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Recovery technology developed from early inefficient chemical recovery to modern large plants. Early rotary units had to fade when new larger and more reliable units came were available in the 1930's. Changes in investment costs, increases in scale, demands placed on energy efficiency and environmental requirements are the main factors directing de...
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... Additionally, using Tomlinson recovery boilers to treat straw black liquor (SBL) is more difficult because of the high silica and chlorine contents, high viscosity and low heat value of SBL [7][8][9]. For these reasons many researchers have focused on developing alternative BL recovery technologies [10][11][12]. These technologies include: supercritical water gasification [13][14][15][16], hydrothermal treatments [17][18][19][20][21], hydrolytic methods [22], activated carbon production [23], biochar production [24,25], organic compound production [26,27], biofuel production [28,29], as well as microbial electrochemical treatment [30], and flocculation [31]. ...
Fluidized bed pyrolysis is a promising technology for recovering value from reed black liquor (RBL) but it can be limited by agglomeration of the bed material and loss of fluidization. To address this challenge, laboratory experiments examined the continuous, fluidized bed pyrolysis of RBL using two different bed materials at temperatures ranging from 530 to 780°C. Pyrolysis with silica sand as the bed material showed sintering within 120 s and loss of fluidization at a bed temperature of 680°C. Pyrolysis with calcium-based zeolite as the bed material retained fluidization for the entire test period of 30 min at all temperatures examined. Increasing pyrolysis temperature with the calcium-based zeolite increased H2 generation and decreased tar production, with the highest temperature examined (780°C) providing the best performance. Fluidized bed combustion of the pyrolysis char (both at 780°C) recovered 87% of the sodium in the RBL. Pyrolysis of RBL using fluidized bed technology with a calcium-based zeolite bed material is feasible and effective.
