Valorization of slow pyrolysis vapor from biomass waste: Comparative study on pyrolysis characteristics, evolved gas evaluation, and adsorption effects.

Pyrolysis vapor is an important byproduct in the production of biochar from biomass waste, and its emission may pose potential environmental risks. To achieve green production of biochar and efficient utilization of pyrolysis vapors, a novel strategy is proposed in this study to use pristine biochar as an adsorbent to adsorb the pyrolysis vapors. According to thermogravimetry-Fourier infrared spectroscopy-mass spectrometry evaluation, the evolved vapors mainly consisted of oxygenated compounds, hydrocarbons, CO2, CO, and H2O. With pyrolysis temperature increasing, ethers, phenols, hydrocarbons, acids/ketones, and CO2 were changed in the same direction based on two-dimensional correlation spectroscopy analysis. Moreover, butene, propargyl alcohol, and butane were the most abundant ionic fragments. After adsorbing pyrolysis vapors, the heating value of the biochar increased by a maximum of 3.2 MJ kg-1 with changes of physicochemical properties. This strategy provides a theoretical basis for green preparation of biochar while recovering energy from pyrolysis vapors.

Physical Model Experiments on Failure Mechanism on Slopes of Weathered Basalt Soils during Heavy Rainfall Events.

Basalt platforms are widely distributed in many areas of China, where landslides occur frequently. It is well recognized that landslide hazards seriously threaten engineering constructions and property safety. It is, therefore, of great significance to understand deformation and failure behaviors and their mechanisms in basalt slopes to reduce the loss caused by landslides. In this work, the Pengshan Landslide in Zhejiang Province is taken as a prototype and slope model tests are carried out. During the tests, real-time monitoring of pore pressure, earth pressure and slope deformation is conducted. Based on the experimental data, the influence of rainfall intensity and the thickness of a weak interlayer on the slope stability are obtained. It is demonstrated that the rainfall and weak interlayer are the most important factors causing the slope instability of a basalt platform. Furthermore, damage from a basalt platform slope usually starts from local failure, and the slope foot is the most likely sliding part. Moreover, when the rainfall intensity is doubled, the initial deformation time of the slope is reduced by about half and the final failure time is advanced by one-third. In addition, when the thickness of the weak interlayer is doubled, the initial deformation time of slope is shortened by about half and the final failure time is advanced by one-quarter.

Study on Shear Creep Characteristics of the Discontinuities with Different 3D Morphologies.

The rheological phenomenon of rock mass affects the long-term safety of rock mass engineering. In this study, gneiss samples with different 3D morphologies are prepared by splitting tests and are tested through multi-step creep tests. The long-term strength of rock discontinuities is determined by using several methods. The test results show that as the 3D morphological parameter increases, the creep deformation, creep rate, and the duration of failure all decrease. The long-term strength of rock discontinuities is linearly related to the 3D morphological parameter. Based on the principle of damage mechanics for rock mass, a damage variable is introduced in the creep model, and an improved non-linear Burgers model is established. Research results are of great theoretical significance and practical value for the design, construction, and long-term safety of rock mass engineering.

Life-cycle assessment of pyrolysis processes for sustainable production of biochar from agro-residues.

Net carbon management of agro-residues has been an important pathway for reducing the environmental burdens of agricultural production. Converting agro-residues into biochar through pyrolysis is a prominent management strategy for achieving carbon neutrality in a circular economy, meeting both environmental and social concerns. Based on the latest studies, this study critically analyzes the life cycle assessment (LCA) of biochar production from different agro-residues and compares typical technologies for biochar production. Although a direct comparison of results is not always feasible due to different functional units and system boundaries, the net carbon sequestration potential of biochar technology is remarkably promising. By pyrolyzing agro-residues, biochar can be effectively produced and customized as: (i) alternative energy source, (ii) soil amendment, and (iii) activated carbon substitution. The combination of life cycle assessment and circular economy modelling is encouraged to achieve greener and sustainable biochar production.

Alternating magnetic field initiated catalytic deconstruction of medical waste to produce hydrogen-rich gases and graphite.

During the coronavirus 2019 (COVID-19) pandemic, there has been a dramatic increase in the use of medical products and personal protective equipment, such as masks, gowns, and disposable syringes, to treat patients or administer vaccines. However, this may lead to generation of large quantities of biohazardous medical waste. Here, an alternating-magnetic-field-initiated catalytic strategy is proposed to convert disposable syringes into hydrogen-rich gases and high-value graphite. Specifically, in addition to selecting heavy fraction of bio-oil as initiator, disposable syringe needles are used as radio frequency electromagnetic wave receptors to initiate the deconstruction of disposable syringe plastic. The highest H2 yield of 39.9 mmol g-1 is achieved, and 30.1 mmol g-1 is maintained after 10 cycles. Moreover, a high carbon yield of 286 mg g-1 can be obtained. Beyond disposable syringes, this strategy could help to solve the emerging issue for other types of medical waste (e.g., mask and protective clothing) disposal.

Economic Burden and Quality of Life of Hepatocellular Carcinoma in Greater China: A Systematic Review.

Background: Hepatocellular carcinoma (HCC) accounts for more than 85%-90% of primary liver cancer globally, and approximately 45% of deaths from HCC occur in greater China. This disease poses a significant economic burden for patients, payers and society and significantly affects patients' quality of life (QoL). However, such impact of HCC in greater China has not been well characterized. This review was conducted to analyze the current evidence about the economic and humanistic impact of HCC in greater China for informing national disease management and identifying clinical gaps yet to be resolved. Methods: A systematic search literature using seven databases (Web of Science, PubMed, Medline, Cochrane Central, China National Knowledge Infrastructure, Wanfang, and Weipu) was performed to identify interventional and observational studies that reported the impact of HCC on cost or QoL and published before April 6, 2021. The focus population included adult patients with HCC in greater China. This review excluded any studies that focused on any specific treatment. Study quality was assessed using the Effective Public Health Practice Project tool. Results: Of 39,930 studies retrieved, 27 were deemed eligible for inclusion. The methodologies, perspectives and data sources used in studies were heterogeneous. In greater China, while few studies reported the health expenditures of HCC patients and investigations about economic burden at national level was lacking, the significant economic impact of HCC on patients and their families had been reported. Health-related costs increased as the disease deteriorated. Additionally, HCC also has a negative impact on the QoL of patients, mostly in terms of physical, cognitive, social functioning and severe symptoms. Conclusions: HCC has brought significant economic and QoL burden to patients in greater China. Both physical and psychological factors predicted QoL in patients with HCC in greater China. Future studies should explore the disease-related economic effects on Chinese patients and their families, the effects of physical and psychological factors on QoL and the relationships of physical and psychological factors in the region.Systematic Review Registration: www.crd.york.ac.uk/prospero/display_record.php?RecordID=278421, PROSPERO: CRD42021278421.

Budget Impact Analysis of Diabetes Drugs: A Systematic Literature Review.

Background: Budget impact analysis (BIA) is an economic assessment that estimates the financial consequences of adopting a new intervention. BIA is used to make informed reimbursement decisions, as a supplement to cost-effectiveness analyses (CEAs). Objectives: We systematically reviewed BIA studies associated with anti-diabetic drugs and assessed the extent to which international BIA guidelines were followed in these studies. Methods: We conducted a literature search on PubMed, Web of Science, Econlit, Medline, China National Knowledge Infrastructure (CNKI), Wanfang Data knowledge Service platform from database inception to June 30, 2021. ISPOR good practice guidelines were used as a methodological standard for assessing BIAs. We extracted and compared the study characteristics outlined by the ISPOR BIA Task Force to evaluate the guideline compliance of the included BIA. Results: A total of eighteen studies on the BIA for anti-diabetic drugs were identified. More than half studies were from developed countries. Seventeen studies were based on model and one study was based on real-world data. Overall, analysis considered a payer perspective, reported potential budget impacts over 1-5 years. Assumptions were mainly made about target population size, market share uptake of new interventions, and scope of cost. The data used for analysis varied among studies and was rarely justified. Model validation and sensitivity analysis were lacking in the current BIA studies. Rebate analysis was conducted in a few studies to explore the price discount that was required for new interventions to demonstrate cost equivalence to comparators. Conclusion: Existing studies evaluating budget impact for anti-diabetic drugs vary greatly in methodology, some of which showed low compliance to good practice guidelines. In order for the BIA to be useful for assisting in health plan decision-making, it is important for future studies to optimize compliance to national or ISPOR good practice guidelines on BIA. Model validation and sensitivity analysis should also be improved in future BIA studies. Continued improvement of BIA using real-world data is necessary to ensure high-quality analyses and to provide reliable results.

High-value utilization of mask and heavy fraction of bio-oil: From hazardous waste to biochar, bio-oil, and graphene films.

At present, it is very common to wear mask outdoors in order to avoid coronavirus disease 19 (COVID-19) infection. However, this leads to the formation of numerous plastic wastes that threaten humans and ecosystem. Against this major background, a novel co-pyrolysis coupled chemical vapor deposition (CVD) strategy is proposed to systematically convert mask and heavy fraction of bio-oil (HB) into biochar, bio-oil, and three-dimensional graphene films (3DGFs) is proposed. The biochar exhibits high higher heating value (HHV) (33.22-33.75 MJ/kg) and low ash content (2.34%), which is obviously superior to that of the walnut shell and anthracite coal. The bio-oil contains rich aromatic components, such as 1,2-dimethylbenzene and 2-methylnaphthalene, which can be used as chemical feedstock for insecticides. Furthermore, the 3DGF800 has a wide range of applications in the fields of oil spill cleanup and oil/water separation according to its fire resistance, high absorbability (40-89 g g-1) and long-term cycling stability. This research sheds new light on converting plastic wastes and industrial by-products into high added-value chemicals.

Novel insights into the enrichment of phenols from walnut shell pyrolysis loop: Torrefaction coupled fractional condensation.

Enriching high-value chemicals from the pyrolysis of agricultural and forestry waste is an efficient way to achieve sustainable development and large-scale application of biomass pyrolysis. Phenols, as important chemical raw materials, spices and food additives, have attracted widespread attention. Herein, a novel technical route of torrefaction pretreatment combined with fractional condensation in pyrolysis loop was proposed to enrich the phenols in liquid products. In this study, the enrichment of phenols from the pyrolysis loop of walnut shell under the combination of torrefaction and fractional condensation was explored using a fixed-bed pyrolysis reactor equipped with a three-stage condensation system. Simultaneously, the effects of torrefaction on feedstocks were investigated through a thermogravimetric analyzer based on the characteristics of feedstocks. The results showed that the torrefaction and pyrolysis loop had a negative impact on the pyrolysis efficiency and the yield of liquid products, while the change in the condensation efficiency depended on the combined effects of torrefaction and pyrolysis loop. In addition, phenols tended to be enriched in the second condensation stage, especially phenol, o-cresol, 4-ethylphenol. Importantly, torrefaction could significantly enrich phenols in the liquid products, and the enrichment of phenols is relatively increased by 109.44% at least. Moreover, the pyrolysis loop was also beneficial to the enrichment of phenols, which was at least 90% higher than that of walnut shell. This study provided a potential route to enrich high value-added products from the pyrolysis loop of lignocellulosic biomass.

Study on the effect of condensing temperature of walnut shells pyrolysis vapors on the composition and properties of bio-oil.

The effect of condensing temperature on composition of bio-oil obtained via fractional condensation was investigated by pyrolysis-condensation experiments of walnut shells at condensing temperatures from 290 K to 370 K. The condensing efficiency of the first stage condenser decreased from 0.59 to 0.12 with increasing temperature. Moisture of bio-oil decreased from 40% to 5%, but the C/O ratio increased from 0.50 to 1.50. Compared with contents observed at the lowest condensation temperature, the maximum content of each component increased by 50%-500%. Combined with variations in condensing efficiency and composition content, the optimum condensing temperature range for declining water in bio-oil was 340-350 K. The condensing temperature associated with the enrichment of acetic acid and furfural was 345 K. The 355 K optimum condensing temperature could be selected to achieve the maximum enrichment of guaiacol and its derivatives.