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Low-carbon methane (CH4) obtained from CO2 hydrogenation is a promising option for reducing greenhouse gases (GHG) emissions from carbon-intensive fossil fuel-based energy production, but catalytic performance, especially in low temperatures, still needs to be improved before large-scale implementation. In this work, it is proposed the use of hydroxyapatite (HAP) as an alternative catalyst support to validate its performance for CO2 hydrogenation to CH4. In addition, for the first time in literature, the influence of process conditions (temperature, gas hourly space velocity and Ni metal load) on the performance of HAP-supported catalysts is investigated on semi-pilot scale. CO2 conversion is favored up to 400 °C, despite the thermodynamic limitations of the hydrogenation reaction. Ni-based catalysts present the best performance for CO2 hydrogenation with a maximum CO2 conversion around 88% under optimized conditions (20 wt.% Ni, T = 350 °C, GHSV = 320 h−1) with 100% CH4 selectivity and no CO production up to 450 °C. Finally, long-term operation of 20Ni/HAP for 50 h on semi-pilot scale shows a robust performance with 83% CO2 conversion, 100% CH4 selectivity and no signs of catalyst deactivation. The performance HAP-based catalyst presented here demonstrates the feasibility of HAP as alternative catalyst support for CO2 hydrogenation and the potential for process upscaling with HAP-supported catalysts. [ABSTRACT FROM AUTHOR]

Purpose: The purpose is to describe and demonstrate the applicability of a bottom-up methodology to build the lifecycle inventory of industrial equipment ubiquitous in chemical processes. The analysis describes concepts of the methodology and demonstrates its functionality in the context of carbon footprint assessment of methanol production. Methods: The methodology proposed assumed unit operations are composed of macroscopic components, six structural including steel, concrete, insulation (glass wool), aluminum, powering, and electronic, and one functional, catalyst. Unit operations included heat exchangers (shell-and-tube and air-cooled systems), separation units (flash tanks and distillation column), and a methanol reactor. Sets of equations were provided to estimate the lifecycle inventory (LCI), while relying on scaling parameters as reported in techno-economic assessment techniques (i.e., surface area to estimate heat exchangers costs). A Power-to-X case study (system boundary) was selected to demonstrate the methodology functionality to build the equipment LCI to estimate the CO2 equivalent emissions to produce 1.0 kg of methanol at 25 °C and 1 atm (functional unit). Results and discussion: The case study showed emissions associated to capital goods amounted to 4146 tonnes of CO2 equivalent, with the methanol reactor having the largest share (67.9%), followed by heat exchangers (23.5%) and separation units (8.6%). Regarding components, steel and concrete comprised the largest contribution for most unit operations (> 53.8% of emissions) excluding the methanol reactor (9.9%). The share of powering and electronics was relevant in the carbon footprint (CF) exercise due to the components intrinsic CF (5.74 and 36.25 kg-CO2 eq./kg-component, respectively) when compared to other major components (i.e., steel, 0.58 kg-CO2 eq./kg-component). The component catalyst had a significant impact on the reactor emissions (80.7%) which originated from the need of being renewed every 2.5-year period. For the system boundary, capital goods only amounted to 0.221% of methanol production emissions or 0.0005 kg-CO2 eq./kg-MeOH. Conclusion: This study described a novel methodology to estimate the LCI and subsequent CF of capital goods. This new methodology has been used in a specific case study for methanol production using PtX. Ultimately, the authors of this study seek to create the basis of a simple but comprehensive methodology to reduce data gaps associated to lifecycle inventory and assessment of industrial equipment in literature. [ABSTRACT FROM AUTHOR]

In this study, the potential of yellow mombin (Spondias mombin L.)–extracted pectin as a film-forming matrix for the elaboration of edible coatings was investigated. The films of chitosan, citric pectin, and carboxymethylcellulose (Sigma/USA) and natural pectin were prepared by casting. The film morphological characterization was performed by scanning electron microscopy (SME), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and atomic force microscopy (AFM). Additionally, total phenolic compounds (TPC), total antioxidant activity (TAC), DPPH scavenging capacity, and antimicrobial activity were assayed for the natural pectin–based films. The results showed that the film based on natural pectin presented a 46% degree of esterification that was higher than commercial (34%), showing its capacity of forming gels. The film formed by chitosan presented a very different behavior for loss of mass during TGA when compared to the other films, occurring a mass loss completely at 647.7 °C in 61 min. The value obtained from the concentration of total phenolics (mg GAE/100 g dried) found in the formulated film based on pectin was 3998.99 ± 42.64 and with solubility in water of almost 100%. Additionally, the scavenging of the DPPH radical with a value of 15.48 ± 1.48 μmol TE/g was found on the film based on natural pectin thus showing antioxidant capacity. Finally, this film showed less significant mechanical properties when compared to other films and a good pronounced antimicrobial effect against the gram-negative bacteria tested. Therefore, it could be potentially used for producing food-active packages. [ABSTRACT FROM AUTHOR]

This study proposes the investigation of curcumin encapsulation into Saccharomyces cerevisiae cells through osmoporation as an efficient way of increasing curcumin stability. The influence of three process parameters (cell, ethanol and curcumin concentrations) on the encapsulation process was evaluated, and the obtained biocapsules were characterised for physical and photochemical stabilisation. Results showed that encapsulation efficiency was favoured by the increase of cells/curcumin ratio and ethanol concentration up to 60%. Differential scanning calorimetry (DSC) curves revealed that yeast encapsulation delayed the curcumin melting point up to 207 °C. Encapsulated curcumin retained over 80% of antioxidant activity after thermal treatment (150 °C) and over 70% after a 50-day exposure to artificial light. Photochemical stability of yeast-encapsulated curcumin was increased by 5.7-fold, and half-life time reached 181 days under illumination conditions. Overall, osmoporation-produced yeast biocapsules confirmed the versatility of osmoporation as an encapsulation technique and successfully improved curcumin stability. [ABSTRACT FROM AUTHOR]