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Title
Pre-treatment of oil palm biomass for alkaline peroxide pulping
Authors
A.Ghazali W. D. Wan Rosli and K. N. Law
Received
July 13, 2009
Published
Volume 43 Issue 7-8 July-August
Keywords
EFB, DTPA, chelation, desilication, silica, minerals, APP
Abstract
Oil palm biomass in the form of an empty fruit bunch (EFB) was examined for defining the extent of pretreatment
required by the biomass before an alkaline peroxide pulping process. Minerals such as silica and
the derivatives of transition metals were identified as problematic to the pulping process. Specifically for
silica removal, initially, hammering and pressing appeared as two powerful processes while, for transition
metals, chelation with diethylenediaminepentaacetic acid (DTPA) was performed. The results obtained show
that a complete treatment removed calcium, copper, manganese and sodium by 50, 100, 95 and 93%,
respectively, while a total of 86% of silica bodies were also identified as removable. From these figures, the
removal of 54% of the silica bodies was determined by the mechanical treatment, while 10% was
attributable to the effect of DTPA. Since silica is inert towards DTPA, it is plausible that silica was closely
associated to other minerals. The removal of the minerals by chelation with DTPA, therefore, reduced the
attachment of the silica bodies to the biomass matrix, resulting in the liberation of silica. The procedure
studied allowed a milder pulping process, eliminating the need for screw pressing, in the case of alkaline
peroxide pulping. The use of DTPA during pulping can be also eliminated.
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