The Effect of Biomass Physical Properties on Top-Lit Updraft Gasification of Woodchips

The performance of a top-lit updraft gasifier affected by biomass (pine wood) particle size, moisture content and compactness was studied in terms of the biochar yield, biomass burning rate, syngas composition and tar content. The highest biochar yield increase (from 12.2% to 21.8%) was achieved by varying the particle size from 7 to 30 mm, however, larger particles triggered tar generation that reached its maximum of 93.5 g/m3 syngas at 30-mm biomass particles; in contrast, the hydrogen content in syngas was at its minimum of 2.89% at this condition. The increase in moisture content from 10% to 22% reduced biochar yield from 12% to 9.9%. It also reduced the tar content from 12.9 to 6.2 g/m3 which was found to be the lowest range of tar content in this work. Similarly, the carbon monoxide composition in syngas decreased to its minimum of 11.16% at moisture content of 22%. Finally, the biomass compactness increased biochar yield up to 17% when the packing mass was 3 kg. However, the addition of compactness also increased the tar content in syngas, but little effect was noticed in syngas composition.The performance of a top-lit updraft gasifier affected by biomass (pine wood) particle size, moisture content and compactness was studied in terms of the biochar yield, biomass burning rate, syngas composition and tar content. The highest biochar yield increase (from 12.2% to 21.8%) was achieved by varying the particle size from 7 to 30 mm, however, larger particles triggered tar generation that reached its maximum of 93.5 g/m3 syngas at 30-mm biomass particles; in contrast, the hydrogen content in syngas was at its minimum of 2.89% at this condition. The increase in moisture content from 10% to 22% reduced biochar yield from 12% to 9.9%. It also reduced the tar content from 12.9 to 6.2 g/m3 which was found to be the lowest range of tar content in this work. Similarly, the carbon monoxide composition in syngas decreased to its minimum of 11.16% at moisture content of 22%. Finally, the biomass compactness increased biochar yield up to 17% when the packing mass was 3 kg. However, the addition of compactness also increased the tar content in syngas, but little effect was noticed in syngas composition

Airflow and insulation effects on simultaneous syngas and biochar production in a top-lit updraft biomass gasifier

The objective of this study was to understand the effect of airflow and insulation on syngas and biochar generations of rice hulls and woodchips in a top-lit updraft gasifier. Biochar yield decreased with increasing airflow. The highest biochar yields of 39% and 27% were achieved at 8 L/min airflow for rice hulls and woodchips, respectively. The mass fraction of syngas in the products increased with increasing airflow, which ranged from 88–89% for rice hulls and 93–94% for woodchips. The H2 composition in syngas also increased at higher airflow rates; it peaked at 4.2–4.4% for rice hulls and 5.7–6.6% (v/v) for woodchips, which was not affected by insulation. The carbon monoxide content in syngas ranged from approximately 12 to 15% (v/v) and was not affected by airflow or insulation. Average tar content in syngas decreased for both biomasses when airflow increased, but adding insulation resulted in significantly higher tar content in syngas. The biomass type also had significant effects on gasifier performance. Biochar yields from rice hulls were greater than that from woodchips at all airflow rates. The lowest tar contents in syngas were approximately 1.16 and 11.88 g/m3 for rice hulls and woodchips, respectively.The objective of this study was to understand the effect of airflow and insulation on syngas and biochar generations of rice hulls and woodchips in a top-lit updraft gasifier. Biochar yield decreased with increasing airflow. The highest biochar yields of 39% and 27% were achieved at 8 L/min airflow for rice hulls and woodchips, respectively. The mass fraction of syngas in the products increased with increasing airflow, which ranged from 88–89% for rice hulls and 93–94% for woodchips. The H2 composition in syngas also increased at higher airflow rates; it peaked at 4.2–4.4% for rice hulls and 5.7–6.6% (v/v) for woodchips, which was not affected by insulation. The carbon monoxide content in syngas ranged from approximately 12 to 15% (v/v) and was not affected by airflow or insulation. Average tar content in syngas decreased for both biomasses when airflow increased, but adding insulation resulted in significantly higher tar content in syngas. The biomass type also had significant effects on gasifier performance. Biochar yields from rice hulls were greater than that from woodchips at all airflow rates. The lowest tar contents in syngas were approximately 1.16 and 11.88 g/m3 for rice hulls and woodchips, respectively

Effect of ultrasonication of Switchgrass on fermentable sugar production and biomass physical structure

Pretreatment of lignocellulosic biomass for enhancing sugar yields has been studied extensively over the years.  Conventional methods employed to preprocess biomass to make it conducive for enzymatic hydrolysis have been hampered by issues like poor energy efficiency and production of undesirable by-products.  Ultrasonication, which involves the treatment of biomass through ultrasonic sound waves in a liquid medium without additional chemicals, is believed to have potential for biomass pretreatment.  In this study the effects of ultrasonication on switchgrass, a potential feedstock for bioethanol production due to its high cellulosic content, were investigated.  Results of compositional analysis and scanning electron microscopy conducted to visualize structural disintegration in sonicated samples were used to select pretreated samples for enzymatic hydrolysis at different enzyme loadings.  Temperature controlled ultrasonication for 60 min at 100% amplitude in a stainless steel vessel, resulted in the highest carbohydrate conversions of 84.6% and 84.7% with Cellic® CTec2 and Alternafuel 200 L at 0.3 g enzyme protein g-1 dry biomass, respectively.  However ultrasonication did not significantly impact composition of switchgrass and subsequent hydrolysis of untreated and treated samples was not significantly different.  Based on the overall results, it is inferred that although ultrasonication alone did not provide enhanced sugar generation from switchgrass, its tendency to disrupt biomass structure could be utilized for preliminary size reduction steps and performance could be improved by further investigation of frequencies, amplitudes, enzyme loadings and process operation parameters.   Keywords: Panicum virgatum, amplitude, pretreatment, hydrolysis, scanning electron microscopy

Analysis of micronized charcoal for use in a liquid fuel slurry

Yellow poplar (Liriodendron tulipifera) was chosen as the woody biomass for the production of charcoal for use in a liquid fuel slurry. Charcoal produced from this biomass resulted in a highly porous structure similar to the parent material. Micronized particles were produced from this charcoal using a multi-step milling process and verified using a scanning electron microscope and laser diffraction system. Charcoal particles greater than 50 µm exhibited long needle shapes much like the parent biomass while particles less than 50 µm were produced with aspect ratios closer to unity. Laser diffraction measurements indicated D10, D50, and D90 values of 4.446 µm, 15.83 µm, and 39.69 µm, respectively. Moisture content, ash content, absolute density, and energy content values were also measured for the charcoal particles produced. Calculated volumetric energy density values for the charcoal particles exceeded the No. 2 diesel fuel that would be displaced in a liquid fuel slurry.Peer reviewedBiosystems and Agricultural Engineerin

Deployment and Analysis of Instance Segmentation Algorithm for In-field Grade Estimation of Sweetpotatoes

Shape estimation of sweetpotato (SP) storage roots is inherently challenging due to their varied size and shape characteristics. Even measuring "simple" metrics, such as length and width, requires significant time investments either directly in-field or afterward using automated graders. In this paper, we present the results of a model that can perform grading and provide yield estimates directly in the field quicker than manual measurements. Detectron2, a library consisting of deep-learning object detection algorithms, was used to implement Mask R-CNN, an instance segmentation model. This model was deployed for in-field grade estimation of SPs and evaluated against an optical sorter. Storage roots from various clones imaged with a cellphone during trials between 2019 and 2020, were used in the model's training and validation to fine-tune a model to detect SPs. Our results showed that the model could distinguish individual SPs in various environmental conditions including variations in lighting and soil characteristics. RMSE for length, width, and weight, from the model compared to a commercial optical sorter, were 0.66 cm, 1.22 cm, and 74.73 g, respectively, while the RMSE of root counts per plot was 5.27 roots, with r^2 = 0.8. This phenotyping strategy has the potential enable rapid yield estimates in the field without the need for sophisticated and costly optical sorters and may be more readily deployed in environments with limited access to these kinds of resources or facilities.Comment: 21 pages, 11 figure

AAPT Diagnostic Criteria for Chronic Cancer Pain Conditions

Chronic cancer pain is a serious complication of malignancy or its treatment. Currently, no comprehensive, universally accepted cancer pain classification system exists. Clarity in classification of common cancer pain syndromes would improve clinical assessment and management. Moreover, an evidence-based taxonomy would enhance cancer pain research efforts by providing consistent diagnostic criteria, ensuring comparability across clinical trials. As part of a collaborative effort between the Analgesic, Anesthetic, and Addiction Clinical Trial Translations Innovations Opportunities and Networks (ACTTION) and the American Pain Society (APS), the ACTTION-APS Pain Taxonomy (AAPT) initiative worked to develop the characteristics of an optimal diagnostic system.59, 65 Following the establishment of these characteristics, a working group consisting of clinicians and clinical and basic scientists with expertise in cancer and cancer-related pain was convened to generate core diagnostic criteria for an illustrative sample of 3 chronic pain syndromes associated with cancer (i.e., bone pain and pancreatic cancer pain as models of pain related to a tumor) or its treatment (i.e., chemotherapy-induced peripheral neuropathy). A systematic review and synthesis was conducted to provide evidence for the dimensions that comprise this cancer pain taxonomy. Future efforts will subject these diagnostic categories and criteria to systematic empirical evaluation of their feasibility, reliability and validity and extension to other cancer-related pain syndromes

Functioning of Coastal River-Dominated Ecosystems and Implications for Oil Spill Response: From Observations to Mechanisms and Models

Coastal river-dominated oceans are physically complex, biologically productive, and intimately connected to human socioeconomic activity. The Deepwater Horizon blowout and subsequent advection of oil into coastal waters of the northern Gulf of Mexico (nGOM) highlighted the complex linkages among oceanographic processes within this river-dominated system and knowledge gaps about it that resulted in imprecise information on both oil transport and ecosystem consequences. The interdisciplinary research program implemented through the CONsortium for oil exposure pathways in COastal River-Dominated Ecosystems (CONCORDE) is designed to identify and quantitatively assess key physical, biological, and geochemical processes acting in the nGOM, in order to provide the foundation for implementation of a synthesis model (coupled circulation and biogeochemistry) of the nGOM shelf system that can ultimately aid in prediction of oil spill transport and impacts. CONCORDE field and modeling efforts in 2015–2016 focused on defining the influence of freshwater input from river plumes in the nGOM. In situ observations, combined with field-deployed and simulated drifters, show considerable variability in the spatial extent of freshwater influence that is related to wind direction and strength. Increased primary production and particle abundance (a proxy for secondary production) was observed during the spring when nGOM shelf waters were becoming stratified. Zooplankton and marine snow displayed intense vertical and horizontal patchiness during all seasons, often aggregating near the halocline. Simulations of a neutrally buoyant tracer released offshore of the Mississippi Bight showed surface advection of low tracer concentrations onto the inner shelf under high river discharge, high stratification, and variable wind conditions compared to almost no advection onto the inner shelf under low discharge, negligible stratification, and generally northeasterly winds. The interconnectedness of environmental variables and biological activity indicate that multiple factors can affect the transport of oil and the resulting ecological impacts. The process-oriented understanding provided by CONCORDE is necessary to predict ecosystem-level impacts of oil spills, and these results are applicable to other river-dominated coastal systems worldwide that often support oil extraction activities

Women’s subsistence strategies predict fertility across cultures, but context matters

While it is commonly assumed that farmers have higher, and foragers lower, fertility compared to populations practicing other forms of subsistence, robust supportive evidence is lacking. We tested whether subsistence activities—incorporating market integration—are associated with fertility in 10,250 women from 27 small-scale societies and found considerable variation in fertility. This variation did not align with group-level subsistence typologies. Societies labeled as “farmers” did not have higher fertility than others, while “foragers” did not have lower fertility. However, at the individual level, we found strong evidence that fertility was positively associated with farming and moderate evidence of a negative relationship between foraging and fertility. Markers of market integration were strongly negatively correlated with fertility. Despite strong cross-cultural evidence, these relationships were not consistent in all populations, highlighting the importance of the socioecological context, which likely influences the diverse mechanisms driving the relationship between fertility and subsistence

Agricultural Research Service Weed Science Research: Past, Present, and Future

The U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) has been a leader in weed science research covering topics ranging from the development and use of integrated weed management (IWM) tactics to basic mechanistic studies, including biotic resistance of desirable plant communities and herbicide resistance. ARS weed scientists have worked in agricultural and natural ecosystems, including agronomic and horticultural crops, pastures, forests, wild lands, aquatic habitats, wetlands, and riparian areas. Through strong partnerships with academia, state agencies, private industry, and numerous federal programs, ARS weed scientists have made contributions to discoveries in the newest fields of robotics and genetics, as well as the traditional and fundamental subjects of weed-crop competition and physiology and integration of weed control tactics and practices. Weed science at ARS is often overshadowed by other research topics; thus, few are aware of the long history of ARS weed science and its important contributions. This review is the result of a symposium held at the Weed Science Society of America\u27s 62nd Annual Meeting in 2022 that included 10 separate presentations in a virtual Weed Science Webinar Series. The overarching themes of management tactics (IWM, biological control, and automation), basic mechanisms (competition, invasive plant genetics, and herbicide resistance), and ecosystem impacts (invasive plant spread, climate change, conservation, and restoration) represent core ARS weed science research that is dynamic and efficacious and has been a significant component of the agency\u27s national and international efforts. This review highlights current studies and future directions that exemplify the science and collaborative relationships both within and outside ARS. Given the constraints of weeds and invasive plants on all aspects of food, feed, and fiber systems, there is an acknowledged need to face new challenges, including agriculture and natural resources sustainability, economic resilience and reliability, and societal health and well-being

The Effect of Air Flow Rate and Biomass Type on the Performance of an Updraft Biomass Gasifier

Airflow and the type of biomass are the two most important factors influencing the performance of a biomass gasifier. In this research, the effects of air flow rate (air-fuel equivalence ratios of 0.21, 0.25, and 0.29) and biomass type (woody biomass, agricultural residue, and perennial grass) on the performance of an updraft biomass gasifier were evaluated based on its tar and producer gas generation. It was found that increasing airflow increased the formation of tar species for all biomass types studied, but no significant differences in producer gas composition were found when the air-fuel equivalence ratio was changed. Thus, air-fuel equivalence ratios ranging from 0.21 to 0.25 were deemed appropriate for minimal tar generation. The results also showed that different biomass types generated producer gas with significantly different tar contents: woodchips yielded the most tar, followed by sorghum stover and prairie hay. The higher heating value of producer gas from various biomass types was also significantly different. Wood chip-derived producer gas had the greatest higher heating value, followed by prairie hay and sorghum stover. The carbon monoxide content in the produce gas of the three biomass types also exhibited significant differences with varying biomass type, similar to the higher heating value, but there were no significant differences in the H2 content with varying biomass type or airflow