• Energy Research
• Closed Access close
• CO close
• English close

18 páginas ; Latin America is starting its energy transition. In Colombia, with its abundant natural resources and fossil fuel reserves, hydrogen (H2 ) could play a key role. This contribution analyzes the potential of blue H2 production in Colombia as a possible driver of the H2 economy. The study assesses the natural resources available to produce blue H2 in the context of the recently launched National Hydrogen Roadmap. Results indicate that there is great potential for low-emission blue H2 production in Colombia using coal as feedstock. Such potential, besides allowing a more sustainable use of non-renewable resources, would pave the way for green H2 deployment in Colombia. Blue H2 production from coal could range from 700 to 8000 ktH2 /year by 2050 under conservative and ambitious scenarios, respectively, which could supply up to 1.5% of the global H2 demand by 2050. However, while feedstock availability is promising for blue H2 production, carbon dioxide (CO2 ) capture capacities and investment costs could limit this potential in Colombia. Indeed, results of this work indicate that capture capacities of 15 to 180 MtCO2 /year (conservative and ambitious scenarios) need to be developed by 2050, and that the required investment for H2 deployment would be above that initially envisioned by the government. Further studies on carbon capture, utilization and storage capacity, implementation of a clear public policy, and a more detailed hydrogen strategy for the inclusion of blue H2 in the energy mix are required for establishing a low-emission H2 economy in the country. ; América Latina está iniciando su transición energética. En Colombia, con sus abundantes recursos naturales recursos naturales y reservas de combustibles fósiles, hidrógeno (H2 ) podría desempeñar un papel clave. Esta contribución analiza el potencial de la producción de H2 azul en Colombia como posible impulsor de la economía del H2. El estudio evalúa los recursos naturales disponibles para producir H2 azul en el contexto del reciente ...

The design of market mechanisms that remunerates the reliability provided by a generator in a power market is a task that aims to ensure the normal operation of the system. For the case of a Hydro-Dominated system, when wind power is introduced and operated under the Merit-Order-Effect, it is possible to assess the effect of the displacement of hydro generation due to wind generation over the system's reliability in terms of firm energy; taking this into account a model that valuates the firm energy provided by wind power in a hydro-dominated system is proposed. This model considers the effect of wind power over the system's reservoirs and the market price of electricity; and valuates the firm energy as the net savings of the system related to the increase in the firm energy of the system when wind power is introduced. The results show that wind power under Merit-Order-Effect increases the firm energy of the system, and decreases the market price of electricity, being the net savings in comparison to the corresponding hydro-only system the reliability income that should be perceived by the wind power generator. © 2016 Elsevier Ltd. All rights reserved.

ABSTRACT: A lab-scale prototype of a bioethanol fuel processor unit to produce H2 suitable for high CO-tolerant fuel cells was developed in this Thesis. To this end, a system that couples bioethanol reforming to produce syngas and the CO removal from the syngas produced in the reformer was designed. Initially, the system was evaluated using powder catalysts in both modules of the fuel processor unit (i.e., the bioethanol reformer and the reactor for CO removal), focusing on selecting an appropriate AuCu-based catalyst to carry out CO removal from an actual syngas in a single catalytic unit. The effect of the Au/Cu ratio and the support on the catalytic performance in CO removal was studied. It was found that an AuCu catalyst with a weight ratio of Au/Cu = 1 supported on polyhedral nanoparticles of CeO2 favors a balance between activity, selectivity and stability, ensuring a CO conversion. > 96%. Afterwards, catalysts structured on monoliths were evaluated for each module of the fuel processor unit. So, syngas was produced over monoliths washcoated with RhPt/CeO2- SiO2, which were evaluated with actual bioethanol (i.e., obtained from sugarcane press). The bioethanol reformer ensured a continuous production for 120 h of a syngas with an H2 content > 60%. Similarly, monoliths washcoated with AuCu catalysts were used for the CO removal, seeking to develop a compact and economical system to connect to the bioethanol reformer. It was identified that a monolith coated with an AuCu catalyst supported on a mixed oxide of CeO2-SiO2 (with molar ratio Si/Ce = 3) favors the production of a suitable gas (i.e., with a concentration of CO < 5%) to be fed to a high temperature proton exchange membrane fuel cell. Finally, the results of the catalytic evaluations were used as a starting point to build a scaled prototype to produce H2 from bioethanol obtained from residual biomass. The prototype had a cost of US$53,000, where 24% corresponds to the bioethanol reformer, 31% correspond to the unit to remove the CO, and the ...

14 páginas ; E-fuels are synthetic fuels produced from renewable sources that have garnered attention because of their potential to reduce environmental impacts in the transport sector. Ethyl levulinate is a fuel additive that can address issues associated with traditional fuels. This product can be obtained from agro-industrial wastes such as rice straw. Therefore, the aim of this study was to assess the technical, economic, and environmental feasibility of producing ethyl levulinate from Colombian rice straw. Aspen Plus v12 and life cycle assessment methodology were used for evaluating the process through the cultivation to the biorefinery stage. A base scenario was analyzed, with an overall yield of 0.115 kg ethyl levulinate/kg rice straw and a total energy consumption of 133.2 kWh/kg of ethyl levulinate produced. A carbon footprint of 2.71 kg CO2-eq/kg Ethyl levulinate was observed, which primarily ascribed to the use of steam derived from fossil fuels. An alternative scenario was proposed by implementing two changes to reduce the environmental impacts. First, steam was generated by the solid hydrolyzed residue combustion, and second, the paddy rice yield was increased to 5.7 t/ha. Reductions of 58.5% and 25.4% in the carbon footprint and ozone depletion were respectively obtained from these improvements. A class V economic assessment is performed for the alternative scenario, yielding a net present value of 18.7 MUSD, payback period of 5 years, and return on investment of 19.6%. Hence, the production of Ethyl levulinate from rice straw is a feasible alternative to boost the e-fuel market while upgrading agro-industrial waste into valuable products. ; Los combustibles electrónicos son combustibles sintéticos producidos a partir de fuentes renovables que han llamado la atención debido a su potencial para reducir el impacto ambiental en el sector del transporte. El levulinato de etilo es un aditivo para combustible que puede abordar los problemas asociados con los combustibles tradicionales. Este producto se ...

ABSTRACT: Waste tire (WT) valorization has gained significant impetus due to the rise in their pernicious disposal and subsequent environmental harm, coupled with the possibility of recovering both energy and materials. Rubber from WT (a mix of natural and synthetic rubber) exhibits high energy density (HHV 35 - 40 MJ/kg), high volatile matter content (55 - 65 wt.%), and a significant amount of carbon black (35 - 40 wt. %). Based on this composition, pyrolysis has been regarded as one of the pathways with a greater potential to recover both liquid and gaseous hydrocarbons, as well as valuable solid materials from WT. Hence, this thermochemical process has been perceived as a roadmap towards a circular and sustainable economy for WT management. In this scenario, this dissertation presents a comprehensive analysis, which starts highlighting the environmental and social issues related to WT, outlines their transformation into a valuable liquid fuel (tire pyrolysis oil) via pyrolysis in a twin-auger reactor using low-cost catalytic materials (CaO), and assesses distillation as an alternative for tire pyrolysis oil upgrading. In addition, the fuel and chemical properties of tire pyrolysis oil and its distillate fractions are studied from a fundamental point of view in order to provide new insights for their implementation in practical combustion applications, as well as for formulating further upgrading strategies. Finally, a model industrial pyrolysis plant is propose based on several experimental studies conducted at lab-scale and a thermoeconomic approach is taken in order to identify the benefits of scaling and modifying the process, as well as the potentials for improvement. In order to carried out this investigation, the initial part of this dissertation considered the study of the operational characteristics of a novel twin-auger reactor to transform WT by intermediate pyrolysis into tire pyrolysis oil (TPO), recovery carbon black (rCB), and tire pyrolysis gas (TPG). The influence of four operating parameters: ...

This paper analysed from the statistical point of view the trends in observed air temperature in major Polish cities and presented a qualitative analysis of their potential impact on the operation of the selected renewable energy sources. It also reviews the relation between the air temperature and observed electrical load as well as changing numbers of cooling and heating degree days. The method involved a statistical analysis of historical mean daily temperature observed in 19 major Polish cities over the 1968–2018 period. The air temperature change impact on renewable energy sector in Poland, by affecting the heating and cooling demand, the electrical load and the renewables working conditions both, on supply and demand side. The analysis reports that the mean daily temperature in all major polish cities is exhibiting a statistically significant increasing trend, up to 0.52 °C/decade. The observed increase in air temperature reduces the heating demand in Poland, beneficially for the environment and renewable supply. Increasing cooling needs in summer raises the energy consumption and indoor thermal stress. The climate warming affects the operation conditions, energy source, driving force, capacity and efficiency of renewable energy sources. The investigated changes were favourable and unfavourable depending on the renewable technology and operation mode, and were stronger on the demand side than on the supply side.

Research on Life Cycle Assessment (LCA) was initially performed to analyze specific products; however, it evolved to assess environmental impacts of more complex systems, such as roads. In this, the construction, use and maintenance stages are usually considered. The results of different studies revealed that all stages have relevant environmental impacts like topsoil loss, change in the use of land, modification of natural drainage and groundwater patterns, landslides, erosion, sedimentation, landscape degradation, increase in noise and dust levels, fuel and oil spills, waste generation, and air, soil and water pollution. This paper presents the results of a literature review on the application of LCA in road construction as a tool to quantify the potential impacts derived from the use of traditional and alternative materials. The research showed that the most common materials found were recycled asphalt (concrete and bitumen), fly ash, and polymer. In addition, the environmental impact categories more commonly assessed were energy consumption and global warming potential (GWP). These results claimed that the construction of roads should be directed towards the fulfilment of technical, social, economic and environmental criteria. Finally, it was found that most of the studies were performed for high traffic volume roads; therefore, for developing countries, research is needed focussed on low traffic ones. © 2018 Elsevier B.V.

ABSTRACT: Herein, the energy recovery from different MSW through an integrated plasma gasification combined cycle (IPGCC) power plant was investigated from an exergoeconomic viewpoint, using the Theory of Exergy Cost methodology. This study was conducted by an implemented model using Aspen Plus. MSWs that fuel the IPGCC power plant are produced in Medellín-Colombia, which are classified according to the sector considering their production rates and moisture contents (MC). Residential (1121 t/day and 57.9% of moisture content), Mixed (1468 t/day, 51.33%), Institutional (75 t/day, 37.92%), Commercial (168 t/day, 32.95%), and Industrial (104 t/day, 26.61%). Regarding the exergy analysis, for all plant cases, the plasma gasifier (PG) and the gas turbine (GT) reached the largest exergy destruction ratio, whose average contribution was 36.2% and 40.3%, respectively. This was ascribed to the exergy destruction by MSW drying into the PG, and by the oxidation reactions in the GT’s combustion chamber. Furthermore, as the MC of wastes increased (26.6% to 57.9%), the exergy destruction ratio of PG increased by 23.5%, leading to decrease the energy and exergy efficiencies of the IPGCC plants by 23.7% on average. This behavior was attributed to the adverse effect of high MC of wastes on the syngas quality. The exergy cost of electricity ranged from 11.0 to 14.5 ¢US$/kWh. Therefore, the plants with a processing capacity from 100 to 1000 t/day require a MSW treatment fee between 86.10 and 50.50 US$/t to equal the unit exergoeconomic cost of electricity with the hydro-electricity price in the Colombian energy market (6.92 ¢US$/kWh).

This study was proposed for evaluating the CO2 fixation by Spirulina platensis in different media, in order to understand the growth dynamics of the photosynthetic microalgae, a useful resource for the mitigation of climate change. The percentage of CO2 fixation by the strain S. platensis UTEX LB 2340 was determined during 11 days of sampling, using four (4) culture media. According to the statistical models, spirulina medium represented the best option in terms of cell growth between the tested ones. In this model, the variable day had presented a significant difference, this could be related to the exponential phase of the microorganism used.

This paper discusses a strategy for establishing an energy consumption baseline for the effects of defining and applying new strategies to improve the effectiveness of energy savings measures. Through this analysis, the energy baseline is adjusted to the dynamics of a typical operation, reducing uncertainty about operating data when it is not possible to determine that a given energy consumption level is typical. The strategy enables focusing efforts on the points in the operation with greatest impact on energy efficiency as a function of frequency of operation.