Pyrolysis decomposition of tamarind seed for alternative fuel

Towards a sustainable waste-to-energy pathway to pequi biomass residues: Biochar, syngas, and biodiesel analysis

The waste-to-energy (WTE) valorization pathway of Caryocar brasiliense (pequi) seeds was investigated via pyrolysis, gasification, and transesterification to understand its potential as biochar, syngas, and biodiesel. First, the pyrolysis (300-700 °C) was conducted in N₂ atmosphere for pequi seeds (PS) and pequi seeds without its extractives (PSWE), characterizing its biochar properties. The PSWE was then gasified at 1000 °C under O₂/N₂, O₂/CO₂/N₂ and O₂/H₂O/N₂ atmospheres to evaluate the characteristics of the producer gas. The PS extractives were then transesterified and characterized for biodiesel production. Finally, a multiple-criteria decision analysis assessed the PS products' potential within the thermochemical routes. The results evidenced better biochar (up to 22.29% HHV enhancement, higher mass and energy yield, up to 75.9 and 85.5% reduction of O/C and H/C, respectively, and enriched N content) via PSWE pyrolysis than PS considering biofuel application and optimistic perceptions for soil amendment. This indicates that the preceding extraction of vegetal fat from PS strengthens the WTE by including further processing of extracted oil. The produced syngas under O₂/H₂O/N₂ gasification atmosphere showed better applicability as a biofuel (16.37 MJ·kg^-1 lower heating value, 107.33% cold gas efficiency, and 113.55% carbon conversion efficiency) with up to 24% higher success rate. The transesterification of the extractives revealed its potential (98% conversion rate) for use as feedstock for in situ power generation, or blended for biodiesel production. The results provide insights into the circular economy in agro-extractivist communities that may support Brazil's small and medium agro-food industries with their energy demands.

Characterization of acerola (Malpighia emarginata) industrial waste as raw material for thermochemical processes

Brazil stands out as one of the largest world powers in the agribusiness sector, and with the increase of production capacity, an enormous amount of waste is generated that cause serious environmental problems. Acerola is evidenced as one of the fruits of growing and important commercialization, contributing significantly to regional development through the export of concentrated powder product. Thus, in order to minimize the environmental impacts generated by the local fruit processing industry, the proximate analysis of its residue after drying in a convective oven at temperatures of 50, 75 and 100 °C was carried out in this work, aiming at the reuse of this residue for thermochemical processes. Moisture, ash, volatile matter (VM), and fixed carbon (FC) content were analyzed, as well as characterizations, such as infrared spectroscopy (FTIR), elemental analysis (CHNO), calorific value (HHV) and thermogravimetry (TG/DTG). The results showed a significant difference in the moisture contents, VM, FC and elemental carbon for the dry residue at 50 °C compared to the temperatures of 75 and 100 °C, while for the ash content there was no significant difference between the temperatures. The dry acerola residue at the three temperatures studied presented adequate properties for thermochemical application, with lignocellulosic compounds that can be converted by thermochemical route, good levels of calorific power, low moisture and ash content, associated with high amount of volatile matter.

Valorization of byproducts from tropical fruits: Extraction methodologies, applications, environmental, and economic assessment: A review (Part 1: General overview of the byproducts, traditional biorefinery practices, and possible applications)

Tropical fruits represent one of the most important crops in the world. The continuously growing global market for the main tropical fruits is currently estimated at 84 million tons, of which approximately half is lost or wasted throughout the whole processing chain. Developing novel processes for the conversion of these byproducts into value-added products could provide a viable way to manage this waste problem, aiming at the same time to create a sustainable economic growth within a bio-economy perspective. Given the ever-increasing concern about sustainability, complete valorization through a bio-refinery approach, that is, zero waste concept, as well as the use of green techniques is therefore of utmost importance. This paper aims to report the status on the valorization of tropical fruit byproducts within a bio-refinery frame, via the application of traditional methodologies, and with specific attention to the extraction of phenolics and carotenoids as bioactive compounds. The different types of byproducts, and their content of bioactives is reviewed, with a special emphasis on the lesser-known tropical fruits. Moreover, the bioactivity of the different types of extracts and their possible application as a resource for different sectors (food, pharmaceutical, and environmental sciences) is discussed. Consequently, this review presents the concepts of tropical fruit biorefineries, and the potential applications of the isolated fractions.

Charcoal production from waste pequi seeds for heat and power generation

Many specialized technologies are available to convert waste biomass into secondary products that have a higher value and are more convenient to process than the original feedstock. This study evaluated the potential of waste pequi seeds to produce high-quality charcoal for subsequent gasification into low-tar producer gas for heat engine applications. We focused on the characterization of pequi seeds, the derived charcoal, and the collected bio-oil from slow pyrolysis conversion of the feedstock. Thermodynamic equilibrium calculations were conducted to assess gasification performance of the parent biomass and its charcoal. We also investigated the thermal degradation kinetics of pequi seeds through non-isothermal thermogravimetric analysis. Finally, a two-step energy-extraction analysis was performed for the carbonization of the parent biomass and further utilization of its charcoal in an integrated gasification gas-engine cycle. Slow pyrolysis of pequi seeds (2 °C min^-1, 430 °C) produced up to 40% of high-grade charcoal with 60% fixed carbon, 43% of bio-oil, and 16% of light gases. The overall energy extraction efficiency was estimated as 61%, based on the higher heating value of wet pequi seeds. The investigation confirmed that waste pequi seeds could be considered a promising renewable energy source for combined heat and power generation for the Brazilian agro-food industry.

Biomass co-pyrolysis: Effects of blending three different biomasses on oil yield and quality

In the present study, pyrolysis and co-pyrolysis of sugarcane bagasse, poppy capsule pulp, and rice husk were conducted in a fixed bed reactor at 550⁰C in nitrogen atmosphere. The moisture (5%-8%), ash (4%-17%), volatile matter (60%-76%), and fixed carbon analyses (11%-24%) of the utilized biomass were conducted. The decomposition behavior of biomasses due to the heat effect was investigated by thermogravimetric analysis/differential thermal analysis . In the pyrolysis of biomasses separately, the highest bio-oil yield was obtained with sugarcane bagasse (27.4%). In the co-pyrolysis of the binary blends of biomass, the highest bio-oil yield was obtained with the rice husk and sugarcane bagasse blends. While the mean bio-oil yield obtained with the separate pyrolysis of these two biomasses was 23.9%, it was observed that the bio-oil yield obtained with the co-pyrolysis of biomass blends was 28.4%. This suggested a synergistic interaction between the two biomasses during pyrolysis. It was observed that as the total ash content in the biomasses used in the pyrolysis increased, the bio-oil yield decreased, and the solid product content increased. Characterization studies of bio-oils were conducted by Fourier-transform infrared spectroscopy, gas chromatography-mass spectrometry (GC-MS), and hydrogen-1 nuclear magnetic resonance analyses. Results of these studies revealed that, all bio-oils were mainly composed of aliphatic and oxygenated compounds. The calorific values of bio-oils were determined by calorimeter bomb. Based on the GC-MS, the bio-oils with high fatty acid and its ester content also had high calorific values. The highest calorific value was 29.68 MJ kg^-1, and this was obtained by pyrolysis of poppy capsule and sugarcane bagasse blend.

Experimental process parameters optimization and in-depth product characterizations for teak sawdust pyrolysis

Pyrolysis is an efficient thermochemical route to obtain biofuels in the form of bio-oil, biochar and pyrolytic gas from the processing of biomass. Pyrolysis experiments were performed with teak sawdust to determine the yield and main characteristics of solid, liquid and gaseous products. Experiments were carried out in the temperature range of 400-700 °C in 100 °C intervals, nitrogen flow rate of 150-250 mL/min, packed bed height in between 2 and 8 cm and particle size in between 0.18 and 0.60 mm. The maximum bio-oil and biochar yield were observed at 600 °C (48.8%) and 400 °C (37.42%), respectively. Physical properties (viscosity, density, carbon residue, pH and HHV) of bio-oil were determined and the chemical properties were investigated using FTIR and GC-MS. Further, biochar was characterized with proximate, ultimate, HHV, FTIR, SEM-EDX, BET surface area and XRD analysis. Non-condensable gases coming out during pyrolysis were analyzed using gas chromatography and amount of H₂, CH₄, CO and CO₂ were determined. According to characterization results, bio-oil can be used as biofuel after up gradation or as source of valuable chemicals, biochar can be utilized as solid fuel or seems to be suitable in waste stream purification as it has very high BET surface area. In addition, pyrolytic gases have significant amount of methane and hydrogen that provides good combustion properties.

Combined impact of EGR and injection pressure in performance improvement and NOx control of a DI diesel engine powered with tamarind seed biodiesel blend

In the process of creating eco-friendly environment and conserving fossil fuels for the future generations, biodiesel has been chosen as a good substitute for diesel. It is a proven fact that biodiesel operated diesel engine can deliver comparable results with diesel. The present work focuses on TSME20 (tamarind seed methyl ester 20% + diesel 80%) as a renewable fuel, and its performance and emission results are analyzed at different exhaust gas recirculation rates and various injection pressures. The process is done in two stages. Firstly, experiments are conducted on TSME20 operated diesel engine at three injection pressures (180, 200, and 220 bar), and the results are analyzed. From the experimental results, improved efficiency by 2.29% and reduced emissions, such as hydrocarbon, smoke, and carbon monoxide, by 53.84, 56.25, and 75.15% are observed at the peak load for the increased injection pressure (220 bar) over 200 bar except NOx levels, which are found high by 11% compared to 200-bar injection pressure. Secondly, tests are again performed at the optimal condition of 220-bar injection pressure with the exhaust gas re-circulation (EGR) rates at different levels, i.e., 10 and 20%. The test results reveal that the addition of 10% EGR to the engine operating at 220 bar counteracts the release of NOx levels, which are found reduced by 80.5% over standard conditions without much compromise in engine performance. Also, the combustion characteristics of diesel engine at 220-bar fuel injection pressure of tamarind biodiesel blend showed enhancement when compared to other fuel injection pressures.

Combined impact of EGR and injection pressure in performance improvement and NOx control of a DI diesel engine powered with tamarind seed biodiesel blend

In the process of creating eco-friendly environment and conserving fossil fuels for the future generations, biodiesel has been chosen as a good substitute for diesel. It is a proven fact that biodiesel operated diesel engine can deliver comparable results with diesel. The present work focuses on TSME20 (tamarind seed methyl ester 20% + diesel 80%) as a renewable fuel, and its performance and emission results are analyzed at different exhaust gas recirculation rates and various injection pressures. The process is done in two stages. Firstly, experiments are conducted on TSME20 operated diesel engine at three injection pressures (180, 200, and 220 bar), and the results are analyzed. From the experimental results, improved efficiency by 2.29% and reduced emissions, such as hydrocarbon, smoke, and carbon monoxide, by 53.84, 56.25, and 75.15% are observed at the peak load for the increased injection pressure (220 bar) over 200 bar except NOx levels, which are found high by 11% compared to 200-bar injection pressure. Secondly, tests are again performed at the optimal condition of 220-bar injection pressure with the exhaust gas re-circulation (EGR) rates at different levels, i.e., 10 and 20%. The test results reveal that the addition of 10% EGR to the engine operating at 220 bar counteracts the release of NOx levels, which are found reduced by 80.5% over standard conditions without much compromise in engine performance. Also, the combustion characteristics of diesel engine at 220-bar fuel injection pressure of tamarind biodiesel blend showed enhancement when compared to other fuel injection pressures.

Pyrolysis of water hyacinth in a fixed bed reactor: Parametric effects on product distribution, characterization and syngas evolutionary behavior

In this investigation, the effect of operating parameters on product distribution for the conversion of water hyacinth into most valuable product bio oil as well as char and gases are investigated. To observe the parametric effect on product distribution, the temperature was varied 300-600 °C, heating rate 10-50 °C/min, particle size of the feed <0.5-2.5 mm and carrier gas nitrogen flow rate 0-12 lpm. The highest bio-oil yield of 44.9 wt% was obtained at 350 °C, 30 °C/min, particle feed size less than 0.5 mm and 6 lpm. The results show that the product yield is strongly influenced by the temperature variation whereas weakly affected by the heating rate. The biomass and the products were characterized by ultimate, proximate, DTG, FTIR, ¹H NMR, and GC-MS. Syngas evolution increase with the increase of temperature except CO₂. The quality of bio-oil is perspective as a source of value-added chemicals and char is a promising source for the production of carbonaceous materials as well as solid fuel.

Pyrolysis of poppy capsule pulp for bio-oil production

The feasibility of biofuel production via the pyrolysis of poppy capsule pulp, the main waste product of Afyon Alkoloid Factory, was investigated. The poppy capsule pulp was shown to have a high volatile matter content (ca. 76%). Pyrolysis experiments were carried out in the temperature range 400-550°C (heating rate 18°C min^-1 and holding time 20 min) under a nitrogen atmosphere. The chemical components of the bio-oil were characterized by Fourier transform infrared spectrometry and gas chromatography-mass spectrometry. The effects of pyrolysis temperature on the production efficiency and the calorific value of the bio-oil were investigated. The maximum bio-oil yield and its calorific value at 500°C were 23.6% and 31.6 MJ kg^-1, respectively. The latter value is close to that of many petroleum fractions. This high-energy bio-oil is therefore a clean fuel precursor and can be upgraded into higher quality fuels.

Thermogravimetric analysis of the gasification of microalgae Chlorella vulgaris

The gasification of microalgae Chlorella vulgaris under an atmosphere of argon and water vapor was investigated by thermogravimetric analysis. The data were interpreted by using conventional isoconversional methods and also by the independent parallel reaction (IPR) model, in which the degradation is considered to happen individually to each pseudo-component of biomass (lipid, carbohydrate and protein). The IPR model allows obtaining the kinetic parameters of the degradation reaction of each component. Three main stages were observed during the gasification process and the differential thermogravimetric curve was satisfactorily fitted by the IPR model considering three pseudocomponents. The comparison of the activation energy values obtained by the methods and those found in the literature for other microalgae was satisfactory. Quantification of reaction products was performed using online gas chromatography. The major products detected were H2, CO and CH4, indicating the potential for producing fuel gas and syngas from microalgae.

Characterization and Properties of Activated Carbon Prepared from Tamarind Seeds by KOH Activation for Fe(III) Adsorption from Aqueous Solution

This research studies the characterization of activated carbon from tamarind seed with KOH activation. The effects of 0.5 : 1–1.5 : 1 KOH : tamarind seed charcoal ratios and 500–700°C activation temperatures were studied. FTIR, SEM-EDS, XRD, and BET were used to characterize tamarind seed and the activated carbon prepared from them. Proximate analysis, percent yield, iodine number, methylene blue number, and preliminary test of Fe(III) adsorption were also studied. Fe(III) adsorption was carried out by 30 mL column with 5–20 ppm Fe(III) initial concentrations. The percent yield of activated carbon prepared from tamarind seed with KOH activation decreased with increasing activation temperature and impregnation ratios, which were in the range from 54.09 to 82.03 wt%. The surface functional groups of activated carbon are O–H, C=O, C–O, –CO₃, C–H, and Si–H. The XRD result showed high crystallinity coming from a potassium compound in the activated carbon. The main elements found in the activated carbon by EDS are C, O, Si, and K. The results of iodine and methylene blue adsorption indicate that the pore size of the activated carbon is mostly in the range of mesopore and macropore. The average BET pore size and BET surface area of activated carbon are 67.9764 Å and 2.7167 m²/g, respectively. Finally, the tamarind seed based activated carbon produced with 500°C activation temperature and 1.0 : 1 KOH : tamarind seed charcoal ratio was used for Fe(III) adsorption test. It was shown that Fe(III) was adsorbed in alkaline conditions and adsorption increased with increasing Fe(III) initial concentration from 5 to 20 ppm with capacity adsorption of 0.0069–0.019 mg/g.

Pyrolysis of mangaba seed: production and characterization of bio-oil

The aim of this study was to evaluate the potential of Hancornia speciosa GOMES (mangaba) seeds as a novel matrix for the production of bio-oil. The study was divided into three steps: (i) characterization of the biomass (through elemental analysis (CHN), infrared spectroscopy (FTIR-ATR), thermogravimetry (TG), and determination of biomass composition; (ii) pyrolysis of mangaba seed to obtain the bio-oil; and (iii) characterization of the bio-oil (thermogravimetry and gas chromatography/mass spectrometry-GC/qMS). The TG of the sample showed a mass loss of around 90% in 450°C. In the pyrolysis experiments the variables included temperature (450 and 600°C), sample mass (5 and 11g) and prior heating (with or without), with the best conditions of 600°C, 11g of seeds and prior heating of the furnace. The GC/qMS analysis identified carboxylic acids and hydrocarbons as the major components, besides the presence of other compounds such as furanes, phenols, nitriles, aldehydes, ketones, and amides.

Thermal and catalytic slow pyrolysis of Calophyllum inophyllum fruit shell

Pyrolysis of Calophyllum inophyllum shell was performed in a fixed bed pyrolyser to produce pyrolytic oil. Both thermal (without catalysts) and catalytic pyrolysis process were conducted to investigate the effect of catalysts on pyrolysis yield and pyrolysis oil characteristics. The yield of pyrolytic oil through thermal pyrolysis was maximum (41% wt) at 425 °C for particle size of 1.18 mm and heating rate of 40 °C/min. In catalytic pyrolysis the pyrolytic oil yield was maximum (45% wt) with both zeolite and kaolin catalysts followed by Al2O3 catalyst (44% wt). The functional groups and chemical components present in the pyrolytic oil are identified by Fourier Transform Infrared Spectroscopy (FT-IR) and Gas Chromatography-Mass Spectrometry (GC-MS) techniques. This study found that C. inophyllum shell is a potential new green energy source and that the catalytic pyrolysis process using zeolite catalyst improves the calorific value and acidity of the pyrolytic oil.

Understanding the stability of pyrolysis tars from biomass in a view point of free radicals

Fast pyrolysis of biomass has attracted increasing attention worldwide to produce bio-tars that can be upgraded into liquid fuels and chemicals. However, the bio-tars are usually poor in quality and stability and are difficult to be upgraded. To better understand the nature of the bio-tars, this work reveals radical concentration of tars derived from pyrolysis of two kinds of biomass. The tars were obtained by condensing the pyrolysis volatiles in 3s. It shows that the tars contain large amounts of radicals, at a level of 10(16)spins/g, and are able to generate more radicals at temperatures of 573K or higher, reaching a level of 10(19)spins/g at 673K in less than 30min. The radical generation in the tar samples is attributed to the formation of THF insoluble matters (coke), which also contain radicals. The radical concentrations of the aqueous liquids obtained in pyrolysis are also studied.