Granulated beet pulp and wheat straw, first separately and then mixed in a weight ratio of 50/50%, underwent a pyrolysis process in a laboratory batch generator with process temperatures of 400 and 500 °C. The feedstock's chemical composition and the pyrolysis products' chemical composition (biochar and pyrolysis gas) were analysed. A synergistic effect was observed in the co-pyrolysis of the combined feedstock, which occurred as an increase the content of the arising gas in relation to the total weight of the products. and as a reduction of bio-oil content. The maximum gas proportion was 21.8% at 500 °C and the minimum between 12.6% and 18.4% for the pyrolysis of individual substrates at 400 °C. The proportions of the gases, including CO, CO2, CH4, H2, and O2, present in the resulting synthesis gases were also analysed. The usage of a higher pyrolysis final temperature strongly affected the increase of the CH4 and H2 concentration and the decrease of CO2 and CO concentration in the pyrolysis gas. The highest percentage of hydrogen in the synthesis gas, around 33%vol, occurred at 500 °C during co-pyrolysis.

• Klíčová slova
• bio-oil, biochar, biomass, gas composition, generator, pyrolysis, synergy,
• Publikační typ
• časopisecké články MeSH

Coffee is a globally consumed beverage that produces a substantial amount of valuable organic waste known as spent coffee grounds (SCG). Although SCG is a non-edible biomass, research initiatives focused on valorizing/utilizing its organic content, protecting the environment, and reducing the high oxygen demand required for its natural degradation. The integration with biorefinery in general and with pyrolysis process in specific is considerered the most successful solid waste management strategy of SCG that produce energy and high-value products. This paper aims at providing a quantitative analysis and discussion of research work done over the last 20 years on SCG as a feedstock in the circular bioeconomy (CBE). Management stratigies of SCG have been thoroughly reviewed and pyrolysis process has been explored as a novel technology in CBE. Results revealed that explored articles belong to Chemical, physical., biological and environmental science branches, with Energy & Fuels as the most reporting themes. Published works correlate SCG to renewable energy, biofuel, and bio-oil, with pyrolysis as a potential valorization approach. Literature review showed that only one study focused on the pyrolysis of defatted spent coffee grounds (DSCG). The insightful conclusions of this paper could assist in proposing several paths to more economically valorization of SCG through biorefinery, where extracted oil can be converted to biofuels or value-added goods. It was highlighted the importance of focusing on the coupling of SCG with CBE as solid waste managment strategy.

• Klíčová slova
• Bio-oil, Biochar, Biorefinery, Pyrolysis, Valorization of SCG,
• MeSH
• biopaliva MeSH
• káva * MeSH
• nakládání s odpady * MeSH
• pyrolýza MeSH
• tuhý odpad MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• biopaliva MeSH
• káva * MeSH
• tuhý odpad MeSH

Different waste materials were pyrolysed in the laboratory pyrolysis unit to the final temperature of 800°C with a 10min delay at the final temperature. After the pyrolysis process a mass balance of the resulting products, off-line analysis of the pyrolysis gas and evaluation of solid and liquid products were carried out. The gas from the pyrolysis experiments was captured discontinuously into Tedlar gas sampling bags and the selected components were analyzed by gas chromatography (methane, ethene, ethane, propane, propene, hydrogen, carbon monoxide and carbon dioxide). The highest concentration of measured hydrogen (WaCe 61%vol.; WaPC 66%vol.) was analyzed at the temperature from 750 to 800°C. The heating values of the solid and liquid residues indicate the possibility of its further use for energy recovery.

• Klíčová slova
• Food waste, Gas chromatography, Hydrogen, Pyrolysis,
• MeSH
• bioreaktory * MeSH
• chromatografie plynová MeSH
• odpadky - odstraňování metody   MeSH
• odpadní produkty analýza   MeSH
• potraviny MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• odpadní produkty MeSH

Thermo-catalytic pyrolysis is considered as a promising process for the chemical recycling of waste polymeric materials aiming at converting them into their original monomers or other valuable chemicals. In this regard, process parameters and reactor type can play important roles for an enhanced recovery of the desired products. Polystyrene (PS) wastes are excellent feedstocks for the chemical recycling owing to the capability of PS to be fully recycled. In this respect, the present work deals with the thermo-catalytic pyrolysis of PS in batch and semi-batch reactor setups. The main goal was to perform a comprehensive study on the depolymerisation of PS, thereby investigating the effect of reactor type, catalyst arrangement, feed to catalyst ratio and residence time on the yields of oil and styrene monomer (SM). A further goal was to identify the optimum operating conditions as well as reactor type for an enhanced recovery of oil and SM. It was demonstrated that the semi-batch reactor outperformed the batch reactor in terms of oil and SM yields in both thermal (non-catalytic) and catalytic tests performed at 400°C. Furthermore, it was shown that the layered arrangement of catalyst (catalyst separated from PS) produced a higher amount of oil with higher selectivity for SM as compared to the mixed arrangement (catalyst mixed with PS). Moreover, the effect of carrier gas flowrate on the product distribution was presented.

• Klíčová slova
• Pyrolysis, chemical recycling, polystyrene, semi-batch reactor, thermo-catalytic process, waste management,
• MeSH
• katalýza MeSH
• odpadní produkty MeSH
• polystyreny * MeSH
• pyrolýza * MeSH
• recyklace MeSH
• vysoká teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• odpadní produkty MeSH
• polystyreny * MeSH

A concept has been proposed for an installation designed to store excess electricity periodically occurring on the grid. Excess electricity will be used for straw pyrolysis. The main pyrolysis product, gas, will be used to generate electricity using a combustion generator to feed back power into the grid during periods of shortage. The resulting biochar from the pyrolysis can be introduced into the soil to improve soil quality and play a significant role in carbon sequestration. The system uses an electrically heated reactor with a screw conveyor. To preliminarily assess the feasibility of this system, experiments were carried out using wheat straw at temperatures of 300, 400, 500, 600, and 700 °C for the pyrolysis reactor. The resulting gas-to-feedstock mass ratio ranged from 29.04 % at 300 °C to 52.7 % at 700 °C reactor temperature, the biochar mass yield ratio to feedstock varied from 39.41 % to 27.36 % (at 700 °C), and the pyrolysis liquid ranged from 31.55 % to 27.36 % (at 700 °C). The pyrolytic liquid contained a high water content relative to its mass, reaching up to 95.2 % at 700 °C, rendering it less suitable as an energy feedstock. At a reactor temperature of 700 °C, the energy value of the gas produced from the feedstock was twice that of the electricity used for the pyrolysis process. These results suggest the feasibility and operation of the proposed installation.

• Klíčová slova
• Biochar, Carbon sequestration, Electricity storage installation, Energy balance, Pyrolysis products, Straw,
• Publikační typ
• časopisecké články MeSH

Co-pyrolysis of orange peel and chicken eggshell was performed for the synthesis of the composite, a co-pyrolysis technique used to promote natural fabrication and to allow the raw material elemental combination effect and the preparatory conditions such as pyrolysis temperature, residence time, and eggshell/orange peel mixing ratio, to be optimized with the response surface methodology through Box-Behnken Design(BBD). BBD involved a randomized series of 17 experimental runs, and the best optimal conditions were found with a pyrolysis temperature of 300 °C, a residence time of 1 h, and 0.5 as the mixing ratio. These conditions gave a maximum adsorption capacity of 167 mg/g for removal of the modal pollutant methylene blue. FTIR spectra of the composite showed new functional peaks of oxygenated groups, at two different bands. XRD confirmed an amorphous surface with inorganic component peaks, while SEM-EDS revealed rich defects sites along with an enhanced percentage of oxygen elements on the surface; the surface area was enhanced from 1 m2 with unmodified peel to 64 m2 with composite. The adsorption behavior of the composite was studied for dye removal and the adsorption behavior was well explained by the Langmuir isotherm model.

• Klíčová slova
• Adsorption, Co-pyrolysis, Methylene blue, Optimization, Orange peel & eggshell composite,
• MeSH
• adsorpce MeSH
• chemické látky znečišťující vodu * MeSH
• kinetika MeSH
• methylenová modř MeSH
• pomerančovník čínský * MeSH
• pyrolýza MeSH
• teplota MeSH
• vaječná skořápka MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• chemické látky znečišťující vodu * MeSH
• methylenová modř MeSH

This study explores the pyrolysis process applied to various non-utilized waste materials, specifically focusing on separated plastics from municipal waste, wood waste (including pallets and window frames), paper rejects, and automotive carpets. Different combinations of these waste materials were subjected to pyrolysis, a process involving high-temperature treatment (600 °C) in a nitrogen atmosphere. The resulting products, including biochar, gas, and liquid fractions, as well as the residual waste materials, underwent comprehensive analysis. The evaluation of pyrolysis products emphasizes their quality, energy content, and potential applications. Notably, the pyrolysis gas derived from the combination of separated municipal plastics and waste wood exhibited the highest calorific value at 49.45 MJ/m3. Additionally, Mixture 2, consisting of plastic and wood waste, demonstrated the highest calorific value for the pyrolysis condensate, reaching 30.62 MJ/kg. Moreover, Mixture 3, benefiting from biochar utilization as a sorbent, displayed the highest iodine value at 90.01 mg/g.

• Klíčová slova
• automotive carpets, calorific value, paper rejects, plastics, pyrolysis, pyrolysis products, wood waste,
• Publikační typ
• časopisecké články MeSH

Unsaturated C4 hydrocarbons are abundant in various petrochemical streams. They can be considered as a potential feedstock for the steam-cracking process, where they must be co-processed with C6 and higher (C6+) hydrocarbons of primary naphtha fractions. Co-pyrolysis experiments aiming at the comparison of different C4 hydrocarbon performances were carried out in a laboratory micro-pyrolysis reactor under standardized conditions: 820 °C, 400 kPa, and 0.2 s residence time in the reaction zone. C4 hydrocarbons were co-pyrolyzed with different co-pyrolysis partners containing longer hydrocarbon chain to study the influence of the co-pyrolysis partner structure on the behavior of C4 hydrocarbons. The yields of the pyrolysis products and the conversion of C4 hydrocarbons were used as the performance factors. A regression model was developed and used as a valuable tool for quantifying the inhibition or acceleration effect of co-pyrolysis on the conversion of co-pyrolyzed hydrocarbons. It was found that the performance of different C4 hydrocarbons in co-pyrolysis is substantially different from the separate pyrolysis of the individual components.

• Klíčová slova
• C4 unsaturated hydrocarbons, butenes, co-pyrolysis, pyrolysis, steam cracking,
• Publikační typ
• časopisecké články MeSH

Sewage sludge was excluded from the list of component materials for the production of EU fertilizing products and it was banned as feedstock to produce pyrolysis & gasification materials in European Commission's technical proposals for selected new fertilizing materials under the Regulation 2019/1009 (STRUBIAS report). This exclusion of pyrolysis as a viable way to treat sewage sludge was mainly due to the lack of data on the fate of organic pollutants at pyrolysis conditions. In this work, we are addressing this knowledge gap. We studied slow pyrolysis as a potential process to efficiently treat organic pollutants present in stabilized sewage sludge. Sewage sludge was pyrolyzed in a quartz fixed bed reactor at temperatures of 400-800 °C for 2 h and the sludge and resulting sludge-chars were analyzed for the presence of four groups of organic pollutants, namely (i) polychlorinated biphenyls (PCBs), (ii) polycyclic aromatic hydrocarbons (PAHs), (iii) pharmaceuticals, and (iv) endocrine-disrupting and hormonal compounds. Pyrolysis at ≥ 400 °C effectively removed pharmaceuticals (group iii) to below detection limits, whereas pyrolysis at temperatures higher than 600 °C was required to remove more than 99.8% of the compounds from groups i, ii and iv. Based on these findings, we propose, that high temperature (>600 °C) slow pyrolysis can satisfactory remove organic pollutants from the resulting sludge-char, which could be safely applied as soil improver.

• Klíčová slova
• Endocrine disruptors, Pharmaceuticals, Polychlorinated biphenyls, Polycyclic aromatic hydrocarbons, Sludge-char,
• MeSH
• látky znečišťující životní prostředí * MeSH
• odpadní vody MeSH
• polycyklické aromatické uhlovodíky * analýza   MeSH
• pyrolýza MeSH
• teplota MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• látky znečišťující životní prostředí * MeSH
• odpadní vody MeSH
• polycyklické aromatické uhlovodíky * MeSH

Biosolids were applied as a fertilizer after drying, torrefaction (220, 320 °C), and pyrolysis (420, 520, 620 °C). Lettuce was grown on contrasting soils, and the transfer of pharmaceuticals to aboveground biomass was assessed. Of 42 compounds detected in dried biosolids, 10 were found in lettuce. Their potency for translocation to aerial parts was in the order: ethenzamide > carbamazepine > mirtazapine~tramadol > N-desmethyltramadol~solifenacin > sertraline~trazodone~venlafaxine > propafenone. Application of dried biosolids resulted in the highest uptake of pharmaceuticals and the neutral soil further intensified the uptake due to prevalent neutral speciation of the ionizable basic molecules. Torrefaction reduced the total pharmaceutical content in biosolids by 92.2% and 99.5% at 220 and 320 °C, respectively. Torrefied biosolids significantly reduced the uptake of pharmaceuticals and led to the highest biomass on acidic soil but were phytotoxic on the neutral soil. Pyrolysed biosolids increased the biomass production of lettuce on both soils and blocked the uptake of pharmaceuticals. A minimum biosolids pyrolysis temperature of 420 °C should be ensured prior to soil application as it represents a good compromise between fertilization potential, pharmaceutical uptake, and homogeneity of plant response regardless of the soil characteristics.

• MeSH
• biosolidy MeSH
• látky znečišťující půdu * analýza   MeSH
• léčivé přípravky * MeSH
• půda MeSH
• pyrolýza MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• biosolidy MeSH
• látky znečišťující půdu * MeSH
• léčivé přípravky * MeSH
• půda MeSH