Catalyzed-Mea conversion of Agro-biomass to paper-pulp: Influence of pulping additives and synergy effect on pulp screened yield

Henry Okwudili Chibudike Henry Okwudili Chibudike,Olubamike Adetutu Adeyoju Olubamike Adetutu Adeyoju,Nkemdilim Ifeanyi Obi Nkemdilim Ifeanyi Obi,Eunice Chinedum Chibudike Eunice Chinedum Chibudike,Nwaebuni Ebube Odega Nwaebuni Ebube Odega

doi:10.30574/wjarr.2021.12.2.0594

Henry Okwudili Chibudike Henry Okwudili Chibudike, Olubamike Adetutu Adeyoju Olubamike Adetutu Adeyoju + Show 3 more

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https://doi.org/10.30574/wjarr.2021.12.2.0594

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Abstract

In this research work, the effect of three (3) pulping additives such as polysulfide, Anthraquinone and surfactant used in the monoethanolamine (MEA) pulping of agro-biomass, their possible interactions and synergy effect on pulp screened yield were investigated. The pulping conditions of the digester were adjusted so that the experimental design considered the following factors and levels: 75% MEA charge, 150oC cooking temperature, 90minutes cooking time, 4 to 1Liquor- Biomass ratio. Factor 1: 0, 0.25 and 0.5% Surfactant charge, Factor 2: 0, 2.0 and 4.0% polysulfide charge, Factor 3: 0, 0.25 and 0.5% anthraquinone charge. The Agro-biomass was evaluated in terms of pulp screened yield. Heating time ranged from 5 to 45minutes and maximum cooking time did not exceed 90minutes, liquor biomass ratio was 4 to 1 and Liquor charge was 75% MEA. The yield for MEA with 4% Polysulfide (PS) dosage without the inclusion of Surfactant and Anthraquinone was highest (59.08%) in all the twenty seven (27) experimental runs, but furnished the highest reject (12.26%) and an unimpressive screened yield of 46.82% standing amongst the least possible outcomes. The yield for MEA with 0.25% Anthraquinone (AQ) dosage without the inclusion of Surfactant and Polysulfide furnished a total yield of 50.32%, pulp screened yield of 50.03% with a minimal reject of 0.29 showing to be more efficient than the use of polysulfide. Monoethanolamine (MEA) pulping with 0.5% surfactant (Surf.) dosage without the inclusion of other additives i.e. AQ and PS achieved 51.12% total screened yield with a reject of only 0.33% furnishing the highest pulp screened yield (50.79%) thereby showing more efficiency amongst the three (3) pulping additives investigated in this research study base on single use. However, the result obtained from the combination of the three (3) pulping additives furnished the highest screened yield (52.43) with 4.23% reject in scenario E, experiment No. 15, involving the combination of 0.25% surfactant, 0.25% anthraquinone and 4% polysulfide charge showing the best synergistic effect. Although the highest screened yield (53.04% and the least reject (0.13%) indicating the best possible outcome amongst the entire twenty seven (27) experimental runs came from the combination of 0.25% surfactant and 2% polysulfide charge. If we have to consider the use of surfactant and polysulfide alone, the best possible outcome came from the combination of 0.25% surfactant and 2% polysulfide charge in experiment 20 of scenario G. Analyses of the overall experimental results show that there is considerable advantage and a positive synergy effect in the use of additives in pulping operation.

Highlights

Pulping is a process where the wood chips or other fibrous raw materials are ruptured mechanically, thermally, chemically or combinations of these treatments into a fibrous mass which known is as pulp
Data were analysed by the analysis of variance (ANOVA), and p- value lower than 0.05 was considered significant in surface response analysis
The fact that palm trees are grown in the southern part of Nigeria and EFB which is the by-product of palm oil extraction process is produced in abundance as waste materials puts it in a position of advantage over some other raw material sources for paper production

Summary

Introduction

Pulping is a process where the wood chips or other fibrous raw materials are ruptured mechanically, thermally, chemically or combinations of these treatments into a fibrous mass which known is as pulp. Chemical pulping is a process where the wood chips or fibrous raw materials are cooked in an aqueous solution at elevated temperatures and pressure with appropriate chemicals. The chemical pulping methods can be classified into two major principles namely; alkaline such as kraft process and soda process and acidic such as sulfite and bisulfite process. The air pollution from the kraft pulping is a major concern with the emission of sulphur gases into the atmosphere with a rate of 0.3-3 kilograms per metric tonne (kg/t) of air-dried pulp (ADP) [3]. Strongly alkaline cooking liquors dissolve carbohydrates to a great extent with negative impact on pulp yield. Most annual plants have a high content of silica, which is dissolved to a high extent in the strongly alkaline cooking liquor and creates serious problems in the evaporators, the recovery boilers and in the causticizing plant [4, 5 and 6]

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