Please use this identifier to cite or link to this item: https://repository.unej.ac.id/xmlui/handle/123456789/105294
Title: Kinetics of silica precipitation in geothermal brine with seeds addition: minimizing silica scaling in a cold re‑injection system
Authors: SETIAWAN, Felix Arie
RAHAYUNINGSIH, Edia
PETRUS, Himawan Tri Bayu Murti
NURPRATAMA, Muhammad Istiawan
Keywords: Geothermal
Seeding
Silica precipitation
Scaling mitigation
Mass transfer
Issue Date: 1-Dec-2019
Publisher: Geotherm Energy
Abstract: The utilization of geothermal energy remains underdeveloped, mainly due to the technical problem of silica scaling. The scaling can eventually disrupt the electricity production process due to frequent pipe maintenance. Although inevitable, scaling can be controlled by accelerating the precipitation process through the addition of silica seeds. Silica gel has an afnity to bind with dissolved silica in geothermal brine that therefore reduces the likelihood of silica to form scale on the pipeline surfaces. In the present work, brine was taken from geothermal well Unit 3A–3B at the Dieng geothermal power plant with an initial silica monomer concentration of approximately 420 ppm. Silica gel seeds were added to the brine at a precise pH and temperature and dissolved silica concentration was analyzed by detecting silica monomers with UV–visible spectrophotometry using the vanadate/molybdate (yellow) method. Experimental results showed that the silica concentration in the liquid phase could be reduced by the addition of these seeds. Silica precipitation was determined by mass transfer of silica monomers from the fuid phase onto solid surfaces, and it was found that precipitation decreased as pH and temperature increased. Calculations also showed that the mass transfer coefcient was enhanced by fuid agitation. The silica precipitation process was optimal at a pH of 7, a temperature of 40 °C and agitation speed of 800 rpm; the result was a mass transfer coefcient of 0.5924 cm/s. In a dimensionless correlation, the mass transfer coefcient can be expressed in the equation (kc·dp/DAB)=1.4242·Re0. 529·Sc0.3333
URI: http://repository.unej.ac.id/xmlui/handle/123456789/105294
ISSN: KODEPRODI1903105#Teknik Kimia
NIDN0018118704
Appears in Collections:LSP-Jurnal Ilmiah Dosen

Files in This Item:
File Description SizeFormat 
FT_FELIX_JURNAL_Kinetics of silica precipitation in geothermal.pdf1.81 MBAdobe PDFView/Open


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.