Estimation of Higher Heating Value for MSW Using DSVM and BSOA

In recent decades,the generation of Municipal Solid Waste(MSW)is steadily increasing due to urbanization and technological advancement.The col-lection and disposal of municipal solid waste cause considerable environmental degradation,making MSW management a global priority.Waste-to-energy(WTE)using thermochemical process has been identified as the key solution in this area.After evaluating many automated Higher Heating Value(HHV)predic-tion approaches,an Optimal Deep Learning-based HHV Prediction(ODL-HHVP)model for MSW management has been developed.The objective of the ODL-HHVP model is to forecast the HHV of municipal solid waste,based on its oxy-gen,water,hydrogen,carbon,nitrogen,sulphur and ash constituents.In addition,the ODL-HHVP model contains a Deep Support Vector Machine(DSVM)regres-sion component that can accurately predict the HHV.In addition,the Beetle Swarm Optimization(BSO)method is utilised as a hyperparameter optimizer in conjunction with the DSVM model,resulting in the highest HHV prediction accu-racy.A comprehensive simulation study is conducted to validate the performance of the ODL-HHVP method.The Multiple Linear Regression(MLR),Genetic Pro-gramming(GP),Resilient backpropagation(RP),Levenberg Marquardt(LM)and DSVM approaches have attained an ineffective result with RMSEs of 4.360,2.870,3.590,3.100 and 3.050,respectively.The experimentalfindings demon-strate that the ODL-HHVP technique outperforms existing state-of-art technolo-gies in a variety of respects.

Analysis of ingredient and heating value of municipal solid waste

Great differences between municipal solid wastes(MSW)produced at different places and different times in terms of such parameters as physical ingredient and heating value lead to difficulty in effective handling of MSW. In this paper, ingredient, heating value and their temporal varying trends of typical MSW in Beijing were continuously measured and analyzed. With consideration of the process in pyrolysis and incineration, correlation between physical ingredients and heating values was induced, favorable for evaluation of heating value needed in handling of MSW from simple analysis of physical ingredients of it.

The Estimation of the Higher Heating Value of Biochar by Data-Driven Modeling

Biomass is a carbon-neutral renewable energy resource.Biochar produced from biomass pyrolysis exhibits preferable characteristics and potential for fossil fuel substitution.For time-and cost-saving,it is vital to establish predictive models to predict biochar properties.However,limited studies focused on the accurate prediction of HHV of biochar by using proximate and ultimate analysis results of various biochar.Therefore,the multi-linear regression(MLR)and the machine learning(ML)models were developed to predict the measured HHV of biochar from the experiment data of this study.In detail,52 types of biochars were produced by pyrolysis from rice straw,pig manure,soybean straw,wood sawdust,sewage sludge,Chlorella Vulgaris,and their mixtures at the temperature ranging from 300 to 800℃.The results showed that the co-pyrolysis of the mixed biomass provided an alternative method to increase the yield of biochar production.The contents of ash,fixed carbon(FC),and C increased as the incremental pyrolysis temperature for most biochars.The Pearson correlation(r)and relative importance analysis between HHV values and the indicators derived from the proximate and ultimate analysis were carried out,and the measured HHV was used to train and test the MLR and the ML models.Besides,ML algorithms,including gradient boosted regression,random forest,and support vector machine,were also employed to develop more widely applicable models for predicting HHV of biochar from an expanded dataset(total 149 data points,including 97 data collected from the published literature).Results showed HHV had strong correlations(|r|>0.9,p<0.05)with ash,FC,and C.The MLR correlations based on either proximate or ultimate analysis showed acceptable prediction performance with test R2>0.90.The ML models showed better performance with test R^(2)around 0.95(random forest)and 0.97–0.98 before and after adding extra data for model construction,respectively.Feature importance analysis of the ML models showed that ash and C were the most important inputs to predict biochar HHV.

An Evaluation of the Calorific Values of the Branches and Stems of 11 Tropical Trees

This work investigated and quantified the calorific values of the main branches and trunks of eleven (11) tropical trees in correlation with their chemical composition in order to assess their suitability for use as credible sources of wood fuel. The determination of the carbon, hydrogen, nitrogen, oxygen and sulphur (CHNOS) content of the samples was done using an organic elemental analyser, while an oxygen bomb calorimeter was used to experimentally determine their corresponding gross heat values. The experimental gross heat values for the branches examined ranged from 18,703.37 kJ/kg in Lophira lanceolata to 21,350.35 kJ/kg in Afzelia africana while that of the trunks ranged from 19,747.74 kJ/kg in Tectonia grandis to 22,408.68 kJ/kg in Prosopis africana. These values were within and about the expected ranges observed for tropical trees and may be considered adequate for wood fuel. The general trend in both branches and trunks was that the higher the carbon content, the higher the gross heat value of sample. The absence of sulphur in almost all the samples except, Prosopis africana, (0.055%) was indicative of the fact that the negative environmental impact with respect to harmful emissions of oxides of sulphur is practically non-existent with respect to these species. In the light of the aforementioned variables, the main branches of Afzelia africana (21,350.35 kJ/kg), Nauclea diderrichii (21,157.30 kJ/kg) and Tectonia grandis (20,257.13 kJ/kg) could be used as credible sources of firewood and charcoal production. With respect to the trunks, the timbers in order of preference would ideally be Prosopis africana (22,408.68 kJ/kg), Nauclea diderichii (21,436.42 kJ/kg) and Brachstigia eurychoma (20,924.7 kJ/kg).

Combustion Characteristics of Animal Manures

A huge amount of waste from the cattle livestock and bird poultry are generated using as manure and solid fuel. In this work, the heat value and proximate parameters of livestock and poultry manures are described. The calorific value of manures (n = 22) was ranged from 2580 - 11,200 kcal/kg with mean value (p = 0.05) of 5333 ± 1073 kcal/kg. The effect of cattle age and additives i.e. NaNO3 and Na2WO4 in the heat value of the manures are discussed. The chemical characteristics of the emitted particulate matters (PM) and ash residues are highlighted.

Combustion Characteristics of Tree Woods

Biomass is a renewable energy source because sun energy is stored in the form of biomass which regrows over a relatively short period as compared to fossil fuel. The biomass on burning released energy with emission of carbon dioxide, volatile organic compounds, particulate matters and ash residue. The combustion characteristics of biomass depends on several factors of plants i.e. bulk density, moisture, organic matter and metal content. In this work, the combustion characteristics i.e. heat value, moisture, volatile matter and ash content as well as emission fluxes of particulate matters (PM10) of trees grown in central India are described. The calorific value (CV) of 53 trees was ranged from 5190 - 8130 kcal/kg with mean value (p = 0.05) of 6380 ± 170 kcal/kg. Bahera tree showed the highest CV, 8130 kcal/kg, and hence, it was chosen for the detailed studies.

Variations in productivity and wood properties of Amazonian tachi-branco trees planted at diff erent spacings for bioenergy purposes

Marilene Olga dos Santos Silva 1·Marcela Gomes da Silva 1·LTachi-branco(Tachigali vulgaris,L.F.Gomes da Silva&H.C.Lima)is a leguminous tree species native to the Amazon rainforest that has drawn attention for its remarkably fast growth,a required trait for biomass/bioenergy plantations.In evaluations of biomass production and wood properties of T.vulgaris planted in homogeneous plantations at diff erent spacings in the Amazonian state of Pará,Brazil,biomass of 7-year-old trees was quantifi ed for individual trees and the entire population.Wood was also sampled to assess properties relevant to bioenergy applications.The choice for spacing dimension for planting nonclonal T.vulgaris should consider whether the priority is greater productivity per tree,achieved with greater spacings(9.0 m 2 and 12.0 m 2),or productivity per area,achieved with closerina Bufalino 1·Maíra Reis de Assis 2·Delman de Almeida Goncalves 3·Paulo Fernando Trugilho 2·Thiago de Paula Protásio 4 spacings(6.0 m 2 and 7.5 m 2).Genetic variability of the T.vulgaris seed stand and/or high heritability of wood traits overcame the eff ect of diff erent spacing on all morphological,physical,chemical and energetic properties of T.vulgaris wood.This species has moderate basic density when cultivated at spacings larger than 6 m 2 and net heating value above 7.95 MJ/kg,which is suitable for bioenergy purposes.The high variation in wood properties within tree spacing is strongly indicative of great potential for genetic breeding.The fast growth and the suitable moderate wood basic density confi rm the outstanding potential of homogeneous plantations of T.vulgaris for providing wood for bioenergy.

Recovering Wood Waste to Produce Briquettes Enriched with Commercial Kraft Lignin

Aiming to use lignocellulosic biomass as energy source, one of the process that may aggregate values is the densification process, which allows the production of bioenergy using solid fuels, mainly for reducing transportation costs. In this research, solid fuel from co-briquetting of wood residues from sawmill using commercial kraft lignin as binder was investigated. The effects of compression pressure (900, 1200 and 1500 PSI) and briquette formulation (varying wood and kraft lignin proportion) on the quality and characteristics of briquettes were evaluated. The main findings were that briquetting of wood residues with kraft lignin resulted in an improvement of bulk density, strength rupture modulus, low heating value (LHV) and high heating value (HHV). The briquettes using 4% and 6% of kraft lignin, and submitted to 1200 to 1500 PSI, presented higher bulk density and strength resistance, respectively. On the other hand, the heating values showed the highest results with the addition of 2% lignin at 900 PSI, being the legal range for additives in briquettes for many countries such as in European Union.

Pre-combustion mercury removal with co-production of hydrogen via coal electrolysis

Pre-combustion mercury removal via coal electrolysis was performed and investigated on a bench-scale coal electrolytic cell(CEC)systemically,and factorial design was used to determine the effect of different operating conditions(coal particle size,operating temperature,operating cell voltage,and flow rate of slurry)on the percentage of mercury removal,percentage of ash removal,and dry heating value change.The results showed that the operating cell voltage,as well as the interaction between operating cell voltage and coal particle size,are significant factors in the percentage of mercury removal.There is no significant factor in the percentage of ash removal and the dry heating value change,but the coal could be purified while keeping the dry heating value almost constant after electrolysis.A co-product of hydrogen could be produced during coal electrolysis with 50%lower energy consumption compared with water electrolysis.Meanwhile,a mechanism for mercury removal in coal was proposed.The facts indicate that coal electrolysis is a promising method for precombustion mercury removal.

The Martin moving grate technology

The thermal treatment of waste using grate-based systems has gained global acceptance as the preferred method for sustainable management of residual waste.This is because the energy content of the waste is utilized and quality products and residues are produced.Modern Waste-to-Energy(WtE)plants are extremely complex.Sound knowledge of“fuel”waste and its effects on the design and operation of WtE plants is crucial for the successful planning and operation of these plants.To respond to new challenges and/or priorities,developing and implementing innovative technologies is necessary.With long-term global partnerships and innovative grate and combustion technologies,Martin guarantees that in future,residual waste will be treated following ecological and economic constraints and in compliance with international legal requirements.

Recycling combustibles from aged municipal solid wastes(MSW)to improve fresh MSW incineration in Shanghai:Investigation of necessity and feasibility

Aged municipal solid wastes(MSW)excavated from landfills and dumpsites were characterized to analyze their fraction composition,moisture content,and lower heat value(LHV).The necessity and feasibility of recycling combustibles from aged MSW to improve the incineration of fresh MSW were investigated.The results showed that combustibles in aged MSW were easily separated from other components and than LHV of the separated combustibles are higher than 11000 kJ/kg.The fresh MSW are of high moisture contents with average LHV below 6500 kJ/kg,making their stable combustion difficult to maintain in MSW incinerators.For both fresh MSW and aged MSW,plastics are the main contributor to their LHV.To improve incineration of fresh MSW that are characterized with low LHV,combustibles separated from aged MSW were made into refuse derived fuel(RDF)pellets and were then added to fresh MSW by 2%wt.–5%wt.LHV variation and air supply resistance change of the MSW layer on the incinerator grate caused by the addition of RDF was checked,and no significant changes were found.No obvious difference was observed for the‘burn-out time’between RDF pellets and fresh MSW either.RDF made from aged MSW combustibles is found to be a promising auxiliary fuel to improve the incineration of fresh MSW,and aged MSW from old landfill cells and dumpsites can be finally disposed of jointly with fresh MSW by recycling combustible from the former to be coincinerated with the latter in the incineration plants.

Effect of glycerol on densification of agricultural biomass

Experiments were conducted to verify the effect of adding glycerol for pelleting of selected agricultural crop residues,namely,wheat,barley,oat and canola straw.Single pelleting tests were conducted to study the effect of biomass type,hammer mill screen size,and crude glycerol content(co-product of biodiesel industry)on pellet quality(density and durability),ash content and gross heat of combustion.Four types of biomass were ground at three different hammer mill screen sizes of 6.4,3.2 and 1.6 mm.Each biomass was mixed with three levels of glycerol of 2.5%,5.0%and 7.5% by weight.Pellets were made at a pre-set load of 4400 N(138.9 MPa)using single-pelleting unit attached to an Instron testing machine.Quality of pellets was determined by measuring pellet density,relaxed density,durability(measured by pellet drop test)and specific energy required to make a pellet.The gross heat of combustion and ash content of pellets were also determined and compared.The highest pellet density(988-1133 kg/m^(3))and relaxed density(992-1142 kg/m^(3))were obtained from biomass ground using a hammer mill screen size of 6.4 mm.A decrease in hammer mill screen size resulted in reduced durability.The highest durability of biomass obtained from hammer mill screen size of 6.4 mm ranged from 97%-100%.Addition of glycerol resulted in lower ash content in majority of pellets.The highest gross heat of combustion was observed in pellets made from wheat straw with 7.5% glycerol content(38.3 MJ/kg).Addition of glycerol resulted in lower pellet densities,lower ash content,no change in durability and higher gross heating values.

Investigation of extracted Sclerocarya birrea seed oil as a bioenergy resource for compression ignition engines

Sclerocarya birrea(Marula)seed oil was extracted and characterized for its physico-chemical properties and fatty acid compositions,respectively,by using standardized laboratory methods of the Association of Official and Analytical Chemist(AOAC).The fuel and lubrication properties of marula oil were also determined by using the ASTM methods,and the oil was evaluated in terms of its antiwear,viscometrics,volatility,stability,environmental compatibility properties and energy content.It was found that the high percentage of mono-unsaturated oleic acid(73.6%)provided the oiliness that makes marula oil a natural alternative to genetically modify high oleic acid sunflower oil used in biodiesel production.The aggregate properties of seed oiliness as exemplified by the high oleic acid content,high saponification value(178.6 mg/KOH)and viscosity(41 mm2/s)makes marula oil to be prospective based oil for engine crank case biolubricants with antiwear and friction reduction properties.However,the higher oil viscosity exhibited by marula seed oil in comparison to diesel could pose some durability problems to compression ignition engines,when used directly as fuel.Nonetheless,the reduction of oil viscosity would be required by heating,blending with diesel fuel,or by transesterification to forestall the risk of engine failure resulting from the use of unmodified marula oil.The flash point of marula oil(235℃)is somewhat close to that of monograde SAE 40 mineral oil(240℃),and appreciably higher than that of diesel fuel(52℃).The high flash point makes the seed oil less flammable and ensures safer handling and transportation.While,the low pour point(-13.7℃)ensures the oil usability for engines at cold start and under low load conditions.The oxidation stability of marula oil is ascribed to the traces of natural antioxidants presented in the oil and improves the oil’s shelf life,notwithstanding the high peroxide value(4.58 mequiv/kg),and linolenic acid content(0.3%),which ought to have been the culprit for lipolytic hydrolysis and rancidity.Furthermore,marula seed oil is more biodegradable and environmentally friendly than oils derived from petroleum crude.The closely related cetane number(47.8)and heating values(38.2 mJ/kg)of marula oil to diesel fuel would undeniably sustain the combustion efficiency of diesel fuel and also supply a comparable engine performance output in compression ignition engines.The candidacy of marula seed oil,as a bioenergy resource for alternative fuel,fuel additives and lubricants,will no doubt expand the energy supply mix,conserve fossil fuel reserves and mitigate environmental contamination.