High-Solid Anaerobic Digestion: Reviewing Strategies for Increasing Reactor Performance

Abstract

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.

Biohydrogen and Methane Production from Sugarcane Leaves Pretreated by Deep Eutectic Solvents and Enzymatic Hydrolysis by Cellulolytic Consortia

“…The accumulation of this product is due to a separate enzymatic hydrolysis process that converts the cellulose in DES-pretreated sugarcane leaves to glucose, which will later be converted in the acidogenesis process to produce VFAs. After the enzymatic hydrolysis process, glucose production increases the VFAs in acidogenesis, which causes the accumulation of VFAs, thereby reducing methane production at the end of AD [60]. Moreover, acetic acid accumulation may be due to the cellulolytic consortium producing such VFAs during cellulose degradation.…”

Energy Balance of Turbocharged Engines Operating in a WWTP with Thermal Hydrolysis. Co-Digestion Provides the Full Plant Energy Demand

“…The electrical efficiency (η el-eng ) is calculated using Equation (7). EP and TP in the formula stand for electrical and thermal power.…”

“…Anaerobic digestion can also contribute to reducing the environmental impact and emission of CH 4 as it allows targeting conversion processes, eliminating uncontrolled degradation and dispersed emission of pollutants. In this way, the valorization of biogas can be achieved in waste treatment plants for producing energy or upgraded to achieve a quality similar to that of natural gas [7].…”

Nanomaterials for biogas augmentation towards renewable and sustainable energy production: A critical review

“…Moreover, studying the role of size, type, and concentration of metallic NPs is still a challenge (Hassanein et al, 2021). After conducting a literature review, Ellacuriage stipulated that to increase volumetric efficiency and reduce initial capital cost, NPs augmentation is the most suitable approach (Ellacuriaga et al, 2021).…”