Sustainable Chemistry for Climate Action最新文献

The present study aims to investigate the catalytic effect of acid mine drainage (AMD) treated sludge based catalyst on the co-pyrolysis of spent coffee grounds and HDPE. The sludge was generated during the treatment of AMD using eggshell and hydrogen peroxide. Theromogravimetric analysis of pyrolysis of spent coffee grounds (SC), HDPE (High density polyethylene), blend of spent coffee grounds and HDPE (SC+HDPE) in the ratio of 1:1, and blended feedstock with sludge derived catalyst (SC+HDPE_AMDC) (1:1 wt. ratio) was conducted at various heating rates of 10 °C/min, 20 °C/min, 30 °C/min and 40 °C/min respectively. Iso-conversional models such as Ozawa Flynn Wall (OFW), Kissinger Akahira Sunose (KAS), Friedman, and Starink were utilized for the determination of activation energy (E_a) of the process. The results showed that using AMD treated sludge based catalyst to the pyrolysis process, enhances its overall efficacy by lowering the activation energy (E_a) (OFW- E_a: 209.11 to 177.14 KJ/mol, KAS-E_a: 208.30 to 173.06 KJ/mol, Friedman- E_a:210.54 to 176.28 KJ/mol, and Starink- E_a:208.60 to 173.44 KJ/mol). Criado's z-master plot (CZMP) method was utilized to analyze the mechanism of the reaction. The pre-exponential factor and thermodynamic parameters were also evaluated. It is concluded that the incorporation of sludge based catalyst (AMDC) lowered enthalpy and randomness of system. Catalytic co-pyrolysis requires less energy, making it more environmental friendly choice for the sustainable processing of biomass and plastics. The present investigation will aid in the design, optimization and scalability.

The manuscript investigates the design, operating, and economic parameters of components in a biomass pyrolysis system. It covers two key components, the pyrolysis reactor and condenser, with plans to discuss other components in future publications. The study relies on experimental data from a fixed-bed reactor, bio-oil retention experiments using various vials, and computational modeling of the pyrolysis process using a lumped model. The experimental data were thoroughly analysed, considering different types of pyrolysis reactors and heating methods. Dimensionless numbers were employed to predict the impact of changing feed characteristics during pyrolysis. The second part of the study focuses on the operation of conventional condensers and how Bio-oil deposition on their surfaces affects efficiency and cost. Experimental estimation of Bio-oil film thickness on stainless steel and glass surfaces is presented, along with its effects. Finally, a hybrid condenser, combining stainless steel with a glass lining, is proposed to enhance efficiency and reduce costs based on operational requirements.

In this study, a series of platinum (Pt)-doped strontium iron oxide (SrFe₂O₄) catalysts with varying particle sizes were synthesized through the four different catalysis synthesis methods such as solution combustion synthesis (SCS), co-precipitation (Co-PPT), oxalic acid assisted sol-gel (OXA) and, hydrothermal (HT). The objective was to investigate the impact of particle size on the catalytic activity and long-term stability of these four catalysts. The XRD and Raman results confirmed the formation of the SrFe₂O₄ perovskite structure. HRTEM, SEM, and other characterizations revealed a clear correlation between the synthesis conditions and the resulting particle sizes. The highest%CH₄ conversion was around 95 % for the catalyst prepared through Solution combustion synthesis and the catalyst was found to be thermally stable up to. 100 h at 800 °C with a negligible variation of conversion while maintaining the H₂/CO ratio at 2.0. To gain insight into catalytic activity, stability, and selectivity of catalysts we have performed Temperature-programmed surface reaction (TPSR) at a controlled temperature ramping program. This study also includes the study of coke deposition on the spent catalysts through different characterization techniques. Furthermore, we have performed a kinetic study to find the initial rate of the reaction and the activation energy of the Pt-doped SrFe₂O₄ catalyst and it has been found that activation energy was 35 KJ/mol for the catalyst Pt/SrFe₂O₄ synthesis through the solution combustion method.

In this study, Zeolitic Imidazolate Framework-8 (ZIF-8) and modified ZIF-8 (ZIF-8@PEI)with polyethyleneimine (PEI) were used as dispersed particles inside the polysulfone (PSF) matrix to separate CO₂ and CH₄. The distributions of dispersed particles in mixed matrix membranes (MMMs) were analysed with the help of Fourier transfer infrared radiation, Thermal gravimetric analysis, Scanning electronic microscope and X-ray diffraction. The mixed matrix membranes investigated the permeability and selectivity of pure gas (CO₂) and mixed gas (CO₂/CH₄). It was highest at 5 wt% ZIF-8@PEI blended into the PSF matrix. In case of pure gas studies, we investigated the CO₂ permeability (18.10 Barrer) and CO₂/CH₄ selectivity (23.91) as compared to ZIF-8/PSF MMM (10.36 Barrer, 5.81); and in case of mixed gas studies, the CO₂ permeability (17.11 Barrer) and CO₂/CH₄selectivity (21.28) as compared to ZIF-8/PSF MMM (7.86 Barrer, 4.21).Using DFT studies, the interaction energies of the ZIF-8@PEI material with CO₂ and CH₄ gas molecules werefound to be -74.39 kJ/mol and -23.25 kJ/mol, respectively. It was more toward the ZIF-8@PEI-CO₂geometry complex.From the observation, the experimentalgas permeation results and DFT studiesinvestigated that ZIF-8@PEI filler can be a good candidate for applying CO₂ capture.