Pachira aquatica fruits shells valorization: renewables phenolics through analytical pyrolysis study (Py-GC/MS)

ABSTRACT: This research valorized Pachira aquatica Aubl.’s fruit shells (PAS) through its energetic characterization and flash pyrolysis for biofuels or chemicals production. The characterization was performed through proximate and ultimate analysis, bulk density, higher heating value (HHV), hemicellulose, cellulose and lignin content, thermogravimetric analysis and absorption spectra in the infrared region obtained by Fourier-transform infrared spectroscopy technique (FTIR). The analytical flash pyrolysis was performed at 500°C in a Py-5200 HP-R coupled to a gas chromatograph (Py-GC/MS). The PAS biomass presents potential for thermochemical energy conversion processes due to its low moisture and ash content, 76.90% of volatile matter, bulk density of 252.6 kg/m3 and HHV of 16.24 MJ/kg. Flash pyrolysis products are mostly phenols or light organic acids derived from the decomposition of polysaccharides. Results confirmed the potential of PAS to produce bio-phenolics, such as 4-methoxyphenol which is an important active ingredient for skin depigmentation used in drugs and cosmetics, and as phenolic extract that can be used as a precursor to resins, applications that convert this forest waste into bio products for industry into a green circular economy.

The effect of plastic type on the yield and quality of lignite and plastic waste pyrolysis products

Lignite is a low rank coal which has great potential in South Kalimantan. However, it has not been used optimally due to its low quality. One of the ways to improve it is pyrolysis. Pyrolysis is the thermal decomposition of organic material in the absence of oxygen which will produce three products (char, tar and gas). Pyrolysis can make lignite into liquid fuel (pyrolysis liquid), but it still requires improvement due to the need for pure hydrogen donors. Plastic waste has a higher hydrogen/carbon ratio than coal. This material can be used as an additive in the pyrolysis process because it is rich in hydrogen. The samples of plastic waste used were ppolyethylene (PE), ppolypropylene (PP), and polystyrene (PS). Samples of lignite and plastic (plastic composition was 25 wt%) were used for every experiment, and pyrolysis was carried out with a holding time of 60 minutes at 500°C. The pyrolysis liquid obtained is then analyzed for its yields and properties (density, kinematic viscosity, heating value). The most feasible result for fuel alternative was obtained with the addition of PE.

Transforming Plastic Waste into Porous Carbon for Capturing Carbon Dioxide: A Review

Plastic waste generation has increased dramatically every day. Indiscriminate disposal of plastic wastes can lead to several negative impacts on the environment, such as a significant increase in greenhouse gas emissions and water pollution. Therefore, it is wise to think of other alternatives to reduce plastic wastes without affecting the environment, including converting them into valuable products using effective methods such as pyrolysis. Products from the pyrolysis process encompassing of liquid, gas, and solid residues (char) can be turned into beneficial products, as the liquid product can be used as a commercial fuel and char can function as an excellent adsorbent. The char produced from plastic wastes could be modified to enhance carbon dioxide (CO2) adsorption performance. Therefore, this review attempts to compile relevant knowledge on the potential of adsorbents derived from waste plastic to capture CO2. This review was performed in accordance with PRISMA guidelines. The plastic-waste-derived activated carbon, as an adsorbent, could provide a promising method to solve the two environmental issues (CO2 emission and solid management) simultaneously. In addition, the future perspective on char derived from waste plastics is highlighted.

Development of Comprehensive Analysis of Pyrolysis Products for Lignocellulose Raw Materials and Sludge Sediments by Chromatographic Methods

This paper presents a study of the pyrolysis products organic raw materials (bio-oil and sludge sediments of treatment facilities) by chromatographic methods. A feature of the work is to optimize the sample preparation procedure by fractionating the pyrolysis products. Using the method of gel permeation chromatography, molecular weight distribution of pyrolysis products was assessed. Determination of the water content in these objects (by Karl Fischer titration) was used to assess the possibility of their direct analysis by gas chromatography. A sample of sludge pyrolysis and several fractions obtained from a bio-oil sample were analyzed. By the method of two-dimensional gas chromatography, where a selfdeveloped column based on an ionic liquid was used as the first measurement column, the pyrolysate of sludge sediments and the ether fraction of bio-oil were analyzed. The obtained chromatograms and quantitative results are presented

Influence of No-Till Practices on the Organic Matter Chemical Composition of Protocalcic, Endocalcic and Pantocalcic Chernozems

Reducing the amount of precipitation in summer in the Chernozems area alters soil organic matter (SOM). To compensate for the lack of moisture, farmers are introducing new agricultural technologies such as no-till cultivation. In turn, no-till practices influence the composition of SOM. We examined the impacts of the rise of aridity and no-till technology on the chemical composition of bioavailable and recalcitrant pools of OM. The properties of SOM were assessed using double-shot pyrolysis with gas chromatography/mass spectrometry (GC/MS). The thermolabile substances that are volatilised in the first stage of pyrolysis (300°C) are considered the bioavailable pool. Accordingly, substances are obtained in the second pyrolysis stage (500°C) were attributed to the recalcitrant pool. Identified in both steps of pyrolysis, products were assigned to different chemical groups (lignin-derivative, polysaccharide-fragments, indoles, etc.) and relative abundances were calculated. In work for the separation of substances, a polar column was used for chromatography of the thermolabile fraction. With an increase in aridity in Сhernozems, the content in the bioavailable pool of polysaccharide fragments decreased and the proportion of indoles increased. In the recalcitrant pool, the abundance of six-membered rings with nitrogen and aromatic compounds decreases at the same time the contents of unsubstituted and O-substituted acyclic compounds as well as pyridine increases. The influence of the NT was more noticeable in the recalcitrant OM. The NT practice promotes biological activity and to rich in nitrogen compounds the bioavailable OM; this process contributes to the accumulation of carbon in the recalcitrant OM.

Influence of Crystallite Size of Nickel and Cobalt Ferrites on the Catalytic Pyrolysis of Buckwheat Straw by Using TGA-FTIR Method

Pyrolysis of buckwheat straw with or without catalysts was investigated using the TGA-FTIR method to determine the influence of nickel and cobalt ferrites on the distribution of pyrolysis products. According to the obtained results, the overall shape of the thermogravimetric and derivative thermogravimetric curves is unchanged in the presence of nickel and cobalt ferrites but different weight losses were observed. All catalysts contribute to the formation of solid residue from BWS pyrolysis. The presence of cobalt ferrites exhibited the highest bio-oil yields, whereas the highest non-condensable gas yield and the lowest bio-oil yield was obtained with the addition of NiFe2O4 (1) catalyst. According to the obtained results, the ability of nickel and cobalt ferrites to catalyze deoxygenation reactions depends on the crystallite size. The nickel or cobalt ferrites with smaller crystallite size (15-22 nm) show a higher ability to catalyzed dehydration reaction than catalysts with larger crystallite size (45-54 nm).