EL CACHORRO [Material gráfico]

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 201

Polygeneration District Heating and Cooling Systems Based on Renewable Resources

Traditional district heating (DH) and district heating and cooling (DHC) systems have to address two principal challenges: phase-out of fossil fuels in favor of renewables; and profit instability related to declines in heating and cooling demands along with electricity price fluctuations. These obstacles can be overcome at once through upgrading these systems to a polygeneration concept by means of a retrofitted air-steam gasifier and gas upgrading equipment, enabling the use of renewable feedstocks such as refuse derived fuel (RDF) and municipal solid waste (MSW). In particular, the polygeneration DHC system will be able to produce simultaneously heating, cooling, electricity and value-added products – char, syngas, synthetic natural gas (SNG) and hydrogen. This work investigates the retrofit of these DHC systems through a case study based on the existing Climaespaco facility, located in Lisboa, Portugal. Thermodynamic, exergy, economic, exergo-economic and environmental models were built in Engineering Equation Software (EES) and Matlab. Overall, both RDF and MSW were found to be technically feasible and economically viable for using as feedstocks in the polygeneration DHC system. SNG production integrated in the polygeneration DHC system through the air-steam gasification and gas upgrading equipment is judged to be practical and also boosts revenues. The highest energy efficiency is achieved for cases where char is the sole by-product. System efficiencies drop as other value-added products are included as system outputs, although the extent of the efficiency decline can be adjusted by regulating syngas and SNG production. The highest discounted net cash flows are found for the scenario where SNG, syngas and char are produced simultaneously. A payback period of 3 years was determined for this and the other cases. From the exergy and exergo-economic perspectives, the scenario of simultaneous char and syngas production is the most promising as the overall exergy efficiency has the highest value and product exergo-economic costs are the lowest. However, from the products diversity viewpoint, the simultaneous production of char, SNG, syngas and H2 is advantageous

Polygeneration District Heating and Cooling Systems Based on Renewable Resources

Traditional district heating (DH) and district heating and cooling (DHC) systems have to address two principal challenges: phase-out of fossil fuels in favor of renewables; and profit instability related to declines in heating and cooling demands along with electricity price fluctuations. These obstacles can be overcome at once through upgrading these systems to a polygeneration concept by means of a retrofitted air-steam gasifier and gas upgrading equipment, enabling the use of renewable feedstocks such as refuse derived fuel (RDF) and municipal solid waste (MSW). In particular, the polygeneration DHC system will be able to produce simultaneously heating, cooling, electricity and value-added products – char, syngas, synthetic natural gas (SNG) and hydrogen. This work investigates the retrofit of these DHC systems through a case study based on the existing Climaespaco facility, located in Lisboa, Portugal. Thermodynamic, exergy, economic, exergo-economic and environmental models were built in Engineering Equation Software (EES) and Matlab. Overall, both RDF and MSW were found to be technically feasible and economically viable for using as feedstocks in the polygeneration DHC system. SNG production integrated in the polygeneration DHC system through the air-steam gasification and gas upgrading equipment is judged to be practical and also boosts revenues. The highest energy efficiency is achieved for cases where char is the sole by-product. System efficiencies drop as other value-added products are included as system outputs, although the extent of the efficiency decline can be adjusted by regulating syngas and SNG production. The highest discounted net cash flows are found for the scenario where SNG, syngas and char are produced simultaneously. A payback period of 3 years was determined for this and the other cases. From the exergy and exergo-economic perspectives, the scenario of simultaneous char and syngas production is the most promising as the overall exergy efficiency has the highest value and product exergo-economic costs are the lowest. However, from the products diversity viewpoint, the simultaneous production of char, SNG, syngas and H2 is advantageous

Polygeneration District Heating and Cooling Systems Based on Renewable Resources

Traditional district heating (DH) and district heating and cooling (DHC) systems have to address two principal challenges: phase-out of fossil fuels in favor of renewables; and profit instability related to declines in heating and cooling demands along with electricity price fluctuations. These obstacles can be overcome at once through upgrading these systems to a polygeneration concept by means of a retrofitted air-steam gasifier and gas upgrading equipment, enabling the use of renewable feedstocks such as refuse derived fuel (RDF) and municipal solid waste (MSW). In particular, the polygeneration DHC system will be able to produce simultaneously heating, cooling, electricity and value-added products – char, syngas, synthetic natural gas (SNG) and hydrogen. This work investigates the retrofit of these DHC systems through a case study based on the existing Climaespaco facility, located in Lisboa, Portugal. Thermodynamic, exergy, economic, exergo-economic and environmental models were built in Engineering Equation Software (EES) and Matlab. Overall, both RDF and MSW were found to be technically feasible and economically viable for using as feedstocks in the polygeneration DHC system. SNG production integrated in the polygeneration DHC system through the air-steam gasification and gas upgrading equipment is judged to be practical and also boosts revenues. The highest energy efficiency is achieved for cases where char is the sole by-product. System efficiencies drop as other value-added products are included as system outputs, although the extent of the efficiency decline can be adjusted by regulating syngas and SNG production. The highest discounted net cash flows are found for the scenario where SNG, syngas and char are produced simultaneously. A payback period of 3 years was determined for this and the other cases. From the exergy and exergo-economic perspectives, the scenario of simultaneous char and syngas production is the most promising as the overall exergy efficiency has the highest value and product exergo-economic costs are the lowest. However, from the products diversity viewpoint, the simultaneous production of char, SNG, syngas and H2 is advantageous

Production of Synthetic Natural Gas from Refuse-Derived Fuel Gasification for Use in a Polygeneration District Heating and Cooling System

Nowadays conventional district heating and cooling (DHC) systems face the challenge of reducing fossil fuel dependency while maintaining profitability. To address these issues, this study examines the possibility of retrofitting DHC systems with refuse-derived fuel (RDF) gasifiers and gas upgrading equipment. A novel system is proposed based on the modification of an existing DHC system. Thermodynamic and economic models were established to allow for a parametric analysis of key parameters. The study revealed that such an upgrade is both feasible and economically viable. In the basic scenario, the retrofitted DHC system can simultaneously produce 60.3 GWh/year of heat, 65.1 GWh/year of cold, 33.2 GWh/year of electricity and 789.5 tons/year of synthetic natural gas. A significant part of the heat load can be generated from the waste heat of the upgrading equipment. The investment in retrofitting the polygeneration DHC system presents a payback period of 3 years