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1.
Sci Rep ; 14(1): 12385, 2024 May 29.
Article in English | MEDLINE | ID: mdl-38811806

ABSTRACT

The technique known as 4D-STEM has recently emerged as a powerful tool for the local characterization of crystalline structures in materials, such as cathode materials for Li-ion batteries or perovskite materials for photovoltaics. However, the use of new detectors optimized for electron diffraction patterns and other advanced techniques requires constant adaptation of methodologies to address the challenges associated with crystalline materials. In this study, we present a novel image-processing method to improve pattern matching in the determination of crystalline orientations and phases. Our approach uses sub-pixel adaptive image processing to register and reconstruct electron diffraction signals in large 4D-STEM datasets. By using adaptive prominence and linear filters, we can improve the quality of the diffraction pattern registration. The resulting data compression rate of 103 is well-suited for the era of big data and provides a significant enhancement in the performance of the entire ACOM data processing method. Our approach is evaluated using dedicated metrics, which demonstrate a high improvement in phase recognition. Several features are extracted from the registered data to map properties such as the spot count, and various virtual dark fields, which are used to enhance the handling of the results maps. Our results demonstrate that this data preparation method not only enhances the quality of the resulting image but also boosts the confidence level in the analysis of the outcomes related to determining crystal orientation and phase. Additionally, it mitigates the impact of user bias that may occur during the application of the method through the manipulation of parameters.

2.
Bioresour Technol ; 401: 130744, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38677384

ABSTRACT

Paper sludge biomass represents an underutilized feedstock rich in pulped and processed cellulose which is currently a waste stream with significant disposal cost to industry for landfilling services. Effective fractionation of the cellulose from paper sludge presents an opportunity to yield cellulose as feedstock for value-added processes. A novel approach to cellulose fractionation is the sidehill screening system, herein studied at the pilot-plant scale. Composition analysis determined ash removal and carbohydrate retention of both sidehill and high-performance benchtop screening systems. Sidehill screening resulted in greater carbohydrates retention relative to benchtop screening (90% vs 66%) and similar ash removal (95% vs 98%). Techno-economic analysis for production of sugar syrup yielded a minimum selling price of $331/metric ton of sugar syrup including disposal savings, significantly less than a commercial sugar syrup without fractionation. Sensitivity analysis showed that screening conditions played a significant role in economic feasibility for cellulosic yield and downstream processes.


Subject(s)
Biomass , Cellulose , Paper , Sewage , Pilot Projects , Cellulose/chemistry , Chemical Fractionation
3.
Arch Craniofac Surg ; 24(5): 236-239, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37919911

ABSTRACT

Porocarcinoma (PC) and basal cell carcinoma (BCC) are distinct skin cancers. Few studies have documented the occurrence of two concurrent types of skin cancers, and to the best of our knowledge, this represents the inaugural report of such a coexisting lesion arising from a capillary malformation. Herein, we report a case of concurrent PC and BCC presenting with capillary malformation. A 93-year-old woman visited our hospital with a protruding mass in her right nasal ala that appeared as a capillary malformation. A biopsy was performed on the skin lesion, and BCC was diagnosed. A wide excision was performed. Permanent biopsy revealed that the skin lesion was a PC with basal cells and squamous differentiation. The safety margin of the deep tissue margin was < 0.1 cm; however, considering the advanced age of the patient, further excision was deemed to not possess any benefits. This case illustrates the importance of recognizing the possibility of multiple skin cancers, even in patients with benign lesions such as capillary malformations. The rarity of this presentation highlights the importance of thorough investigation and histopathological examination of skin lesions in guiding appropriate surgical excision.

4.
ChemSusChem ; 16(24): e202300729, 2023 Dec 19.
Article in English | MEDLINE | ID: mdl-37642403

ABSTRACT

The demand for electrochemical energy storage is increasing rapidly due to a combination of decreasing costs in renewable electricity, governmental policies promoting electrification, and a desire by the public to decrease CO2 emissions. Lithium-ion batteries are the leading form of electrochemical energy storage for electric vehicles and the electrical grid. Lithium-ion cell anodes are mostly made of graphite, which is derived from geographically constrained, non-renewable resources using energy-intensive and highly polluting processes. Thus, there is a desire to innovate technologies that utilize abundant, affordable, and renewable carbonaceous materials for the sustainable production of graphite anodes under relatively mild process conditions. This review highlights novel attempts to realize the aforementioned benefits through innovative technologies that convert biocarbon resources, including lignocellulose, into high quality graphite for use in lithium-ion anodes.

5.
J Plast Reconstr Aesthet Surg ; 84: 62-70, 2023 09.
Article in English | MEDLINE | ID: mdl-37327734

ABSTRACT

BACKGROUND: The most common concern in nipple reconstruction is the loss of long-term nipple projection. This study aimed to demonstrate a novel method of nipple reconstruction using a modified C-V flap combined with purse-string sutures in the nipple base to maintain nipple projection. METHODS: From January 2018 to July 2021, patients who underwent nipple reconstruction using the novel modified C-V flap method and conventional C-V flap were retrospectively reviewed. The ratio of projection at the 3, 6, and 12-month postoperative follow-up to the initial nipple projection was calculated and compared. RESULTS: A total of 116 patients were included in this study, which was comprised of 41 patients in the conventional C-V flap group (conventional) and 75 patients in the modified C-V flap with purse-string sutures group (modified). The modified group showed a significantly higher ratio of nipple projection maintenance at postoperative 3 months (79.82%, conventional; 87.25%, modified; p < 0.001), 6 months (68.29%, conventional; 73.18%, modified; p < 0.001), and 12 months (53.98%, conventional; 60.19%, modified; p < 0.001), and a significantly lower revision rate (13/75 patients, 17.33%) than the conventional group (16/41 patients, 39.02%) (p = 0.009) during a mean of 17.67-month follow-up. CONCLUSIONS: Nipple reconstruction using a modified C-V flap with purse-string sutures in the nipple base is a safe and effective method for the maintenance of long-term nipple projection owing to the reduction and stabilization of the nipple base.


Subject(s)
Mammaplasty , Nipples , Humans , Retrospective Studies , Nipples/surgery , Mammaplasty/methods , Surgical Flaps/surgery , Sutures
6.
Int J Biol Macromol ; 243: 125085, 2023 Jul 15.
Article in English | MEDLINE | ID: mdl-37247712

ABSTRACT

The growing concern for the environment has resulted in renewed interest in bio-based resources. This study aims to produce a hydrogel adsorbent from cellulose and examine its adsorption performance. In pursuit of this goal, we report a simple one-pot synthesis of cellulose acetate sulfate (CAS), followed by the formation of CAS hydrogels and their subsequent adsorption performances. The CAS includes both hydrophilic and hydrophobic functional groups, enable the formation of a single-component hydrogel through intermolecular interactions in deionized water. The thermal reversibility of CAS hydrogels makes them easily processable into various shapes. The durability of the CAS hydrogel adsorbents can be improved by introducing divalent cations (e.g., Ca2+), which create ionically crosslinked hydrogels. The ionically a crosslinked CAS hydrogel adsorbent exhibits a maximum adsorption capacity of 245 mg/g for methylene blue (MB) at 23 °C and a pH of 7. The adsorption behavior of MB on the CAS hydrogel follows both the pseudo-second-order model and the Langmuir adsorption isotherm model. Furthermore, the CAS hydrogel adsorbent maintains a 70 % removal ratio after five cycles. The simplicity of synthesis and hydrogel formation opens up new possibilities for producing and utilizing cellulose-based hydrogels as adsorbents for aqueous contaminants.


Subject(s)
Hydrogels , Water Pollutants, Chemical , Hydrogels/chemistry , Water , Cellulose , Sulfates , Adsorption , Methylene Blue/chemistry , Water Pollutants, Chemical/chemistry , Kinetics , Hydrogen-Ion Concentration
7.
Melanoma Res ; 33(4): 326-331, 2023 08 01.
Article in English | MEDLINE | ID: mdl-37199704

ABSTRACT

Cutaneous malignant melanomas of the head and neck (HNM) are proposed to have notable histological and clinical differences from those at other sites (other melanoma); however, HNMs among Asians have remained poorly understood. This study aimed to investigate the clinicopathological features and prognostic factors of HNM in Asians. Asian melanoma patients who underwent surgical treatment from January 2003 to December 2020 were retrospectively reviewed. The clinicopathological features and risk factors for local recurrence, lymph node metastasis, and distant metastasis were analyzed. Among 230 patients, 28 (12.2%) were diagnosed with HNM, and 202 (87.8%) with other melanoma. The histologic subtype significantly differed as the nodular type was predominant in HNM whereas the acral lentiginous type was predominant in other melanoma ( P  < 0.001). HNM was significantly associated with higher local recurrence ( P  = 0.045), lymph node metastasis ( P  = 0.048), distant metastasis ( P  = 0.023), and lower 5-year disease-free survival ( P  = 0.022) than other melanoma. Ulceration was the risk factor for lymph node metastasis based on multivariable analysis ( P  = 0.013). A high proportion of HNM present as the nodular subtype in Asians, leading to poor outcomes and low survival. Therefore, more cautious surveillance, evaluation, and aggressive treatment are required.


Subject(s)
Asian , Head and Neck Neoplasms , Melanoma , Skin Neoplasms , Humans , Asian/statistics & numerical data , Head and Neck Neoplasms/ethnology , Head and Neck Neoplasms/mortality , Head and Neck Neoplasms/pathology , Head and Neck Neoplasms/surgery , Lymphatic Metastasis , Melanoma/ethnology , Melanoma/mortality , Melanoma/pathology , Melanoma/surgery , Neoplasm Staging , Prognosis , Retrospective Studies , Skin Neoplasms/ethnology , Skin Neoplasms/mortality , Skin Neoplasms/pathology , Skin Neoplasms/surgery , Skin Ulcer/ethnology , Skin Ulcer/etiology , Melanoma, Cutaneous Malignant
8.
Heliyon ; 9(5): e15765, 2023 May.
Article in English | MEDLINE | ID: mdl-37180912

ABSTRACT

In this study, the production and characterization of activated carbons (ACs) from agricultural and forest residue using physical activation are discussed. Biomass-based biochars produced during fast pyrolysis process is introduced as alternative precursors to produce AC and the integrated process for the co-production of porous adsorbent materials from biochar via the fast pyrolysis process is suggested. Moderate surface areas and good adsorption capacities were obtained from switchgrass (SWG) and pine tops (PT) based AC. The surface areas were 959 and 714 m2/g for SWG- and PT-based AC, respectively. The adsorption capacities using toluene as pollutant for two model systems of 180 and 300 ppm were measured and ranged between 441-711 and 432-716 mg/g for SWG-based and PT-based AC, respectively. The nitrogen adsorptive behavior, Lagergren pseudo-second-order kinetic (PSOK) model and kinetics isotherms studies describe a heterogeneous porous system, including a mesoporous fraction with the existence of a multilayer adsorption performance. The presence of micropores and mesopores in SWG- and PT-based AC suggests potential commercial applications for using pyrolytic biochars for AC production.

9.
Materials (Basel) ; 14(21)2021 Oct 28.
Article in English | MEDLINE | ID: mdl-34771997

ABSTRACT

Textile-reinforced mortar (TRM) is a strengthening material in which textiles are attached to reinforced concrete (RC) structures using an inorganic matrix. Although many studies on structural behavior, various factors that affect TRM behavior could not be determined clearly. Especially, the uncertainty in bonds due to inorganic materials was not considered. In this study, the flexural behavior of TRM-strengthened beams was determined considering intermediate crack debonding occurred. The TRM beam strengthening limit and TRM coefficients were defined considering the possibility of premature failure and experimental results of four other research on 22 specimens. Therefore, it is expected that a conservative design would be possible when the suggested strengthening limit coefficient is applied.

10.
Biotechnol Biofuels ; 14(1): 191, 2021 Sep 29.
Article in English | MEDLINE | ID: mdl-34587989

ABSTRACT

BACKGROUND: Woody biomass has been considered as a promising feedstock for biofuel production via thermochemical conversion technologies such as fast pyrolysis. Extensive Life Cycle Assessment studies have been completed to evaluate the carbon intensity of woody biomass-derived biofuels via fast pyrolysis. However, most studies assumed that woody biomass such as forest residues is a carbon-neutral feedstock like annual crops, despite a distinctive timeframe it takes to grow woody biomass. Besides, few studies have investigated the impacts of forest dynamics and the temporal effects of carbon on the overall carbon intensity of woody-derived biofuels. This study addressed such gaps by developing a life-cycle carbon analysis framework integrating dynamic modeling for forest and biorefinery systems with a time-based discounted Global Warming Potential (GWP) method developed in this work. The framework analyzed dynamic carbon and energy flows of a supply chain for biofuel production from pine residues via fast pyrolysis. RESULTS: The mean carbon intensity of biofuel given by Monte Carlo simulation across three pine growth cases ranges from 40.8-41.2 g CO2e MJ-1 (static method) to 51.0-65.2 g CO2e MJ-1 (using the time-based discounted GWP method) when combusting biochar for energy recovery. If biochar is utilized as soil amendment, the carbon intensity reduces to 19.0-19.7 g CO2e MJ-1 (static method) and 29.6-43.4 g CO2e MJ-1 in the time-based method. Forest growth and yields (controlled by forest management strategies) show more significant impacts on biofuel carbon intensity when the temporal effect of carbon is taken into consideration. Variation in forest operations and management (e.g., energy consumption of thinning and harvesting), on the other hand, has little impact on the biofuel carbon intensity. CONCLUSIONS: The carbon temporal effect, particularly the time lag of carbon sequestration during pine growth, has direct impacts on the carbon intensity of biofuels produced from pine residues from a stand-level pine growth and management point of view. The carbon implications are also significantly impacted by the assumptions of biochar end-of-life cases and forest management strategies.

11.
Bioresour Technol ; 340: 125726, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34426244

ABSTRACT

This study assesses the economic performance of a biorefinery producing xylo-oligosaccharides (XOS) from miscanthus by autohydrolysis and purification based on a rigorous model developed in ASPEN Plus. Varied biorefinery capacities (50-250 oven dry metric ton (ODMT)/day) and three XOS content levels (80%, 90%, 95%) are analyzed. The XOS minimum selling price (XOS MSP) is varied between $3,430-$7,500, $4,030-$8,970, and $4,840-$10,640 per metric ton (MT) for 80%, 90%, and 95% content, respectively. The results show that increasing biorefinery capacity can significantly reduce the XOS MSP and higher purity leads to higher XOS MSP due to less yield, and higher capital and operating costs. This study also explores another system configuration to produce high-value byproducts, cellulose microfiber, by utilizing the cellulose to produce microfiber instead of combusting for energy recovery. The XOS MSP of cellulose microfiber case is $2,460-$7,040/MT and thus exhibits potential economic benefits over the other cases.


Subject(s)
Cellulose , Oligosaccharides , Biomass , Hydrolysis , Lignin
12.
ACS Omega ; 6(26): 16934-16942, 2021 Jul 06.
Article in English | MEDLINE | ID: mdl-34250352

ABSTRACT

Mechanical refining (MR) is a cost-effective pretreatment in biochemical conversion processes that is employed to overcome biomass recalcitrance. This work studied the effects of MR on biogas and methane produced by the anaerobic digestion (AD) of dairy manure. The cumulative gas volume and yield from the AD of manure refined at 6k revolutions increased by 33.7 and 7.7% for methane and by 32.0 and 6.4% for biogas, respectively, compared to the unrefined manure. This enhancement was reached by increasing manure solubilization, reducing particle size, and achieving external fibrillation and internal delamination of fibers in manure. However, the highly refined manure (subjected to 60k revolutions) exhibited methane and biogas yields that were reduced by 9.5 and 1.5%, respectively. This decrease was observed because the pore structure was ruptured, and finely ground manure particles were aggregated together at high revolutions (60k), thereby inhibiting the release of organic matter from the manure. Therefore, this study indicates that the MR for pretreatment of dairy manure could have great potential for significantly enhancing AD of dairy manure. Further studies will include optimization of conditions of mechanical refining (i.e., mechanical intensity, process time), a continuous AD of dairy manure pretreated by the MR, and scale-up with cost evaluation.

13.
ChemSusChem ; 13(17): 4613-4623, 2020 Sep 07.
Article in English | MEDLINE | ID: mdl-32452146

ABSTRACT

Changes to the molecular properties of lignin over the course of biorefinery processing were investigated by using sweetgum as a feedstock. Hydrothermal pretreatment has been used because it is an economically attractive, green process. Three representative biorefinery lignin preparations were obtained, with about 70 % yield based on raw lignin. The three fractions included soluble lignin adsorbed on resin (XADL), solvent-extracted lignin (HTCELp), and an additional ball-milled residual lignin (HTRELp). By comparing the raw and biorefinery lignin preparations, it can be concluded that lignin undergoes both degradation and condensation throughout the various stages of the hydrothermal-based biorefinery process. The two fractions made soluble by biorefinery processing, XADL and HTCELp, were found to be low-molecular-weight degradation products enriched with free phenolic hydroxyl groups. In addition, about 15 % of noncondensed phenolic units were involved in condensation reactions. Quantitative NMR spectroscopy analysis revealed that at least about 28 % of ß-O-4' substructures were cleaved. Hibbert's ketones were identified in XADL and HTRELp, which provided evidence of lignin undergoing acidolysis. The contents of ß-5' and ß-ß' did not change significantly upon biorefinery processing. Finally, episyringaresinol was detected in XADL and HTCELp. It is hoped that these findings will help to further demonstrate the specific effects of biorefinery processing on lignin in hardwood and facilitate its utilization to improve biorefinery economics.

14.
Materials (Basel) ; 13(5)2020 Mar 04.
Article in English | MEDLINE | ID: mdl-32143407

ABSTRACT

In this study, nine specimens were experimentally tested to analyze the strengthening efficiency of textile-reinforced mortar (TRM) and the difference in flexural behavior between prestressed and non-prestressed TRM-strengthened reinforced concrete beam. The test results show that TRM strengthening improves the flexural strength of TRM-strengthened reinforced concrete beams with alkali-resistant-(AR-) glass textile as well as that with carbon textile. However, in the case of textile prestressing, the strengthening efficiency for flexural strength of the AR-glass textile was higher than that of the carbon textile. The flexural stiffness of AR-glass textiles increased when prestressing was introduced and the use of carbon textiles can be advantageous to reduce the decreasing ratio of flexural stiffness as the load increased. In the failure mode, textile prestressing prevents the damage of textiles effectively owing to the crack and induces the debonding of the TRM.

15.
RSC Adv ; 10(71): 43282-43289, 2020 Nov 27.
Article in English | MEDLINE | ID: mdl-35519667

ABSTRACT

A deicing agent from renewable resources is necessary to overcome the disadvantages of traditional deicing agents. In this study, biomass autohydrolyzate was evaluated for its applicability as corrosion inhibiting deicing agents. Autohydrolyzates treated with alkali showed significant freezing point depression and corrosion inhibiting effects on mild steel. Freezing points for autohydrolyzate treated with 2% (w/w) sodium hydroxide were depressed at -64.0 °C (56% solids content), and its maximum corrosion inhibiting efficiency was 61.5%. This material was found to be more effective than a tested commercial deicing agent. This strong performance is considered due to the xylooligosaccharides being degraded to various sugar acid compounds under alkaline treatment conditions, providing the mixture with solutes with corrosion inhibition potency. In conclusion, alkaline treated autohydrolyzate could replace traditional deicing agents based on superior performance and a sustainable production scheme.

16.
Tree Physiol ; 40(1): 73-89, 2020 01 01.
Article in English | MEDLINE | ID: mdl-31211386

ABSTRACT

Cellulose synthase A genes (CesAs) are responsible for cellulose biosynthesis in plant cell walls. In this study, functions of secondary wall cellulose synthases PtrCesA4, PtrCesA7-A/B and PtrCesA8-A/B were characterized during wood formation in Populus trichocarpa (Torr. & Gray). CesA RNAi knockdown transgenic plants exhibited stunted growth, narrow leaves, early necrosis, reduced stature, collapsed vessels, thinner fiber cell walls and extended fiber lumen diameters. In the RNAi knockdown transgenics, stems exhibited reduced mechanical strength, with reduced modulus of rupture (MOR) and modulus of elasticity (MOE). The reduced mechanical strength may be due to thinner fiber cell walls. Vessels in the xylem of the transgenics were collapsed, indicating that water transport in xylem may be affected and thus causing early necrosis in leaves. A dramatic decrease in cellulose content was observed in the RNAi knockdown transgenics. Compared with wildtype, the cellulose content was significantly decreased in the PtrCesA4, PtrCesA7 and PtrCesA8 RNAi knockdown transgenics. As a result, lignin and xylem contents were proportionally increased. The wood composition changes were confirmed by solid-state NMR, two-dimensional solution-state NMR and sum-frequency-generation vibration (SFG) analyses. Both solid-state nuclear magnetic resonance (NMR) and SFG analyses demonstrated that knockdown of PtrCesAs did not affect cellulose crystallinity index. Our results provided the evidence for the involvement of PtrCesA4, PtrCesA7-A/B and PtrCesA8-A/B in secondary cell wall formation in wood and demonstrated the pleiotropic effects of their perturbations on wood formation.


Subject(s)
Populus/genetics , Cell Wall , Gene Expression Regulation, Plant , Plants, Genetically Modified/genetics , Wood , Xylem/genetics
17.
3 Biotech ; 10(1): 1, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31815083

ABSTRACT

In this research, the binding of cellulolytic enzymes in Cellic® CTec2 on six lignin isolates obtained from alkali (0.5, 1.0, and 1.5% NaOH at 121 °C for 30 min) and acid (1, 2, and 3% H2SO4 at 121 °C for 60 min) pretreated switchgrass was investigated. Briefly, the hydrolysis of cellobiose and Avicel with and without (control) lignin isolates was performed via CTec2 (5 and 10 FPU g-1 carbohydrate) to determine whether the presence of lignin and binding of cellulolytic enzymes to the isolated lignin can affect the sugar production using three carbohydrate-lignin loadings, namely, 0.5:0.25, 0.5:0.5, and 0.5:1.0% (wv-1). Based on SDS-PAGE results, ß-glucosidase (BG) was significantly bound to all lignin isolates. Some enzymes in CTec2 presumed to be cellobiohydrolases, endo-1,4-ß-glucanases, and xylanase, were also observed to partially bind to the lignin isolates. Up to 0.97 g glucose g-1 cellobiose was produced via hydrolysis (72 h and pH 4.8) with CTec2 (5 and 10 FPU g-1 carbohydrate). Similarly, up to 0.23 and 0.46 g glucose g-1 Avicel were produced via hydrolysis (72 h and pH 4.8) with 5 and 10 FPU g-1 carbohydrate, respectively. Results indicated that the addition of lignin isolates during cellobiose and Avicel hydrolysis did not significantly (p > 0.05) reduce glucose production regardless of type and amount of lignin isolate. Hence, even though BG was significantly bound to lignin isolates, it could maintain its functionality as a biological catalyst in this study.

18.
Biotechnol Bioeng ; 117(4): 924-932, 2020 04.
Article in English | MEDLINE | ID: mdl-31885079

ABSTRACT

Mechanical refining results in fiber deconstruction and modifications that enhance enzyme accessibility to carbohydrates. Further understanding of the morphological changes occurring to biomass during mechanical refining and the impacts of these changes on enzymatic digestibility is necessary to maximize yields and reduce energy consumption. Although the degree of fiber length reduction relative to fibrillation/delamination can be impacted by manipulating refining variables, mechanical refining of any type (PFI, disk, and valley beater) typically results in both phenomena. Separating the two is not straightforward. In this study, fiber fractionation based on particle size performed after mechanical refining of high-lignin pulp was utilized to successfully elucidate the relative impact of fibrillation/delamination and fiber cutting phenomena during mechanical refining. Compositional analysis showed that fines contain significantly more lignin than larger size fractions. Enzymatic hydrolysis results indicated that within fractions of uniform fiber length, fibrillation/delamination due to mechanical refining increased enzymatic conversion by 20-30 percentage points. Changes in fiber length had little effect on digestibility for fibers longer than ~0.5 mm. However, the digestibility of the fines fractions was high for all levels of refining even with the high-lignin content.


Subject(s)
Biomass , Cellulase/metabolism , Lignin , Wood , Chemical Fractionation , Hydrolysis , Lignin/analysis , Lignin/chemistry , Lignin/metabolism , Wood/analysis , Wood/chemistry , Wood/metabolism
19.
Bioresour Technol ; 297: 122493, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31836278

ABSTRACT

The decarbonization of agriculture faces many challenges and has received a level of attention insufficient to abate the worst effects of climate change and ensure a sustainable bioeconomy. Agricultural emissions are caused both by fossil-intensive fertilizer use and land-use change, which in turn are driven in part by increasing demand for dietary protein. To address this challenge, we present a synergistic system in which organic waste-derived biogas (a mixture of methane and carbon dioxide) is converted to dietary protein and ammonia fertilizer. This system produces low-carbon fertilizer inputs alongside high-quality protein, addressing the primary drivers of agricultural emissions. If the proposed system were implemented across the United States utilizing readily available organic waste from municipal wastewater, landfills, animal manure, and commercial operations, we estimate 30% of dietary protein intake and 127% of ammonia usage could be displaced while reducing land use, water consumption, and greenhouse gas emissions.


Subject(s)
Fertilizers , Manure , Agriculture , Ammonia , Animals , Dietary Proteins , Greenhouse Effect , Methane
20.
Waste Manag ; 102: 909-918, 2020 Feb 01.
Article in English | MEDLINE | ID: mdl-31841983

ABSTRACT

Ex-situ co-pyrolysis of sugarcane bagasse pith and polyethylene terephthalate (PET) was investigated over zeolite-based catalysts using a tandem micro-reactor at an optimised temperature of 700 °C. A combination of zeolite (HZSM-5) and sodium carbonate/gamma-alumina served as effective catalysts for 18% more oxygen removal than HZSM-5 alone. The combined catalysts led to improved yields of aromatic (8.7%) and olefinic (6.9%) compounds. Carbon yields of 20.3% total aromatics, 18.3% BTXE (benzene, toluene, xylenes and ethylbenzene), 17% olefins, and 7% phenols were achieved under optimal conditions of 700 °C, a pith (biomass) to PET ratio of 4 and an HZSM-5 to sodium carbonate/gamma-alumina ratio of 5. The catalytic presence of sodium prevented coke formation, which has been a major cause of deactivation of zeolite catalysts during co-pyrolysis of biomass and plastics. This finding indicates that the catalyst combination as well as biomass/plastic mixtures used in this work can lead to both high yields of valuable aromatic chemicals and potentially, extended catalyst life time.


Subject(s)
Zeolites , Biomass , Catalysis , Hot Temperature , Hydrocarbons , Plastics , Pyrolysis , Sodium
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