Total Chlorine-Free Bleaching ofPopulus deltoidesKraft Pulp by Oxone

Abstract

Since the bleaching process is one of the most important environmental pollutant stages in the pulp and paper industry, here, the total chlorine-free (TCF) bleaching of poplar kraft pulp by applying Oxone and peroxide under alkaline conditions has been investigated. The pulp samples were bleached in two stages of Oxone (O X ) treatment using an AO X1 O X2 sequence (A: acid pretreatment), and then the treated pulps were bleached by peroxide (P) to achieve target brightness (about 80%). The influence of various reaction parameters such as alkali charge, temperature, reaction time, and bleaching agent dosage was optimized. The final achieved brightness was more than 78%. Accelerated aging experiments showed more stability in brightness for the Oxone treated pulp, because alkali Oxone bleaching stops thermal degradation. Similarly, the AO X1 O X2 P bleaching sequence was found to be effective in regaining some strength that had been lost during acidification of the pulp. Improvement in pulp strength made with acid treatment was achieved along with significant amount of lignin removal and it demonstrates the feasibility of Oxone in TCF bleaching. Furthermore, other results indicated the feasibility of Oxone bleaching as an environmentally favorable alternative TCF bleaching sequence, compared with elemental chlorine-free bleaching approaches and also other TCF bleaching sequences.

Isolation and characterization of lignin-degrading bacterium Bacillus aryabhattai from pulp and paper mill wastewater and evaluation of its lignin-degrading potential

“…This eliminates bleaching with elemental chlorine that releases dioxins and furans into the environment. This also fulfills the market demand of non-chlorine based chemical bleached pulp (Miri et al 2015;Yaqoob et al 2010Yaqoob et al , 2011.…”

“…An increased use of TCF bleaching was expected worldwide especially outside of Europe. However, TCF is currently used in few countries only, accounting 5% of the total bleached pulp production worldwide in 2010 because of low market uptake, higher bleaching cost, lower pulp strength, reduction in the removal of hexenuronic acid, and more brightness reversion compared to the elemental chlorinefree bleached pulp (Miri et al 2015). Thus, it is necessary to adequately treat the generated wastewaters before its final discharge into the environment.…”

Valorization of orange bagasse through one‐step physical and chemical combined processes to obtain a cellulose‐rich material

“…Considering the heterogeneity of the lignocellulosic materials, it is challenging to generalize treatments for cellulose extraction from these materials and, in the past decade, there has been an increasing interest in the use of less polluting methods, employing totally chlorine‐free processes with nonchlorine chemicals. Non‐chlorine reagents have been used successfully in the delignification of wood lignocellulose and agro‐industrial wastes 19–21 . Peroxide and peroxy acids in combination with physical and chemical processes comprises a strategy to reduce the energy consumption and overall processing costs with respect to producing commercially competitive cellulose 17–22,23 …”

Using Oxone and TAED activator in non-chlorine bleaching of soda bagasse pulp

“…These components produce new bleaching agents with higher oxidative capacity, which improve the bleaching process in lower retention times and temperatures (Khristova et al 2003). Peroxide activators include ammonium molybdate, sodium nonanoyloxy benzene sulfonate (NOBS), polypyridines, peracids, oxone and tetra acetyl ethylene diamine (TAED) (Khristova et al 2003, Zeinaly et al 2013, Jafari et al 2014, Miri et al 2015.…”