The Effect of Alkali Pretreatment of Rice Straw for Anaerobic Digestion

2011 ◽  
Vol 347-353 ◽  
pp. 2555-2558
Author(s):  
Ping Ai ◽  
Yuan Yuan Wang ◽  
Yan Lin Zhang ◽  
Wu Li ◽  
Shui Ping Yan
Keyword(s):  
Anaerobic Digestion ◽  
Rice Straw ◽  
Crop Residues ◽  
Methane Yield ◽  
Alkali Pretreatment ◽  
Efficient Utilization ◽  
Biogas Yield

The anaerobic digestion is an efficient utilization way of crop residues and alkali pretreatment are often used to enhance the degradation. Alkali pretreatment based on Ca(OH)2addition of rice straw was studied.The tests of 3 g/l, 9 g/l Ca(OH)2 addition had an significant effect on enhancing solubilization and rapid acidification, the results were 1521.2 gCOD/l and 935 ml biogas yield of 3 g/l Ca(OH)2addition, 1600.7 gCOD/l and 1200 ml biogas yield of 9 g/l Ca(OH)2addition , compared to 405.5 gCOD/l and 1162 ml of control( 0 g/l Ca(OH)2addition) . The results also showed that tests of 15 g/l , 21 g/l of Ca(OH)2addition were entirely inhibited to biogas yield. The result of the present work implied that although alkali pretreatment to rice straw can significantly enhance solubilization, the inhibition to methane yield was liable to occur.

Methane potential and biodegradability of rice straw, rice husk and rice residues from the drying process

2012 ◽  
Vol 65 (6) ◽  
pp. 1142-1149 ◽  
Author(s):  
L. M. Contreras ◽  
H. Schelle ◽  
C. R. Sebrango ◽  
I. Pereda
Keyword(s):  
Rice Straw ◽  
Rice Husk ◽  
Crop Residues ◽  
Batch Reactor ◽  
C:N Ratio ◽  
Methane Yield ◽  
Drying Process ◽  
Biogas Yield ◽  
Environmentally Sustainable ◽  
Rice Residues

Agricultural solid residues are a potential renewable energy source. Rice harvesting and production in Sancti Spíritus province, Cuba, currently generates residues without an environmentally sustainable disposal route. Rice residues (rice straw, rice husk and rice residues from the drying process) are potentially an important carbon source for anaerobic digestion. For this paper, rice residues were placed for 36 days retention time in anaerobic batch reactor environments at both mesophilic (37 °C) and thermophilic (55 °C) conditions. Biogas and methane yield were determined as well as biogas composition. The results showed that rice straw as well as rice residues from the drying process had the highest biogas and methane yield. Temperature played an important role in determining both biogas yield and kinetics. In all cases, rice straw produced the highest yields; under mesophilic conditions the biogas yield was 0.43 m3 kgVS−1, under thermophilic conditions biogas yield reached 0.52 m3 kgVS−1. In the case of the rice husk, the biodegradability was very low. Methane content in all batches was kept above 55% vol. All digested material had a high carbon:nitrogen (C:N) ratio, even though significant biodegradation was recorded with the exception of rice husk. A first-order model can be used to describe the rice crop residues fermentation effectively.

scholarly journals Co-Digestion of Rice Straw with Cow Manure in an Innovative Temperature Phased Anaerobic Digestion Technology: Performance Evaluation and Trace Elements

Energies ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2561
Author(s):  
Furqan Muhayodin ◽  
Albrecht Fritze ◽  
Oliver Christopher Larsen ◽  
Marcel Spahr ◽  
Vera Susanne Rotter
Keyword(s):  
Trace Elements ◽  
Anaerobic Digestion ◽  
Greenhouse Gas ◽  
Rice Straw ◽  
Methane Yield ◽  
Methane Formation ◽  
Cow Manure ◽  
Volatile Solids ◽  
Mass Fractions ◽  
Cu And Zn

Rice straw is an agricultural residue produced in abundant quantities. Open burning and plowing back the straw to the fields are common practices for its disposal. In-situ incorporation and burning cause emissions of greenhouse gas and particulate matter. Additionally, the energy potential of rice straw is lost. Anaerobic digestion is a technology that can be potentially used to utilize the surplus rice straw, provide renewable energy, circulate nutrients available in the digestate, and reduce greenhouse gas emissions from rice paddies. An innovative temperature phased anaerobic digestion technology was developed and carried out in a continuous circulating mode of mesophilic and hyperthermophilic conditions in a loop digester (F1). The performance of the newly developed digester was compared with the reference digester (F2) working at mesophilic conditions. Co-digestion of rice straw was carried out with cow manure to optimize the carbon to nitrogen ratio and to provide the essential trace elements required by microorganisms in the biochemistry of methane formation. F1 produced a higher specific methane yield (189 ± 37 L/kg volatile solids) from rice straw compared to F2 (148 ± 36 L/kg volatile solids). Anaerobic digestion efficiency was about 90 ± 20% in F1 and 70 ± 20% in F2. Mass fractions of Fe, Ni, Co, Mo, Cu, and Zn were analyzed over time. The mass fractions of Co, Mo, Cu, and Zn were stable in both digesters. While mass fractions of Fe and Ni were reduced at the end of the digestion period. However, no direct relationship between specific methane yield and reduced mass fraction of Fe and Ni was found. Co-digestion of rice straw with cow manure seems to be a good approach to provide trace elements except for Se.

scholarly journals Mass and Energy Balances of Dry Thermophilic Anaerobic Digestion Treating Swine Manure Mixed with Rice Straw

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Sheng Zhou ◽  
Jining Zhang ◽  
Guoyan Zou ◽  
Shohei Riya ◽  
Masaaki Hosomi
Keyword(s):  
Anaerobic Digestion ◽  
Rice Straw ◽  
Swine Manure ◽  
Rice Production ◽  
Methane Yield ◽  
Manure Treatment ◽  
Thermophilic Anaerobic Digestion ◽  
Forage Rice ◽  
Energy Balances ◽  
Mass And Energy Balances

To evaluate the feasibility of swine manure treatment by a proposed Dry Thermophilic Anaerobic Digestion (DT-AD) system, we evaluated the methane yield of swine manure treated using a DT-AD method with rice straw under different C/N ratios and solid retention time (SRT) and calculated the mass and energy balances when the DT-AD system is used for swine manure treatment from a model farm with 1000 pigs and the digested residue is used for forage rice production. A traditional swine manure treatment Oxidation Ditch system was used as the study control. The results suggest that methane yield using the proposed DT-AD system increased with a higher C/N ratio and shorter SRT. Correspondently, for the DT-AD system running with SRT of 80 days, the net energy yields for all treatments were negative, due to low biogas production and high heat loss of digestion tank. However, the biogas yield increased when the SRT was shortened to 40 days, and the generated energy was greater than consumed energy when C/N ratio was 20:1 and 30:1. The results suggest that with the correct optimization of C/N ratio and SRT, the proposed DT-AD system, followed by using digestate for forage rice production, can attain energy self-sufficiency.

Influence of Total Solid and Stirring Frequency on Performance of Dry Anaerobic Digestion Treating Cattle Manure

2011 ◽  
Vol 79 ◽  
pp. 48-52 ◽  
Author(s):  
Hong Li Li ◽  
Yan Wang
Keyword(s):  
Anaerobic Digestion ◽  
Total Solid ◽  
Performance Parameter ◽  
Cattle Manure ◽  
Methane Yield ◽  
Operational Parameter ◽  
Experimental Procedure ◽  
Methane Generation ◽  
Biogas Yield ◽  
Dry Anaerobic Digestion

The aim of this paper was to analyze the biomethanization process of cattle manure with four different total solid percentages (15%, 20%, 25%, 30% TS) and three different stirring frequency. The experimental procedure was programmed to select the initial performance parameter and the operational parameter in a lab-reactor. The values of VFAs indicated that all the reactors showed no destabilization and at the end of the experiment the VFAs were consumed completely. The best performance for cattle manure biodegradation and methane generation was the reactor with 20% TS, with the biogas yield of 0.22 L/g VS and the methane yield of 0.11 LCH4/g VS. Furthermore, the better operational parameter of stirring frequency was stirring once every two days.

scholarly journals Possibilities of Using White Sweetclover Grown in Mixture with Maize for Biomethane Production

Agronomy ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1407
Author(s):  
Antonín Kintl ◽  
Jakub Elbl ◽  
Tomáš Vítěz ◽  
Martin Brtnický ◽  
Jiří Skládanka ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Plant Biomass ◽  
Arable Land ◽  
Arable Soil ◽  
Biogas Plant ◽  
Methane Yield ◽  
Soil Protection ◽  
Mixed Cropping ◽  
Fermentation Inhibitors ◽  
Biogas Yield

Methods of growing plant biomass for the production of biogas in anaerobic digestion plants have a decisive influence on arable land and on the evaluation of biogas plant technologies from the environmental point of view. The main benefit of anaerobic digestion is the possibility to use various agricultural crops for energy production. Some of these plant species, e.g., legumes, are generally considered to be beneficial for arable soil quality, as compared with maize monocultures with frequently manifested soil degradation and adverse environmental impact on arable land. A possible change is offered by cultivation systems composed of two and more crops and defined as mixed cropping (MC) systems. The systems are characterized by a more efficient utilization of natural resources of the site as well as by a greater potential for arable soil protection. A question remains as to whether the MC system of growing maize and white sweetclover can be used for biogas yield. In the presented research study, a mixed cropping system was tested with maize (Zea mays L.) and white sweetclover (Melilotus albus MED.). The goal of our research was to determine an optimum ratio of maize and white sweetclover (s.c.) shreddings in silage for a biogas plant. For this purpose, model micro-silages of monocultures were prepared: maize (100%), white s.c. (100%), as well as variants with different weight shares of these two crops (maize:white s.c.; 3:7, 1:1, 7:3, 8:2, 8.5:1.5, 9:1). The silages were subjected to biomethanation tests, in order to determine the influence of the increased addition of white s.c. biomass on methane yield and methane concentration in biogas. The highest values of biogas yield were recorded in the maize monoculture and in the MC variant of maize and white s.c. at 9:1 (>0.26 m3/kgVS). The lowest methane yield values were recorded in the white s.c. monoculture (0.16 m3/kgVS). It was found out that the yield of methane decreased with an increasing share of white sweetclover in the maize silage, due to the increased content of poorly degradable organic substances and the presence of fermentation inhibitors (e.g., coumarin).

Enhanced Biogas Production in the Duckweed Anaerobic Digestion Process

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Hongyan Ren ◽  
Nan Jiang ◽  
Tao Wang ◽  
M. Mubashar Omar ◽  
Wenquan Ruan ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Methane Yield ◽  
Mixed Substrates ◽  
Excess Sludge ◽  
Alkali Pretreatment ◽  
Gas Generation ◽  
Digestion Process ◽  
Substrate To Inoculum Ratio ◽  
Group 1

In order to enhance biogas production in the anaerobic digestion of duckweed, and duckweed with excess sludge as single and mixed substrates, the effects of hot alkali pretreatment and variation of the ratio of substrate to inoculum were investigated. The results showed that the delayed stage of anaerobic gas generation could be shortened when the two substrates were mixed during methane production, to give a cumulative gas yield of 2963 mL, which was 11% higher than the calculated value for the complementary substrate. The methane content was 57%, which was 13% higher than that from the duckweed group and 9% higher than from the excess sludge group. Furthermore, the methane yield was improved by 8% after the duckweed was pretreated with hot alkali. When the substrate to inoculum ratio was 1:1, the maximum biogas production of 3309 mL was achieved, with a methane yield of 1883 mL which, respectively, increases of 151 mL and 304 mL compared with the worst group (1:2.5).

scholarly journals Steam Explosion Conditions Highly Influence the Biogas Yield of Rice Straw

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3492 ◽  
Author(s):  
David Steinbach ◽  
Dominik Wüst ◽  
Simon Zielonka ◽  
Johannes Krümpel ◽  
Simon Munder ◽  
...  
Keyword(s):  
Rice Straw ◽  
Steam Explosion ◽  
Reaction Times ◽  
Methane Yield ◽  
Morphological Properties ◽  
Drastic Reduction ◽  
Biogas Yield ◽  
Pretreatment Conditions ◽  
Maximum Temperatures ◽  
Severity Parameter

Straws are agricultural residues that can be used to produce biomethane by anaerobic digestion. The methane yield of rice straw is lower than other straws. Steam explosion was investigated as a pretreatment to increase methane production. Pretreatment conditions with varying reaction times (12–30 min) and maximum temperatures (162–240 °C) were applied. The pretreated material was characterized for its composition and thermal and morphological properties. When the steam explosion was performed with a moderate severity parameter of S0 = 4.1 min, the methane yield was increased by 32% compared to untreated rice straw. This study shows that a harsher pretreatment at S0 > 4.3 min causes a drastic reduction of methane yield because inert condensation products are formed from hemicelluloses.

scholarly journals Utilization of Oak (Quercus petreae (Matt.) Liebl.) Bark for Anaerobic Digested Biogas Production

2017 ◽  
Vol 13 (2) ◽  
pp. 125-134 ◽  
Author(s):  
Ádám Nándor Makk ◽  
Tamás Rétfalvi ◽  
Tamás Hofmann
Keyword(s):  
Anaerobic Digestion ◽  
Anaerobic Fermentation ◽  
Biogas Production ◽  
Methane Yield ◽  
Tree Bark ◽  
Basic Material ◽  
Pedunculate Oak ◽  
Key Factors ◽  
Biogas Yield ◽  
Lignocellulosic Residue

Abstract Fossil fuel depletion has led to an increasing number of research studies and applications focusing on renewable energy, such as different types of biomass. Lignocellulosic biomass represents an abundant source of biomass suitable for energy production in various forms. The present research investigates the application possibility of pedunculate oak bark (Quercus petrea (Matt.) Liebl.) for the production of biogas via anaerobic digestion. This research has significant novelty, as only a few examples on the utilization of tree bark wastes for the production of biogas can be found in the scientific literature. One of the key factors of increasing biogas yield is the efficient hydrolysis of the basic material, which is achieved by different pretreatment methods. In this study, oak bark was pretreated by microwave energy, by extraction, and by the combination of these two methods. The semi-continuous thermophylic anaerobic digestion of untreated oak bark resulted a 76.3 ml/g volatile solid specific methane yield over a 50-day period, which was not significantly lower than methane yield gained from pretreated basic material. Results indicated that oak bark is suitable for the production of biogas even without the application of the investigated pretreatment techniques. As extraction of oak bark does not impair biogas production, the complex biorefinery utilization of oak bark in the form of extraction bark polyphenols and the subsequent anaerobic fermentation of lignocellulosic residue can be accomplished in the future.

scholarly journals Performance and Kinetic Model of a Single-Stage Anaerobic Digestion System Operated at Different Successive Operating Stages for the Treatment of Food Waste

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 600 ◽  
Author(s):  
Sagor Kumar Pramanik ◽  
Fatihah Binti Suja ◽  
Mojtaba Porhemmat ◽  
Biplob Kumar Pramanik
Keyword(s):  
Experimental Data ◽  
Anaerobic Digestion ◽  
Kinetic Model ◽  
Removal Efficiency ◽  
Food Waste ◽  
Biogas Production ◽  
Gompertz Model ◽  
Methane Yield ◽  
Biogas Yield ◽  
Modified Gompertz Model

A large quantity of food waste (FW) is generated annually across the world and results in environmental pollution and degradation. This study investigated the performance of a 160 L anaerobic biofilm single-stage reactor in treating FW. The reactor was operated at different hydraulic retention times (HRTs) of 124, 62, and 35 days under mesophilic conditions. The maximum biogas and methane yield achieved was 0.934 L/g VSadded and 0.607 L CH4/g VSadded, respectively, at an HRT of 124 days. When HRT decreased to 62 days, the volatile fatty acid (VFA) and ammonia accumulation increased rapidly whereas pH, methane yield, and biogas yield decreased continuously. The decline in biogas production was likely due to shock loading, which resulted in scum accumulation in the reactor. A negative correlation between biogas yield and volatile solid (VS) removal efficiency was also observed, owing to the floating scum carrying and urging the sludge toward the upper portion of the reactor. The highest VS (79%) and chemical oxygen demand (COD) removal efficiency (80%) were achieved at an HRT of 35 days. Three kinetic models—the first-order kinetic model, the modified Gompertz model, and the logistic function model—were used to fit the cumulative biogas production experimental data. The kinetic study showed that the modified Gompertz model had the best fit with the experimental data out of the three models. This study demonstrates that the stability and performance of the anaerobic digestion (AD) process, namely biogas production rate, methane yield, intermediate metabolism, and removal efficiency, were significantly affected by HRTs.

Sign in / Sign up

Export Citation Format

Share Document