Alkaline hydrogen peroxide pretreatment of energy crops for biogas production

2014 ◽  
Vol 68 (7) ◽  
Author(s):  
Karina Michalsk ◽  
Stanisław Ledakowicz
Keyword(s):  
Hydrogen Peroxide ◽  
Biogas Production ◽  
Energy Crops ◽  
Alkaline Hydrogen Peroxide ◽  
High Concentration ◽  
H2o2 Decomposition ◽  
Miscanthus Giganteus ◽  
Alkaline Conditions ◽  
Plant Sources ◽  
H2o2 Pretreatment

AbstractIn this study, the influence of alkaline hydrogen peroxide (H2O2) pretreatment of the three different plant sources: Miscanthus giganteus, Sorghum Moench, and Sida hermaphrodita, for biogas production was investigated. The influence of temperature, reaction time, and H2O2 concentration on the efficiency of biomass degradation and on the further methanogenic fermentation were studied. The results obtained after chemical pretreatment indicate that using H2O2 at alkaline conditions leads to the decomposition of three major structures: lignin, hemicellulose, and cellulose. The best results were achieved for the process performed at 25°C for 24 h with the use of a 5 mass % H2O2 solution. Although the degradation level was very high for all three plant sources, the biogas production from the energy crops pretreated chemically was strongly inhibited by byproducts and the residual oxygen formed after H2O2 decomposition. This fact indicates that alkaline H2O2 pretreatment is a very promising method for plant material degradation for further biogas production, but pretreated biomass must be separated from supernatant before the fermentation process because of the high concentration of inhibitors in the hydrolysates. The best results were obtained for Sida with biogas and methane production of 2.29 Ndm3 and 1.06 Ndm3, respectively.

scholarly journals Enhanced effects of reducing agent on oxalate chelated Fe(II) catalyzed percarbonate system for benzene degradation

2021 ◽  
Author(s):  
Xiaori Fu ◽  
Xinyan Wei ◽  
Wei Zhang ◽  
Wupeng Yan ◽  
Peng Wei ◽  
...  
Keyword(s):  
Hydroxylamine Hydrochloride ◽  
Reducing Agent ◽  
Sodium Ascorbate ◽  
High Concentration ◽  
H2o2 Decomposition ◽  
Benzene Degradation ◽  
Benzene Removal ◽  
Alkaline Conditions ◽  
Negative Effect ◽  
Neutral Conditions

Abstract The addition of hydroxylamine hydrochloride (HAH), ascorbic acid (ASC), sodium ascorbate (SAS) to the OA-Fe(II)/SPC system could promote the generation of HO• by accelerating Fe(II)/Fe(III) recycles and H2O2 decomposition. The enhancement of HAH on HO• generation surpasses ASC and SAS in the OA-Fe(II)/SPC system. The generation of O2•− was also enhanced by HAH, ASC and SAS, and more significant promotion of O2•− generation was observed with ASC and SAS addition. More effective benzene removal was achieved in an OA-Fe(II)/SPC system with suitable HAH, ASC and SAS addition, compared to the parent system. Excessive HAH, ASC or SAS had a negative effect on benzene removal. Results of scavenger tests showed that HO• is indeed the dominant free radical for benzene removal in every system, but the addition of HAH, ASC and SAS increased the contribution of O2•− to benzene degradation. HAH, ASC and SAS enhanced OA-Fe(II)/SPC systems could be well utilized to acidic and neutral conditions, while HCO3−, high concentration of HA and alkaline conditions were not favorable to benzene removal. Moreover, the addition of HAH, ASC and SAS are conducive to benzene removal in actual groundwater, and HAH was the optimal reducing agent for the enhancement of the OA-Fe(II)/SPC system.

scholarly journals Influence of a Polycarboxylate Based Solution on Stability of Hydrogen Peroxide and Application to E-waste Leaching

2020 ◽  
Vol 26 (1) ◽  
pp. 17-23
Author(s):  
Ersin Y. Yazici
Keyword(s):  
Hydrogen Peroxide ◽  
Printed Circuit Boards ◽  
Catalytic Decomposition ◽  
Copper Extraction ◽  
Circuit Boards ◽  
H2o2 Decomposition ◽  
Printed Circuit ◽  
High Consumption ◽  
Alkaline Conditions ◽  
Extraction Of Metals

Hydrogen peroxide with its high oxidising potential is commonly used in hydrometallurgical extraction of metals from ores, anode slimes and waste materials (e.g. WEEE) and treatment of cyanidation effluents. Main detraction to H2O2 is its rapid catalytic decomposition leading to prohibitively high consumption. Effect of pH (0-4), Cu(II) (0-10 g.l-1) and temperature (20-80°C) on H2O2 stability was investigated using response surface methodology. Influence of neutral-alkaline conditions (pH 7.3-11.8) and presence of solids (1-20% w/v) was also tested. A polycarboxylate based solution (PBS) was utilised to improve H2O2 stabilisation. The significance order of parameters on H2O2 decomposition was temperature > pH > Cu(II). Elevating the level of these parameters increased H2O2 decomposition. The activation energy (60.7±2.5 kJ.mol-1) indicated a chemically controlled process. Alkaline conditions (up to pH 11.8) led to higher H2O2 decomposition. Presence of solids adversely affected H2O2 stability under certain conditions. The addition of PBS significantly improved (up to 54%) H2O2 stability in the presence of copper. The presence of PBS in H2SO4-H2O2 leaching of waste of printed circuit boards (WPCBs) enhanced copper extraction by up to 19%. PBS can be suitably utilised to stabilise and hence reduce H2O2 consumption in aqueous solutions particularly in the presence of copper.

scholarly journals Alkaline Hydrogen Peroxide Pretreatment of Cladodes of Cactus (Opuntia Ficus-Indica) for Biogas Production

Heliyon ◽  
2021 ◽  
pp. e08002
Author(s):  
Jemal Beshir Belay ◽  
Nigus Gabbiye Habtu ◽  
Venkata Ramayya Ancha ◽  
Ali Seid Hussen
Keyword(s):  
Hydrogen Peroxide ◽  
Biogas Production ◽  
Alkaline Hydrogen Peroxide ◽  
Opuntia Ficus Indica

Effect of thermal and alkaline pretreatment of giant miscanthus and Chinese fountaingrass on biogas production

2015 ◽  
Vol 73 (4) ◽  
pp. 849-856 ◽  
Author(s):  
Valentine Nkongndem Nkemka ◽  
Yongqiang Li ◽  
Xiying Hao
Keyword(s):  
Soil Conservation ◽  
Biogas Production ◽  
Energy Crops ◽  
Alkaline Pretreatment ◽  
Untreated Sample ◽  
Naoh Pretreatment ◽  
Miscanthus Giganteus ◽  
Volatile Solids ◽  
Giant Miscanthus ◽  
Pennisetum Alopecuroides

Giant miscanthus (Miscanthus×giganteus) and Chinese fountaingrass (Pennisetum alopecuroides (L.) Spreng), cultivated for landscaping and soil conservation, are potential energy crops. The study investigated the effect of combined thermal and alkaline pretreatments on biogas production of these energy crops. The pretreatment included two types of alkali (6% CaO and 6% NaOH) at 22, 70 and 100 °C. The alkaline pretreatment resulted in a greater breakdown of the hemicellulose fraction, with CaO more effective than NaOH. Pretreatment of giant miscanthus with 6% CaO at 100 °C for 24 h produced a CH4 yield (313 mL g−1 volatile solids (VS)) that was 1.7 times that of the untreated sample (186 mL g−1 VS). However, pretreatment of Chinese fountaingrass with 6% CaO or 6% NaOH at 70 °C for 24 h resulted in similar CH4 yields (328 and 302 mL g−1 VS for CaO and NaOH pretreatments) as the untreated sample (311 mL g−1 VS). Chinese fountaingrass was more easily digestible but had a low overall CH4 yield per hectare (1,831 m3 ha−1 y−1) compared to giant miscanthus (6,868 m3 ha−1 y−1). This study demonstrates the potential of thermal/alkaline pretreatment and the use of giant miscanthus and Chinese fountaingrass for biogas production.

The behavior of chromophoric structures in softwood mechanical pulp on bleaching with alkaline hydrogen peroxide

2006 ◽  
Vol 21 (3) ◽  
pp. 359-364 ◽  
Author(s):  
Eva Svensson Rundlöf ◽  
Eric Zhang ◽  
Liming Zhang ◽  
Göran Gellerstedt
Keyword(s):  
Hydrogen Peroxide ◽  
Alkaline Hydrogen Peroxide ◽  
Mechanical Pulp

scholarly journals Au Modified F-TiO2 for Efficient Photocatalytic Synthesis of Hydrogen Peroxide

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3844
Author(s):  
Lijuan Li ◽  
Bingdong Li ◽  
Liwei Feng ◽  
Xiaoqiu Zhang ◽  
Yuqian Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction System ◽  
Reaction Medium ◽  
Pure Tio2 ◽  
H2o2 Production ◽  
Tio2 Photocatalyst ◽  
H2o2 Decomposition ◽  
Spin Resonance ◽  
Photocatalytic Synthesis

In this work, Au-modified F-TiO2 is developed as a simple and efficient photocatalyst for H2O2 production under ultraviolet light. The Au/F-TiO2 photocatalyst avoids the necessity of adding fluoride into the reaction medium for enhancing H2O2 synthesis, as in a pure TiO2 reaction system. The F− modification inhibits the H2O2 decomposition through the formation of the ≡Ti–F complex. Au is an active cocatalyst for photocatalytic H2O2 production. We compared the activity of TiO2 with F− modification and without F− modification in the presence of Au, and found that the H2O2 production rate over Au/F-TiO2 reaches four times that of Au/TiO2. In situ electron spin resonance studies have shown that H2O2 is produced by stepwise single-electron oxygen reduction on the Au/F-TiO2 photocatalyst.

A review of lignin hydrogen peroxide oxidation chemistry with emphasis on aromatic aldehydes and acids

Holzforschung ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ajinkya More ◽  
Thomas Elder ◽  
Zhihua Jiang
Keyword(s):  
Hydrogen Peroxide ◽  
Oxidative Degradation ◽  
Reaction Medium ◽  
Dicarboxylic Acids ◽  
Aromatic Aldehydes ◽  
Product Distribution ◽  
Reaction Conditions ◽  
Alkaline Conditions ◽  
The Stability ◽  
Oxidation Chemistry

Abstract This review discusses the main factors that govern the oxidation processes of lignins into aromatic aldehydes and acids using hydrogen peroxide. Aromatic aldehydes and acids are produced in the oxidative degradation of lignin whereas mono and dicarboxylic acids are the main products. The stability of hydrogen peroxide under the reaction conditions is an important factor that needs to be addressed for selectively improving the yield of aromatic aldehydes. Hydrogen peroxide in the presence of heavy metal ions readily decomposes, leading to minor degradation of lignin. This degradation results in quinones which are highly reactive towards peroxide. Under these reaction conditions, the pH of the reaction medium defines the reaction mechanism and the product distribution. Under acidic conditions, hydrogen peroxide reacts electrophilically with electron rich aromatic and olefinic structures at comparatively higher temperatures. In contrast, under alkaline conditions it reacts nucleophilically with electron deficient carbonyl and conjugated carbonyl structures in lignin. The reaction pattern in the oxidation of lignin usually involves cleavage of the aromatic ring, the aliphatic side chain or other linkages which will be discussed in this review.

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