Abstract:Anaerobic digestion is a well-known technology with wide application in the treatment of high-strength organic wastes. The economic feasibility of this type of installation is usually attained thanks to the availability of fiscal incentives. In this review, an analysis of the different factors associated with this biological treatment and a description of alternatives available in literature for increasing performance of the process were provided. The possible integration of this process into a biorefinery as … Show more
“…Thus, reducing compression stages by supplying biogas directly to large consumers will avoid additional compression costs. If biogas is to be considered a substitute for natural gas or to be used as a supplementary fuel along with natural gas, then upgrading is imperative, but this also causes an increment in costs that when summed up to the already high installation costs of this type of facilities makes this mature technology just a promising process that encounters several difficulties in attaining economic feasibility [7]. Great efforts should be placed on developing high rate reactors with an outstanding capacity to operate under solid-phase conditions without experiencing detriments in biogas yields.…”
Section: Discussionmentioning
confidence: 99%
“…The presence of improper materials in organic wastes and in some cases, high concentrations of heavy metals, translates into a plant design of high complexity needing special pre-treatment units for preparing a homogenous feeding slurry. We should also add the intrinsic difficulty of separating inert materials and avoiding the presence of toxic elements in digestates that prevents any agronomic use [7].…”
Anaerobic digestion is traditionally used for treating organic materials. This allows the valorization of biogas and recycling of nutrients thanks to the land application of digestates. However, although this technology offers a multitude of advantages, it is still far from playing a relevant role in the energy market and from having significant participation in decarbonizing the economy. Biogas can be submitted to upgrading processes to reach methane content close to that of natural gas and therefore be compatible with many of its industrial applications. However, the high installation and operating costs of these treatment plants are the main constraints for the application of this technology in many countries. There is an urgent need of increasing reactor productivity, biogas yields, and operating at greater throughput without compromising digestion stability. Working at organic solid contents greater than 20% and enhancing hydrolysis and biogas yields to allow retention times to be around 15 days would lead to a significant decrease in reactor volume and therefore in initial capital investments. Anaerobic digestion should be considered as one of the key components in a new economy model characterized by an increase in the degree of circularity. The present manuscript reviews the digestion process analyzing the main parameters associated with digestion performance. The novelty of this manuscript is based on the link established between operating reactor conditions, optimizing treatment capacity, and reducing operating costs that would lead to unlocking the potential of biogas to promote bioenergy production, sustainable agronomic practices, and the integration of this technology into the energy grid.
“…Thus, reducing compression stages by supplying biogas directly to large consumers will avoid additional compression costs. If biogas is to be considered a substitute for natural gas or to be used as a supplementary fuel along with natural gas, then upgrading is imperative, but this also causes an increment in costs that when summed up to the already high installation costs of this type of facilities makes this mature technology just a promising process that encounters several difficulties in attaining economic feasibility [7]. Great efforts should be placed on developing high rate reactors with an outstanding capacity to operate under solid-phase conditions without experiencing detriments in biogas yields.…”
Section: Discussionmentioning
confidence: 99%
“…The presence of improper materials in organic wastes and in some cases, high concentrations of heavy metals, translates into a plant design of high complexity needing special pre-treatment units for preparing a homogenous feeding slurry. We should also add the intrinsic difficulty of separating inert materials and avoiding the presence of toxic elements in digestates that prevents any agronomic use [7].…”
Anaerobic digestion is traditionally used for treating organic materials. This allows the valorization of biogas and recycling of nutrients thanks to the land application of digestates. However, although this technology offers a multitude of advantages, it is still far from playing a relevant role in the energy market and from having significant participation in decarbonizing the economy. Biogas can be submitted to upgrading processes to reach methane content close to that of natural gas and therefore be compatible with many of its industrial applications. However, the high installation and operating costs of these treatment plants are the main constraints for the application of this technology in many countries. There is an urgent need of increasing reactor productivity, biogas yields, and operating at greater throughput without compromising digestion stability. Working at organic solid contents greater than 20% and enhancing hydrolysis and biogas yields to allow retention times to be around 15 days would lead to a significant decrease in reactor volume and therefore in initial capital investments. Anaerobic digestion should be considered as one of the key components in a new economy model characterized by an increase in the degree of circularity. The present manuscript reviews the digestion process analyzing the main parameters associated with digestion performance. The novelty of this manuscript is based on the link established between operating reactor conditions, optimizing treatment capacity, and reducing operating costs that would lead to unlocking the potential of biogas to promote bioenergy production, sustainable agronomic practices, and the integration of this technology into the energy grid.
“…However, trying to set a specific C/N ratio for industrial digesters in an attempt to extrapolate results is not always easy. Large-scale digestion plants have to deal with the resources available in their surroundings all year round [18]. Therefore, these findings help predict 1.…”
Section: The Effect Of Organic Loading On Digestion Performancementioning
confidence: 99%
“…However, trying to set a specific C/N ratio for industrial digesters in an attempt to extrapolate results is not always easy. Large-scale digestion plants have to deal with the resources available in their surroundings all year round [18]. Therefore, these findings help predict the effect on plant performance based on the carbon proportion of the feed, although industrial plants still have to operate under optimum conditions based on the resources available to them.…”
Section: The Effect Of Organic Loading On Digestion Performancementioning
confidence: 99%
“…Several pre-treatment methods have been evaluated with success under laboratory conditions, achieving a significant enhancement in the solubilization of organics. However, the capacity of thermal pre-treatments to recover heat makes these superior when considering their performance in terms of the energy balance [18].…”
High-solid and solid-state anaerobic digestion are technologies capable of achieving high reactor productivity. The high organic load admissible for this type of configuration makes these technologies an ideal ally in the conversion of waste into bioenergy. However, there are still several factors associated with these technologies that result in low performance. The economic model based on a linear approach is unsustainable, and changes leading to the development of a low-carbon model with a high degree of circularity are necessary. Digestion technology may represent a key driver leading these changes but it is undeniable that the profitability of these plants needs to be increased. In the present review, the digestion process under high-solid-content configurations is analyzed and the different strategies for increasing reactor productivity that have been studied in recent years are described. Percolating reactor configurations and the use of low-cost adsorbents, nanoparticles and micro-aeration seem the most suitable approaches to increase volumetric production and reduce initial capital investment costs.
The textile industry utilizes numerous chemicals ranging from solvents to resins and caustic soda to bleach, having a harsh environmental impact. A large amount of colored dye in wastewater is released. Non-biodegradable heavy metals and chlorine accumulate in organs of marine and terrestrial life, leading to various diseases. So, there is an urgent need to treat textile wastewater. Up to date, techno-economic analyses of all electrochemical processes have not been reviewed for textile wastewater treatment. In this review, the focus is on the tertiary treatment methods, mainly on electrochemical treatments, i.e., electrocoagulation, electro-Fenton, electrooxidation, photoelectrochemical (PEC) process, and solar electrophoto-Fenton process (SPEF) with their mechanisms and techno-economic analyses. SPEF treatment was found to be advantageous in terms of efficiency and economic perspective as it utilizes solar energy instead of electrical energy and the cost of the PEC process can also be recovered by the generation of hydrogen.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.