CO2 Capture/utilization

Mensurar a QAU frente aos aspectos ambientais sugere correlações do ser humano frente às inter-relações com o espaço urbano da cidade, a fim de determinar ou exprimir qualidade(s). A coleta de opiniões da população vislumbra a trilogia AFETO-COGNIÇÃO-COMPORTAMENTO, pautada no potencial informativo do espaço do bairro e da cidade do Salvador, onde a percepção é passada pelo espírito de entendimento ou comportamento das pessoas, suas crenças e conhecimento relativo do lugar, no domínio das suas atividades psíquicas, sentimentais, emocionais e volitivas.

Chemical looping combustion (CLC) is an encouraging technology for hydrogen and power co-generation with efficient CO2 capture. Utilization of the captured CO2 is a much more important task to realize negative CO2 emissions. The objective of the work is to explore a case study of carbon dioxide utilization (CDU) in the form of formic acid synthesis using the captured CO2 and co-generated H2 from coal direct chemical looping (CDCL) power plant. Steady-state simulations are performed on the power and H2 co-generation CDCL plant integrated with formic acid synthesis and presented a comparison of overall performance of the CDCL plants with and without CDU integration. The simulation results revealed that the formic acid synthesis integrated CDCL plant avoids release of 62.49 kg.CO2/GJ of fuel input into the environment and utilizes the captured CO2 completely with the net electrical efficiency penalty of 5.8%.

Dry reforming of methane (DRM) is one of the attractive methods for the utilisation of greenhouse gases (e.g., CH4 , CO2) to produce valuable fuels. In the quest for an efficient development in DRM, several technologies have been practised, while dielectric barrier discharge (DBD) cold plasma technology garners special attention in the utilisation of CO 2 and CH 4 through DRM process due to easy upscaling opportunities and mild operating conditions. However, the low energy efficiency (EE) of DBD plasma is a distinct challenge and it offers an in-depth insight into its basic operational understandings. This review presents the overall status and current developments in DBD plasma for DRM. In the mainstream, challenges in DBD plasma technology, catalyst-plasma interactions and developments in plasma catalysts to improve the yield and selectivity of DRM have been discussed. The current status and developments in DBD reactor configuration based on reactor geometry, such as the electrode morphology, discharge gap (D gap), discharge volume (V D) and material packing to maximise the productivity of DRM are specifically investigated. The effects of the operating parameters, such as gas hourly space velocity (GHSV), specific input energy (SIE) and feed ratio are critical for product distribution. The current status of reaction kinetics and prospects in fluid modelling of catalytic DBD plasma DRM reactor is reviewed to understand the underlying reaction mechanism. Finally, further advancements in the catalytic DBD plasma DRM has become a requisite to make it commercially viable for the successful production of valuable fuels.

This study suggests that the waste-to-resource supply chain can offer an approach to address simultaneously the issues of waste management and CO 2 emissions toward a circular economy. Alkaline solid wastes can be used to mineralize CO 2 through an accelerated carbonation reaction, especially if the wastes are generated near the point source of CO 2 , to achieve environmental and economic benefits. To enhance the performance of accelerated carbonation, a high-gravity carbonation process using a rotating packed bed reactor was developed and deployed. Due to additional energy consumption in high-gravity carbonation, the environmental benefits and economic costs should be critically assessed from a life-cycle perspective. In this study, the resource potential of alkaline solid wastes in Taiwan was first determined for CO 2 mineralization and utilization using the high-gravity carbonation process. Then, the performances of the process from engineering, environmental, and economic perspectives were evaluated and exemplified by a steelmaking plant. The results indicated that, with a CO 2 removal ratio of 97−98%, the energy consumption of the high-gravity carbonation was estimated to be ∼345 kWh/t-CO 2. From the perspective of environmental benefits, CO 2 emission from the cement industry could be indirectly avoided by roughly one t-CO 2-eq/t-slag due to the utilization of carbonated products.

Carbon-based fuels contribute majorly towards global energy demand; however, it results in global warming. The increasing energy demand and climate change highlights the need to develop cost-effective carbon sequestration schemes. Amine-based CO2 scrubbing have been widely used for their high selectivity and production of pure CO2. However, a challenge in implementing amine-based technology is high energy consumption with a low capture ratio. The energy penalty can be reduced either by introducing new solvents, optimizing parameters, or through process modifications. Recently, ammonia has tempted attraction in place of amines. In this present work, a Radfrac model in Aspen Plus is developed involving heat integration and absorption enhancement to overcome the barriers. The heat integration is performed with a rich solvent split and absorption enhancement is done with split flow arrangement. Further, the model is evaluated at different split ratios by performing heat integration between different streams of the flowsheet. Moreover, the process configurations used in this system is compared with MEA based process modifications concerning energy reduction. A competitive reduction in regeneration duty was observed which was 36% less than the reference NH3 and 47% less than the MEA process. This evaluated modification will result in maximum efficiency, a maximum level of CO2 capture, and a reduction in the reboiler duty. The rich solvent split and split flow process reduced the reboiler duty by 15.8% and 32.8%, respectively. The split flow process also indicated an increase of 17.2% in rich loading to recover 90% CO2.

A nivel mundial se tiene presente que ciertos fenómenos meteorológicos, así como "patrones climáticos", han sufrido cambios en frecuencia, intensidad, duración y época en la que se dan, esto en función de los registros y se nota en la lluvia, viento, temperatura, deshielo de glaciares, por decir algunos.

To cite this article: Tamil Selvan Silambarasan, Kulvinder Bajwa & Ramamurthy Dhandapani (2017) Optimization and mass culture of Acutodesmus obliquus RDS01 under open phototrophic pond cultivation for enhancing biodiesel production, Biofuels, 8:2, 243-252,

We have used computational methodology based on the density functional theory to describe both copper(I) and copper(II) oxides, followed by the investigation of a number of different low index CuO surfaces. Different magnetic orderings of all the surfaces were studied, and reconstructions of the polar surfaces are proposed. A detailed discussion on stabilities, electronic structure, and magnetic properties is presented. CuO(111) and CuO(111) were found to have the lowest surface energies, and their planes dominate in the calculated Wulff morphology of the CuO crystal. We next investigated the adsorption of CO 2 on the three most exposed CuO surfaces, viz., (111), (111), and (011), by exploring various adsorption sites and configurations. We show that the CO 2 molecule is activated on the CuO surfaces, with an adsorption energy of −93 kJ/mol on the (011) surface, showing exothermic adsorption, while (111) and (111) surfaces show comparatively weak adsorption. The activation of the CO 2 molecule is characterized by large structural transformations and significant charge transfer, i.e., forming a negatively charged bent CO 2 −δ species with elongated C−O bonds, which is further confirmed by vibrational analyses showing considerable red shift in the frequencies as a result of the activation.

Anthropogenic gas of CO2 level was higher than CO2 atmospheric safety limit of 350 ppm since 80’s. It can be assumed that CO2 level growth directly proportional to the population and development. Hence, studies on CO2 capture have been extensively established in between year of 2000-2010. Metal oxide can be a good adsorbent but it has the weakness in surface area and sintered after regeneration process. Thus, activated carbon was used to enhance the surface area which mainly responsible for physical adsorption. Fe2O3 supported on activated carbon (Fe2O3/AC) were prepared by impregnation method and used for CO2 adsorption-desorption studies. The XRD result shows that precursor of ferric nitrate used to impregnated on AC (activated carbon) support was directly dissociated to Fe2O3 metal oxide by thermal treatment under N2 atmosphere temperature at 450 °C. The loading amount of Fe2O3 by weight ratio affect the textural properties and CO2 capturing capacity. The surface area and pore volume of the catalyst decrease with the loading of Fe2O3. Highest Fe2O3 loading shows greater amount chemically adsorbed of CO2. Nevertheless, it drastically reduced the surface area of the AC, which is chiefly responsible for CO2 physisorption, thus decreasing the carrying capacity of ACs at 25 °C. The 20Fe2O3/AC was found to be optimum loading for better physi and chemisorptions of CO2. Keywords: Adsorption; iron oxide; activated carbon; carbon dioxide Abstrak Peningkatan gas antropogen seperti CO2 telah pun melebihi tahap keselamatan atmosfera iaitu 350 ppm semenjak tahun 80-an. Peningkatan CO2 boleh dianggap berkadar langsung dengan populasi dan pembangunan. Oleh sedemikian, kajian dalam bidang ini telah meningkat di antara tahun 2000-2010. Logam oksida merupakan penjerap yang baik, namun ia mempunyai kelemahan dari segi ciri luas permukaan dan menjadi sinter selepas proses penghasilan semula. Dengan menggunakan karbon aktif (AC) sebagai penyokong, boleh mempertingkatkan luas permukaan penjerap yang memainkan peranan penting dalam penjerapan sacara fizikal. Fe2O3 yang disokong pada karbon aktif (Fe2O3/AC) disediakan dengan kaedah impregnasi atau pengisitepuan, seterusnya digunakan dalam kajian penjerapan-penyahjerapan CO2. Keputusan XRD menunjukkan ferum nitrat yang disokong pada AC telah dileraikan kepada logam oksida, Fe2O3, dengan pemanasan yang dialirkan N2 pada suhu 450 °C. Jumlah muatan Fe2O3 yang berdasarkan nisbah jisim memberi kesan pada ciri teksturnya dan keupayaan penjerapan CO2. Luas permukaan dan isi padu liang pemangkin berkurangan dengan penambahan muatan Fe2O3 pada penyokong. Muatan Fe2O3 yang tinggi menunjukkan peningkatan jumlah CO2 yang dijerap secara kimia. Walaubagaimanapun, ia memberi kesan penurunan luas permukaan karbon aktif secara mendadak, dimana ia memainkan peranan utama dalam pejerapan secara fizikal. Oleh sedemikian, ia merendahkan keupayaan penjerapan yang rendah karbon aktif tersebut pada suhu 25 °C. Kajian ini mendapati sampel 20Fe2O3/AC merupakan muatan optimum untuk penjerapan CO2 yang lebih berkesan dari segi fizikal dan kimia.