Study of the kinetic behaviour of biomass and coal during oxyfuel co-combustion

In this study,the thermogravimetric analysis(TGA)method has been used to evaluate the kinetic behavior of biomass,coal and its blends during oxyfuel co-combustion.The thermogravimetric results have been evaluated by the Coats-Redfern method and validated by Criado’s method.TG and DTG curves indicate that as the oxygen concentration increases the ignition and burn out temperatures approach a lower temperature region.The combustion characteristic index shows that biomass to coal blends of 28%and 40%respectively can achieve enhanced combustion up to 60%oxygen enrichment.In the devolatilization region,the activation energies for coal and blends reduce while in the char oxidation region,they increase with rise in oxygen concentration.Biomass,however,indicates slightly different combustion characteristic of being degraded in a single step and its activation energies increase with rise in oxygen concentration.It is demonstrated in this work that oxygen enrichment has more positive combustion effect on coal than biomass.At 20%oxygen enrichment,28%and 40%blends indicate activation energy of 132.8 and 125.5 kJ·mol^-1 respectively which are lower than coal at 148.1 kJ·mol^-1 but higher than biomass at 81.5 kJ·mol^-1 demonstrating synergistic effect of fuel blending.Also,at char combustion step,an increase in activation energy for 28%blend is found to be 0.36 kJ·mol^-1 per rise in oxygen concentration which is higher than in 40%blend at 0.28 kJ·mol^-1.

Advanced Functional Electromagnetic Shielding Materials:A Review Based on Micro‑Nano Structure Interface Control of Biomass Cell Walls

Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.

Flexible Co-Combustion of High Ratios of Sustainable Biomass with Coal in Oxy-CFB Boiler for CO₂Capture

Coal-fired plants are under pressure to reduce their carbon-intensity. Available options include co-firing CO2-neutral biomass, oxy-fuel-combustion as part of a carbon capture process or a combination of both to give a “CO2-negative” power plant. BioCCS, the combination of CO2 Capture and Storage (CCS) with sustainable biomass conversion, is the only large-scale technology that can achieve net negative emissions. Combining, developing and demonstrating the oxy-combustion of high ratios of sustainable biomass with coal in flexible circulating fluidized bed (CFB) boiler will bring significant advances in the reduction of greenhouse gases (GHG) emissions. Areas addressed include possibilities for: biomass characterization;handling and feeding;co-firing ratios definition;CFB oxy-co-combustion studies;combustion performance;boiler flexibility in fuel and load;main emissions analysis;slaging, fouling and agglomeration;corrosion and erosion;and implications on plant operation and associated costs. The article will detail a comprehensive understanding on sustainable biomass supply, co-firing ratios and how direct biomass co-combustion under oxy-fuel conditions can be implemented. It seeks to push biomass co-combustion in future large-scale oxy-fuel CFB power stations to high thermal shares while enhancing the power plants’ operational flexibility, economic competitiveness and give operational procedures. There will be a need to consider the public acceptance of power production from coal and coal sustainability, by its combination with renewable sources of energy (biomass).

Co-combustion of municipal solid waste and coal gangue in a circulating fluidized bed combustor

Mixed incineration of municipal solid waste (MSW) in existing coal gangue power plant is a potentially highefficiency and low-cost MSW disposal way. In this paper, the co-combustion and pollutants emission characteristic of MSW and coal gangue was investigated in a circulating fluidized bed (CFB) combustor. The effect of MSW blend ratio, bed temperature and excess air ratio was detailedly studied. The results show the NOX and HC1 emission increases with the increasing MSW blend ratio and the SO2 emission decreases. With the increase of bed temperature, the CO emission decreases while the NOX and SO2 emission increases. The HC1 emission is nearly stable in the temperature range of 850-950℃. The increase of excess air ratio gradually increases the NOX emission but has no significant effect on the SO2 emission. The HC1 emission firstly increases and then decreases with the increase of excess air ratio. For a typical CFB operating condition with excess air ratio of 1.4, bed temperature of 900℃ and MSW blend ratio of 10%, the original CO, NOX, SO2 and HC1 emissions are 52, 181, 3373 and 58 mg/Nm^3 respectively.

Study on Co-combustion Characteristics of Superfine Coal with Conventional Size Coal in O₂/CO₂Atmosphere

The pulverized coal combustion in O2/CO2 atmosphere is one of the promising new technologies which can reduce the emission of carbon dioxide and NOx. In this study, the combustion behaviors of different mixing ratio of Shenhua coal with 20 μm and 74 μm particle size in the O2/CO2 atmosphere and air atmosphere were studied by using a thermal-gravimetric analyzer. The combustion characteristics such as ignition and burnout behavior were investigated in the temperature from 20℃ to 850℃. The influence of mixing ratio on combustion characteristics was conduced. The results obtained showed that the ignition temperature of the two kinds of particle size in O2/CO2 atmosphere is higher than in the air, while the activation energy in O2/CO2 atmosphere is lower. With the increasing ratio of 20 μm superfine pulverized coals, the ignition temperature and the activation energy decreased, while the DTG peak value increased, the maximum burning rate position advanced. There were three trends for the ignition temperature curve with the increasing of superfine coal ratio: the ignition of the mixed coal decreased rapidly, then changed less, at last reduced quickly.

Controllable heterogeneous interfaces and dielectric modulation of biomass-derived nanosheet metal-sulfide complexes for high-performance electromagnetic wave absorption

Constructing new environmentally friendly dielectric coupling models is an effective strategy for design-ing high-performance wave absorbers.However,biomass carbon materials with high potential energy and a lack of magnetic response mechanism do not fulfill the requirements.In this work,the effects of different pyrolysis temperatures and the introduction of different metal sulfides on the microscopic morphology and dielectric-magnetic properties of the composites were investigated.Among them,K el-ement detected in the biomass effectively modulates the conduction loss.The minimum reflection loss(RL_(min))of-62.42 dB at 1.8 mm and the maximum effective absorption bandwidth(EAB_(max))of-62.42 dB at 1.9 mm were obtained due to the non-uniform interfacial-induced polarization of the metal-sulfide nanosheets and the scattering of the electromagnetic waves(EW)by the“island”microstructures.This study provides a powerful reference for the modification and application of biomass materials.

Biomass-enhanced Janus sponge-like hydrogel with salt resistance and highstrength for efficient solar desalination

Interfacial solar-driven evaporation technology shows great potential in the field of industrial seawater desalination, and the development ofefficient and low-cost evaporation materials is key to achieving large-scale applications. Hydrogels are considered to be promising candidates;however, conventional hydrogel-based interfacial solar evaporators have difficulty in simultaneously meeting multiple requirements, including ahigh evaporation rate, salt resistance, and good mechanical properties. In this study, a Janus sponge-like hydrogel solar evaporator (CPAS) withexcellent comprehensive performance was successfully constructed. The introduction of biomass agar (AG) into the polyvinyl alcohol (PVA)hydrogel backbone reduced the enthalpy of water evaporation, optimized the pore structure, and improved the mechanical properties. Meanwhile, by introducing hydrophobic fumed nano-silica aerogel (SA) and a synergistic foaming-crosslinking process, the hydrogel spontaneouslyformed a Janus structure with a hydrophobic surface and hydrophilic bottom properties. Based on the reduction of the evaporation enthalpy andthe modulation of the pore structure, the CPAS evaporation rate reached 3.56 kg m^(-2) h^(-1) under one sun illumination. Most importantly, owingto the hydrophobic top surface and 3D-interconnected porous channels, the evaporator could work stably in high concentrations of salt-water(25 wt% NaCl), showing strong salt resistance. Efficient water evaporation, excellent salt resistance, scalable preparation processes, and low-costraw materials make CPAS extremely promising for practical applications.

Towards carbon neutrality of calcium carbide-based acetylene production with sustainable biomass resources

Acetylene is produced from the reaction between calcium carbide(CaC_(2))and water,while the production of CaC_(2) generates significant amount of carbon dioxide not only because it is an energy-intensive process but also the raw material for CaC_(2) synthesis is from coal.Here,a comprehensive biomass-to-acetylene process was constructed that integrated several units including biomass pyrolysis,oxygen-thermal CaC_(2) fabrication and calcium looping.For comparison,a coal-to-acetylene process was also established by using coal as feedstock.The carbon efficiency,energy efficiency and environmental impacts of the bio-based calcium carbide acetylene(BCCA)and coal-based calcium carbide acetylene(CCCA)processes were systematically analyzed.Moreover,the environmental impacts were further evaluated by applying thermal integration at system level and energy substitution in CaC_(2) furnace.Even though the BCCA process showed lower carbon efficiency and energy efficiency than that of the CCCA process,life cycle assessment demonstrated the BCCA(1.873 kgCO_(2eq) kg-prod^(-1))a lower carbon footprint process which is 0.366 kgCO_(2eq) kg-prod^(-1) lower compared to the CCCA process.With sustainable energy(biomass power)substitution in CaC_(2) furnace,an even lower GWP value of 1.377 kgCO_(2eq) kg-prod^(-1) can be achieved in BCCA process.This work performed a systematic analysis on integrating biomass into industrial acetylene production,and revealed the positive role of biomass as raw material(carbon)and energy supplier.

Numerical Simulation of Co-Combustion of Pulverized Coal and Different Proportions of Refused Derived Fuel in TTF Precalciner

Based on the theory of computational fluid dynamics(CFD),pulverized coal combustion alone,and the co-combustion of pulverized coal and refuse-derived fuel(RDF)in a Trinal-sprayed calciner(TTF)precalciner were simulated.The results revealed that when coal was used as a single fuel,the velocity field in the precalciner had good symmetry,and formed three spray effects and multiple recirculation zones.The main combustion zone was distributed in the lower tertiary air and pulverized coal area,and the highest temperature reached up to 1,500 K.According to the simulation results,the predicted decomposing rate of raw meal was 90.12%,which is in good agreement with the actual measured result.In addition,with the increase in RDF content,the average temperature of the furnace,the decomposition rate of the raw meal,and the NO_(x) concentration all exhibited a downward trend.Under the condition of ensuring the normal operation of the precalciner,blending with 20%RDF is the most reasonable strategy,and the NO_(x) emissions decreased by approximately 16%.

No effect of invasive tree species on aboveground biomass increments of oaks and pines in temperate forests

Prunus serotina and Robinia pseudoacacia are the most widespread invasive trees in Central Europe.In addition,according to climate models,decreased growth of many economically and ecologically important native trees will likely be observed in the future.We aimed to assess the impact of these two neophytes,which differ in the biomass range and nitrogen-fixing abilities observed in Central European conditions,on the relative aboveground biomass increments of native oaks Qucrcus robur and Q.petraea and Scots pine Pinus sylvestris.We aimed to increase our understanding of the relationship between facilitation and competition between woody alien species and overstory native trees.We established 72 circular plots(0.05 ha)in two different forest habitat types and stands varying in age in western Poland.We chose plots with different abundances of the studied neophytes to determine how effects scaled along the quantitative invasion gradient.Furthermore,we collected growth cores of the studied native species,and we calculated aboveground biomass increments at the tree and stand levels.Then,we used generalized linear mixed-effects models to assess the impact of invasive species abundances on relative aboveground biomass increments of native tree species.We did not find a biologically or statistically significant impact of invasive R.pseudoacacia or P.serotina on the relative aboveground,biomass increments of native oaks and pines along the quantitative gradient of invader biomass or on the proportion of total stand biomass accounted for by invaders.The neophytes did not act as native tree growth stimulators but also did not compete with them for resources,which would escalate the negative impact of climate change on pines and oaks.The neophytes should not significantly modify the carbon sequestration capacity of the native species.Our work combines elements of the per capita effect of invasion with research on mixed forest management.

Cross-upgrading of biomass hydrothermal carbonization and pyrolysis for high quality blast furnace injection fuel production:Physicochemical characteristics and gasification kinetics analysis

The paper proposes a biomass cross-upgrading process that combines hydrothermal carbonization and pyrolysis to produce high-quality blast furnace injection fuel.The results showed that after upgrading,the volatile content of biochar ranged from 16.19%to 45.35%,and the alkali metal content,ash content,and specific surface area were significantly reduced.The optimal route for biochar pro-duction is hydrothermal carbonization-pyrolysis(P-HC),resulting in biochar with a higher calorific value,C=C structure,and increased graphitization degree.The apparent activation energy(E)of the sample ranges from 199.1 to 324.8 kJ/mol,with P-HC having an E of 277.8 kJ/mol,lower than that of raw biomass,primary biochar,and anthracite.This makes P-HC more suitable for blast furnace injection fuel.Additionally,the paper proposes a path for P-HC injection in blast furnaces and calculates potential environmental benefits.P-HC of-fers the highest potential for carbon emission reduction,capable of reducing emissions by 96.04 kg/t when replacing 40wt%coal injec-tion.

Sustainable Furfural Biomass Feedstocks Electrooxidation toward Value-Added Furoic Acid with Energy-Saving H_(2) Fuel Production Using Pt-Decorated Co_(3)O_(4) Nanospheres

Here,furfural oxidation was performed to replace the kinetically sluggish O_(2)evolution reaction(OER).Pt-Co_(3)O_(4)nanospheres were developed via pulsed laser ablation in liquid(PLAL)in a single step for the paired electrocatalysis of an H_(2)evolution reaction(HER)and furfural oxidation reaction(FOR).The FOR afforded a high furfural conversion(44.2%)with a major product of 2-furoic acid after a 2-h electrolysis at 1.55 V versus reversible hydrogen electrode in a 1.0-M KOH/50-mM furfural electrolyte.The Pt-Co_(3)O_(4)electrode exhibited a small overpotential of 290 mV at 10 mA cm^(-2).As an anode and cathode in an electrolyzer system,the Pt-Co_(3)O_(4)electrocatalyst required only a small applied cell voltage of~1.83 V to deliver 10 mA cm^(-2),compared with that of the pure water electrolyzer(OER||HER,~1.99 V).This study simultaneously realized the integrated production of energy-saving H_(2)fuel at the cathode and 2-furoic acid at the anode.

The Use of Secondary Grape Biomass in Beef Cattle Nutrition on Carcass Characteristics, Quality and Shelf Life of Meat

We determined whether the inclusion of 100 g/kg dry matter of grape pomace silage (GPS) and grape pomace bran (GPB) as substitutes for other traditional fiber sources in the diet of steers (Charolais x Nellore) would improve carcass characteristics, meat quality and composition, and shelf life. Twenty-four animals (248 ± 19.32 kg of initial body weight) were fed a high concentrate diet for 121 days. Carcass characteristics were measured, and the longissimus dorsi muscle was analyzed for fatty acid (FA) profile and composition. The meat was sliced and stored in air-permeable packages for 10 days. On each sampling day (d 1, 3, 7, and 10), oxidative stability, bacterial load, lipid and protein oxidation, and staining were analyzed. The experimental diets influenced the pH of cold carcasses only. The GPS group had a higher pH than the control. The GPS and GPB groups showed improved oxidant status (i.e., lower lipid peroxidation and concentrations of reactive oxygen species were in the meat of both groups than in control). On the first day of storage, the antioxidant enzyme glutathione S-transferase activity was more significant in the meat of the GPS and GPB groups than in the control. The bacterial loads in the meat were attenuated by GPS inclusion;there were lower total coliform counts and a trend toward lower counts for enterobacteria in the control group. The diets altered the FA profile of the meat;i.e., the GPB diet allowed for a more significant amount of the n-6 omegas in the meat, while the GPS diet showed a tendency for a more significant amount of n-6 and 9 omegas. Both diets (GPS and GPB) increased the amounts of long-chain FAs. The GPS diet decreased saturated FA levels. We conclude that the dietary treatments GPS and GPB are a promising alternative to maintain meat quality standards throughout in real-world retail conditions. These treatments gave rise to an improvement in the nutritional value of the meat due to the more significant amounts of FAs that improve human health.

Species-specific and generalized allometric biomass models for eight Fagaceae species in the understory of evergreen broadleaved forests in subtropical China

Quantifying the biomass of saplings in the regeneration component is critical for understanding biogeochemical processes of forest ecosystems.However,accurate allometric equations have yet to be developed in sufficient detail.To develop species-specific and generalized allometric equations,154 saplings of eight Fagaceae tree species in subtropical China’s evergreen broadleaved forests were collected.Three dendrometric variables,root collar diameter(d),height(h),and crown area(ca)were applied in the model by the weighted nonlinear seemingly unrelated regression method.Using only d as an input variable,the species-specific and generalized allometric equations estimated the aboveground biomass reasonably,with R _(adj)^(2) values generally>0.85.Adding h and/or ca improved the fitting of some biomass components to a certain extent.Generalized equations showed a relatively large coefficient of variation but comparable bias to species-specific equations.Only in the absence of species-specific equations at a given location are generalized equations for mixed species recommended.The developed regression equations can be used to accurately calculate the aboveground biomass of understory Fagaceae regeneration trees in China’s subtropical evergreen broadleaved forests.

Renewable Biomass as a Platform for Preparing Green Chemistry

1 About the Special Issue Editor Qiaoguang Li is an associate professor and master’s supervisor in the Department of College of Chemistry and Chemical Engineering,Zhongkai University of Agriculture and Engineering.He received his PhD from Institute of Chemical Industry of Forestry Products,Chinese Academy of Forestry in 2018.He has been focusing his research on the chemical basis and application of natural resources.He has published nearly 30 international peer reviewed papers and applied for 10 patents.

Integrating remote sensing and 3-PG model to simulate the biomass and carbon stock of Larix olgensis plantation

Accurate estimations of biomass and its temporal dynamics are crucial for monitoring the carbon cycle in forest ecosystems and assessing forest carbon sequestration potentials.Recent studies have shown that integrating process-based models(PBMs)with remote sensing data can enhance simulations from stand to regional scales,significantly improving the ability to simulate forest growth and carbon stock dynamics.However,the utilization of PBMs for large-scale simulation of larch carbon storage distribution is still limited.In this study,we applied the parameterized 3-PG(Physiological Principles Predicting Growth)model across the Mengjiagang Forest Farm(MFF)to make broad-scale predictions of the biomass and carbon stocks of Larix olgensis plantation.The model was used to simulate average diameter at breast height(DBH)and total biomass,which were later validated with a wide range of observation data including sample plot data,forest management inventory data,and airborne laser scanning data.The results showed that the 3-PG model had relatively high accuracy for predicting both DBH and total biomass at stand and regional scale,with determination coefficients ranging from 0.78 to 0.88.Based on the estimation of total biomass,we successfully produced a carbon stock map of the Larix olgensis plantation in MFF with a spatial resolution of 20 m,which helps with relevant management advice.These findings indicate that the integration of 3-PG model and remote sensing data can well predict the biomass and carbon stock at regional and even larger scales.In addition,this integration facilitates the evaluation of forest carbon sequestration capacity and the development of forest management plans.

Biomass valorization via electrocatalytic carbon–carbon bond cleavage

Renewable electrocatalytic upgrading of biomass feedstocks into valuable chemicals is one of the promising strategies to relieve the pressure of traditional energy-based systems.Through electrocatalytic carbon–carbon bond cleavage of high selectivity,various functionalized molecules,such as organic acids,amides,esters,and nitriles,have great potential to be accessed from biomass.However,it has merely received finite concerns and interests in the biorefinery.This review first showcases the research progress on the electrocatalytic conversion of lipid/sugar-and lignin-derived molecules(e.g.,glycerol,mesoerythritol,xylose,glucose,1-phenylethanol,and cyclohexanol)into organic acids via specific carbon–carbon bond scission processes,with focus on disclosing reaction mechanisms,recognizing actual active species,and collecting feasible modification strategies.For the guidance of further extensive studies on biomass valorization,organic transformations via a variety of reactions,including decarboxylation,ring-opening,rearrangement,reductive hydrogenation,and carboxylation,are also disclosed for the construction of similar carbon skeletons/scaffolds.The remaining challenges,prospective applications,and future objectives in terms of biomass conversion are also proposed.This review is expected to provide references to develop renewed electrocatalytic carbon–carbon bond cleavage transformation paths/strategies for biomass upgrading.

Research Progress of Biomass-Based Porous Oil-Absorbing Materials

As oil is now an important resource for the survival and development of mankind,the consumption of oil continues to increase each year,and there have been a number of major oil spills in history,such as the oil spill from the Deepwater Horizon drilling rig.Therefore,oil spills during storage and transportation have become an issue of serious concern.Current methods such as incineration and chemical methods cause secondary environmental pollution and fail to enable resource recovery.The adsorption method by porous materials has attracted worldwide attention due to its simplicity,portability,and efficiency.It has become an important factor to explore how porous adsorption materials can adsorb efficiently and reduce environmental pollution.Biomass resources are abundant,cost-effective,biodegradable,and sustainable,which have been extensively explored for the production of porous materials.Herein,recent advances in cellulose-based,chitosan-based,wood-based and other biomassbased oil-absorbing porous materials are summarized,and cellulose-based porous materials,such as nanocellulose,bacterial cellulose,and regenerated cellulose and their related derivatives,are further expanded.In addition,typical environmentally friendly manufacturing methods and the oil adsorption capacities of various oil-absorbing porous materials are also discussed.Compared with the traditional petrochemical adsorption materials,the development advantages of biomass porous oil absorption materials are analyzed.The reasons hindering the popularization and use of oil-absorbing biomass materials are summarized and the future application fields are prospected.

Regulation of different light conditions for efficient biomass production and protein accumulation of Spirulina platensis

Light plays an important role in the photosynthesis and metabolic process of microalgae.However,how different light conditions regulate the biomass production and protein accumulation of microalgae is mostly unknown.In this study,the influence of different light conditions,including light colors,densities,and light:dark cycles on the cell growth and biochemical composition of Spirulina platensis was symmetrically characterized.Under different colored lights,S.platensis all shows an increase trend within the increased light intensity ranges;however,each showing different optimal light intensities.At the same light intensity,different colored lights show different growth rate of S.platensis following the sequence of red>white>green>yellow>blue.The maximum growth rate and protein accumulation were determined as 21.88 and 5.10 mg/(L·d)when illuminated under red LED.The energy efficiency of different light sources was calculated and ranked as red>white>blue≈green>yellow.Transcriptomic analysis suggests that red light can promote cell growth and protein accumulation by upregulating genes related to photosynthesis,carbon fixation,and C-N metabolism pathways.This study provides a conducive and efficient way to promote biomass production and protein accumulation of S.platensis by regulating light conditions.

Effect of Soil Fertility and Planting Density on the Partitioning of the Above-Ground Biomass of Eucalyptus in a Plantation (Pointe-Noire, Republic of Congo)

Afforestation and reforestation are useful approaches to improve carbon sequestration. With the advent of forest plantations, growing environment conditions have become increasingly restrictive for light, soil nutrients, and interactions between trees to acquire available resources. Tree biomass data are essential for understanding the forest carbon cycle and plant adaptations to the environment. The distribution of tree biomass depends on the sum of multiple stand conditions. The data are from a dedicated experiment with two very contrasting areas of fertility, and two planting densities, including a high density at planting in order to achieve thinning. The plant material consists of the high-performance clones of Eucalyptus urophylla × E. grandis and the reference clone E. PF1. We hypothesize that the distribution of biomass changes as the intensity of competition changes and that this is accelerated by the fertility of the sites in time. The results indicate that fertilization, planting density and clones have an impact on biomass partitioning.