scholarly journals Processing High-Solid and High-Ammonia Rich Manures in a Two-Stage (Liquid-Solid) Low-Temperature Anaerobic Digestion Process: Start-Up and Operating Strategies

2020 ◽  
Vol 7 (3) ◽  
pp. 80 ◽  
Author(s):  
Prativa Mahato ◽  
Bernard Goyette ◽  
Md. Saifur Rahaman ◽  
Rajinikanth Rajagopal
Keyword(s):  
Anaerobic Digestion ◽  
Energy Demand ◽  
Biogas Production ◽  
Oxygen Demand ◽  
High Energy ◽  
Poultry Production ◽  
Livestock Farming ◽  
Two Stage ◽  
Batch Mode ◽  
Digestion Process

Globally, livestock and poultry production leads to total emissions of 7.1 Gigatonnes of CO2-equiv per year, representing 14.5% of all anthropogenic greenhouse gas emissions. Anaerobic digestion (AD) is one of the sustainable approaches to generate methane (CH4) from manure, but the risk of ammonia inhibition in high-solids AD can limit the process. Our objective was to develop a two-stage (liquid–solid) AD biotechnology, treating chicken (CM) + dairy cow (DM) manure mixtures at 20 °C using adapted liquid inoculum that could make livestock farming more sustainable. The effect of organic loading rates (OLR), cycle length, and the mode of operation (particularly liquid inoculum recirculation-percolation mode) was evaluated in a two-stage closed-loop system. After the inoculum adaptation phase, aforementioned two-stage batch-mode AD operation was conducted for the co-digestion of CM + DM (Total Solids (TS): 48–51% and Total Kjeldahl Nitrogen (TKN): 13.5 g/L) at an OLR of 3.7–4.7 gVS/L.d. Two cycles of different cycle lengths (112-d and 78-d for cycles 1 and 2, respectively) were operated with a CM:DM mix ratio of 1:1 (w/w) based on a fresh weight basis. Specific methane yield (SMY) of 0.35 ± 0.11 L CH4g/VSfed was obtained with a CH4 concentration of above 60% for both the cycles and Soluble Chemical Oxygen Demand (CODs) and volatile solid (VS) reductions up to 85% and 60%, respectively. For a comparison purpose, a similar batch-mode operation was conducted for mono-digestion of CM (TS: 65–73% and TKN: 21–23 g/L), which resulted in a SMY of 0.52 ± 0.13 L CH4g/VSfed. In terms of efficiency towards methane-rich biogas production and ammonia inhibitions, CM + DM co-digestion showed comparatively better quality methane and generated lower free ammonia than CM mono-digestion. Further study is underway to optimize the operating parameters for the co-digestion process and to overcome inhibitions and high energy demand, especially for cold countries.

scholarly journals Feasibility of Coupling Anaerobic Digestion and Hydrothermal Carbonization: Analyzing Thermal Demand

2021 ◽  
Vol 11 (24) ◽  
pp. 11660
Author(s):  
Rubén González ◽  
Marcos Ellacuriaga ◽  
Alby Aguilar-Pesantes ◽  
Daniela Carrillo-Peña ◽  
José García-Cascallana ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Energy Demand ◽  
Biological Process ◽  
Biogas Production ◽  
Hydrothermal Carbonization ◽  
Energy Performance ◽  
High Energy ◽  
Subsequent Treatment ◽  
Treatment Unit ◽  
Pre Treatment

Anaerobic digestion is a biological process with wide application for the treatment of high organic-containing streams. The production of biogas and the lack of oxygen requirements are the main energetic advantages of this process. However, the digested stream may not readily find a final disposal outlet under certain circumstances. The present manuscript analyzed the feasibility of valorizing digestate by the hydrothermal carbonization (HTC) process. A hypothetical plant treating cattle manure and cheese whey as co-substrate (25% v/w, wet weight) was studied. The global performance was evaluated using available data reported in the literature. The best configuration was digestion as a first stage with the subsequent treatment of digestate in an HTC unit. The treatment of manure as sole substrate reported a value of 752 m3/d of biogas which could be increased to 1076 m3/d (43% increase) when coupling an HTC unit for digestate post-treatment and the introduction of the co-substrate. However, the high energy demand of the combined configurations indicated, as the best alternative, the valorization of just a fraction (15%) of digestate to provide the benefits of enhancing biogas production. This configuration presented a much better energy performance than the thermal hydrolysis pre-treatment of manure. The increase in biogas production does not compensate for the high energy demand of the pre-treatment unit. However, several technical factors still need further research to make this alternative a reality, as it is the handling and pumping of high solid slurries that significantly affects the energy demand of the thermal treatment units and the possible toxicity of hydrochar when used in a biological process.

scholarly journals Green biomass to biogas – A study on anaerobic monodigestion of para grass

2019 ◽  
Vol 1 (3) ◽  
pp. 32-38
Author(s):  
Ajcharapa Chuanchai ◽  
Sawitree Tipnee ◽  
Yuwalee Unpaprom ◽  
Keng-Tung Wu
Keyword(s):  
Anaerobic Digestion ◽  
Energy Demand ◽  
Biogas Production ◽  
Sustainable Energy ◽  
High Energy ◽  
Environmental Concerns ◽  
Chemical Pretreatment ◽  
Good Source ◽  
Biogas Yield ◽  
The Moment

Recently, biogas production through anaerobic digestion technology has advanced massively. At the moment, caused by high energy demand and environmental concerns as the world’s population increases, the drive for anaerobic digestion processes is achievement drive within research and the industry for sustainable energy generation. The study evaluated biogas production from anaerobic mono-digestion of para grass in laboratory scale studies. In addition, improvement of the biogas yield from the grass via chemical pretreatment and leaching bed reactors was studied. Methane content of biogas was 54.36 % by mono- substrate. The results revealed that para grass can be treated anaerobically and are a good source of biogas.

scholarly journals Removal of solids and chemical oxygen demand in poultry litter anaerobic digestion with different inocula

2020 ◽  
Vol 15 (2) ◽  
pp. 1
Author(s):  
Joseane Bortolini ◽  
Maria Hermínia Ferreira Tavares ◽  
Dayane Taine Freitag ◽  
Osvaldo Kuczman
Keyword(s):  
Anaerobic Digestion ◽  
Chemical Oxygen Demand ◽  
Poultry Litter ◽  
Oxygen Demand ◽  
Poultry Production ◽  
Digestion Process ◽  
Operation Conditions ◽  
Volatile Solids ◽  
Waste Loading ◽  
Plot Design

 Population growth has contributed to increasing poultry production, entailing a high waste loading, mainly poultry litter. One of the alternatives to treat such residues is anaerobic digestion, in which digester startup and generated-digestate quality are related to the material to be digested and to operation conditions, wherein inoculum use is one of the factors. This study therefore aimed to investigate how digestates, such as inocula, influence poultry litter (PL) anaerobic digestion, as well the reduction of solids and chemical oxygen demand (COD). For this, two inocula (bovine and swine digestates) were tested in the digestion process. The inocula were added at loads of 0.67, 1.00 and 1.67 gVS.L-1day-1. A split-plot design was developed and data underwent analysis of variance with means compared by the Tukey's test at 5% significance. Concerning bovine and swine inocula, it was concluded that both are indicated in the process. However, swine inoculum is better indicated because it had a better removal of total solids (TS), volatile solids (VS) and COD.

scholarly journals Modification of municipal wastewater for improved biogas recovery

2020 ◽  
Vol 15 (3) ◽  
pp. 683-696
Author(s):  
Vaileth Hance ◽  
Thomas Kivevele ◽  
Karoli Nicholas Njau
Keyword(s):  
Anaerobic Digestion ◽  
Energy Demand ◽  
Municipal Wastewater ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Organic Content ◽  
Municipal Wastewater Treatment ◽  
Naoh Solution ◽  
Municipal Wastewater Treatment Plants

Abstract The energy demand, which is expected to increase more worldwide, has sparked the interest of researchers to find sustainable and inexpensive sources of energy. This study aims to integrate an energy recovering step into municipal wastewater treatment plants (MWWTPS) through anaerobic digestion. The anaerobic digestion of municipal wastewater (MWW), and then co-digestion with sugar cane molasses (SCM) to improve its organic content, was conducted at 25 °C and 37 °C. The results showed a substrate mixture containing 6% of SCM and total solids (TS) of 7.52% yielded a higher amount of biogas (9.73 L/L of modified substrate). However, chemical oxygen demand (COD) of the resulting digestate was high (10.1 g/L) and pH was not stable, and hence needed careful adjustment using 2 M of NaOH solution. This study recommends a substrate mixture containing SCM (2%) and TS (4.34%) having biogas production (4.97 L/L of modified substrate) for energy recovery from MWWTPS, since it was found to have more stable pH and low COD residue (1.8 g/L), which will not hold back the MWW treatment process. The annual generation of modified substrate (662,973 m3) is anticipated to generate about 16,241 m3 of methane, which produces up to 1.8 GWh and 8,193 GJ per annum.

scholarly journals Batch and Semi-Continuous Anaerobic Digestion of Industrial Solid Citrus Waste for the Production of Bioenergy

Processes ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 648
Author(s):  
Erik Samuel Rosas-Mendoza ◽  
Andrea Alvarado-Vallejo ◽  
Norma Alejandra Vallejo-Cantú ◽  
Raúl Snell-Castro ◽  
Sergio Martínez-Hernández ◽  
...  
Keyword(s):  
Anaerobic Digestion ◽  
Oxygen Demand ◽  
Continuous Mode ◽  
Citrus Industry ◽  
Batch Mode ◽  
Volatile Solids ◽  
Working Volume ◽  
Plant Level ◽  
Citrus Waste ◽  
Mesophilic Conditions

The aim of this paper is to describe a study of the anaerobic digestion of industrial citrus solid waste (ISCW) in both batch and semi-continuous modes for the production of bioenergy without the elimination of D-limonene. The study was conducted at the pilot plant level in an anaerobic reactor with a working volume of 220 L under mesophilic conditions of 35 ± 2 °C. Cattle manure (CM) was used as the inoculum. Three batches were studied. The first batch had a CM/ISCW ratio of 90/10, and Batches 2 and 3 had CM/ISCW ratios of 80/20 and 70/30, respectively. In the semi-continuous mode an OLR of approximately 8 g total chemical oxygen demand (COD)/Ld (4.43 gVS/Ld) was used. The results showed that 49%, 44%, and 60% of volatile solids were removed in the batch mode, and 35% was removed in the semi-continuous mode. In the batch mode, 0.322, 0.382, and 0.316 LCH4 were obtained at STP/gVSremoved. A total of 24.4 L/d (34% methane) was measured in the semi-continuous mode. Bioenergy potentials of 3.97, 5.66, and 8.79 kWh were obtained for the respective batches, and 0.09 kWh was calculated in the semi-continuous mode. The citrus industry could produce 37 GWh per season. A ton of processed oranges has a bioenergy potential of 162 kWh, which is equivalent to 49 kWh of available electricity ($3.90).

scholarly journals Biogas potential of organic waste onboard cruise ships — a yet untapped energy source

2021 ◽  
Author(s):  
Kai Schumüller ◽  
Dirk Weichgrebe ◽  
Stephan Köster
Keyword(s):  
Energy Source ◽  
Anaerobic Digestion ◽  
Sewage Sludge ◽  
Food Waste ◽  
Energy Demand ◽  
Organic Waste ◽  
Biogas Production ◽  
Biogas Yield ◽  
Cruise Ships ◽  
Detailed Presentation

AbstractTo tap the organic waste generated onboard cruise ships is a very promising approach to reduce their adverse impact on the maritime environment. Biogas produced by means of onboard anaerobic digestion offers a complementary energy source for ships’ operation. This report comprises a detailed presentation of the results gained from comprehensive investigations on the gas yield from onboard substrates such as food waste, sewage sludge and screening solids. Each person onboard generates a total average of about 9 kg of organic waste per day. The performed analyses of substrates and anaerobic digestion tests revealed an accumulated methane yield of around 159 L per person per day. The anaerobic co-digestion of sewage sludge and food waste (50:50 VS) emerged as particularly effective and led to an increased biogas yield by 24%, compared to the mono-fermentation. In the best case, onboard biogas production can provide an energetic output of 82 W/P, on average covering 3.3 to 4.1% of the total energy demand of a cruise ship.

Alkali pre-treatment of Sorghum Moench for biogas production

2013 ◽  
Vol 67 (9) ◽  
Author(s):  
Karina Michalska ◽  
Stanisław Ledakowicz
Keyword(s):  
Anaerobic Digestion ◽  
Chemical Oxygen Demand ◽  
Volatile Fatty Acids ◽  
Biogas Production ◽  
Oxygen Demand ◽  
Total Phenolic ◽  
Methane Generation ◽  
Pre Treatment ◽  
Alkali Hydrolysis ◽  
Almost All

AbstractThis work studies the influence of the alkali pre-treatment of Sorghum Moench — a representative of energy crops used in biogas production. Solutions containing various concentrations of sodium hydroxide were used to achieve the highest degradation of lignocellulosic structures. The results obtained after chemical pre-treatment indicate that the use of NaOH leads to the removal of almost all lignin (over 99 % in the case of 5 mass % NaOH) from the biomass, which is a prerequisite for efficient anaerobic digestion. Several parameters, such as chemical oxygen demand, total organic carbon, total phenolic content, volatile fatty acids, and general nitrogen were determined in the hydrolysates thus obtained in order to define the most favourable conditions. The best results were obtained for the Sorghum treated with 5 mass % NaOH at 121°C for 30 min The hydrolysate thus achieved consisted of high total phenolic compounds concentration (ca. 4.7 g L−1) and chemical oxygen demand value (ca. 45 g L−1). Although single alkali hydrolysis causes total degradation of glucose, a combined chemical and enzymatic pre-treatment of Sorghum leads to the release of large amounts of this monosaccharide into the supernatant. This indicates that alkali pre-treatment does not lead to complete cellulose destruction. The high degradation of lignin structure in the first step of the pre-treatment rendered the remainder of the biomass available for enzymatic action. A comparison of the efficiency of biogas production from untreated Sorghum and Sorghum treated with the use of NaOH and enzymes shows that chemical hydrolysis improves the anaerobic digestion effectiveness and the combined pre-treatment could have great potential for methane generation.

scholarly journals Enhancing Anaerobic Digestion: The Effect of Carbon Conductive Materials

2018 ◽  
Vol 4 (4) ◽  
pp. 59 ◽  
Author(s):  
Judith González ◽  
Marta Sánchez ◽  
Xiomar Gómez
Keyword(s):  
Anaerobic Digestion ◽  
Energy Demand ◽  
Biogas Production ◽  
Global Energy ◽  
Conductive Materials ◽  
Different Types ◽  
Interesting Approach ◽  
Feasible Alternative

Anaerobic digestion is a well-known technology which has been extensively studied to improve its performance and yield biogas from substrates. The application of different types of pre-treatments has led to an increase in biogas production but also in global energy demand. However, in recent years the use of carbon conductive materials as supplement for this process has been studied resulting in an interesting way for improving the performance of anaerobic digestion without greatly affecting its energy demand. This review offers an introduction to this interesting approach and covers the different experiences performed on the use of carbon conductive materials proposing it as a feasible alternative for the production of energy from biomass, considering also the integration of anaerobic digestion and thermal valorisation.

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