). Despite decades of study, the fundamental science of biomass pyrolysis is still lacking and detailed models capable of describing the chemistry and transport in real-world reactors is unavailable. Developing these descriptions is a challenge because of the complexity of feedstocks and the multiphase nature of the conversion process. Here, we identify ten fundamental research challenges that, if overcome, would facilitate commercialization of pyrolytic biofuels. In particular, developing fundamental descriptions for condensed-phase pyrolysis chemistry (i.e., elementary reaction mechanisms) are needed since they would allow for accurate process optimization as well as feedstock flexibility, both of which are critical to any modern high-throughput process. Despite the benefits to pyrolysis commercialization, detailed chemical mechanisms are not available today, even for major products such as levoglucosan and hydroxymethylfurfural (HMF). Additionally, accurate estimates for heat and mass transfer parameters (e.g., thermal conductivity, diffusivity) are lacking despite the fact that biomass conversion in commercial pyrolysis reactors is controlled by transport. Finally, we examine methods for improving pyrolysis particle models, which connect fundamental chemical and transport descriptions to real-world pyrolysis reactors. Each of the ten challenges is presented with a brief review of relevant literature followed by future directions which can ultimately lead to technological breakthroughs that would facilitate commercialization of pyrolytic biofuels. Paper bodyAs the world population grows, there is a need for new energy technologies that are domestic and sustainable. Achieving both objectives requires improving existing energy systems as well as utilizing renewable feedstocks, such as biomass. In addition to supporting agricultural economies, biomass is the only renewable source for liquid fuels and chemicals. 1,2 For this reason, the U.S. Department of Energy has made it a goal to replace 30% of all transportation fuels with biofuels. 3 The 2005 'Billion-Ton Study' (BTS) sponsored by the U.S. Department of Energy employed conservative assumptions to determine that more than a billion tons of biomass (unrestricted by price) is available annually for biofuels. This amount of biomass is capable of displacing 30% of U.S. petroleum consumption, as put forth in the government targets. 3 In 2011, an update to the BTS revisited the resource availability and confirmed the findings of the 2005 study. 4 Both government-

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Section: Challenge #5: How Do Inorganic Catalysts Influence Condensed...mentioning

confidence: 99%

Section: Challenge #6: How Does Char Form In Pyrolysis?mentioning

confidence: 99%

Section: Challenge #6: How Does Char Form In Pyrolysis?mentioning

confidence: 99%

See 1 more Smart Citation

Top ten fundamental challenges of biomass pyrolysis for biofuels

Mettler

Vlachos

Dauenhauer

2012

Energy Environ. Sci.

Self Cite

502

402

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show abstract

“…In one example, Binder and Raines are producing furans from lignocellulosic biomass [14 ]. Colby et al have described a process of partial catalytic oxidation in which biomass carbon is taken to carbon monoxide in 100% yield [15 ]. This is significant for producing a synthesis gas stream without loss of biomass carbon as carbon dioxide or char.…”

Section: Biotechnological and Chemical Engineering Hybrid Approachesmentioning

confidence: 98%

Engineering microbes to produce biofuels

Wackett

2011

Current Opinion in Biotechnology

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“…In this context, emerging intensification approaches are being considering and consist of different strategies of catalyst integration that target both reduction of biomass residence time in the gasification reactor and simplification of downstream syngas treatment before its subsequent catalytic conversion [6]. Two different strategies can be considered: (i) http catalyst/reactor integration through the development of new catalytic microreactors or microstructured catalysts [8][9][10], and (ii) catalyst/biomass integration through the development of a new concept of integrated catalytic biomass gasification [6]. The catalyst/biomass integration strategy is being developed by our group as an alternative process intensification approach to the highly expensive noble metal-based catalytic microreactors and lead to new concept of integrated catalytic biomass gasification, illustrated in Fig.…”

Section: Introductionmentioning

confidence: 99%