Enhanced separation of cellulose from bamboo with a combined process of steam explosion pretreatment and alkaline-oxidative cooking

2020 ◽  
Vol 35 (3) ◽  
pp. 386-399
Author(s):  
Hongxia Lu ◽  
Xiaoyu Lin ◽  
Beihai He ◽  
Lihong Zhao
Keyword(s):  
Steam Explosion ◽  
Oxygen Demand ◽  
Raw Material ◽  
Pollution Level ◽  
Lignin Removal ◽  
Platform Chemicals ◽  
Steam Explosion Pretreatment ◽  
Bamboo Fibers ◽  
Spent Liquor ◽  
Total Lignin

AbstractA synergistic process with steam explosion pretreatment (SEP) followed by sodium carbonate-oxygen cooking (SCOC) upon bamboo was evaluated for its effect on separating hemicellulose and lignin from bamboo while preserving cellulose, providing cellulose substrate susceptible to chemicals in producing platform chemicals such as levulinic acid. The results showed that through the SEP with 2.5 MPa for 10 min, the hemicellulose content reduced by 60.85 %, the specific surface area of bamboo fiber increased to 1.9494 m2g-1 from 0.8061 m2g-1 of raw material. The synergistic SEP-SCOC significantly removed 73.33 % lignin, and yielded 73.9 % cellulose under the optimal condition of SEP with 2.5 MPa for 10 min and followed by SCOC with 30 % total titratable alkali (TTA) at 180 °C for 2 h and 2 MPa oxygen pressure. The results also proved the total lignin removal was improved by 8.07–18.95 % for the steam exploded bamboo fibers than the untreated one, indicating SEP increased the accessibility of cooking reagents to fibre during subsequent SCOC process. Furthermore, the low value of biological oxygen demand (BOD) and chemical oxygen demand (COD) in the final spent liquor indicated the lower pollution level of the process.

Steam Explosion Pretreatment and Ethanol Extraction of Wheat Straw

2011 ◽  
Vol 183-185 ◽  
pp. 635-638
Author(s):  
Lan Feng Hui ◽  
Ting Zhao ◽  
Chuan Ling Si ◽  
Zhong Liu
Keyword(s):  
Wheat Straw ◽  
Steam Explosion ◽  
High Performance ◽  
Reaction Times ◽  
Raw Material ◽  
Pulp Yield ◽  
Agricultural Residue ◽  
Steam Explosion Pretreatment ◽  
Different Temperatures ◽  
Chemical Products

It has been increasing the interest in the study of alternative pulping processes that conciliate high performance and protection to the environment. In the same way, the use of agricultural residues has been more and more reminded as promising raw material for production of bioethanol and chemical products. The wheat straw is a very abundant agricultural residue and it has been used in many countries for the production of cellulosic pulps. This work describes the effect of the pretreatment by steam explosion on the ethanol-water extraction of wheat straw. The samples of wheat straw were treated by steam explosion at 190°C and 210 °C for 4 minutes and later transferred to the treatment with ethanol-water (1:1, v:v) at different temperatures (140, 160 and 200 °C) and 60 minutes as reaction times. The pretreatment led to an increase in the amount of extracted lignin in the ethanol pulping. This effect was more pronounced in the pulping performed at lower temperatures. The use of higher temperatures in the treatment by steam explosion was more significant as shown by lower pulp yield and higher extractive extent.

Environmental benefits of magnesium hydroxide-based peroxide bleaching of mechanical pulp – mill results

TAPPI Journal ◽  
2013 ◽  
Vol 12 (6) ◽  
pp. 9-15 ◽  
Author(s):  
TOMI HIETANEN ◽  
JUHA TAMPER ◽  
KAJ BACKFOLK
Keyword(s):  
Sodium Hydroxide ◽  
Magnesium Hydroxide ◽  
Oxygen Demand ◽  
Pulp Mill ◽  
Transition Metal Ions ◽  
Environmental Benefits ◽  
Raw Material ◽  
Paper Machine ◽  
High Brightness ◽  
Peroxide Bleaching

The use of a new, technical, high-purity magnesium hydroxide-based peroxide bleaching additive was evaluated in full mill-scale trial runs on two target brightness levels. Trial runs were conducted at a Finnish paper mill using Norwegian spruce (Picea abies) as the raw material in a conventional pressurized groundwood process, which includes a high-consistency peroxide bleaching stage. On high brightness grades, the use of sodium-based additives cause high environmental load from the peroxide bleaching stage. One proposed solution to this is to replace all or part of the sodium hydroxide with a weaker alkali, such as magnesium hydroxide. The replacement of traditional bleaching additives was carried out stepwise, ranging from 0% to 100%. Sodium silicate was dosed in proportion to sodium hydroxide, but with a minimum dose of 0.5% by weight on dry pulp. The environmental effluent load from bleaching of both low and high brightness pulps was significantly reduced. We observed a 35% to 48% reduction in total organic carbon (TOC), 37% to 40% reduction in chemical oxygen demand (COD), and 34% to 60% reduction in biological oxygen demand (BOD7) in the bleaching effluent. At the same time, the target brightness was attained with all replacement ratios. No interference from transition metal ions in the process was observed. The paper quality and paper machine runnability remained good during the trial. These benefits, in addition to the possibility of increasing production capacity, encourage the implementation of the magnesium hydroxide-based bleaching concept.

scholarly journals An extensive parameter study of hydrotropic extraction of steam-pretreated birch

2021 ◽  
Author(s):  
Johanna Olsson ◽  
Michael Persson ◽  
Mats Galbe ◽  
Ola Wallberg ◽  
Ann-Sofi Jönsson
Keyword(s):  
Residence Time ◽  
Steam Explosion ◽  
Room Temperature ◽  
Initial Step ◽  
Parameter Study ◽  
Hydrothermal Degradation ◽  
Steam Explosion Pretreatment ◽  
Lignin Extraction ◽  
Extraction Step ◽  
Lignin Recovery

AbstractEfficient fractionation of lignocellulosic biomass is an important step toward the replacement of fossil-based products. However, the utilisation of all of the components in biomass requires various fractionation techniques. One promising process configuration is to apply steam explosion for the recovery of hemicelluloses and a subsequent hydrotropic extraction step for the delignification of the remaining solids. In this work, the influence of residence time, temperature and biomass loading on lignin recovery from birch using sodium xylene sulphonate as a hydrotrope was investigated. Our results show that residence time, temperature and biomass loading correlate positively with lignin extraction, but the effects of these parameters were limited. Furthermore, when steam explosion was implemented as the initial step, hydrotropic extraction could be performed even at room temperature, yielding a lignin extraction of 50%. Also, hydrothermal degradation of the material was necessary for efficient delignification with sodium xylene sulphonate, regardless of whether it occurs during steam explosion pretreatment or is achieved at high temperatures during the hydrotropic extraction.

scholarly journals Phytoremediation Potential of Vetiver System Technology for Improving the Quality of Palm Oil Mill Effluent

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Negisa Darajeh ◽  
Azni Idris ◽  
Paul Truong ◽  
Astimar Abdul Aziz ◽  
Rosenani Abu Bakar ◽  
...  
Keyword(s):  
Palm Oil ◽  
Oxygen Demand ◽  
Raw Material ◽  
Biofuel Production ◽  
Palm Oil Mill Effluent ◽  
System Technology ◽  
High Concentration ◽  
Low Concentration ◽  
Control Sets ◽  
Palm Oil Mill

Palm oil mill effluent (POME), a pollutant produced by the palm oil industry, was treated by the Vetiver system technology (VST). This technology was applied for the first time to treat POME in order to decrease biochemical oxygen demand (BOD) and chemical oxygen demand (COD). In this study, two different concentrations of POME (low and high) were treated with Vetiver plants for 2 weeks. The results showed that Vetiver was able to reduce the BOD up to 90% in low concentration POME and 60% in high concentration POME, while control sets (without plant) only was able to reduce 15% of BOD. The COD reduction was 94% in low concentration POME and 39% in high concentration POME, while control just shows reduction of 12%. Morphologically, maximum root and shoot lengths were 70 cm, the number of tillers and leaves was 344 and 86, and biomass production was 4.1 kg m−2. These results showed that VST was effective in reducing BOD and COD in POME. The treatment in low concentration was superior to the high concentration. Furthermore, biomass of plant can be considered as a promising raw material for biofuel production while high amount of biomass was generated in low concentration of POME.

Anaerobic treatment of residual lemon pulp in digesters with semi-continuous feed

2013 ◽  
Vol 67 (3) ◽  
pp. 514-520
Author(s):  
A. R. Navarro ◽  
Z. Lopez ◽  
J. Salguero ◽  
M. C. Maldonado
Keyword(s):  
Industrial Waste ◽  
Animal Feed ◽  
Oxygen Demand ◽  
Anaerobic Treatment ◽  
Raw Material ◽  
Comparative Tests ◽  
Economic Problems ◽  
The North ◽  
Potential Applications ◽  
Continuous Feed

Lemon growing areas in the north of Argentina have industries that produce concentrated juice, peel and essential oil and generate a significant amount of liquid and solid waste as lemon pulp. In Argentina, despite the potential applications that the pulp has as animal feed and human and industrial raw material, only 10% is used for these purposes and the rest is discarded into the environment causing many ecological and economic problems. There is little information in the literature on biotechnologies for the treatment of this industrial waste. This paper shows that lemon pulp is a suitable substrate to be treated by anaerobic digestion. We obtained 86 and 92% reduction of chemical oxygen demand in a digester with a semi-continuous feed and retention time of 10 and 20 days respectively and a productivity of 0.406 g CH4/g VS h. Comparative tests showed that pre-digesting the pulp improved the process of digestion and increased biogas generation by 20%.

scholarly journals Red Mud-Based Polyaluminum Ferric Chloride Flocculant: Preparation, Characterization and Flocculation Performance

2021 ◽  
Author(s):  
Yong Cheng ◽  
Longjun Xu ◽  
Chenglun Liu ◽  
Zao Jiang ◽  
Qiyuan Zhang ◽  
...  
Keyword(s):  
Red Mud ◽  
High Efficiency ◽  
Low Cost ◽  
Oxygen Demand ◽  
Industrial Applications ◽  
Iron Chloride ◽  
Raw Material ◽  
Molar Ratio ◽  
Polymerization Temperature ◽  
Solution Ph

Abstract In this work, red mud was used as raw material to extract Al and Fe with hydrochloric acid. The high-efficiency polyaluminum iron chloride (PAFC) flocculant was prepared via adjusting the pH of the leaching solution, the molar ratio of aluminum and iron, and the polymerization temperature. The effect of synthesis and flocculation conditions on the flocculation performance of aged landfill leachate was investigated. The results confirmed that the PAFC prepared at the polymerization pH of 2.5, the Al/Fe molar ratio of 8, and the polymerization temperature of 70 °C had the optimum flocculation effect. The flocculation consequences of PAFC and commercial polyaluminum iron chloride flocculant (CPAFC) under different flocculation conditions were compared. The chemical oxygen demand (COD), UV254, chroma and settlement height of PAFC at flocculant concentration of 60 g/L and solution pH of 6 were 72.2%, 79.2%, 82.9% and 9.5 cm (within 90 min), respectively. PAFC has excellent flocculation performance and can be used as a simple, potentially low-cost wastewater treatment agent in industrial applications.

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