Char Production Research Articles

Beyond the Bench: Contextualizing the Impacts of Char Redox Properties on Biogeochemical Cycling and Microbial Ecosystem Services.

The electrochemical properties of chars have been recently described, positioning chars as active participants in microbial redox processes through functional groups, aromatic structures, redox-active metals, and radicals. While bench-scale studies have advanced mechanistic understanding of char's behavior and potential effects, translating these findings to complex ecosystems remains challenging. This is mainly due to the complexities of microbial communities and the unique properties of various ecosystems. Factors like char aging and patina formation, and environmental parameters including oxygen and moisture availability, pH, and organic matter content can significantly affect char electrochemical properties and microbial interactions. This highlights the need for a broader understanding of char redox processes to predict and effectively manage unintended environmental impacts or enhance beneficial effects. Long-term monitoring of complex systems amended with char is also needed to determine whether char accumulation has long-term redox effects on microbial ecosystem services, including biogeochemical cycling. Predictive understanding of these processes would inform the production of chars to enhance beneficial processes such as increased soil productivity, and provide new opportunities for engineered environmental remediation. Here, we summarize how char redox properties affect well-defined microbial systems and discuss key factors that determine whether the effects of char redox properties are enhanced or attenuated in complex systems. We also identify critical knowledge gaps about chars' role in microbial redox processes that are important for environmental sustainability and postulate that managing char's redox properties, such as electron donating, accepting, or conducting ability, is an emerging opportunity to influence microbial ecosystem services.

Techno-economic evaluation of pyrolysis and electrolysis integration for methanol and char production

Techno-economic evaluation of pyrolysis and electrolysis integration for methanol and char production

Evaluation of char properties from co-pyrolysis of biomass/plastics: effect of different types of plastics

Co-pyrolysis of biomass/plastics is a viable method to obtain high-quality carbon materials. The synergistic effect in the char production process of co-pyrolysis of biomass/plastics affects the properties of the obtained char. However, the synergistic effect research on the char production process of co-pyrolysis of biomass/plastics is facing challenges owing to highly varying composition of different plastics. In this study, the synergistic effect during co-pyrolysis of bamboo (BM) and plastics (polypropylene (PP), polystyrene (PS), polyethylene terephthalate (PET), polycarbonate (PC), and polybutylene terephthalate (PBT)) was investigated. TG results showed that PP, PS, PET, and PBT promoted the release of biomass volatiles and increased co-pyrolysis char yield. Notably, the O-aromatic structure in PC underwent cleavage and deoxygenation reactions, inhibiting the production of co-pyrolysis char during co-pyrolysis process. Char yield from co-pyrolysis process decreased from 24.80% for bamboo pyrolysis to 15.74% for co-pyrolysis of bamboo/PC. The results of physicochemical tests on char samples indicated that the addition of polyhydrocarbon plastics (PP and PS) increased H/C ratio, O/C ratio, heating value and oxidative reactivity of the char compared to bamboo char due to the vapor deposition of hydrocarbons derived from thermal decomposition of plastics on the biomass char. While, co-pyrolysis of biomass and polyester plastics (PET, PC, PBT) improved the pore structure of char and increased oxygen content.

Sustainable valorisation of cigarette butts waste through pyrolysis: An insight into the pyrolytic products and subsequent aqueous heavy metals removal by pyrolytic char

In this study, cigarette butts (CB) waste was pyrolyzed over a wide temperature range (400–700 °C) using Pyro/GC–MS and slow pyrolysis experiments. The feedstock and char products were extensively investigated using TGA, elemental analysis, surface area and porosity analysis, SEM-EDS, XRD, and FT-IR, and subsequently tested for their ability to remove Ni (II) and Cu (II) from aqueous solutions. The Pyro/GC–MS analysis revealed the presence of several useful compounds including acids, esters and hydrocarbons. Char yields ranged from 26.6 to 20.1 wt%, and carbon contents varied from 65.3 to 60.8 wt%. The chars produced at medium temperatures (500-600 °C) were highly porous, with a specific surface area of 272.9–270.8 m2/g. The heavy metal adsorption studies revealed that CB 500 °C had the highest adsorption capacity of 13.8 mg/g with 53.4 % nickel removal, while CB 600 °C had the highest adsorption capacity of 23.4 mg/g with 94.7 % copper removal.

Carbonization of Refuse-Derived Fuel Pellets with Biomass Incorporation to Solid Fuel Production

In this work, dry carbonization (DC) and hydrothermal carbonization (HTC) of refuse-derived fuel (RDF) pellets were conducted to evaluate the physical, chemical, and fuel properties of the produced chars. In the dry carbonization tests, biomass sawdust was incorporated in different proportions on the samples to minimize agglomeration caused by the melting of the plastic fraction. The experiments were carried out in a temperature of 400 °C (DC) and 250–300 °C (HTC), in a residence time of 30 min. The respective chars and hydrochars were characterized according to their mass yield, apparent density, proximate, elemental, and mineral composition, chlorine content, high heating value, thermogravimetric profile, and surface functional groups. The results showed that the dry carbonization of RDF pellets with biomass incorporation, followed by a washing step, resulted in the production of chars with improved properties such as higher fixed carbon and higher heating value (HHV) (25–26 MJ/kg) and lower ash and chlorine content. Additionally, the HTC experiments demonstrated that hydrochars showed improved properties without the need for biomass addition and washing, however, with no significant difference in the HHV (20–21 MJ/kg). Therefore, DC of RDF pellets with 10% biomass incorporation seems to be a promising option to overcome the constraints of RDF utilization as an alternative fuel.

Detailed modelling of a double fluidised bed steam gasifier processing woody biomass and solid recovered fuel mixtures

Abstract Double fluidized bed gasification is based on the circulation of an inert bed between two reaction sections: the gasification reactor, where a solid feedstock, generally biomass. is converted into a syngas by steam or air oxidation; the combustor or riser, where residual char from the thermal decomposition of the feedstock is oxidized by air (in some cases with additional fuel) to provide the energy contribution for the gasification reactions and ensure autothermal operation of the system. In this work, detailed modelling of a dual fluidized bed steam gasification reactor is performed in Aspen Plus by incorporating: (1) gas, char and tar production during thermal decomposition of the feedstock according to experimental correlations developed and taken from the literature, (2) heterogeneous and homogeneous reaction kinetics in the gasifier bed and in the freeboard. The model has been validated by comparison with experimental results on different mixtures containing solid recovered fuels and woody biomass. The model is quite accurate in predicting the gas products composition for different feedstocks mixtures (root mean square error of 12% for CO, CO2, H2 and CH4) and enables coupling with different downstream liquid fuels synthesis processes (synthetic natural gas, methanol, dimethyl-ether, Fischer-Tropsch products etc.).

Results of departmental control of bacteriological water pollution within the limits of the “One Health” concept

The article is devoted to the analysis of the state of contamination of water from surface reservoirs and drinking water by bacteriological agents at the facilities of operators of the market of char products under the control of the State Production and Consumer Service in the Kharkiv region and the importance of studying this factor of contamination. Using the sources of domestic and foreign literature, the data of our research, the article presents information on the spread of bacteriological contamination of surface water bodies (from fish farms) and drinking water in the production of food products and the results of sanitary and microbiological control of drinking water samples. Sanitary and microbiological control of water quality establishes the degree of its safety under the requirements for a centralized drinking water supply. The main sanitary test for water contamination by intestinal secretions of warm-blooded animals remains bacteria of the group Escherichia coli (E. coli). Unlike the vast majority of countries, stricter requirements for the quality of drinking water concerning this indicator have been preserved in Ukraine, that is, all types of glucose-positive coliform bacteria are taken into account, not only lactose-positive variants. This approach is justified since many lactose-negative intestinal bacteria can not only enter but also multiply under appropriate conditions in drinking water and harm human health. Water as the main or auxiliary raw material is used in the vast majority of technological processes of food production. Practically all food production is connected with the consumption of water from the water supply system, boreholes, or wells. Although the drinking water that «reaches» the «faucet» of the enterprise producing food products undergoes several stages of purification, it still remains a risk factor for contamination, including bacteriological contamination. The increase in the number of operators of the food market, and non-compliance with the requirements during the circulation of objects of sanitary measures leads to an increase in the risks of contamination and infection of people. Only periodic laboratory bacteriological control of the state of drinking water at the facilities of the food market operator can ensure the circulation of food products that do not harm human health and are suitable for consumption. The relevance of the problem of fecal contamination of drinking water is also due to the periodic lack of electricity, as water purification systems work unstable. Also, it should be noted that the summer of 2024 in Ukraine was abnormally warm. The reproduction of pathogens often depends on the temperature of the water, which is manifested as a ratio of favorable temperature and the manifestation of clinical signs of the disease. Pathogens also have optimal temperature ranges for reproduction. An increase in water temperature will increase the introduction of exotic pathogens originating from regions with a higher environmental thermal index. The destruction of the infrastructure leads to the deterioration of the sanitary and hygienic condition of settlements, and life support facilities, and the complication of the epidemic and epizootic situation. An environment favorable for the spread of dangerous infectious diseases is created. One Health and climate change adaptation can significantly contribute to food security, environmental sanitation, and steps towards regional and global integrated surveillance and response systems

Production Of Oil From Plastic Waste Through Thermal Degradation Process

The production of bio-oil from plastic waste through the thermal degradation process is a sustainable and innovative approach that addresses both environmental and waste management challenges. Pyrolysis is one of the thermal degradation processes that involve heating organic materials in the absence of oxygen, leading to the decomposition of complex organic compounds into simpler products, including bio-oil. In this study, healthcare waste, which typically consists of various organic materials such as medical plastics, syringes, bandages, and medical glucose bottles among other disposable items, is considered. Among these, medical glucose bottles are chosen as feedstock for pyrolysis due to their significant contribution to daily waste in the medical field and their negligible environmental and human health concerns. The pyrolysis process involves heating the medical glucose bottles to high temperatures between 400 and 500 °C in a controlled environment. This conversion process results in the production of bio-oil, char, and gases from the medical glucose bottles. The maximum yield rate of medical glucose bottle waste (MGBW) oil at 450°C of heating temperature will be solid (21%), liquid (27%), and gas (43%), with a calorific value of 42.5 MJ/kg, which is comparable to diesel. The bio-oil obtained from this process has several potential applications, such as in furnaces, and it can also be suitable for CI engines as an alternative fuel.

Transformation and control of organic sulfur during pyrolysis of sludge under conditions relevant to smoldering combustion: Role of oxygen and CaO

This study focused on the effect of oxygen (0–15 %) and 5 % CaO addition on the organic-S control and transformation behavior during pyrolysis (400–600 °C) of sludge under the conditions relevant to smoldering combustion. The results show that oxygen inhibits the total emission of gaseous sulfur (decreased by 25.6–36.9 %). At low temperatures (<500 °C), oxygen enhances the oxidation of aliphatic-S, aromatic-S/thiophene-S, and sulfide-S, leading more sulfur retains in the form of sulfone-S and sulfate-S in char products, also migrates to water-soluble products (especially sulfone-S). At high temperatures (>500 °C), the formed sulfur species in char products mainly further decompose into water-soluble sulfone-S, and partially generate SO2. After the addition of CaO during oxidative pyrolysis, the synergistic promotion effect on the sulfur fixation in char products is found, mainly due to the generation of more amount of stable sulfone-S and sulfate-S in char products. This leads to a decrease in gaseous sulfur by 12.4–14.6 % and an increase in sulfur content of char products by 31.3–202.9 %.

Production and characterization of two-step condensation bio-oil from pyrolysis

The goal of this project is to investigate the potential of fuel production directly from slow pyrolysis of straw pellets without further refining. A two-step condensation was used to separate liquids from the volatiles. The thermal process chosen is slow pyrolysis at 500°C to couple the fuel production with carbon capture by maximizing the char production alongside bio-oils collection. Condensation parameters were tuned to improve the pyrolysis oil quality. To assess the oil quality some requirements on marine fuels, bio-oils and boiler fuels were taken as reference. Three condensation conditions were inspected: the best pyrolysis overall process was repeated three times for a total of five pyrolysis processes (lately referred to as runs). As expected, the bio-oil characteristic changed with the condensation temperature. As a result of lowering the bio-oil condensation temperature, the bio-oil results less viscous, less dense, with lower heating value and with higher water content. The final bio-oil produced was almost compliant to ISO 8217:2017 for residual marine fuels K 380, apart from water content and acid number, while it was almost compliant for the standard EN 16900:2017 for industrial boilers fuels, apart for the kinematic viscosity. It was assessed that the char is produced with an average yield of 27 w% on dry basis, while bio-oil has a yield between 5 and 10 w%. It is possible to recover an average of 72 % of the total energy contained in the straw in the valuable products, gas, char and bio-oil. The carbon captured with charcoal was around 49 w% of the total present in straw. The pyrolysis experiments were performed using an innovative semi-batch, packed-bed reactor with gas re-circulation and a new two-fraction condensation appliance that is DTU patented. The innovation is both in the reactor, where the gas is directly heated and flushed back into the pyrolyser, and in the condensation section, where the bio-oil is separated from the water fraction during the pyrolysis. The company Stiesdal SkyClean A/S showed interest in further development and scale up of this pyrolysis and condensation system.

Co‐Pyrolysis and Pyrolysis of Corn‐Cob Biomass and Waste Plastic: Comprehensive Study Based on Kinetic and Thermodynamic Approach

AbstractThis study focuses on the utilization of agro‐residual corn‐cob biomass, waste plastic and the combination of both for pyrolysis reaction using thermal analysis. Circular bioeconomy is assured by closing all the resource materials loops through co‐pyrolysis process. The conversion profiles of corn cob pyrolysis at various heating rates reveal a three‐stage decomposition process, and plastic waste exhibits single stage degradation. Due to the interaction between the blended materials, additional degradation peaks arise during the co‐pyrolysis of waste plastic (PET bottles) and biomass (corn cobs). The apparent activation energy fluctuates in the range of 120–260 kJ/mol with the conversion, according to Flynn‐Wall‐Ozawa (FWO) and Kissinger‐Akahira‐Sunose (KAS) kinetic methods. Notably, for co‐pyrolysis the apparent activation energy is lower (168 kJ/mol using FWO) than the individual biomass (179 kJ/mol using FWO) and plastic (175 kJ/mol using FWO), suggesting a positive synergistic effect during charring. The liquid crude and char product analysis from corn cob pyorlysis through FTIR and XRD confirms the application of the products in energy and chemical processes. The results obtained in this study can be utilized for co‐pyrolysis reactor analysis specifically using waste plastic bottles that are accumulating in the environment.

Micropore effects on coal pyrolysis process investigated by using reactive molecular dynamics

The micropore structure can serve as the diffusion channels for intermediates and light tar products during coal pyrolysis, which is very important for modulating the desired tar or char products. In this work, the micropore effects on product distribution and the reaction mechanisms during Hailaer coal pyrolysis was explored for the first time from the atomistic simulation point of view by using large-scale ReaxFF MD simulation and the reasonable model with the artificially adding micropore strategy. The results suggest that the micropore structure indeed has a significant impact on the major tar product distribution and competitive reactions during coal pyrolysis process at high temperature. The micropore can promote decomposition reactions through accelerating C–C bond breaking significantly and inhibit the recombination reactions accompanied with the char formation with more carbon in sp2 structure. Based on the oxygen-containing bond behaviors in char products obtained from coal pyrolysis process, it is unraveled that the more micropore exits in coal structure, the more Csp3-O bonds and less Csp2-O bonds in char precursors. Particularly, the light tar products with ring groups are more influenced by micorpore structures than those chain products. Considering that the limitation of current experimental techniques in micropore detection, the strategy sheds new light on the depth investigation of micropore effects on reactions, which can provide complement for experimental observations and tar product modulation.

Insights into the co-pyrolysis interaction of cellulose and Zhundong coal via ReaxFF molecular dynamics simulation

Experiments on the co-pyrolysis of coal and cellulose were conducted using a fixed-bed reactor in this paper. The results demonstrated that co-pyrolysis increases gas and char yields while reducing tar yield. The reactive force field molecular dynamics (ReaxFF MD) was then used to simulate co-pyrolysis in order to analyze the mutual reaction between coal and cellulose from the perspective of carbon skeleton, enabling the co-pyrolysis mechanism to be examined precisely. The results demonstrated that co-pyrolysis accelerates the crosslinking of cellulose fragments and coal char. The cellulose-derived component in cross-linked char (char products containing both cellulose and coal fragments) rises from 0.21 wt% at 2000 K to 12.82 wt% at 3000 K, resulting in higher char production. The examination of the yields and distribution of co-pyrolysis products at 2400 K reveals that the volatiles generated by cellulose and coal char undergo mainly crosslinking reaction, resulting in a lower tar yield and a higher inorganic gas yield. Due to the combination of oxygen-containing functional groups in the coal char with cellulose volatiles and free hydroxyl groups, the oxygen-containing active functional groups were consumed, rendering the cross-linked char more stable and inactive, thereby suppressing coal polymerization.

Sugar derived hydrochar catalysts for enhanced biodiesel production via esterification

Sugars and sugar alcohols are renewable raw materials which can be used for char production. Their acid-catalyzed hydro-carbonization results in the formation of carbon materials with acidic functional groups on the surface, which makes them suitable to be used as heterogeneous catalysts in esterification reactions. Hydrochars materials were prepared by low-temperature slow carbonization of glycerol, xylitol, sucrose, and glucose in the presence of different amounts of H2SO4 (mass ratios from 1 to 4). The hydrochars were extensively characterized and tested in the methanolysis reaction of oleic acid. All the carbon materials were amorphous with features of polyaromatic sheets with hydroxyl (–OH), carboxylic acid (–COOH), and sulfonic (−SO3H) functional groups. The effect of the oleic acid water content on catalytic performance was studied, showing a strong inhibition effect due to the hygroscopic character of catalysts induced by sulfonic groups and other surface groups with oxygen. Under the conditions evaluated (5 % wt. of catalyst, methanol/oleic acid = 9 M ratio, methanol reflux temperature) the sucrose-derived catalyst prepared with the highest H2SO4 content showed the best performance, leading to methyl oleate yield > 90 % after 2 h of reaction, which is only achieved by the majority of analogous catalysts reported in the literature after 4 to 8 h of reaction. The data showed that there is a correlation between the methyl ester yield and the graphitization of the catalyst, as this makes the catalyst more hydrophobic, which is an advantage in esterification catalysts.

Benefits from co-pyrolysis of biomass and refuse derived fuel for biofuels production: Experimental investigations

The application of renewable fuels and waste for energy production is crucial environmentally and economically. Co-pyrolysis of biomass and refuse derived fuel (RDF) offers a promising pathway for valuable products that combine various benefits including enhanced energy recovery, waste valorisation, improved product quality, and environmental sustainability. Consideration of specific feedstocks and optimization of process parameters are necessary to maximise the efficiency and effectiveness of the co-pyrolysis process. This work presents investigations of the co-pyrolysis process of lignocellulosic biomass wastes (rye straw and agriculture grass) and RDF. These biomasses ensure efficient decomposition. The RDF, high in carbon (78.5 %) and hydrogen (11.8 %), was predominantly plastic based. Based on Py-GC-MS studies at 600 °C, it was observed that the addition of RDF to biomass caused a significant decrease in the share of organic oxygen compounds among the released decomposition products. Laboratory tests were performed in a fixed-bed reactor for raw biomass and RDF and 1:1 and 3:1 biomass to RDF mass ratio. The results demonstrated that the yield of char production decreased with the addition of RDF, which promoted the bio-oil yield. Despite, RDF pyrolysis meets problems, it was proved that co-pyrolysis of biomass and RDF is a good solution for their utilization.

Discernment of synergism in co-pyrolysis of starch, lignin, and cellulose: Properties and reactivity of char production

Starch, lignin, and cellulose are selected as representatives of solid waste, and the effects of these three main components and their interactions on the characteristics of the corresponding pyrolysis char are researched. The findings indicate that the interaction between starch (0.0216 min−1) and lignin (0.0203 min−1) could result in a lower oxidation reaction rate (0.0172 min−1) of the pyrolysis of their char mixture, which is associated with a slight collapse of the fibrous sheet structure. According to the comparison of the crystalline phases identified by X-ray diffractometry research, the interaction between lignin and cellulose improves the degree of carbon ordering, leading to the presence of C-faces (100) in the lignin + cellulose char sample. Raman analysis explains that the interaction between starch and lignin results in increased size and thickness of graphitic domains, and a similar trend is observed in the starch and cellulose char samples. Conversely, the band area ratio ID4/IG values of the mixed char samples are comparable to those of the two corresponding single-component char samples, indicating that no interaction occurs in the sp2–sp3 mixed structures. The results indicate that the carbon conversion increases with increasing temperature. Otherwise, the interaction between lignin and cellulose improves the degree of carbon ordering. The results of this study are anticipated to contribute to a better understanding of the mechanisms involved in the interactions of waste components on char production by pyrolysis of solid wastes.

Evaluating the Potential of Carbon Black for Safening of Herbicides in Soil

ABSTRACT Finely divided carbon char products offer a cost-effective method for the safening of herbicides in soil. In this investigation, two contrasting carbon char sources: Virgin Activated Charcoal (VAC) and Recovered Carbon Black (RCB) products were evaluated for safening of metsulfuron, sulfentrazone and pyroxasulfone herbicides in soil using sugar beet bioassay, and of rimsulfuron using perennial ryegrass bioassay. Plants were grown for seven days in WhirlPack® bags in soil with added carbon char product and added herbicide, and the root or shoot lengths were measured. The VAC was more efficacious in herbicide safening than the RCB. For the VAC, concentrations in soil (wt/wt) as low as 0.375% fully deactivated metsulfuron, sulfentrazone and pyroxasulfone, while for the RCB product a gradual degree of safening was observed, except for pyroxasulfone that was completely deactivated by both VAC and RCB. The VAC at concentrations of 3% and above fully deactivated rimsulfuron, while RCB did not. The two carbon char products examined in this study had different physical properties, of which the specific surface area (91 and 515 m2 g−1 for the RCB and VAC, respectively) and specific surface area of pores (75 and 247 m2 g−1 for RCB and VAC, respectively) showed the greatest difference. Higher surface area promoting greater sorption may explain more effective deactivation of herbicides by the VAC. To obtain the same degree of herbicide safening, more RCB would be required.

Laser-induced graphene formation on different wood species: Dependence of electronic performance on intrinsic features of certain types of wood

Conductive, 3D, porous graphene can be produced with a CO2 laser from a large variety of materials, including wood, at room temperature, and under inert atmosphere or after treatment for fire protection. Here, we investigated the suitability for direct conversion of 46 typical European and Asian woods into laser-induced graphene (LIG), without pre-treatment. The LIG was characterized by resistance measurements to determine if a conductive layer had formed, and via Raman spectroscopy. Here, we show, for the first time, that it is possible to produce LIG on certain woods under atmospheric conditions without additional fire protection treatment. We determined that the ability to produce LIG on untreated, natural wood under ambient atmosphere is favoured overall by a high density and a diffuse-porous xylem structure, as well as a high soluble lignin content. Some of these characteristics are similar to those required for high yields in char production. Problematic for the production of LIG-based electronics is the presence of pronounced growth rings, or other geometric wood features, with density variations, which can be reduced using specific cuts with minimized growth rings and absence of rays. This is the first time that untreated wood has been directly converted into LIG using a conventional CO2 laser and ambient atmosphere. Our results represent a further step towards the development of a new generation of sustainable electronics relying on natural materials.

Quantification of degree of interactions during co-pyrolysis of nine typical carbonaceous wastes

Organic municipal waste is a mixture of carbonaceous feedstock and cross-interaction of volatiles in their co-pyrolysis has been well documented, but quantifying their extent of interactions in co-pyrolysis is difficult. In this study, the ratio of char yield from co-pyrolysis to calculated average of pyrolysis of single feedstock was used as an indicator to probe the interaction in co-pyrolysis of every two typical carbonaceous wastes (sawdust, rice, spinach, chicken manure, office paper, corrugated paper, plastic bottles/films, fiber towel) at 550 °C. The results indicated that the co-pyrolysis of sawdust and corrugated paper had the highest degree of interaction (0.44). Sawdust and rice with ash-rich feedstock (spinach, chicken manure and office paper) resulted in dominance of gasification reactions to reduce char production in co-pyrolysis process. In comparison, the organics from the degradation of spinach and corrugated/office paper could react with the derivatives (mostly radicals) of plastic bottle (PET), plastic film (PE) or fiber towel (polyesters) via secondary condensation to generate more char. The chicken manure with high ash content hardly forms char of enhanced yield during its co-pyrolysis with other feedstocks. The enhancing char yield through secondary condensation generally resulted in additional oxygen-containing deposit on char and reduced thermal stability, which was the opposite to the formation of char with dominance of gasification. Co-pyrolysis of varied feedstock also led to change of morphologies of char via filling mechanism or formation of organics.

Evaluating the blending potential of two different biomass via co-pyrolysis as sustainable pathway using RSM optimization for bioenergy and bio char production

The present study addresses the co pyrolysis of Lantana Camara (LC) and Spent Coffee Grounds (SCG) to produce renewable biofuels. The aim is to optimize the process by determining the optimal blending ratio, temperature, and residence time to obtain the highest bio-oil yield. The experiments were performed using a fixed-bed pyrolysis reactor, and the parameters were optimized using response surface methodology. The physicochemical properties of the products were analyzed using GC MS, XRD, FTIR, and TGA analysis. The results of the study show that the highest bio-oil yield was obtained at a blending ratio of 5(LC):5(SCG), a temperature of 500 °C, and a residence time of 6 min. The bio-oil yield increased from 23.3 wt.% at 400 °C to a maximum of 40.2 wt.% at 500 °C. Kinetic analysis was done using TGA data by plotting Coats Redfern plot. Activation energy for LC and SCG were found to be 31258.442 and 56766.714 J/mol, respectively, and Arrhenius parameters for LC and SCG were 113.66 and 8783.017, respectively. The bio char produced has potential applications in water treatment. Overall, the study identified optimal conditions for maximizing bio-oil yield, demonstrating a significant increase compared to traditional methods.