Increase In Heating Value Research Articles

Торрефикация — ресурсосберегающее направление термохимической переработки биомассы

Significant scales in which biomass accumulates have prompted specialists to search ways of efficiently using its energy potential at the background of the crisis of non-renewable energy sources. One of such ways is torrefaction – thermochemical pyrolysis of biomass by subjecting it to slow heating and holding at a temperature of 200–300°C to obtain a solid carbon-containing product. Investigations carried out in the biomass torrefaction field are reviewed and analyzed. Biomass properties and various ways of processing it for use as power-generating fuel are considered. The properties of non-torrefied and torrefied pellets are compared. The latter, in comparison with the source ones, feature an increased heating value, low hygroscopicity, sufficient bulk density, and good grindability. The main torrefaction technologies and types of torrefaction reactors are considered. A mathematical model of a wood waste torrefaction plant was developed in the Aspen Plus software environment. The study results have revealed the effect the specific heat admission to the torrefaction reactor and the initial moisture content in the material have on the process operating parameters: the mass fraction of carbon transferred into solid torrefaction products and the pyrolysis gas specific yield, composition, heating value, and temperature. The possibility to arrange autonomous heating of the reactor using the chemical heat of pyrolysis gas has been shown. The reactor heating requires 44% of the gas waste from the torrefaction process; the other 56% can be used as an energy source in related technologies. The obtained results can be used in studying and designing the reactor and torrefaction plant.

Comparative Biodrying Performance of Municipal Solid Waste in the Reactor under Greenhouse and Non-greenhouse Conditions

The high moisture content of municipal solid waste yields a lower energy content of solid fuel that affects the thermal conversion efficiency. Biodrying is an alternative drying method using bio-heat generated by microbial metabolism to reduce the moisture content of municipal solid waste. This research was conducted in three pilot-scale biodrying reactors, two under greenhouse conditions compared with one conventional non-greenhouse condition. Two bunkers with greenhouse cladding were connected with aerators, and airflow rates were set at 0.4 and 0.6 m3/(kgwaste·day), respectively. Meanwhile, a passive aeration method was applied to the non-greenhouse bunker. This study aims to investigate the effect of the greenhouse condition on the biodrying process and assess the performance of the drying process through different operating conditions. The result shows that the greenhouse mainly affects the air temperature rise in the reactor. The aeration rate is positively correlated with weight reduction (r = 0.93). At 0.6 m3/(kgwaste·day) airflow rate, the treatment can reach a moisture content less than 30% on average within ten days, while at 0.4 m3/(kgwaste·day) airflow rate, it takes 15 days to reduce the moisture content to less than 30%. Biodrying under the greenhouse condition with active aeration potentially achieves desirable moisture content reduction and heating value increase more efficiently than the common biodrying. However, the airflow rate is a crucial factor in determining the suitable drying time in biodrying under the greenhouse condition.

Characterization of Refuse Derived Fuel Production from Municipal Solid Waste: The Case Studies in Latvia and Lithuania

Abstract The authors determined the morphological composition of refuse derived fuel (RDF) produced in Latvia and Lithuania by manually sorting. The parameters of RDF (moisture, net calorific value, ash content, carbon, nitrogen, hydrogen, sulphur, chlorine, metals) was determined using the EN standards. Comparing obtained results with data from literature, authors have found that the content of plastic is higher but paper and cardboard is lower than typical values. Results also show that the mean parameters for RDF can be classified with the class codes: Net heating value (3); chlorine (3); mercury (1), and responds to limits stated for 3rd class of solid recovered fuel. It is recommended to separate biological waste at source to lower moisture and ash content and increase heating value for potential fuel production from waste.

Analysis of Upgrading Process of South Sumatera Low Rank Coal

This research aims to find a method of removing moisture of Indonesian low rank coal by using a combined equipment of evaporator and heater. The heating equipment was controlled at varied temperatures of 343 K, 353 K and 363 K. This method is expected to increase heating value and reduce moisture content of coal. Based on this study, the removal of moisture content of Indonesian low rank coals was affected by the heating temperature and particle size of coals. Ambient air was passed through the evaporator tubes to decrease the temperature until reaching the dew point temperature of the air and then through the heating elements of a heater before entering the fluidised bed of pulverized coal. The results of this research showed that the heating value of coal can be increased up to 35.4% and also the moisture content can be reduced up to 29.8%, both at heater temperature of 363 K and particle size of (-20 +40) mesh.

Catalytic upgrading of tars generated in a 100 kWth low temperature circulating fluidized bed gasifier for production of liquid bio-fuels in a polygeneration scheme

Gasification of wheat straw, an agricultural residue with high ash content, was investigated in a low temperature circulating fluidized bed (LT-CFB) gasifier in combination with catalytic tar upgrading as a flexible process to co-produce high quality bio-oil, nutrient rich char, and utilize the producer gas for heat and power production. The change in product distribution and bio-oil quality was studied when conducting the catalytic treatment with HZSM-5/γ-Al2O3 and lower-cost γ-Al2O3. The fuel properties of the raw and upgraded bio-oils were analyzed by elemental composition, moisture, total acid number, size exclusion chromatography, basic nitrogen content, gas chromatography–mass spectrometry with flame ionization detection (GC–MS/FID), 1H nuclear magnetic resonance (NMR), 13C NMR, and two-dimensional heteronuclear single-quantum correlation (2D HSQC) NMR. The operating temperature of the LT-CFB pyrolysis chamber determined the tar yield and quality in the producer gas. With decrease in pyrolysis temperature from 690 to 570 °C, the tar concentration in the producer gas increased, while the higher heating value of the condensed oil phase decreased from ~35 to 30 MJ/kg and the oxygen content, moisture content, and acidity of the bio-oil increased. Both HZSM-5/γ-Al2O3 and γ-Al2O3 were effective catalysts as the tar treatment improved the bio-oil quality in terms of increased heating value and revaporization efficiency, and a reduction in oxygen content, moisture content, total acid number, and basic nitrogen content. Catalytic vapor treatment, e.g. using HZSM-5/γ-Al2O3 at 500 °C, decreased the energy content in the condensed bio-oil slightly from ~22% to ~20%. The oil quality improved significantly, as the oxygen content (water-free) and TAN of the bio-oil decreased from 13 wt% O and 34 mg KOH/g to 11 wt% O and 3 mg KOH/g, respectively. The catalytically treated bio-oils are thus better suited for further processing in existing oil refineries.

Enhancement of Gasoline Fuel Quality with Commercial Additives to Improve Engine Performance

In this study, a comparison was made to evaluate fuel properties and engine performance when using local gasoline fuel MU0 with two types of commercial fuel optimizer. MU1 (1/200 addition ratio of commercial additive U1 with local gasoline MU0), and MU2 (1/100 addition ratio of commercial additive U2 with local gasoline MU0) was investigated in addition to commercial enhanced gasoline MU3. Local gasoline MU0 has been adopted as a threshold for comparison. Performance tests conducted in a single-cylinder four stroke sparkignition engine using fuel samples (MU0, MU1, MU2, MU3) at engine speed range from 1200 to 2800 rpm with increment of 400 rpm and open throttle valve100% (WOT). The results showed an increased octane number and viscosity of fuel MU1 by about (3.49%, 16.92%) respectively, and reduction in the heating value by about 19.4%, with addition U1. Increase heating value and viscosity of fuel MU2 by about (1.68%, 22.31%), with addition U2. As well as, increase brake power by about (4%, 16%) at 2800 rpm with MU2 and MU3 respectively compared to local gasoline MU0. In addition, brake specific fuel consumption reduced with fuel MU3 and increased with (MU1, MU2). The brake thermal efficiency was enhanced with fuel MU1 and MU3 and the better improvement obtained for MU1 by about 22.47% at 2400 rpm.

Improvement of bark pyrolysis oil and value added chemical recovery by pervaporation

Pyrolysis oil produced from forestry residues is used as a low-grade fuel in applications such as heating oil. However, the high water and acid content can lead to fuel instability, phase separation, poor lubrication, and corrosion. In this work, pervaporation has been studied as a process to simultaneously upgrade a pyrolysis oil produced from Canadian softwood bark to meet a boiler fuel standard and extract value-added chemicals. Commercial polyacrylonitrile-supported polyvinyl alcohol membranes from DeltaMem AG were used at temperatures of 60 and 80 °C to separate water and volatile organic components, including methanol, acetic acid, and acetol. A design of experiment study was used to define the range of operating conditions. A temperature of 80 °C and a low feed flow rate of 0.1 mL min−1 resulted in the highest quality oil. The upgraded pyrolysis oil (pervaporation retentate) showed an increased heating value from incomplete combustion to 16.07 MJ kg−1 and the water content was lowered from 70.2 wt% in the feedstock to 21.4 wt%, demonstrating the potential for this process on a larger scale.

Experimental and numerical study of coal swirl fluidized bed drying on 100 angle of guide vane

Currently, low-rank coal is widely used as fuel in power plants. The swirl flow method is quite effective used to increase heating value through the drying process. This research studies the characteristics of low-rank coal drying using a swirl fluidized method with 100 angle of blade inclination experimentally and numerically. Coal with a moisture content of 25.17 % and a size of 6 mm was dried by dry air with a temperature of 55 °C, the relative humidity of 10.5 % and flow rate of 0.06 kg/sec. Moisture content is measured by the ASTM D3173. Numerical simulations performed in 3 dimensional, transient and multicomponent. The results of the experiment show that drying was effective in the first 5 minutes, which reduced moisture ratio to 0.26 while the simulation results reduced moisture ratio to 0.28. Numerical simulations show the pathline, velocity vectors, temperature, and humidity contours. Particle trajectory as simulation results agrees to the experiment.

Influence of physical and chemical compositions on the properties and energy use of lignocellulosic biomass pellets in Brazil

Lignocellulosic residues are potential sources of renewable energy, but these materials have low energy density and undesirable properties for energy use. For this reason, pelleting is a viable alternative for the biomass energy valorization because it produces high-energy-density solid biofuels. The aim of this research is to evaluate the physical, chemical, and energetic characteristics of pellets produced with lignocellulosic biomass blends (elephant grass [EG], eucalyptus wood [EW], and sugarcane bagasse [SB]) for bioenergy generation. For biomass and pellets, bulk and energy densities, chemical compositions, and heating values, were determined. For pellets, the mechanical durability, fines content, diametrical compression, diameter, length, and unit density were measured. Pellets presented increased heating value, bulk and energetic density, and reduced moisture content. The highest absolute ash contents were found in the compositions and pellets produced with high amounts of EG (2.89%–6.48%). The reduction of EG in the blends has improved the energy properties of pellets. A 55% reduction of ash content was observed in the pellets produced with 50% EG and 50% EW compared with the pellets produced with 100% EG. The pellets produced with biomass blends obtained better energy and mechanical performances when compared with those produced with only one biomass.

Pyrolysis characteristics, fuel properties, and compositional study of Madhuca longifolia seeds over metal oxide catalysts

The present study was focused on the bioenergy potential of Madhuca longifolia (mahua, MH) seeds to produce renewable fuel via thermocatalytic conversion. The physicochemical characterization of MH seed confirmed its bioenergy potential. Three model-free models were used to predict the pyrolysis kinetics of MH. The thermodynamic and kinetic analysis showed that MH has complex reaction kinetics which depends on the reaction rate as well as reaction order. Mahua seed was pyrolyzed in a semi-batch cylindrical shaped reactor with (CuO, Al2O3, and NaOH) and without catalysts. The yield of pyrolytic liquid during thermal pyrolysis was 51.2 wt%, whereas the use of catalysts decreased the liquid yield slightly at various biomass to catalyst ratios. Further, characterization results revealed that the use of catalysts improved the properties of pyrolytic oil by reducing viscosity, oxygenated compounds and with increasing heating value and acidity. FTIR spectra of pyrolytic oil confirmed the existence of phenols, aromatics, water, and acids which was also supported by the 1H NMR analysis. Further, GC-MS analysis confirmed reduction in oxygenated compounds and increase in alcohol.

Dry and wet torrefaction of empty fruit bunch to produce clean solid fuel for cooking application

Empty fruit bunch (EFB) is one of the biomass source in Indonesia which has abundant availability generated from palm oil industry. The aim of the present work is to study the dry and wet torrefaction of EFB in a fixed bed reactor for green energy production in a cooking application. The feedstock used in these experimental works was empty fruit bunch. The collected EFB has a high moisture content which was then dried in the sun for three days in order to remove some the water content. The samples were then crushed into smaller particle size to made it easily put into the reactor. The results showed that the higher the reaction temperature and holding time, the lower the solid yields. The dry torrefaction of EFB can produce around 34-91% of the solid product. The results also showed that increasing the dry torrefaction temperature resulted in the increase of heating value. Wet torrefaction has the similar trend with the dry torrefaction. The solid product from wet torrefied EFB which can be obtained is in the range of 64-83%. Dry torrefied EFB produced higher energy yield than that of wet torrefied EFB. The difference reaction medium, temperature, and pressure resulted in different energy yield.

Assessing the suitability of recovering shrub biowaste involved in wildland fires in the South of Europe through torrefaction mobile units

Several types of shrubs and oak inducing high wildland fire risk in the South of Europe were evaluated for their potential valorization through torrefaction. Biomasses were firstly characterized in terms of macromolecular and elemental composition. Lab-scale TGA-GC/MS torrefaction experiments allowed the in-depth study of the solid mass transformation and the production profile of 23 volatile species (200 to 300 °C at 3 °C·min−1 and 300 °C for 30 min). The proportion of the torrefied products (solid, CO, CO2, water and volatile species) was evaluated through mass balance in a lab-scale furnace under typical torrefaction conditions (300 °C, 40 min). The results show a similar characterization and behavior in torrefaction for oak and shrublands, and slightly different characteristics for fern. However, fern may grow separately from shrublands and is considered to present a low fire risk. This suggests that the in-situ direct valorization of these biomasses through torrefaction mobile units seems promising. However, other properties, such as density, flowability and grindability need to be studied to confirm the feasibility of the process. Regarding torrefaction products, a higher carbon content and an interesting increase in heating value were measured for the torrefied solid, which makes it suitable for energetic valorization, among other uses. The composition of permanent gases was evaluated and found in agreement with previous studies. Finally, the volatile species released were studied in function of the torrefaction temperature, in view of their possible valorization as green chemicals.

Biomass torrefaction in a standard retort: A study on oil palm solid residues

This study evaluates the torrefaction of oil palm empty fruit bunches (EFB) and mesocarp fiber in a standard retort at laboratory scale (according to standard ISO 647). The influence of torrefaction temperature (220 °C−270 °C), residence time (up to 60 min) and reactor heating rate (5 K/min–15 K/min) are determined on solid, liquid and gas yields, as well as their chemical and fuel properties. Torrefaction yielded between 64 wt-% and 92 wt-% solid that exhibited lower heating value increase between 11 % and 28 % compared to the original biomass. The liquid fraction ranges between 6 wt-% and 26 wt-% of the raw biomass, containing 26 wt-%–42 wt-% of water and LHV up to 11 MJ/kg. The gas fraction represents 1 wt-%–9 wt-% of the original biomass with LHV between 0,6 MJ/kg–2,4 MJ/kg. Optimum trade-offs for solid yields and lower heating values were obtained for torrefaction with a heating rate of 10 K/min and a residence time of 30 min at 272 °C for EFB (62,8 wt-% solid yield and 17,7% increase in the original LHV) and at 282 °C for fiber (65,3 wt-% solid yield and 25,8% increase in LHV). A formal reaction kinetic model for pyrolyis coupled to a thermal model of the retort has been tested and used to simulate the solid mass yield and lower heating value during torrefaction and to determine the optimum trade-offs between both parameters. Simulated temperature gradients inside the retort solid bed are as high as 55 °C during heating up at a torrefaction temperature of Ttorr = 250 °C and around 25 °C after a residence time of 30 min at this temperature. These results are relevant and decisively influence the solid yield during torrefaction in the retort.

Catalytic Hydrodeoxygenation of Cork Oak Pyrolysis Oil Over Ni/Al-MCM-41.

Catalytic hydrodeoxygenation (HDO) of cork oak pyrolysis oil was performed using a high pressure batch type reactor. Cork oak pyrolysis oil, obtained from the fast pyrolysis of cork oak, was upgraded into high quality oil under HDO conditions (260 °C, 80 bar) over 20 wt.% Ni/Al-MCM-41. Compared to the cork oak pyrolysis oil, HDO oil had a smaller oxygen content, increased heating value, and improved viscosity and acidity due to the high contents of esters and hydrocarbons.

Effects of impregnated potassium on biomass torrefaction

Abstract Torrefaction is a pre-treatment process which can improve the properties of biomass, such as improving grindability, increasing heating value, and reducing the hygroscopic nature. Potassium is a well-known alkali catalyst in the thermal reactions of biomass. The influence of potassium on the devolatilization behavior was dependent on the amount of loading potassium. The aim of this study is to figure out the effect of potassium on the thermal degradation of biomass, the rubber wood sawdust was adopted as the feedstock, and the biomass sample was crushed and then dried in an atmospheric oven. Impregnation was used to prepare samples with different potassium ion content equably and adequately. Thereafter, the sample was torrefied by in a thermogravimetric analyser (TG) at different temperature (150, 20, 250, and 300 °C). The experimental results show that the addition potassium can significantly change the chemical kinetics, and further enhanced the thermal degradation of biomass during torrefaction.

Estimation of power generation from municipal solid wastes: A case Study of Ilorin metropolis, Nigeria

In this study, attempt was made to estimate the quantity of municipal solid waste (MSW) generated per annum, the generation rate in kg/capita/day as well as the quantity and the fractions of the waste streams available for energy production. The physical characterization of the waste streams into fractions was conducted. The proximate and ultimate analyses of the waste fractions were performed. Heating values of the waste streams was determined experimentally using a bomb calorimeter. It was concluded that 1% increase in carbon and sulphur will increase heating value by 79.08% and 10.83% respectively while 1% increase in hydrogen and nitrogen decrease heating value by 30.2% and 619.1% respectively. The energy potential (EPMSW) of the MSW based on the energy content of 584 tons/day MSW, is about 3,244,444 kWh or 3,244 MWh, Electrical Power (EPPMSW) of about 40555 kW or 41 MW and Power to Grid of 27 MW.

Thermal and catalytic pyrolysis of pine sawdust (Pinus ponderosa) and Gulmohar seed (Delonix regia) towards production of fuel and chemicals

In this work, two waste biomass (pine sawdust, PW and gulmohar seeds, SG) were thermochemically converted with and without catalysts to find out their potential towards producing fuels and chemicals. Physicochemical characterization of these biomass confirmed their bioenergy potential for producing renewable fuel. Thermal pyrolysis of the biomass was performed at 500 °C temperature, 0.5 mm particle size, 80 °C min−1 heating rate, and 100 mL min−1 nitrogen flow rate, whereas catalytic pyrolysis was performed with CaO, CuO, and Al2O3 at different catalyst loading of 10 wt%, 20 wt%, 30 wt%, and 40 wt% respectively. The total pyrolytic liquid yield by thermal pyrolysis was found to be 39.39% for PW and 36.68% for SG, whereas catalytic pyrolysis at 20 wt% loading increased the liquid yield by 2.34–4.79 wt% for both the biomass. Thermal pyrolytic oil demonstrated increase in viscosity, density and decrease in acidity and heating value, whereas catalytic pyrolytic oil resulted in increased heating value, acidity, moisture, and decreased viscosity and density. FTIR analysis demonstrated the presence of aromatic compounds, phenols, alkanes, alcohols, acids, and aldehydes. GC-MS analysis confirmed that use of catalysts reduced the content of oxygenated and acidic compounds and increased that the amounts of alcohols and aldehydes in catalytic pyrolytic oil.

Emission and vibration analysis of diesel engine fuelled diesel fuel containing metallic based nanoparticles

This experimental study reports the results of emission and vibration characteristics of compression ignition (CI) engine with variable compression ratios (VCR) using nanoparticles added to diesel fuels. Three different nanoparticles namely, titanium (IV) dioxide (TiO2), copper (II) nitrate (Cu(NO3)2) and cerium (III) acetate hydrate (Ce(CH3CO2)3·H2O) were used with conventional diesel fuel at the dosage of 25 ppm and 50 ppm in order to prepare the four different test fuels. The engine tests were implemented in a single cylinder diesel engine under 4 Nm and 8 Nm engine load at a constant engine speed of 1500 rpm and at compression ratios (CR) of 17:1 and 18:1. The results showed that nanoparticles addition in the diesel fuels in ppm level did not caused any complications in the physicochemical properties but a slightly increase in heating value and cetane number. In addition, the combined effect of titanium dioxides and cerium acetate hydrate nanoparticles significantly reduced pollutants emissions regardless of NOx emissions. Especially, addition of cerium acetate hydrate into the blend fuels has become a dominant factor in the reduction of the harmful exhaust emissions. Furthermore, it was revealed that sound pressure level of engine block decreased with the addition of nanoparticles into diesel fuel which is parallel to vibration results.

Low temperature microwave assisted hydrothermal carbonization (MAHC) reduces combustion emission precursors in short rotation coppice willow wood

The combustion of biomass can be both CO2 neutral and economically beneficial. One major negative aspect are the gaseous and particle emissions that are formed by inorganic precursors in the biomass. These inorganic elements also cause slag formation. Short rotation coppice (SRC) willow wood contains a relatively large proportion of these precursors. This paper investigates the potential of low temperature Microwave Assisted Hydrothermal Carbonization (MAHC) for the reduction of emission precursors in SRC willow wood. Most of the respective elements were significantly reduced at the selected temperatures of 150 °C, 170 °C, and 185 °C. The most efficient combination of energy input, increasing heating value and decreasing mineral content was obtained at 170 °C. This shows the high potential of the MAHC treatment for utilizing low quality biomass as biofuel.

Biochar production from microalgae cultivation through pyrolysis as a sustainable carbon sequestration and biorefinery approach

Microalgae cultivation and biomass to biochar conversion is a potential approach for global carbon sequestration in microalgal biorefinery. Excessive atmospheric carbon dioxide (CO2) is utilized in microalgal biomass cultivation for biochar production. In the current study, microalgal biomass productivity was determined using different CO2 concentrations for biochar production, and the physicochemical properties of microalgal biochar were characterized to determine its potential applications for carbon sequestration and biorefinery. The indigenous microalga Chlorella vulgaris FSP-E was cultivated in photobioreactors under controlled environment with different CO2 gas concentrations as the sole carbon source. Microalgal biomass pyrolysis was performed thereafter in a fixed-bed reactor to produce biochar and other coproducts. C. vulgaris FSP-E showed a maximum biomass productivity of 0.87 g L−1 day−1. A biochar yield of 26.9% was obtained from pyrolysis under an optimum temperature of 500 °C at a heating rate of 10 °C min−1. C. vulgaris FSP-E biochar showed an alkaline pH value of 8.1 with H/C and O/C atomic ratios beneficial for carbon sequestration and soil application. The potential use of microalgal biochar as an alternative coal was also demonstrated by the increased heating value of 23.42 MJ kg−1. C. vulgaris FSP-E biochar exhibited a surface morphology, thereby suggesting its applicability as a bio-adsorbent. The cultivation of microalgae C. vulgaris FSP-E and the production of its respective biochar is a potential approach as clean technology for carbon sequestration and microalgal biorefinery toward a sustainable environment.