Continuous Pyrolysis System Research Articles

Energy Independence and Financial Stability of Economic Entities in the Conditions of War

Russia’s invasion of Ukraine has caused many social, economic, environmental and energy problems. Most business entities faced problems at the national level that affected their financial and economic activities. The mass departure of workers abroad, rising natural gas prices, internal relocation, and constant shelling force business entities to search for new approaches to the management and development of their enterprises. The purpose of the study – substantiate and test the scientific and methodological approach to achieving energy independence of economic entities as a way to avoid their insolvency in times of war. In the course of the study, a critical analysis of the thematic literature was performed, and a set of general scientific and special research methods was used: expert assessments, observation, analogy, grouping, obtaining a consensus, deductive, inductive reasoning, systematisation, system-functional, measurement, analysis, comparison, logical generalisation, systematisation, hypothesis, a repeated combination of independent scenarios, extrapolation, elasticity estimation and graphical. The study identified the consequences of the military invasion of Ukraine and developed an algorithm for actions during the war. Four scenarios have been identified, under which the investigated business entity can solve the urgent problems. It is substantiated that the best scenario is the one in which it is required to increase its production capacity by setting up a “full cycle” production using a continuous pyrolysis system for the recycling of worn-out tires. The rationality of its use is proved. The scientific and methodological tools for interaction between business entities and the state during the war have been improved based on a systematic approach, which, unlike the existing ones, deepens the significance of shifting the centre of gravity from the macro to the micro level and is based on the proposed algorithm of actions (identifying the problem, developing possible scenarios for its immediate solution, compliance of the chosen scenario with the national interests of the state, finding a source of funding for the implementation of one of the scenarios), which determines the most optimistic scenario of the balance of interests between the state and business entities. The practical value of the proposed lies in the identification of economic, social, environmental and energy efficiency of the developed algorithm of actions in practice, on the example of financial and economic activities of the entity. Such an approach, on the one hand, allows for achieving energy independence soon and is a way to avoid the insolvency of economic entities in the conditions of war. On the other hand, it should become a reliable base for the national economy in the period of post-war reconstruction.

A comprehensive assessment on bioavailability, leaching characteristics and potential risk of polycyclic aromatic hydrocarbons in biochars produced by a continuous pyrolysis system

Biochar application as a soil amendment has attracted worldwide attention. Nevertheless, polycyclic aromatic hydrocarbons (PAHs) formed during biochar production might enter into ecosystems and threaten human health after application to soil. Continuous pyrolysis systems tend to cause an accumulation of PAHs in biochar owing to short residence time and rapid cooling. This study conducted a comprehensive assessment regarding potential risk of PAHs in biochars produced by a continuous pyrolysis system based on bioavailability, leaching behavior, toxic equivalent quantity, health risk and phytotoxicity of PAHs. Results showed that the concentrations of total PAHs in biochars were in the range of 93.40–172.40 mg/kg, exceeding the European Biochar Certificate standard. 3-rings PAHs were the predominant groups. The percentages of total freely dissolved and leachable PAHs were lower than 1%. RH contained the least bioavailable and leachable PAHs concentration and phytotoxicity compared with CS and PS, which might attribute to the characteristic of three biochars. CS and PS were acidic and exhibited high levels of DOC and VFAs, while RH was strongly alkaline and presented greater aromaticity and higher surface area, which might have resulted in high adsorptive capacity and decreased bioavailability of PAHs. When the biochar application rate was higher than 0.6 t/ha, the incremental lifetime cancer risk value for human exposure to biochar-borne PAHs through the biochar-amended soil was over 10−6, suggesting carcinogenic risks. Germination index values of biochars ranged from 25.66 to 88.95%. Phytotoxicity mainly was caused by bioavailable PAHs and dissolved organic compounds. Overall, these findings highlighted that although the percentage of bioavailable PAHs was low, the potential health risk and phytotoxicity of PAHs in biochars produced by a continuous pyrolysis system was of a great concern. High biochar application rates should be avoided without processing both for soil safety and human health.

Acclimatized activated sludge for enhanced phenolic wastewater treatment using pinewood biochar

Activated sludge acclimatization was assessed for pinewood biochar to study phenol biodegradation from synthetic effluents. The biochar was produced in a continuous pyrolysis system (auger reactor) at 525 °C and was characterized by scanning electron microscopy (SEM), X-ray diffraction, Fourier Transform Infrared (FTIR), elemental analysis, and particle size evaluation. Sludge acclimatization greatly facilitated the phenol biodegradation rate, especially in the presence of biochar. Specific biodegradation rates increased from 0.0017 (g phenol/g VSS/h) for as-received activated sludge to 0.0184 (g phenol/g VSS/h) and 0.041 (g phenol/g VSS/h) for activated sludge acclimatized without (control) and with biochar, respectively at pH ~6.5, for a phenol concentration of 250 mg/L and at room temperature (T = 15–18 °C). The results furthermore demonstrated the positive effects of biochar on microbial colonization and growth. The volatile suspended solids (VSS) increased from 1 g/L for as-received sludge to 1.97 g/L and 2.96 g/L for control and activated sludge acclimatized in the presence of biochar. The sludge volume index decreased from 108 (mL/g MLSS) to 60, while for the control it increased to 298 (mL/g MLSS). The system studied showed a high degree of stability and resistance to the load shock loading when the initial phenol concentration was increased from 250 to 500 mg/L.

A comparative study on pyrolysis of bundle and fluffy shapes of waste packaging plastics

The pyrolysis of waste packaging plastic was performed in a semi-batch reactor to study the effect of the shape of reactant on the compositions of pyrolysis oils under N2 gas inflow conditions. Bundle and fluffy shapes of reactants were pyrolyzed at 400 °C for 90 min at N2 inflow rates from 0 to 300 mL/min. The yields of pyrolysis oils were between 67.7 and 76.1% under the reaction conditions, and diesel-like middle oil (C11–C22) was mainly produced with mass fractions over 64%. The main oil product was mostly composed of n-paraffin and n-olefin compounds, and its mass fraction was considerably influenced by the reactant shape and the N2 flow rate. The pyrolysis of the fluff reactant exhibited higher middle oil fractions with higher fraction ratios of n-paraffins to n-olefins than the bundle reactant. This study suggests that the compositions of pyrolysis oil could be controlled by the reactant shape and the N2 inflow, which will provide important information for improving the quality of oil products in a large-scale of pyrolysis processes, and for developing a continuous pyrolysis system because the fluffy shape of reactant is more suitable for continuous feeding.

A multi-criteria-based hazard and operability analysis for process safety

Multi-criteria Decision Making (MCDM) is widely used for problem-solving in various research fields and has shown good results in risk analysis as well. However, given the gaps found in previous studies in the context of risk analysis, this article proposes and conducts a novel MCDM-based HAZOP analysis: a hybrid methodology with an MCDM approach, Strategic Options Development and Analysis (SODA), and Intuitionistic Fuzzy Sets (IFS). We combine their advantages by using SODA with Intuitionistic Fuzzy Cognitive Maps and by reducing the inherent uncertainty and subjectivity of HAZOP with an IFS-based MCDM sorting algorithm. To demonstrate the usefulness and flexibility of this approach, a real application with a continuous pyrolysis system was conducted, and a comparative analysis was made of the main related studies to demonstrate the advantages of the approach now proposed. On applying it, 40 hazards were identified (seven more than a previous analysis conducted in 2016), and only 3 (7.5 %) of them required special attention. Among the positive points highlighted by the team, the most cited were the resource-saving, greater focus and objectivity, and a more realistic perception of hazards. In particular, we show that our methodology is more consistent and appropriate than those in previous related articles. To assist future users, we provide a framework for the application.

High-yield production of fuel- and oleochemical-precursors from triacylglycerols in a novel continuous-flow pyrolysis reactor

In this study, conversion of soybean oil was carried out in a continuous pyrolysis system with feed injected through an atomizer. This allowed introduction of micron-sized droplets of oil that could be rapidly vaporized inside the reactor. With this novel design, we were able to achieve feed vapor residence times (τ) of 6–300s without use of carrier gas, which would significantly reduce the overall cost of pyrolysis. Effects of reaction temperature (450<T<500°C) and τ on conversion, product yields and composition were investigated. At the optimum experimental conditions of T=500°C and τ=60s, the yield of pyrolysis liquids was as high as 88% (relative to feed mass). Under these conditions, the identified products consisted of 38% hydrocarbons (22% C5C12 and 16%>C12), 33% long-chain fatty acids (C16C18, but primarily oleic acid) and 15% short-chain fatty acids (C6C12). Upon distillation of the liquid products, the long-chain fatty acids were cleanly separated from the hydrocarbons. Overall, our results demonstrate the feasibility of producing liquid products at high yields, including a wide range of fuels (gasoline, jet and diesel) and enriched oleic acid (for oleochemicals production), using our reactor design for pyrolytic conversion of vegetable oil.

Catalytic hydrodechlorination of PCDD/Fs from condensed water with Pd/[formula omitted]-Al2O3

A continuous pyrolysis system (CPS) with effective air pollution control devices (APCDs) is designed and constructed to remediate the soil containing high-concentration PCDD/Fs. The quench tower of the APCDs system can capture the pollutants of high boiling points from the flue gas of CPS and produces condensed water of high PCDD/Fs concentration (16–44 ng I-TEQ/L), and needs further treatment. First, the result of activated carbon adsorption test displays the PCDD/Fs toxicity concentration of effluents meet the regulatory standards as the liquid to solid ratio is controlled at 3: 1. However, large amount of activated carbon need to achieve the high removal efficiency leads to high cost, so catalytic hydrodechlorination technology with Pd/Al2O3 as catalyst is applied to treat the condensed water. The PCDD/Fs mass removal efficiency achieved without the reducing agent is 53.21% with the operating time of 180 min. As 5% reducing agent (methanol) is added, the removal efficiency increases to 71.86%. In addition, to better understand the differences between molecular hydrogen and hydrogen donor, the condensed water was pre-aerated with hydrogen and catalytic hydrodechlorination test with palladium as catalyst was conducted. The results show that the PCDD/Fs mass removal efficiency increases to 97.34% with the operating time of 180 min, demonstrating the high PCDD/Fs removal efficiency of catalytic hydrodechlorination.

Hydrogen production by catalytic cracking of rice husk over Fe 2O 3/γ-Al 2O 3 catalyst

Fe 2O 3/γ–Al 2O 3 catalyst is prepared by incipient wetness impregnation. The catalyst is characterized by temperature programmed reduction (TPR), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The catalytic activity of Fe 2O 3/γ–Al 2O 3 catalysts is evaluated via the experimental study on the catalytic cracking of rice husk to produce hydrogen in a self made biomass continuous pyrolysis system. The results show that the reaction activities of the catalysts are greatly influenced by the calcinations temperature for catalyst, the secondary catalytic pyrolysis temperature and the mass ratio of Fe to Al. When the calcinations temperature is 550 °C, the pyrolysis temperature is 500 °C, the secondary catalytic pyrolysis temperature is 700 °C, and the Fe to Al mass ratio is 0.07, the experimental results indicate that Fe 2O 3/γ–Al 2O 3 catalyst could fully convert the volatile matters from biomass pyrolysis into small molecular gases such as H 2, CH 4, CO, CO 2, C 2H 4 and C 2H 6. Meanwhile, the catalyst has shown fine catalytic activity and stability as well as good resistance to coke deposition.

Comparison of products from the pyrolysis and catalytic pyrolysis of rice husks

Fe2O3/γ–Al2O3 catalyst is prepared by incipient wetness impregnation. The catalyst is characterized by temperature programmed reduction (TPR), X-ray diffraction (XRD), scanning electron microscope (SEM) and thermogravimetric analysis (TGA). The catalytic activity of Fe2O3/γ–Al2O3 catalysts is evaluated via the experimental study on the catalytic cracking of rice husk to produce hydrogen in a self made biomass continuous pyrolysis system. The results show that the reaction activities of the catalysts are greatly influenced by the calcinations temperature for catalyst, the secondary catalytic pyrolysis temperature and the mass ratio of Fe to Al. When the calcinations temperature is 550 °C, the pyrolysis temperature is 500 °C, the secondary catalytic pyrolysis temperature is 700 °C, and the Fe to Al mass ratio is 0.07, the experimental results indicate that Fe2O3/γ–Al2O3 catalyst could fully convert the volatile matters from biomass pyrolysis into small molecular gases such as H2, CH4, CO, CO2, C2H4 and C2H6. Meanwhile, the catalyst has shown fine catalytic activity and stability as well as good resistance to coke deposition.

5437237 Continuous pyrolysis system : Digre John L Sacramento, CA, 95821, United States

5437237 Continuous pyrolysis system : Digre John L Sacramento, CA, 95821, United States