In remote areas, such as India, Africa and Southeast Asia, typically not connected to the natural gas distribution grid, tissue paper drying process is currently carried out using a Yankee cylinder, heated with saturated steam, and hot air hoods warmed with saturated steam or diathermic oil. In this way the drying impingement air is heated, at maximum, at around 250 °C, with consequent low levels of dried paper production in comparison to modern hoods heated with natural gas. In this context, the present study intends to evaluate the technical and economic feasibility of using a CHP plant fully powered by biomass, for the production of steam and electricity in order to satisfy all the electrical needs of the paper mill and the steam for the Yankee cylinder, while a wood biomass fixed bed downdraft gasification plant is utilised for the production of syngas to be used as fuel in the gas hoods, in order to reach high drying temperatures (around 500 °C), comparable with those of the current natural gas powered hoods. Using previously developed calculation codes, an evaluation of the overall energy performances of the paper drying system and of the gasification plant has been performed. Results show that, for a paper mill with a production of about 80 t/day of paper, two gasification reactors with a thermal output of about 1.95 MWt, and a consumption of dry biomass of 0.86 t/h, are required. For the steam system, the net electric power needed to meet the needs of the paper mill is about 3100 kW with a consumption of 4.72 t/h of moist biomass and a net efficiency of 23.9 %. The performances of this innovative biomass fueled CHP plant are finally compared with those of a traditional natural gas fueled CHP plant.
Energy and Economic Comparison between natural gas fired and biomass fired Combined Heat and Power (CHP) plants for tissue paper production in remote areas
Frigo Stefano;
2019-01-01
Abstract
In remote areas, such as India, Africa and Southeast Asia, typically not connected to the natural gas distribution grid, tissue paper drying process is currently carried out using a Yankee cylinder, heated with saturated steam, and hot air hoods warmed with saturated steam or diathermic oil. In this way the drying impingement air is heated, at maximum, at around 250 °C, with consequent low levels of dried paper production in comparison to modern hoods heated with natural gas. In this context, the present study intends to evaluate the technical and economic feasibility of using a CHP plant fully powered by biomass, for the production of steam and electricity in order to satisfy all the electrical needs of the paper mill and the steam for the Yankee cylinder, while a wood biomass fixed bed downdraft gasification plant is utilised for the production of syngas to be used as fuel in the gas hoods, in order to reach high drying temperatures (around 500 °C), comparable with those of the current natural gas powered hoods. Using previously developed calculation codes, an evaluation of the overall energy performances of the paper drying system and of the gasification plant has been performed. Results show that, for a paper mill with a production of about 80 t/day of paper, two gasification reactors with a thermal output of about 1.95 MWt, and a consumption of dry biomass of 0.86 t/h, are required. For the steam system, the net electric power needed to meet the needs of the paper mill is about 3100 kW with a consumption of 4.72 t/h of moist biomass and a net efficiency of 23.9 %. The performances of this innovative biomass fueled CHP plant are finally compared with those of a traditional natural gas fueled CHP plant.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
