Akwasi Boateng

ABSTRACT Much has been said of farmer-participated distributed processing as the key to economically producing advanced biofuels from cellulosic feedstocks. However, there is much yet to be done to realize the overarching goal of distributed on-farm production of biofuels and chemicals to contribute to the 2022 Energy Independence and Security Act (EISA) goals on advanced biofuels production. Counting on the potential for pyrolysis to provide small footprints that are adaptable to the farm setting, the USDA’s Agricultural Research Service’s (ARS) pyrolysis program at the Eastern Regional Research Center (ERRC) in Philadelphia has developed a compendium of catalytic and non-catalytic pyrolysis conversion technologies. These endeavors show potential for on-farm pyrolysis to be a truly carbon negative pathway to producing market entry fuels, such as heating oil, gasoline, diesel/jet fuel, and chemical intermediates, but critical barriers still exist. Although village or farm scale pyrolysis production has been modeled, distributed pyrolysis production has not been successfully demonstrated to determine the true economics of an actual integrated system; collective farmer participation is equally unproven and socio-economic and technological barriers still remain. FarmBio3 is a government-university-industry partnership led by ARS and funded by USDA-NIFA under the Biomass Resource and Development Initiative (BRDI) program. The overarching objective of FarmBio3 is to leverage existing synergies among partners to address some of these barriers and optimize pyrolysis pathways to commodity fuels and chemicals at various scales following a specific logic model. This presentation will introduce the Consortium members and provide an overview of the work to date. Accomplishments include near complete construction of a two metric ton per day patent-pending dual fluidized bed, combustion-reduction integrated pyrolysis unit (CRIPS), and the development of novel robust catalysts with appropriate chemical selectivity designed for on-the-farm operation.

ABSTRACT ARS/USDA is investigating the local utilization of equine waste as an alternative and replacement fuel source for heat generation using bio-oil produced via fast pyrolysis at the equine rehabilitation facility at Morrisville State College (MSC) with potential expansion to local farms. The Aspen Plus based simulation models the production of pyrolysis oil and its combustion in an existing boiler for the generation of hot water. Ultimate and proximate analysis on the manure and its pyrolysis products enabled the defining of the manure as a non-conventional compound and the pyrolysis products as conventional compounds based on stoichiometric formula. This results in quantifying the production of pyrolysis oil and bio-char which are valuable and sustainable energy sources that can be utilized at the local facility. Pyrolysis oil can be used as fuel in an existing hot water boiler system at MSC that produces hot water for the facility via diesel. The results show potential for displacing the diesel fuel by the pyrolysis oil produced from the locally generated equine waste, while also alleviating a waste disposal problem. Based on mass and energy balances of the system, heat integration is possible. Using a portion of the co-product bio-char for combustion provides all the heat required to run the pyrolyser. The fluidized bed pyrolyser will circulate sand from the pyrolysis unit through a combustion unit for reheating and then return it hot to the pyrolysis unit. Excess bio-char can be utilized in surrounding soils acting as a soil amendment. By incorporating the heat sources and heat integration in the model, energy requirements to run the system are significantly reduced. The mass and energy balances generated by Aspen Plus will be the basis for a Techno Economic Analysis for locating such a system at MSC; this will be presented and discussed further.

ABSTRACT This study aims to address two problems important to agriculture, production of drop-in fuels from biomass and disposal of agricultural plastics via co-pyrolysis of both materials. Mixtures of biomass (cellulose and switchgrass) and polypropylene (PP) or polyethylene terephthalate (PET) were subjected to catalytic fast pyrolysis (CFP) at 650oC in the presence of H-ZSM5 using a micro pyrolyzer coupled with GC/MS (py-GC/MS). Yields of the aromatic hydrocarbons, toluene, naphthalene and p-xylene, were enhanced for the CFP of mixtures of cellulose and plastic versus the CFP of biomass or plastic alone, suggesting a synergistic effect that enhanced the carbon efficiency of the CFP process. To further probe this effect, CFP of uniformly labeled 13C biomass with non-labeled (12C) PP and PET in the presence of H-ZSM5 were co-pyrolyzed. The resultant aromatic compounds had varying 13Cx12Cy compositions, proving that each reactant provides carbon to a pool from which aromatics are formed. Further analysis allowed for a more detailed picture of the source of carbon for each individual product. For example, it was found that for CFP of 13C biomass and PP pyrolysis, 69% of the toluene product was composed of at least four carbon atoms from PP. In this presentation the results of the catalytic co-pyrolysis of biomass and plastics and the isotopic labeling experiments will be discussed in detail in terms of yields of individual products, product selectivities and implications for the operative CFP mechanisms.

ABSTRACT Fast pyrolysis is proving to be a useful method for direct conversion of biomass into oxygenated liquid hydrocarbons, the product of which resembles crude oil (i.e. “bio-oil”). One major problem hindering the direct and cost-effective use of pyrolysis bio-oil is the presence of heteroatom contaminants. In particular, oxygenated components prevent bio-oil utilization due to repolymerization of pyrolyzed matter, acid corrosion of equipment, and attraction of unwanted moisture. An efficient process which removes significant amounts of oxygen would enhance the economic feasibility of biofuels for many applications. Furthermore, few works have investigated the effects of varying the feedstock source on the behavior and products of bio-oil upgrading by hydrodeoxygenation (HDO). To evaluate the potential of plant biomass as drop-in fuels, pyrolysis bio-oils from various feedstocks underwent hydrodeoxygenation (HDO) treatment in a pressurized batch reactor. This talk will discuss the effects of both feedstock type and HDO processing parameters on the upgraded oil composition. Carbon-supported transition-metal catalysts like platinum and ruthenium catalyze the removal of oxygen. Bio-oils studied were produced from feedstock sources including switchgrass and Eucalyptus benthamii. Also studied were partially deoxygenated bio-oils produced utilizing an HZSM-5 catalyst during the pyrolysis step. The batch reactions were typically performed isothermally at temperatures greater than 300 oC for several hours. Both the aqueous and organic phases post-HDO are characterized for their composition, water content, and acidity. The feedstock choice directly impacts the composition of bio-oil, and hence affects upgradability.

ABSTRACT Currently, there is research interest at the federal level through the Energy Independence and Security Act (EISA) to develop advanced biofuels that can serve as “drop-in” replacements for petroleum products that can utilize existing refining and distribution networks. Research in this area aims to both decarbonize and address energy security issues related to liquid fuel demand. Biofuels are renewable, low carbon fuels that are derived from biomass converted through different thermo-chemical or bio-chemical processes. Among the possible conversion processes, fast pyrolysis, the rapid thermal decomposition in the absence of oxygen, is considered to be an effective technology by which biomass, can be converted to valuable pyrolysis oil (bio-oil), biochar and gaseous products. Bio-oil and bio-char can each be used as a fuel and the gas can be recycled back into the process. In particular, bio-oils are attractive because of their high energy density and convenience in usage, storage and transport. Bio-char, rich in carbon, is resistant to degradation and can be either used as a source of energy for the process or as a soil amendment to enhance the sustainability of biomass harvesting and a means of carbon sequestration. The latter strategy will allow more residues to be removed from land by providing soil organic carbon (SOC) while benefiting from carbon storage. This study investigates the life cycle (LC) greenhouse gas (GHG) emissions and cost of different scenarios of pyrolysis of corn stover to bio-oil. A LC model is developed using data from literature, prior work (Spatari et al., 2010, Pourhashem et al.2010), and SimaPro life cycle inventory data to characterize the corn stover feedstock; and an Aspen Plus chemical process design developed by the United States Department of Agriculture (USDA) on the pyrolysis of the corn stover feedstock to bio-oil in a 200 ton/day scale facility. We study the cost effectiveness of the options for producing bio-oil as a final product or upgrading it to a drop-in transportation fuel; and the two options of utilizing the biochar byproduct i.e., as a source of energy or using it as a soil amendment and a means of sequestering carbon. The GHG emissions of the bio-oil and drop-in fuel produced are compared to low-grade heating fuel oils and gasoline, respectively. Results from this research show how different input parameters along the feedstock-fuel pathway affect the economics and net carbon intensity of different biorefinery products.

ABSTRACT Pyrolysis of biomass produces bio-oils that are highly oxygenated and acidic. Along with high water content and low higher heating values (HHV), these bio-oils are also unstable. Catalytic pyrolysis can alleviate these issues by producing bio-oils that consist of more desirable aromatic hydrocarbons. However, the low H/C nature of biomass leads to inefficient biomass carbon conversion and produces a great deal of CO, CO2 and coke that eventually causes catalyst deactivation. The incorporation of a co-feedstock with a higher H/C ratio could address these issues. The catalytic co-pyrolysis of biomass and plastic has been shown to produce products that incorporate C from both feedstocks and increases the production of desirable aromatic hydrocarbons. The use of agricultural plastics as a co-feed for the pyrolysis of biomass has the added benefit of providing a method for disposal of this waste. Switchgrass and used hay bale covers composed of polyethylene (PE) were mixed and subjected to catalytic pyrolysis in the presence of HZSM5 in a bench-scale fluidized-bed system. The catalytic pyrolysis oils were analyzed and compared to oils produced via regular pyrolysis and pyrolysis using a tail-gas reactive pyrolysis (TGRP) method. Yields were tracked on a mass and carbon basis. Complete chemical and physical property analysis including CHNS/O composition, energy content, and acidity were conducted. Chemical compositions of the pyrolysis oils were determined and compared with those produced from biomass alone.

The phenylpropanoid biosynthetic pathway that generates lignin subunits represents a significant target for altering the abundance and composition of lignin. The global regulators of phenylpropanoid metabolism may include MYB transcription factors, whose expression levels have been correlated with changes in secondary cell wall composition and the levels of several other aromatic compounds, including anthocyanins and flavonoids. While transcription factors correlated with downregulation of the phenylpropanoid biosynthesis pathway have been identified in several grass species, few transcription factors linked to activation of this pathway have been identified in C4 grasses, some of which are being developed as dedicated bioenergy feedstocks. In this study we investigated the role of SbMyb60 in lignin biosynthesis in sorghum (Sorghum bicolor), which is a drought-tolerant, high-yielding biomass crop. Ectopic expression of this transcription factor in sorghum was associated with higher expression levels of genes involved in monolignol biosynthesis, and led to higher abundances of syringyl lignin, significant compositional changes to the lignin polymer and increased lignin concentration in biomass. Moreover, transgenic plants constitutively overexpressing SbMyb60 also displayed ectopic lignification in leaf midribs and elevated concentrations of soluble phenolic compounds in biomass. Results indicate that overexpression of SbMyb60 is associated with activation of monolignol biosynthesis in sorghum. SbMyb60 represents a target for modification of plant cell wall composition, with the potential to improve biomass for renewable uses.

... Sci., 51, 4167-4181. Boateng, A. A. and Barr, PV (1997) "Granular Flow Behaviour in the Transverse Plane of a Partially Filled Rotating Cylinder". ... Boateng, AA, Thoen, ER and Orthlieb, FL (1997) "Modelling the Pyroprocess Kinetics of Shale Expansion in a Rotary Kiln", Trans. ...

... Such unstable conditions are related to the rheological properties of the material and will be ... flow theory it is not only the local values of the particle velocity, granular temperature and ... Suchbehaviour can expedite mathematical modelling of the flow field since it lends itself to ...

A mathematical model was developed to predict heat transfer from the freeboard gas to the bed of a rotary kiln. The thermal model incorporates a two-dimensional representation of the bed's transverse plane into a conventional one-dimensional, plug flow model for rotary ...

ABSTRACT Bioenergy plants such as sorghum, bioenergy rice, corn stover, and switchgrass can be thermochemically converted by pyrolysis to produce bio-oil, synthesis gas from noncondensable gases, and biochar. The biochar fraction can be recycled back to the production field to improve soil physical qualities and nutrient status. Although previous publications have described the beneficial effects of pyrolysis biochar on soil physical properties; relatively little has been published on the recovery of mineral nutrients from pyrolysis co-products. This work quantified the recovery of nutrients (P, K, Ca, and Mg) from pyrolysis coproducts from various feedstocks using two distinct reactors. Nutrient mass balances, on a feedstock basis, were calculated for comparison of the two reactors' efficiency in the recovery of the nutrients. The results revealed the recovery of nutrients varied by (1) species, (2) reactor design, and (3) correlated highly with nutrient mass loss in biochar. Computations also revealed P recoveries of 93% (fixed-bed reactor) and 58% and 55% (fluidized-bed reactor) for pyrolyzed sorghum. The recovery of key mineral nutrients in pyrolysis coproducts (primarily biochar) is directly related to the feasibility of nutrient recycling through biochar. © 2012 American Institute of Chemical Engineers Environ Prog, 2012

... Sci., 51, 4167-4181. Boateng, A. A. and Barr, PV (1997) "Granular Flow Behaviour in the Transverse Plane of a Partially Filled Rotating Cylinder". ... Boateng, AA, Thoen, ER and Orthlieb, FL (1997) "Modelling the Pyroprocess Kinetics of Shale Expansion in a Rotary Kiln", Trans. ...

Guyana is a leading rice producing country in the English Speaking Caribbean. While rice husk is considered as a waste in the rice milling industries in Guyana, it is finding useful applications in other developing countries. One such application is the use of its silica rich ash as a ...

Thermal processing of materials in rotary kilns involves heat transfer from the freeboard to the boundary surfaces of bed material and the distribution of this thermal energy within the granular bed. Although the former has been reasonably well characterized, the latter has ...

... the 1960s and 1970s place cement making at 12,000,000 BC when reactions between limestone and oil shale occurred during spon-taneous combustion to form ... counter current flow whereby the bed and gas flows are in opposite directions although co-current flow may ...