Process for producing eco-flex biofuel from lignocellulosic biomass, including eucalyptus wood chips

Abstract

The present invention relates to a process for producing eco-flex biofuel from lignocellulosic biomass, preferably eucalyptus wood chips, which generates high-energy-yield products such as biochar, bio-oil and condensable gases with low energy consumption and low cost, whilst being sustainable, suitable and having a low environmental impact. The present invention also relates to biofuel produced from biomass, which is suitable for use in the steel industry, particularly, but not exclusively, in blast furnaces.

Description

"PROCESS FOR THE PRODUCTION OF ECO-FLEX BIOFUEL FROM LIGNOCELLULOSIC BIOMASS INCLUDING EUCALYPTUS CHIPS" FIELD OF THE INVENTION

[0001] The present invention relates to the Energy, Metallurgy and Steelmaking sector and describes a process for producing biofuel from lignocellulosic biomass, including eucalyptus wood chips, which has a significantly high calorific value.

[0002] Furthermore, the present invention relates to the biofuel obtained by this process and its applications. FUNDAMENTALS OF THE INVENTION

[0003] The search for more sustainable and renewable energy sources has been a major concern today, driven by the need to mitigate the adverse effects of climate change and reduce dependence on fossil fuels. In this context, biofuels have emerged as a promising alternative, capable of driving the energy transition and significantly reducing greenhouse gas emissions. The main advantage of biofuels is that they can directly replace fossil fuels in internal combustion engines and furnaces, without requiring major modifications to existing infrastructure.

[0004] A significant advance in biofuel research is the use of thermochemical conversion technologies, such as pyrolysis and gasification, to produce new solid and / or liquid biofuels, such as bio-oil and biochar, from different sources. Types of biomass. The bio-oil fraction can be used as a substitute for petroleum in various applications, including thermal energy production and electricity generation. Biochar, on the other hand, can be used in areas such as agriculture, environmental remediation, and energy generation.

[0005] Below, we highlight some state-of-the-art teachings relevant to this subject:

[0006] Document CN105349204 describes a charcoal briquette that includes the following raw materials by weight: 40-50 parts pulverized charcoal, 30-40 parts modified eucalyptus bark, 2-5 parts powdered corn straw, 5-8 parts powdered soybean straw, 2-5 parts powdered rice husk, 0.5-1 part calcium oxide, 1-2 parts combustion enhancer, and 5-8 parts binder. It is stated that the biomass charcoal briquette has the advantages of good thermal stability, high reactivity, low pollutant content in the smoke after combustion, and good marketability.

[0007] Document EP3527648 describes a method for removing inorganic substances, especially chlorine, sodium, potassium, calcium, and magnesium, from biomass of the genus Eucalyptus ssp. for the production of solid biofuel in the form of pellets or other forms, with low ash and chlorine content, thus allowing the product access to the international market for wood pellets and other solid biofuels.

[0008] Document CN 109082320 discloses a method for preparing biofuels in which hardwood and softwood are mixed in a weight ratio of 2:1, ensuring the average hardness of the prepared biofuel particles, so that the biofuel particles are Easily formed and having a high calorific value. The prepared biofuel particles are sufficiently dried through sand washing, steam explosion and drying processes and are easily burned and transported (due to their low density) resulting from their composition: animal oil and fat, lubricating oil and oxygen-boosting agents are added so that the prepared biofuel particles are easily burned.

[0009] Document JP5529995 discloses a method for producing biomass charcoal, capable of improving the yield of biomass charcoal in the production of biomass charcoal through the carbonization of biomass using a shaft furnace. amostraalso including less reduction in the quality of biomass charcoal, which includes carbonizing biomass 1, producing biomass charcoal and an exhaust gas 3 containing bio-oil, bringing at least a portion of the bio-oil in the exhaust gas 3 into contact with biomass 1 and / or biomass charcoal, and producing biomass charcoal 2 to which the bio-oil 4 is bound and deposited as a carbonized material.

[0010] Document PI0901948 describes a process with independent reactors for drying and pyrolysis of plant material and an independent vessel for cooling the charcoal. In this process, volatile products – non-condensable gases and condensable pyroligneous vapors – are burned in an independent combustion chamber to generate the heat necessary for the process. As a result, the burning of part of the wood is avoided and polluting condensable products are not released into the atmosphere. In the system, it is possible to interrupt the carbonization process at the end of the drying stage, or at the end. from the endothermic phase of pyrolysis, thus obtaining anhydrous wood or burnt wood, which are very convenient fuels.

[0011] Therefore, there is no equivalent solution in the state of the art to that presented here in the present invention that combines technical differentiators, economic advantages, safety and reliability. OBJECTIVES OF THE INVENTION

[0012] Thus, it is an objective of the present invention to provide a new solid biofuel from lignocellulosic biomass, preferably including eucalyptus chips, for application in steelmaking, in blast furnaces and / or furnaces and systems that require a pulverized biofuel with low particle size and high calorific value, low cost and low environmental impact as a replacement for fossil fuels.

[0013] Another objective of the present invention is to provide a clean, sustainable, and low-cost process for producing biofuel from lignocellulosic biomass, preferably eucalyptus wood chips.

[0014] It is also another objective of the present invention to provide a biofuel with a significantly high calorific value.

[0015] It is also another objective of the present invention to provide a biofuel capable of completely or partially replacing the non-renewable fuel currently used. SUMMARY OF THE INVENTION

[0016] The present invention achieves these and other objectives through a process for producing eco-flexible biofuel from eucalyptus wood chips, comprising the following steps: a) Select raw material (lignocellulosic biomass) such as eucalyptus wood chips; b) Characterize and standardize the raw material in relation to moisture, volatile content, ash content, and fixed carbon content; c) Obtain a particle size of the raw material smaller than 250 μm; d) Perform pyrolysis; e) Obtain bio-oil, condensable gases and biochar; f) Separate the products using a condensation system.

[0017] The present invention achieves these and other objectives by means of a biofuel obtained from the above process and the use of this biofuel in blast furnaces in steelmaking. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be described based on the attached drawings, which illustrate:

[0019] Figure 1 represents thermogravimetric curves of eucalyptus wood chips;

[0020] Figure 2 represents Fourier Transform infrared spectra for biomass and biochar;

[0021] Figure 3 illustrates thermogravimetric curves for biochar;

[0022] Figure 4 illustrates a comparison between the thermogravimetric profile of eucalyptus wood chips (red) and biochar (blue). DETAILED DESCRIPTION OF THE INVENTION

[0023] The present invention relates to a low-cost eco-flex biofuel production process from eucalyptus wood chips that involves optimizing the biochar production process via a pyrolysis thermoconversion route.

[0024] This step aims to optimize biochar production by evaluating the properties inherent to energy generation and thermal stability necessary for good biochar performance in steelmaking, particularly, but not exclusively, in blast furnace tuyeres. The process of the present invention results in optimized products under conditions with the best possible energy performance (highest calorific value and highest fixed carbon), within the evaluated technical parameters of interest and with production process conditions that consume less energy, i.e., with lower temperature and time that fall within the established limits of good biochar.

[0025] Preferably, the resulting product has the following characteristics: Higher heating value > 30 MJ / Kg; Ash content < 30%; Fixed carbon > 70%; Particle size < 0.149 mm.

[0026] The present invention offers numerous technical and economic advantages when compared to the state of the art, some of which are listed below: - This is a new solid biofuel derived from biomass, preferably eucalyptus wood chips, for application particularly, but not exclusively, in blast furnaces; - involves the production of a new liquid biofuel from vegetable bio-oil that can be applied in renewable hydrocarbon production processes; - It is a process for producing biofuel from clean, sustainable eucalyptus wood chips, with low cost and low energy consumption; - It is a biofuel with a significantly high calorific value; - It meets current sustainability and environmental requirements; - It can be applied to power generation in other situations of interest.

[0027] Below are some characteristics of the present invention:

[0028] FTIR and elemental analyses demonstrate that the products obtained by the process of the present invention exhibit a reduction in oxygenated functional groups compared to biomass;

[0029] The thermal stability of the biochar obtained is greater than that of biomass. Furthermore, when biomass is converted into biochar according to the process of the present invention, the resulting energy release, in the thermogravimetric analysis, increases by 101.71% of the original value of the biomass, which is proven by the lower calorific value of the biochar with 31.96 ± 0.47 MJ / Kg, representing a value 80.97% higher than the LHV of the biomass, which was 17.66 ± 0.37 MJ / Kg. Process of the present invention The process of the present invention comprises the following steps: Step 1 - Choice of raw material = lignocellulosic biomass, such as eucalyptus chips, pine, bamboo, sugarcane bagasse, etc.

[0030] The raw material used to obtain the product of the present invention is eucalyptus wood chips that have undergone pre-treatment and conditioning. Physicochemical characterizations of the raw material are performed in its natural state, in order to compare them with the bioproducts generated by the process of the present invention.

[0031] The levels of the macroconstituents of eucalyptus wood chips are listed below in Table 01: Table 01: Macroconstituent content of biomass. Macroconstituents Content (%) Total Extracts 7.28 ± 0.90 Total Lignin 2629 ± 2.48 Cellulose 42.08 ± 0.28 Hemicellulose 21.91 ±0.28 Ash.02 ± 0.05

[0032] Cellulose and hemicellulose carbohydrates represent 63.99% of the biomass composition used in the process of the present invention. These carbohydrates will be converted during pyrolysis into volatile materials, such as non-condensable gases and bio-oil, as will be seen later.

[0033] The total lignin content (26.29%) is responsible for the formation of the solid material retained in the reactor, biochar, due to its greater thermal stability. Therefore, the inventors concluded that the biochar production yield will have values ​​that revolve around the lignin content.

[0034] The main functional groups found in the eucalyptus wood chip biomass used in the present invention and their respective identification are listed below in Table 2: Table 02: Functional groups identified in eucalyptus wood chips. N" wave (cnr'j Assignment) s í0 3331.19 Stretch Õ-H 2920 Aliphatic fractions of extractives 1731.85 C=O Stretch Alide / Ketone 1593.09 Aromatic ring vibration + C=O stretching of the ignition 1504.79 Aromatic ring vibration 1454.46 Deformation of the CH group 1422.46 Aromatic ring combined with C~H 1318.67 C-0 Hico siring ring 1228.35 Stretch CC + CO 1028.53 C-O stretching of alcohol, CC, COC

[0035] The elemental composition of biomass from eucalyptus wood chips is described below in Table 03: Table 03: Element (%) Biomass Carbon 46.86 ± 6.86 Hydrogen 6.35 + 0.16 Nitrogen 0.18 ± 0.01 Sulfur 0.00 ± 0.00 Oxygen 42.64 ± 1.73

[0036] The carbon and oxygen content comprises 89.50% of this material. The high content of these elements is due to the functional groups found in the biomass, as listed above. The low nitrogen content identified is a result of the biomass source used (eucalyptus), where a maximum of 0.4% nitrogen is found for these elements. amostra s. Step 2 - Characterization of the raw material

[0037] The initial stage of the process of the present invention comprises the physicochemical characterization of the biomass (wood chips). eucalyptus) and subsequent testing under standardized conditions in order to lead to the efficient production of biochar and vegetable bio-oil.

[0038] Characterizing biomass is fundamental because it allows for a thorough understanding of its physical, chemical, and energy properties, providing crucial information for adjusting the operational parameters of the sequential process steps and ensuring consistency in the quality of the products generated.

[0039] It begins with the pre-treatment and conditioning of the raw material. In this phase, the lignocellulosic biomass is preferably ground in a knife mill with 5 and 3 mm sieves to reduce particle size and stored free of moisture.

[0040] Preferably, the ground biomass (eucalyptus chips) is subjected to particle size classification, preferably in a sieve shaker agitated at 15 Hz for 10 minutes. For the process of the present invention, a particle size of <250 µm is selected as raw material. This is a crucial factor in obtaining an ideal product for the application of interest, as this characteristic is directly related to the high calorific value achieved. Preferably, the biofuel is processed according to the following standards: 100% passing through <149 µm as described in Table 4: Table 04: Particle sizes of biomass for pyrolysis. Granulometry (pm) Mass (g) Temperature (°C) Time (min.) 500-250 100 550 60 250-212 100 550 60 212-149 100 550 60 < 149 00 550 60

[0041] Particle size distribution is directly related to the operating parameters of the pyrolysis stage.

[0042] The calorific value corresponds to the energy produced in the form of heat during the complete combustion of a fuel, for example, biomass. The higher calorific value is generally greater than the lower calorific value because it takes into account the energy generated / used for the complete vaporization of the water that constitutes the fuel.

[0043] Since the "humidity" factor is known to be essential for developing the product of interest in the present invention, this should be a parameter to be evaluated.

[0044] To determine the moisture content (%M), weigh approximately 1.0 g of ammonium chloride. amostra, precisely 1 mg in an open crucible. Then, place it in an oven at 105 ± 5 °C for 90 minutes. Immediately after, remove it from the oven and place it in a desiccator to cool. The calculation of Moisture Content (%U) is performed using Equation 1: ín -i - Í'Í2 %U = × 100 In what way: %U is the moisture content of the am amostra , expressed as a percentage (%); m1 is the mass of the crucible with am amostra before drying in the oven, expressed in grams (g); m2 is the mass of the crucible with am amostra after removal from the oven, expressed in grams (g) and mam amostra it's mass of am amostra initial, expressed in grams (g).

[0045] Another important parameter for the present invention is the volatile matter content. To determine this content (%V), the following procedure is used: approximately 1.0 g of ammonium chloride is weighed. amostra(biomass) after the process of determining the moisture content in a crucible with a lid, previously dried and tared. The crucibles with the am amostra They are placed on the door of a muffle furnace that has been preheated to a temperature of 950 ± 10 °C for 2 minutes. Then, the crucibles are placed inside the muffle furnace and the door is closed, remaining there for 6 minutes at the aforementioned temperature. After removing the crucibles... amostra After removing the samples from the muffle furnace, they are cooled in a desiccator to determine the final mass. The volatile matter content (%V) is calculated using Equation 2: m am In what way: %V is the volatile matter content of the ammonium chloride. amostra , expressed as a percentage (%); m2 is the mass of the crucible with am amostra after removal from the oven, expressed in grams (g); mam amostra it's the mass of am amostra initial, in grams (g) and m4 is the mass of the crucible with amamostra after removal of volatiles, in grams (g).

[0046] Another characteristic that must be monitored in the present invention is the Ash Content (%Z). To determine the ash content, the following is used: amostra (biomass) after removal of volatile material. Then, it is calcined in an open crucible at a temperature of 575 ± 25 °C for 4 hours. Immediately afterwards, the am amostra It is cooled in a desiccator and the final mass is weighed. To calculate the ash content (%Z), Equation 3 is used: %Z = × 100 m amostra In what way: %Z is the ash content of the am amostra , in percentage (%); m5 is the mass of the crucible with am amostra after the process, in grams (g); m1 is the mass of the crucible with am amostra before drying in the oven, in grams (g); mam amostra it's the mass of am amostra initial, in grams (g).

[0047] The fourth aspect that must be monitored to obtain the product of the present invention is the Fixed Carbon Content (%FC). To determine the fixed carbon content (%FC), the moisture content (%U), volatile matter (%V), and ash content (%Z) are summed and subtracted from 100%. The calculation of the fixed carbon content is performed using Equation 4. %CF = 100 - (%U + %V + %Z)

[0048] Thus, with the conclusion of this stage, it is as described. in Table 05: Table 05: Biomass Content (%) Moisture 0.0 to 10.0% Volatile Matter 40.0 to 90% Ash 0.0 to 10% Fixed Carbon 5.0 to 40.0%

[0049] Other components present in biomass can also be evaluated, such as: inorganic content, macroconstituents: cellulose, hemicellulose and lignin, elemental analysis (CHNS-O).

[0050] To determine the Extractives Content (%Ext), weigh approximately 3.0 g of ammonium chloride. amostraThe mixture is in powder form and then wrapped in filter paper to form a cartridge. This determination is made in triplicate, and the cartridges are placed in a forced-air oven at 105°C to eliminate excess moisture. Afterwards, the cartridges are placed in a Soxhlet extractor.

[0051] This determination is carried out in two stages. In the first reflux stage, acetone is added to the flasks, the ammonium chloride is added to the fluid. amostra The cartridge is refluxed with this solvent for 5 hours. At the end, the cartridge is removed from the extractor and the excess solvent is allowed to evaporate in the open air. Then, the cartridge is placed back in a forced-air oven at 105°C for complete drying.

[0052] In the second stage, the system is reassembled and the cartridge is inserted after drying. In this stage, water is used as the solvent and the system remains under reflux for 8 hours. Finally, the process is repeated, the excess water is allowed to evaporate, and then the cartridge is dried in an oven with air circulation.

[0053] To determine the lignin content, weigh 0.3g of the sample in triplicate. amostra The extractive-free solution contained in the cartridge is added to a pressure tube, followed by 3.0 ml of a 72% (w / w) sulfuric acid solution. The pressure tube is closed and the acid and the solution are manually homogenized. amostra Next, place in an urn shaker at 30.0±1.0°C and let it shake continuously at 200 rpm for 10 minutes. Then, remove the lid and, using a glass rod, mix thoroughly to macerate the aroma. amostra The rod is placed inside the tube and then added to the acid.

[0054] Next, this tube with the rod attached inside is again inserted into the shaker at 30.0 ± 1.0 °C, at 200 rpm. Every 5 minutes, the shaking is stopped to manually macerate the mixture using the rod. amostra Then, return the tube to the shaker and shake for another 5 minutes. Repeat this procedure until 50 minutes have elapsed. Next, remove the tube from the shaker and add 84ml of ultrapure water to the mixture to rinse the wand. Seal the tube tightly and homogenize the mixture. amostra It is then placed in a CS vertical autoclave at 121°C for 1 hour. It is cooled to room temperature and filtered. amostra s in a crucible. This initial filtrate, the hydrolyzed fraction, is collected for determination of soluble lignin.

[0055] The solid fraction retained in the crucible is washed with distilled water until excess acid is removed and dried in a forced-air oven at 105°C until constant mass is reached. Then, this crucible containing the ammonium chloride is calcined. amostra In a muffle furnace at 575±25°C for 4 hours. Insoluble lignin and acid ash are quantified by mass difference.

[0056] The concentration of soluble lignin is determined in a UV-Vis spectrophotometer. A 1.0 cm optical path quartz cuvette is used, measuring the absorbance corresponding to wavelengths of 215 and 280 nm.

[0057] To determine carbohydrate content - Cellulose and Hemicellulose - the samples are filtered. amostra hydrolyzed using a syringe filter with a PTFE membrane and 0.22 µm porosity, into a vial of am amostra (vial type) compatible with the equipment.

[0058] The determination of structural carbohydrates, cellulose, and hemicelluloses is carried out using an HPLC (High-performance liquid chromatography) instrument coupled to a refractive index detector.

[0059] The analyzed material exhibits low hygroscopic moisture and a high volatile matter content (82.29%). The volatiles present in this biomass originate from extractives, cellulose, hemicellulose, and external lignin fractions. The low ash content (1.02%) favors the use of this raw material in the production of solid, liquid, and gaseous biofuels, since, during the thermoconversion process, this inorganic material content results in a low level of non-reactive residual material formed during the process.

[0060] Through analysis of the inorganic content using XRF technique, the ash content of the selected biomass is found to be 1.02 ± 0.05%. Furthermore, it is found that the most abundant inorganic elements in the eucalyptus wood chips used as raw material in the process of the present invention are: calcium (Ca) with 55.73% of the ash content, representing 568.45 ppm of the biomass; potassium (K) with 16.293% of the ash content, representing 166.19 ppm of the biomass; and chlorine with 8.166% of the ash content, representing 83.29 ppm of the biomass. Step 3 - pyrolysis

[0061] After evaluation and characterization of the raw material, pyrolysis is carried out in a material volatilization system, with a fixed-bed reactor, preferably coupled to a chiller to assist in cooling the heat exchanger and condensing the gases.

[0062] Through pyrolysis, bio-oil, bio-char, and condensable gases are obtained.

[0063] Preferably, the temperature ranges from 339 to 762°C, the processing time ranges from 48 to 132 minutes, and the mass of the... amostra from 70 to 166 grams.

[0064] With the results presented by the thermogravimetric profile of the biomass (TG) with its respective derivative (DTG), as well as the exothermic transition as a function of temperature (DSC), which is illustrated in Figure 1, it is possible to select the temperature that will be used in step 3. Furthermore, it was also possible to evaluate and identify the presence of 04 biomass thermodegradation events as described in Table 06: Table 06: Thermal degradation events identified in biomass. Event Temperature (°C) Phenomenon 01 80-100 Moisture removal 02 225-315 Hemicellulose degradation 03 315-380 Cellulose degradation 04 390-550 Lignin degradation

[0065] At the peak of greatest intensity, at 355.7 °C (Figure 1), a mass loss of 18.25% is observed. This peak is related to the thermal degradation of cellulose, as this is the major component of the analyzed material.

[0066] For exothermic phenomena, it is observed that in the region Between 390 and 550 °C, the most thermally stable component (lignin) degrades in this region. The maximum energy release is evidenced at a peak at 524.4 °C with a release of 17.97 mW.g-1. After 550°C, there is a constant mass representing the non-reactive materials of the biomass.

[0067] Based on the results obtained in this analysis, a temperature of 550 °C was selected for the standard condition tests for the production of bio-oil and bio-oil.

[0068] After pyrolysis, three products are obtained: biochar, bio-oil, and syngas, with the average yields shown below in Table 7: Table 07: Yield of products obtained via biomass pyrolysis. Am amostra Yield on a dry basis (%) Tar 28.38 ± 2.33 Biô PC 30.17 ± 2.69 Gas 41.40 ± 4.96

[0069] The average evaluated yield of biochar was 30.17% ± 2.69, a value that corroborates the lignin content analyzed in the material. Furthermore, the combined yields of bio-oil and non-condensable gases are approximately 69.8%, corresponding to the cellulose, hemicellulose, and extractives content present in the biomass. Step 4 - Physicochemical characterization of biochar

[0070] The spectra obtained via FTIR for biomass and biochar are illustrated in Figure 2.

[0071] It is observed that after the pyrolysis of biomass, the resulting material in the reactor (biochar) loses most of its functional groups, mainly at 3331.19 and 1028.53 cm⁻¹, which are... These refer to the OH groups, the C-O stretching of alcohol, CC and COC respectively; these functional groups are present in the structures of cellulose, hemicellulose, lignin, and the moisture contained in biomass.

[0072] Furthermore, an increase in the intensity of the CH peaks is also observed in the 800 cm-1 region, an effect that is linked to the degradation of the content of other functional groups, thus indicating that the process of the present invention is effective for the conversion of biomass into biochar.

[0073] It is possible to identify that after the conversion of biomass into biochar, the carbon content increases by 80.90%, while the hydrogen and oxygen contents decrease by 68.66% and 92.54%, respectively. For both am amostra s, no sulfur content was identified.

[0074] Immediate analysis of the biochar indicates that the volatile matter content decreased from 82.29% to 10.99%, representing an 86.64% drop in volatile content, indicating that most of the volatiles present in the biomass were converted into biochar under the pyrolysis conditions used.

[0075] Also noteworthy is the increase from 13.99% to 85.06% in fixed carbon content, a value that represents a 508% increase in the fixed carbon initially assessed in the biomass. The evaluation of this parameter is important because it is related to the energy content released during combustion, indicating that the solid fuel produced (biochar) has a high capacity for energy generation.

[0076] Furthermore, it is observed that the ash content remained below 5%, increasing from 1.02% to 2.99%, which corroborates the objective of using biochar as a biofuel. Low residual material content, eliminating the need for equipment cleaning and ash removal routines, as shown in Table 8: Table 08: Immediate analysis of biomass and BioPCI Bio PCI Eucalyptus Chip Content (%) Moisture 2.70 ± 0.29 0.96 + 0.08 Volatile Matter 82.29 + 0.35 10.99 + 0.29 Ash 1.02 + 0.05 2.99 + 0.19 Fixed Carbon 13.99 + 0.44 85.06 + 0.25

[0077] It is possible to identify that after pyrolysis, the higher heating value increased from 19.09 MJ / Kg in the biomass to 32.41 MJ / Kg in the biochar, and the lower heating value increased from 17.66 MJ / Kg in the biomass to 31.96 MJ / Kg in the biochar, indicating an increase in HHV and LHV of 69.77% and 80.97%, respectively, as shown in Table 9: Table 09: Higher Heating Value (HHV) and Lower Heating Value (LHV) of biomass and BioLHV Heating Value Unit Eucalyptus Chip BioPCI Kcai / Kg 4,560.13 ± 39.48 7,740.08 ± 12.87 Higher MJ / Kg 19.09 ± 0.37 32.41 ± 0.47 Kcal / Kg 4,217.23 ± 89.48 7,632.82 ± 12.87 Lower MJ / Kg 17.66 ±0.37 31.96 ± 0.47 Analysis conditions for determining calorific value.

[0078] The following equation was used to determine the Lower Heating Value (LHV): PCI = PCS — 600 (9H / 100) In what way: • PCS corresponds to the Higher Heating Value provided by the equipment, cal / g; • H corresponds to the hydrogen content, %.

[0079] Figure 3 illustrates the TG, DTG, and DSC curves for biochar, where only two thermal degradation events can be identified. It can be observed that after pyrolysis, the produced solid biofuel exhibits greater thermal stability, as its decomposition begins at 480 °C, while for biomass, this phenomenon occurs at 260 °C. Furthermore, the mass drop in the raw material is more abrupt than that observed for biochar, with biomass being completely degraded at 600 °C and biochar still having a resulting mass to be converted at a temperature of 950 °C, which was the final temperature of the analysis.

[0080] Figure 4 shows a comparison of the thermograms obtained from the raw material and the biochar.

[0081] Exothermic data (DSC curves) demonstrate that the maximum energy release for biomass and biochar is 17.5 and 35.3 mW.mg-1, respectively. This indicates that when biomass is converted into biochar, the energy release increases by 101.71%, making the development of high-calorific-value solid biofuels from biomass promising. Step 5 - Physicochemical characterization of bio-oil

[0082] Elementary analysis for am amostra biomass and bio-oil m amostra that both materials exhibit quantities Similar hydrogen compounds are present in its composition; however, after the production of bio-oil, the carbon content increases from 46.86% to 68.28%, a rise of 45.71%, and the oxygen content decreases from 42.64% to 10.78%, representing a reduction of 74.72% in the bio-oil.

[0083] This result indicates that biomass pyrolysis under the standard conditions employed in this first stage of the project also helps reduce oxygenated functionals and increase the carbon content of the bio-oil.

[0084] The acidity index (AI) is a parameter indicating the quality of a liquid biofuel because it indicates the amount of base, expressed in milligrams of KOH, needed to neutralize the acidic constituents in 1 gram of ammonium chloride. amostra In am amostra In pyrolytic bio-oils, the IA (Index of Fatty Acids) generally presents high values, as they are directly related to the content of free fatty acids that are generated during pyrolysis, mainly from the hemicellulose fraction.

[0085] In addition to the iodine value (IV), water content is also a control parameter for biofuels and should be as low as possible. However, for tars derived from pyrolysis, these values ​​are also high, ranging from 50-90% depending on the process and raw material used. Step 6 - Characterization of syngas

[0086] The results of gas chromatography analyses with flame ionization and thermal conductivity detectors (FID / TCD) of the syngas collected at the beginning and end of eucalyptus wood chip pyrolysis indicate a variation in their composition. Nitrogen gas is the only one that increased, going from 6.48% to 53.34%; the remaining gases showed a decrease in composition. Particle size analysis

[0087] The particle size distribution of the biomass used in the pyrolysis processes is shown below. The highest and lowest yields obtained were in the range of 500-250 and 212-149 µm, respectively, as described in Table 10: Table 10: Particle size distribution of biomass used in pyrolysis processes (Phase 1 - optimization of experimental conditions) Initial mass Particle size Mass Content (g) (Mm) (g) (%) > 500 642.83 26.75 500-250 912.13 37.96 2.403 250-212 223.21 9.29 212-149 219.27 9.12 < 149 405.56 16.88

[0088] Below are presented the yields and particle size distribution of the biochars produced in each biomass particle size range, as described in Table 11: Table 11: Particle Size Distribution and Biomass and BioPCI Yield Particle Size Distribution Yield Yield (%) Yield (%) Biomass (pm) BioPCi (%) BioPCI < 143 m BioPCI < 74 pm 500-250 28.27 12.30 1.84 250-212 28.62 67.60 6.56 212-149 29.01 89.30 6.78 < 149 31.97 92.90 49.45

[0089] Furthermore, the relationship between the calorific value and the operating parameters of the process of the present invention is presented as shown in Table 12: Table 12: PCS (cal / g) PCS (MJ / Kg) PCI (cal / g) PCI (MJ / Kg) Experiment Average SD Average SD Average SD Average SD Biomass 4560.13 89.48 19.09 0.37 4217.23 89.48 17.66 0.37 (460'0; 120 min; 70 gj 6188.70 225.31 25.91 0.94 6069.34 225.31 25.41 0.94 2 (550'C; 90 min; 110 g) 7148.09 56.88 29.93 0.24 6967.59 5ô.88 29.17 3.24 3 (400'C; 60 min; 150 g) 6696.84 295.26 28.04 1.24 6600.72 295.26 27.64 1.24 4 (70Q :'C; 120 min; 150 g) 7889.17 170.09 32.95 0.71 7881.12 170.09 33.00 0.71 5 (700'C; 60 min; 70 g) 7527.95 167.18 31.52 0.70 7421.07 167.18 31.07 0.70 6 (550'0; 90 min; 1 0 g? 7130.15 83.08 29.85 0.35 7006.64 83.08 29.34 0.35 7 (400'C; 120 min; 150 g) 6400.37 38.82 26.80 0.16 6165.78 38.82 25.81 0.16 8 (700°C; 120 min; 70 g) 7786.64 93.91 32.60 0.39 7712.52 93.91 32.29 0.39 9 (400°C; 60 min; 70 g) 5947.05 260.73 24.90 1.09 5807.04 260.73 24.31 1.09 10 (700' C; 50 min; 150 g 7532.26 113.04 31.54 0.47 7473.13 113.04 31.29 0.47 11 (550'0; 48 min; 100 g} 7003.35 189.25 29.32 0.79 6897.53 189.25 28.88 0.79 12 {550'C; 132 min; 110 g) 7588.00 140.58 31.77 0.59 7353.21 140.58 30.79 3.5$ 13 (550'0; 90 min; 10 g) 7171.75 185.16 30.03 0.78 7007.22 185.16 29.34 0.78 14 (550'0; 90 min; 166 g 7204.64 86.28 30.16 0.36 7059.73 86.28 29.56 0.36 15 (762' C; 90 min; 110 g) 7601.97 143.53 31.83 0.60 7626.39 143.53 31.93 0.60 16 (550'0; 90 min; 70 g) 7279.33 215.84 30.48 0.90 7021.19 215.84 29.40 0.90 17 (339'0; 90 min; 110 g) 5168.23 239.19 21.64 1.00 4986.58 239.19 20.88 1.00 AVERAGE PC 7150.00 108.37 29.94 0.45 6993.82 108.37 29.28 0.45 .

[0090] The lowest higher heating value (21.64 MJ / Kg) is obtained for pyrolysis carried out at a temperature of 339 °C; while the highest value (32.95 MJ / Kg) is obtained for pyrolysis carried out at a temperature of 700 °C. These results demonstrate that high temperatures produce fuels with high heating value.

[0091] These results are essential for the optimized production of solid biofuels that exhibit high calorific values ​​for use in blast furnaces (> 30 MJ / Kg). Biochar production under optimized conditions

[0092] Following the optimization reactions of the biochar that is the subject of the present invention, Regression Equations were generated, which were used to develop a simulation matrix using the Solver statistical function of the Excel software.

[0093] Using this matrix, two optimized conditions were simulated: a. Condition 01: aims to generate a Biochar with the best possible energy performance, that is, with the highest values ​​of Calorific Value and Carbon Content; b. Condition 02; designed to be generated using the mildest possible process conditions, provided that it complies with the minimum quality limits of the biochar of the present invention, i.e., with lower temperature and residence time.

[0094] No, however, biochar under both conditions must meet the established limits of HBV > 30 MJ / Kg; Ash content <30%; Fixed carbon >70%; Particle size: 100% passing through 0.149mm.

[0095] Condition 1 for the production of biochar with optimized energy properties (Calorific Value and Fixed Carbon) as described in Table 13: Table 13: Variables Property Unit Theoretical Temperature 750.00 BioPCI % 29.04 fC) Tar % 32.14 Gas % 37.89 Time (min.) 120.00 PCS MJ / Kg 33.64 Volatiles % 5.09 Mass (g) 70.00 Fixed Carbon % 91.12 Volume in reactor 30% C content % 89.16 Reactor: H content % 1.06, O content % 2.71, C / H molar ratio 6.41 Molar ratio C / O 42.73

[0096] Condition 2 for biochar production with an optimized industrial process (reduced time and temperature and maximum mass) as revealed in Table 14: Table 14: Variables Property Unit Theoretical Temperature 550.00 BioPCi % 28.94 ('G) Tar % 40.22 Gas % 32.84 Time (min.) 60.00 PCS MJ / Kg 30.77 Volatiles % 14.67 Mass (g) 150.00 Fixed Carbon % 79.89 Volume of C % 82.70, 65% Reactor: H content % 2.81, O content % 7.05, C / H molar ratio 2.19 Molar ratio C / O 28.94 Evaluation in a blast furnace simulator of the combustibility of biochar under blast furnace tuyere conditions

[0097] The combustibility test was carried out using a paired raceway simulator consisting of two furnaces: one for preheating air or oxygen to the blast furnace temperature (800 to 1100 °C) and another to simulate the thermal conditions in the combustion zone (1600 °C).

[0098] The flammability index was calculated indirectly (Equations below) considering: (i) operational aspects of the blast furnace (injection rate, oxygen enrichment and air volume); (ii) characteristics of the am amostra injected (carbon) and (iii) combustion products (gases generated - CO, CO2 and CnHm). Injection Rate Weight of Am amostra (mgj = l4Ç €aí Enrichment 02+ Air volume Fuel Index (%) = IC = Cte * (CO + CO2 + C n H m ) / (O2 Enrichment + Air Volume) Oxygen enrichment + Air volume In what way: Cte - line pressure and volume of the regions.

[0099] The conditions for the tests were defined by varying the oxygen enrichment (0% and 4%) and injection rate (150 kg / t and 200 kg / t).

[0100] Having described an example of a preferred embodiment of the present invention, it should be understood that the scope of the present invention encompasses other possible variations of the inventive concept described, being limited only by the content of the appended claims, including possible equivalents.

Claims

CLAIMS 1. Process for producing eco-flexible biofuel from lignocellulosic biomass, preferably eucalyptus wood chips, characterized by comprising the following steps: a) Select raw material, which is eucalyptus wood chips; b) Characterize and standardize the raw material in relation to moisture, volatile content, ash content, and fixed carbon content; c) Perform pyrolysis; d) Obtain biochar, condensable gases and bio-oil; e) Separate biochar, condensable gases, and bio-oil by condensation.

2. Process according to claim 1, characterized in that step b) has: moisture content equal to or less than 5% and particle size smaller than 250 µm.

3. Process according to claim 1 or 2, characterized in that step b) exhibits properties as described in Table 01: Table 01 Biomass Content (%) Moisture 0.0 to 10.0% Volatile Matter 40.0 to 90% Ash 0.0 to 10% Fixed Carbon 5.0 to 40.0% 4. Process according to any one of claims 1 to 3, characterized in that step d) is carried out in a material volatilization system, with a fixed-bed reactor, preferably coupled to a chiller to assist in cooling the heat exchanger and condensing the gases.

5. Process according to claim 4, characterized in that step c) is carried out with a temperature ranging from 339 to 762°C; process time ranging from 48 to 132 minutes; and quantity of raw material characterized from 70 to 150 grams.

6. Process according to any one of claims 1 to 5, characterized in that step d) exhibits: 100% passing at <149 pm and 85% passing at <74 pm.

7. Process according to claim 6, characterized in that step e) is as described in Table 02: Table 02: Am amostra Yield on a dry basis (%j) Tar 28.38 ± 2.33 Bio PCI 30 7 *2.69 Gas 41.40 ± 4.96 8. Eco-flexible biofuel characterized by being obtainable from a process as defined in any one of claims 1 to 7.

9. Biofuel according to claim 8 characterized by having a higher heating value greater than 30 MJ / Kg; ash content less than 30%; fixed carbon content greater than 70%; particle size: 100% passing through 0.149 mm.

10. Biofuel according to claim 8 or 9 characterized by being suitable for blast furnace tuyeres, or in other steelmaking processes that use coal or other carbon sources.

11. Use of biofuel as defined in any of the Claims 8 to 10 are characterized by being suitable for blast furnace tuyeres.

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