Pulp and paper
Farzaneh Shiralizadeh; Sahab Hejazi; Mohammad Ahmadi
Abstract
In this research, rice straw was used as raw material. Potassium hydroxide was combined with monoethanolamine (MEA) as liquor. In another processes NaOH/Na2So3, KOH/K2So3 and KOH 14% was used as references pulp. The results showed that using pure MEA(15%) produced the highest yield and the highest kappa ...
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In this research, rice straw was used as raw material. Potassium hydroxide was combined with monoethanolamine (MEA) as liquor. In another processes NaOH/Na2So3, KOH/K2So3 and KOH 14% was used as references pulp. The results showed that using pure MEA(15%) produced the highest yield and the highest kappa number. By using potassium hydroxide as a additive agent in MEA pulping, the amount of reject, yield and kappa number was decreased and the lowest yield and the lowest kappa number relevant to MEA(15%) combined with KOH (40%). In addition, in KOH pulping observed that, with increasing concentration of MEA, as additive agent, the amount of total yield increased but the kappa number and reject content was decreased. Results showed that the highest tensile index and tear index were relevant to MEA (15%) combined with KOH (20%) and the highest burs index relevant to NaOH/Na2SO3 treatment. According to the optical properties, it was found that the highest brightness was achieved in K2SO3/KOH. The highest opacity relevant to the KOH14% .The result shows that MEA process in combined with Potassium hydroxide can be done success fully on rice straw and properties of pulp production, specially in aspect of mechanical strength, in term of combination is superior than soda and Potassium hydroxide process
Somayeh Ghasemi; Rabie Behroz
Abstract
Using high consistency pulp especially in bleaching plant is highly attractive due to considerable reduction in energy and water consumptions and low effluent volume. This research investigates the effect of consistency CMP pulp on bleaching by hydrogen peroxide. For this purpose, unbleached mixed hardwood ...
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Using high consistency pulp especially in bleaching plant is highly attractive due to considerable reduction in energy and water consumptions and low effluent volume. This research investigates the effect of consistency CMP pulp on bleaching by hydrogen peroxide. For this purpose, unbleached mixed hardwood CMP pulp of Mazandaran wood and paper CO. mill was used. Bleaching was carried out with QP sequences. Pretreatment or Q stage was carried out by DTPA as a chelating agent for removing transition metals. Chelating stage had a similar condition for all pulps. bleaching with hydrogen peroxide was carried out in three levels of hydrogen peroxide 2, 3, 4% and proportion NaOH to H2O2: 0.8, 0.7, 0.6 by adding 3% sodium silicate in 70˚C and 150min at four consistency level (10, 15, 25 and 30%). After bleaching, handsheets were made with grammage 60gr/m2 from bleached pulp. The experimental results showed that high brightness and opacity and lower yellowness was obtained at 30% consistency by 2 and 3% peroxide charge. However, by using 4% hydrogen peroxide, higher brightness and lower yellowness attained at 25% consistency. Brightness is increased continuously by increasing consistency from 10 to 30% at 2, 3% peroxide. But at 4% peroxide charge, brightness is increased from 10, 15 and 25%, and then at 30% consistency is decreased significantly. Also under conditioning of 2% peroxide and 30% consistency and 2% peroxide at 25% consistency can obtain similar brightness to 3% peroxide and 25% consistency and 4% peroxide at 10% consistency. That it means of 25, 30% decrease in consumption peroxide and sodium hydroxide.
