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App\Controller\AppController::getPrevNext() - APP/Controller/AppController.php, line 669
App\Controller\PublicationsController::view() - APP/Controller/PublicationsController.php, line 135
Cake\Controller\Controller::invokeAction() - CORE/src/Controller/Controller.php, line 606
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Cake\Routing\Dispatcher::dispatch() - CORE/src/Routing/Dispatcher.php, line 66
Cake\Controller\Controller::requestAction() - CORE/src/Routing/RequestActionTrait.php, line 181
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App\Controller\AppController::getPrevNext() - APP/Controller/AppController.php, line 689
App\Controller\PublicationsController::view() - APP/Controller/PublicationsController.php, line 135
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Cake\Http\ActionDispatcher::_invoke() - CORE/src/Http/ActionDispatcher.php, line 120
Cake\Http\ActionDispatcher::dispatch() - CORE/src/Http/ActionDispatcher.php, line 94
Cake\Routing\Dispatcher::dispatch() - CORE/src/Routing/Dispatcher.php, line 66
Cake\Controller\Controller::requestAction() - CORE/src/Routing/RequestActionTrait.php, line 181
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Publication | Peer reviewed papers | Potentiale, Bioenergiesysteme, Logistik
Single Pellet Combustion of Sewage Sludge and Agricultural Residues with a Focus on Phosphorus
Published 8 June 2021
Citation: Häggström G, Hannl TK, Hedayati A, Kuba M, Skoglund N, Öhman M. Single Pellet Combustion of Sewage Sludge and Agricultural Residues with a Focus on Phosphorus. Energy & Fuels. 8 June 2021.
Abstract
Recycling of phosphorus in combination with increased utilization of bioenergy can mitigate material and global warming challenges. In addition, co-combustion of different fuels can alleviate ash-related problems in thermal conversion of biomass. The aim of this study is to investigate the ash transformation reactions of mainly P in co-combustion of P-rich sewage sludge (SS) with K-rich sunflower husks (SH) and K- and Si-rich wheat straw (WS). Single pellets of 4 mixtures (10 and 30 wt % SS in WS and 15 and 40 wt % SS in SH) and pure SS were combusted in an electrically heated furnace at process temperatures relevant for fluidized bed combustion (800 and 950 °C). Collected ash fractions were analyzed by inductively coupled plasma techniques, ion chromatography, scanning electron microscopy–energy-dispersive X-ray spectroscopy, and X-ray diffraction. Thermodynamic equilibrium calculations were performed to interpret the results. Over 90% of K and P was found to be captured within the residual ash with 30–70% P in crystalline K-bearing phosphates for mixtures with low amounts of SS (WSS10 and SHS15). The significant share of K and P in the amorphous material could be important for P recovery. For the lower percentage mixtures of SS (WSS10 and SHS15), P in crystalline phases was mainly found in K-whitlockite and CaKPO4. For the higher percentage SS mixtures, most of P was found in whitlockites associated with Fe and Mg, and no crystalline phosphates containing K were detected. For P recovery, co-combustion of the lower SS mixtures is favorable, and they are suggested to be further studied concerning the suitability for plant growth.
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