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- CO2 Capture in Chemically and Thermally Modified Activated Carbons Using Breakthrough Measurements: Experimental and Modeling StudyPublication . Silva, José A.C.; Karimi, Mohsen; Gonçalves, Carmem Natália de Pina; Díaz de Tuesta, Jose Luis; Rodrigues, Alírio; Gomes, HelderThe development of adsorption-based technologies for CO2 capture in the post combustion processes requires finding materials with high capacity of adsorption and low cost of preparation. In this study, the modification of a commercial activated carbon (Norit ROX 0.8), considered as a solid adsorbent for CO2 capture, and the effects of different methods of activations, chemically (hydrogen peroxide, sulfuric acid, nitric acid, and urea) and thermally (at 800 °C) on adsorption performance, have been investigated. Then, CO2 adsorption capacity was studied at different temperatures and pressures to evaluate the effects of various agents on sample performance. The textural properties of the samples were determined using adsorption−desorption isotherms of nitrogen at −196 °C. Finally, the obtained data were modeled by Response Surface Methodology (RSM) and Langmuir isotherm. The results showed that the prepared sample by successive treatments with nitric acid, urea, and thermal calcination has a higher uptake capacity than other modified samples.
- Uptake capacity of adsorbent materials derived from municipal solid waste for CO2 capture at post combustion conditionPublication . Díaz de Tuesta, Jose Luis; Karimi, Mohsen; Gonçalves, Carmem Natália de Pina; Silva, José A.C.; Gomes, Helder; Rodrigues, AlírioThe global climate change, as well as the accumulations of solid waste on landfills, are two of the primary issues nowadays, which it needs the significant attempts to reduce the impact on the ecosystem and environment from both of them [1]. In this work, the production of materials from organic solid waste is considered to produce adsorbent materials, which are assessed in the CO2 capture.
- Compost from municipal solid wastes as a source of biochar for CO2 capturePublication . Karimi, Mohsen; Díaz de Tuesta, Jose Luis; Gonçalves, Carmem Natália de Pina; Gomes, Helder; Rodrigues, Alírio; Silva, José A.C.ncreasing greenhouse gas emissions contributing to the global climate change are a major concern of environmental protection. Developing adsorbents from low-cost and renewable resources is an attractive strategy. On the other hand, the high capacity of production rates of municipal solid waste, besides high methane emissions, is the origin of some eco-systemic challenges. The combination of the two environmental problems is considered by introducing the compost from a mechanical biological treatment of municipal solid wastes as a low-cost source of adsorbent for CO2 capture. The obtained compost was thermally and chemically activated and the CO2 adsorption capacities of prepared samples were evaluated. Samples prepared sequentially with sulfuric acid and heated at 800 degrees C and vice versa, respectively, had the highest uptake capacities and were comparable with commercial adsorbents.
- Comparison between the ability of sulphuric acid, nitric acid and urea as chemical activators of commercial activated carbons for CO2 capturePublication . Gonçalves, Carmem Natália de Pina; Karimi, Mohsen; Díaz de Tuesta, Jose Luis; Silva, José A.C.; Rodrigues, Alírio; Gomes, HelderPhysical adsorption process has been considered as a promising technique for CO2 capture, due to low energy consumption and high efficiency. In this way, several adsorbents including activated carbons [1], zeolites [2] and MOFs [3] have been extensively studied for CO2 adsorption in the recent years. Activated carbon has attracted much attention, because of amorphous porous form, hydrophobic character and low energy for desorption [4]. To preparation of this adsorbent, physically (thermally) and chemically methods are the two main strategies. In the first method, the materials are carbonized in the temperature range of 400-850 0C, while in the second one by using some chemical components activation takes place by heating the mixture of precursor and dehydrating agent or oxidant. Hereby, based on BLUE Map Scenario of the International Energy Agency (IEA) [5], an activated carbon (Norit ROX 0.8) has been modified by using different chemical and thermal treatments, following the procedures described elsewhere [6]. In order to obtain adsorbents with smaller particle size, commercial activated carbon was first grinded and sieved to particle sizes ranging from 0.106 to 0.250 mm, resulting in a powder activated carbon (PAC). Three of the materials were prepared directly from the PAC sample by liquid phase treatments with hydrogen peroxide, sulphuric acid and nitric acid, resulting in PACHP, PACSA and PACNA materials, respectively. The treatment with hydrogen peroxide was performed wetting 25 g of PAC with 500 mL of hydrogen peroxide solution 30% (w/v) at room temperature for 24 h. In sulphuric acid oxidation, 25 g of PAC was immersed in 500 mL of 18 M acid solution for 3 h at 423 K. Oxidation with nitric acid was carried out boiling 25 g of PAC in 500 mL of 5 M nitric acid solution for 3 h. After the liquid phase treatments, all samples were thoroughly washed with distilled water until the neutrality of the rinsing waters and further dried in oven for 18 h at 383 K, resulting in samples PACHP, PACSA and PACNA, respectively. The other two samples were obtained in successive treatments of the PACNA material. 2 g of PACNA was immersed in 50 mL of 1 M urea solution and kept in a 125 mL stainless steel high pressure batch reactor under its own atmosphere at 473 K for 2 h, the recovered solids being thoroughly washed with distilled water until the neutrality of the rinsing waters, and further dried overnight in oven at 383 K, resulting in the PACNAU material. Then, a gas phase thermal treatment was applied, in which 1 g of PACNAU was heated, under a N2 flow (100 cm3 min−1), at 393 K, 673 K and 873 K during 60 min at each temperature and then at 1073 K for 240 min, resulting in the PACNAUT material.
- Breakthrough measurement of carbon dioxide adsorption on lowcost activated carbons derived from solid wastesPublication . Karimi, Mohsen; Díaz de Tuesta, Jose Luis; Gonçalves, Carmem Natália de Pina; Silva, José A.C.; Rodrigues, Alírio; Gomes, HelderIn this study, based on the scopes of CCS strategy and municipal solid waste management, a novel Integrated Environment Management (IEM) strategy has been proposed. In this way, the obtained compost in the mechanical biological treatment from municipal solid wastes has been considered as a source of adsorbents for CO2 capture. In this way, the maturated compost waste was modified by liquid phase treatment with sulfuric acid and thermal treatment at 800 0C. Then, the prevalent operational conditions of post-combustion processes have been considered to find the best prepared samples for CO2 capture.
- Preparation and characterization of natural and pillared clays for catalytic wet peroxide oxidation of 4-nitrophenolPublication . Díaz de Tuesta, Jose Luis; Kalmakhanova, Marzhan; Massalimova, Bakytgul Kabykenovna; Gomes, HelderThis work deals with the evaluation of two natural clays (NCs) extracted from Karatau (KNC) and Akzhar (ANC) deposits (located in the Zhambyl region of Kazakhstan) to prepare pillared clays (PILCs) for catalytic wet peroxide oxidation (CWPO) of 4-nitrophenol (4-NP), used as model pollutant. NCs were washed with HCl 1 M and then pillared using a solution containing Fe, Cu and Zr. NCs and PILCs were characterized by Electron Microprobe (EMP), X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron Microscopy (TEM), as detailed elsewhere [1,2]. EMP confirms the cation exchange of the Ca contained in the NCs (Ca > 15%) in the form of calcite (according to DRX and FTIR), by polycations of the pillaring solution (Ca < 2% for the PILCs). TEM reveals that the impregnation of polycations on the washed NCs also take place, coupling with its pillarization. CWPO runs were performed following the methodology and operational conditions described in previous works [1,2]. All materials show catalytic activity, since the H2O2 is consumed (Fig. 1A) to oxidize the 4-NP. Both KPILC and APILC, prepared from KNC and ANC, respectively, allow the complete removal of 4-NP after 4 h, whereas the conversion of 4-NP was less than 20% with the NCs (Fig. 1B). TOC conversions higher than 60 % were achieved with PILCs after 8 h. The subtraction of the theoretical TOC contribution of 4-NP from experimental TOC allowed to observe the formation of oxidazable intermediate compounds (maximum value of TOCexperimental- TOC4-NP at 1 h of reaction), which are oxidized to form refractory products (Fig. 1C). Based on these contributions of the TOC, a kinetic model based on TOC lumping into three blocks (TOCA à TOCB à TOCC, corresponding to the initial TOC of 4-NP, oxidazable intermediates and refractory products, respectively) was developed for the NCs and PILCs, predicting suitably the evolution of 4-NP, H2O2 and TOC in the CWPO of 4-NP (Fig. 1).
- Application of catalysts developed from compost derived from municipal solid waste in the removal of caffeine by wet peroxide oxidationPublication . Almeida, Flávio V.M.; Oliveira, Jéssica; Díaz de Tuesta, Jose Luis; Praça, Paulo; Guerreiro, Mário C.; Barreiro, M.F.; Silva, Adrián; Faria, Joaquim; Gomes, Helder; Oliveira, JessícaNowadays, waste management through mechanical biological treatment (MBT) consists on the use of the separated organic fraction of municipal solid waste (MSW) to feed anaerobic digestion processes, resulting therein a solid stream, further processed to compost, which can be used as fertilizer. Currently, the production of compost from MBT is higher than the existing demand, and the expected developments on up-coming directives ruling “End-of-waste” criteria are leading to barriers on the use of waste-derived fertilizers (European Commision, 2013). In this context, the current work proposes an alternative strategy to the valorisation of compost, through the production of low-cost materials to be applied in the catalytic wet peroxide oxidation (CWPO) of synthetic wastewater effluents contaminated with caffeine, used as a model pollutant of emerging concern. Caffeine is the most consumed psychoactive drug worldwide. It is one of the components of painkillers, medication against migraine, fatigue, drowsiness and breathing problems. Its consumption is also associated with an overall lower risk of malignant growth like hepatocellular, endometrial or colorectal cancer (Ganzenko et al., 2015). However, the effect of caffeine and its environmental degradation products on aquatic living species is not properly known. Caffeine, is a world wide consumed psychoactive drug, in a way that becomes a persistent compound and cannot be efficiently removed by municipal wastewater treatment facilities (Ganzenko et al., 2015). As a consequence, caffeine and its metabolites are present in the effluents of wastewater treatment plants (Gracia-Lor et al., 2017).
- Simultaneous removal of o-and p-nitrophenol from contaminated water by wet peroxide oxidation using carbon-coated magnetic ferrite as catalystPublication . Dias, Arnaldo; Silva, Adriano S.; Silva, Ana P. F.; Roman, Fernanda; Díaz de Tuesta, Jose Luis; Oliveira, Jéssica; Ferrari, Ana M.; Lenzi, Giane G.; Gomes, Helder; Oliveira, JessícaGroundwater is the most common source of drinking water worldwide and is currently facing contamination problems with the discharge of pollutants into aquatic systems through different means, namely through municipal, industrial and agricultural activities. Contaminants, such as herbicides, pharmaceuticals, phenolic compounds and personal care products are not removed by conventional treatments from wastewater treatment plants, leading to their accumulation in the environment. In this regard, o-nitrophenol (o-NP) and p-nitrophenol (p-NP), commonly used as raw materials in chemical and pharmaceutical engineering, represent a severe risk to humans and aquatic life, leading to the necessity to properly treat wastewaters containing these contaminants before discharge into the aquatic environment. Catalytic wet peroxide oxidation (CWPO) showed promising results for removing nitrophenols from wastewater in previous works. In this technology, H2O2 is used as an oxidant, and its interaction with a suitable catalyst leads to the formation of hydroxyl radicals under determined conditions already established in literature (pH and temperature have a strong influence) [1]. Typical catalysts employed have a transition metal in its structure. Carbon-based catalysts also have activity in this technology, mostly ascribed to the electronic properties of the carbonaceous surface. Furthermore, carbon-coated metal oxide materials (hybrid) have also demonstrated potential applications in CWPO. Those structures combine carbon and metal activities with the advantage of protecting the metal core from leaching, increasing the efficiency and stability of the catalysts.
- Green magnetic nanoparticles CoFe2O4@Nb5O2 applied in Paracetamol removalPublication . Oliveira, Jéssica; Ribas, Laura S.; Napoli, José Salvador; Abreu, Eduardo; Díaz de Tuesta, Jose Luis; Gomes, Helder; Tusset, Angelo M.; Lenzi, Giane G.; Oliveira, JessícaThis study describes the synthesis of an innovative nanomaterial (patent application number BR 1020210000317) composed of cobalt ferrite functionalized in niobium pentoxide CoFe2O4@Nb5O2 (CFNb), synthesized via green synthesis using tangerine peel extract. The material emphasizes the combination of a magnetic material (which allows for easy recovery after application) with niobium pentoxide (a metal which is abundant in Brazil). CFNb was applied as a catalyst for the paracetamol (PCT) degradation by photocatalysis. The new materials were characterized through surface and pore analysis (S-BET, S-EXT, S-mic, V-mic, and V-TOTAL), photoacoustic spectroscopy (PAS), zero charge point (pHPZC, scanning electron microscopy (SEM/EDS), and X-ray diffraction (XRD). The reaction parameters studied included pH and catalyst concentration. The results indicated that the CFNb nanocatalysts were efficient in the paracetamol degradation, presenting better results in conditions of low pH (close to 2) and low catalyst concentration under irradiation of the 250Wmercury vapor lamp (greater than 28 mW center dot cm(-2)) at 60 min of reaction.
- Kinetic insights on wet peroxide oxidation of caffeine using EDTA-functionalized low-cost catalysts prepared from compost generated in municipal solid waste treatment facilitiesPublication . Díaz de Tuesta, Jose Luis; Almeida, Flávio V.M.; Oliveira, Jéssica; Praça, Paulo; Guerreiro, Mário C.; Gomes, Helder; Oliveira, JessícaNowadays, sorted organic fraction of municipal solid waste is typically treated by anaerobic digestion processes, resulting therein a solid stream, further processed to obtain compost, whose production is higher than the existing demand as fertilizer. The current work proposes an alternative strategy for the recovering of compost through the production of low-cost catalysts by calcination (1073 K) and sulfuric acid treatments, followed by sequential functionalization with tetraethyl orthosilicate (TEOS) and ethylenediamine tetraacetic acid (EDTA). Activity and stability of the catalysts are assessed in the wet peroxide oxidation of synthetic wastewater effluents contaminated with caffeine, a model micro-pollutant, achieving its complete removal after 6 h at 353– 383 K and catalyst loads of 0.5–2.5 g L−1. The increase of the catalytic activity of the materials upon functionalization with TEOS and EDTA is demonstrated and a kinetic modeling of caffeine degradation and hydrogen peroxide consumption with the best catalyst is assessed by pseudo-first power-law rate equations.