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A pretreatment method can increase the rate of anaerobic digestion (pretreatment b) or can increase the methane yield (pretreatment c). Both effects will improve the running of a biogas plant. However, depending when a BMP test is ended, different interpretations are possible (t1: pretreatment b doubles the methane yield; t2: none of the pretreatment methods increase methane yield; t3: pretreatment c increases the methane yield by 25% but pretreatment b has no effect).
Contexts in source publication
Context 1
... method gives information about the amount of biogas produced and its production rate. However, this method can be interpreted differently, depending on the dura- tion of the batch test (as visible in Figure 3) and the inoculum used. ...
Context 2
... found up to 20% more methane yield from steam- exploded straw than from untreated straw in batch tests. However, Vivekanand et al. (2012) showed that meth- ane yields from steam exploded rape straw were similar to untreated rape straw, although there was an increase in the rate of biogas production (also important, see Figure 3). ...
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A series of laboratory experiments were conducted under anaerobic mesophilic conditions. Cumulative biogas production of codigested vegetables (potato, carrot, and spinach), fruits (grape and orange) and mixture of fruits, vegetables and cooked oil collected from restaurants was determined. Experiments were conducted in laboratory reactors (6L) ope...
Citations
... The highest biogas was recorded by day 8 of the retention time with a temperature of 23 • C and treatment conditions of 20 mg/L of Fe 3 O 4 additives combined with a 6 mm particle size. This contradicts the previous report that smaller particle sizes released the highest biogas and methane yields [23,24]. This may be due to the improved hydrolysis rate caused by increased surface area that enhanced the nanoparticle attachment. ...
... Thus, pretreatment of biomass is an appropriate approach for the maximum biogas production. However, more research is needed to address issues such as plant biomass accessibility for AD, anaerobic bacteria adaptation to degrade lignocellulosic feedstock, adaptability of the microbial population on different pretreated substrates, the effect of inhibitors formed during the pretreatment process on AD, and the invention of innovative, low-cost pretreatment techniques for AD (Lucy et al. 2014). ...
Weeds are invasive or unwanted plants that are non-native to the ecosystem grow along with food crops threatening the food security, health, economic development and biodiversity. They are competitive, able to persist and grow under any stressed conditions with high propagating capability. India having temperate to tropical zones possesses rich plant diversity spread across different crop and non-croplands. Weeds grow everywhere consuming the nutrients, soil moisture, space, etc., meant for food crops and thus ultimately affect the crop productivity adversely. Parthenium is a weed that invaded India with imported food grains in the mid-1950s. This weed alone was reported (2001–2007) to invade over 14.5 million hectares of farmland in India (Directorate of Weed Science Research—DWSR). It was also opined that the swift growth of this weed is a threat to environment, biodiversity and country’s economy. Various strategies involving many voluntary organizations, individuals and government agencies in the weed management on a regional scale were organized. Though several eradication measures were undertaken in this regard, not a single method is still a choice for the complete eradication of weed. Therefore, the status of weed controlling is envisaged with respect to “large-scale utilization”. Over a century, several studies have been reported that weed can be a potential biomass. Weed can be used as a green manure, biocontrol agent, soil ameliorate, compost which in turn improves physical, chemical and biological composition of the soil and also in the generation of significant quantities of energy. In this age of renewable energy, there is an ever-rising demand for the alternative energy source which calls for exploring and exploiting new sources of energy biomethanation is a process of production of biogas (methane), during which the organic matter is converted into an alternative fuel. Biomethanation offers an effective way to manage the weed biomass in eco-friendly and cost-effective way.
... Chemical treatment processes are also not widely used on an industrial scale due to the lack of economic viability currently resulting from the high cost of alkali. However, this type of treatment may be the only option for highly acidic or lignin-rich substrates to ensure a stable anaerobic digestion process [103]. ...
... In a study by Liu et al. [104], a 21% higher methane efficiency was achieved by introducing a pre-acidification stage for household waste. In addition, it resulted in the benefit of a higher methane concentration in biogas [103,104]. Compared to other pretreatment methods, biological methods require a more extended period of substrate preparation while having low efficiency [105]. Research conducted by Mshandete et al. [106] also presents pretreatment methods involving aeration. ...
... Table 2 shows the advantages effect of pretreatment on the fermentation process from selected methods. Table 2. Effect of pretreatment on the fermentation process (own elaboration based on [94][95][96][97][98][99][100][101][102][103][104][105][106][107]). ...
New technologies based on the anaerobic digestion process make it possible to manage problematic waste. Methane efficiency depends largely on the level of the hydration of the substrates used for biogas production and their ability to decompose easily. The aim of this study was to present the current state of knowledge and practices in substrate hydration characteristics, focusing on pretreatment methods as the preferred method for improving efficiency. The paper discusses issues related to the degree of hydration of substrates in the context of their use in biogas plants. Reference was also made to topics related to the transportation and logistics of raw material supply regarding environmental impact. Biogas plant projects should be expanded to include an element related to assessing the impact of raw material deliveries on the immediate environment. Previous papers have not sufficiently analyzed the aspect related to the hydration of substrates used in anaerobic digestion processes. The presented and discussed research results can be implemented to optimize biogas plant water management processes. By replacing standard feedstock transportation methods with a pipeline, the environmental impact can be reduced by nearly ten times.
... Research suggests [94][95][96] degradation of the cell walls of biomass by various thermochemical processes allows for more access to nutrients for methanogenic bacteria and could be used as a pretreatment for enhanced biogas production. In order to test the feasibility of cascading extraction residues, a 377 Nm3 t-1 of methane yield [97] or 13,500 MJ is assumed. ...
Spent brewer’s yeast (SBY) is a byproduct of the brewing industry traditionally used as a feed additive, although it could have much broader applications. In this paper, a comprehensive review of valorization of SBY for the production of high-value products, new materials, and biofuels, as well as environmental application, is presented. An economic perspective is given by mirroring marketing of conventional SBY with innovative high-value products. Cascading utilization of fine chemicals, biofuels, and nutrients such as proteins, carbohydrates, and lipids released by various SBY treatments has been proposed as a means to maximize the sustainable and circular economy.
... particle size combined with 20 mg/L of Fe 3 O 4 additive produces the highest organic dry matter and fresh mass biogas yield, which is contrary to what was observed in earlier reports that smaller particle sizes have the highest biogas yield [50,51]. Lower biogas yield from 2 mm can result from loss of some carbon content during further reduction below 2 mm and production of some inhibitory compounds that hinder the biogas yield. 2 mm particle size provides a larger surface area for microbial attachment, which will improve the Fe 3 O 4 additive penetration. ...
This study experimented biogas production from Arachis hypogea shells subjected to combined pretreatments, namely particle size reduction and Fe3O4 additives. Further to this, the biogas production based on organic dry matter biogas (oDMBY), fresh mass biogas (FMBY), organic dry matter methane (oDMMY), and fresh mass methane (FMMY) were modeled using machine learning algorithms. A fuzzy c-means (FCM)-clustered Adaptive neuro-fuzzy inference systems (ANFIS) and optimized artificial neural network (ANN) model were developed using significant operating parameters of temperature, retention time, and pretreatment methods as input variables. The maximum daily gas yield of 100.4 lN/kgoDM, 18.4 lN/kgFM, 75.7 lNCH4oDM, and 16.1 lNCH4FM were recorded when different particle sizes were combined with Fe3O4 additives. Single pretreatment with Fe3O4 improves the oDMBY, FMBY, oDMMY, and FMMY by 150, 20.7, 79.39, and 176.19%, while the combination with particle size improves the yields by 256.03, 138.96, 155.74, and 283.33%, respectively. The models’ performances were evaluated using relevant statistical metrics. The ANN model gave Root Mean Square Error (RMSE), Mean Absolute Percentage Error (MAPE), Mean Absolute Deviation (MAD), and Correlation Coefficient (R²) values of 1.9354, 6.3213, 1.0234, and 0.9496. The FCM-ANFIS model with ten clusters outperformed the ANN model with RMSE, MAPE, MAD, and Coefficient (R²) values of 1.2343, 5.2343, 1.2463, and 0.9850. The result shows that the pretreatment applied enhanced the biogas and methane yields of Arachis hypogea shells. This study showed that FCM-clustered ANFIS can predict biogas yield of pretreated Arachis hypogea shells satisfactorily, and it is recommended for other similar studies.
Graphical Abstract
... In mechanical pretreatment, the size of the feedstock gets altered by crushing, grinding, and milling, which will increase the surface area of the microbes [38]. Milling of the feedstock will reduce the viscosity inside the digester, which makes the missing easier and avoids floating [39]. A twin-screw extruder was used for roll milling of feedstock with a rotation speed of 17 min − 1 , where the instrument is equipped with counter-rotating screw modules [32]. ...
In recent years, there has been considerable attention to renewable energy resources for environmental protection to handle and treat food wastes and organic wastes. Anaerobic digestion is a promising option to manage and treat food and organic wastes. Biogas plants will act as energy suppliers and fertilizers to protect our environment. This paper will give an overview of the research achievements and technologies of biogas plants in recent years. This article mainly focuses on characterization, fabrication, and factors that affect biogas production over the years. The major factors like temperature, hydraulic retention time, pH, and organic loading rate will play major roles in production efficiency. Pretreatment technologies and additives inhibition will promote biogas yield., This paper will review different pretreatments and additives followed. There are several microbes found in nature, and these microbes will directly stimulate the action of a particular enzyme to increase efficiency, which can easily reduce the hydraulic retention time. The presence of microbial cultures and bacterial species such as acetomycetes increased methane generation while lowering COD levels.
... However, they require extra care, since depending on the chemical reagents applied, toxic compounds can be formed. Some chemicals pretreatments such as sulphuric acid (H 2 SO 4 ), hydrochloric acid (HCl), and nitric acid (HNO 3 ) can further damage operational equipment by corrosion and failure of metals [18][19][20]. Biological pretreatments (i.e., fungi, bacteria, microbial consortia, enzymes) act in synergy with microbial metabolism, promoting the acceleration of the degradation of organic matter [16]. Avoiding the addition and generation of harmful chemicals promotes an environmentally healthier AD system. ...
The textile industry is one of the largest environmental polluters in the world. Although waste management via anaerobic digestion (AD) is a sustainable strategy to transform waste into clean energy and water recovery, the efficiency of the AD process is reduced by the presence of recalcitrant materials, chemicals, and toxic contents. This study aims to investigate the performance of several chemical, physical, and biological pretreatments applied to improve the biodegradability of textile waste. We performed a meta-analysis with 117 data extracted from 13 published articles that evaluated the efficiency of pretreatments applied to textile waste prior to AD to increase biogas production measured as methane (CH4 ) yield. Even though the majority of the studies have focused on the effect of chemical and physical pretreatments, our results showed that the application of biological pretreatments are more efficient and eco-friendlier. Biological pretreatments can increase CH4 yield by up to 360% with lower environmental risk and lower operating costs, while producing clean energy and a cleaner waste stream. Biological pretreatments also avoid the addition of chemicals and favor the reuse of textile wastewater, decreasing the current demand for clean water and increasing resource circularity in the textile industry.
... It should be noted that the production of biogas via AD is beneficial over other processes or biomass-driven procedures such as bioethanol production; this is because substrates of different types may successfully undergo AD [9]. Biogas is also of great environmental significance when assorted waste such as waste from livestock or slaughterhouse waste and other forms of agricultural waste are collected through the AD and subsequently used for the production of electricity [10]. ...
Soil conditioners like manure and slurry from farmyard and digestate which supply important nutrients to plants are known to contain pathogens that are equally withering to plants. Anaerobic digestion (AD) is an organic or biological process that uses stored energy in organic compounds for biogas production. Ongoing research work has focused on the best possible ways of improving digestive processes. This work thus contains recent contributions towards the effective AD process parameter in biogas yield, the most important parameters affecting the production of biogas and its process parameters (process configuration, temperature, pH, organic loading rate, retention time, concentration of hydrogen, agitation, moisture content, and inoculum). However, with improvements in technology, AD bottlenecks caused by the physicochemical properties of the substrate are addressed and the hazardous greenhouse gas present in biogas yield is easily removed from AD processing yield. In this study, some of the process parameters and latest technologies for improved biogas yield have been revealed.
... In general, there are two types of digester is in use namely single and double stage. Double stage digester is found highly advantageous over single type because the first two steps (hydrolysis, acidogenesis) can be cleaved from the subsequent steps (acetogenesis, methanogenesis) and the specificity towards metabolic processes, operational conditions (temperature, moisture, nutritional demand) and retention time can be managed precisely ( Hubenov et al., 2015 ;Montgomery and Bochmann, 2014 ). Bio slurry generated additionally proved beneficial for soil health and crop productivity ( Nguyen et al., al.,2015 ). ...
Sustainable management of surplus paddy residue in the Indo-Gangetic plain is a back-breaking task for farmers due to lack of viable options. Eventually, farmers prefer to incinerate it mindlessly. Sustainable residue management is important because paddy straws are rich in nutrients and can be translated into value added products. Several important reasons like short span of sowing time for wheat, limited farm mechanisation, scarce manpower and poor acceptability of paddy straw as fodder are the root causes behind this residue burning. The aim of this paper is to find the root causes behind this illicit practice and mark the harmful effects of residue burning on ecosystem. This manuscript also deciphers in depth strategies, environmental laws, socio-economic policy frameworks and future thrusts which would offer multifaceted avenues for the sustainable management of crop residues. Losses of essential nutrients in the soil and in the residue with emission of potential greenhouse gases (GHGs) are the major repercussions of this mal-practice. Adaption and commercialisation of resource conservation technologies like conservation agriculture (CA) with low silica content in rice varieties are excellent opportunities to look after. Value addition by preparation of compost, mushroom production, biogas/oil generation, and producing energy in the power plants are new avenues to convert this waste into wealth. Respective state and central government along with different private organisations are working hand in hand to spread awareness and control stubble burning. Fostering the current technologies through policy interventions and organising training camps in the village level with monetary incentives are the important strategies to look for.
... Oxidative pre-treatment with ozone in presence hydrogen peroxide results in hydroxyl radicals. These hydroxyl radicals break the aromatic ring by electrophilic substitution followed by side chain transfer and cleavage of alkyl group (Montgomery and Bochmann, 2014;M'Arimi et al., 2020). ...
Biogas can be an alternate clean renewable energy option generated from the anaerobic digestion of biodegradable organic waste at no cost. It involves a complex cascade of processes that are regulated by different groups of microorganisms. A good interaction between the substrate and the microorganism is essential for efficient substrate utilization and biogas production. Therefore, an attempt has been made to review the different physico-chemical factors that influence the microbial-substrate interaction and focus on the new advances to produce biogas more resourcefully. The review ends with a look into the future, saying that metagenomic analysis, metabolic flux analysis, and other similar methods can help a lot with understanding these interactions in the future.
