Lignocellulosic biomass (LCB) is the most abundantly available bioresource amounting to about a global yield of up to 1.3 billion tons per year. The hydrolysis of LCB results in the release of various reducing sugars which are highly valued in the production of biofuels such as bioethanol and biogas, various organic acids, phenols, and aldehydes. The majority of LCB is composed of biological polymers such as cellulose, hemicellulose and lignin, which are strongly associated with each other by covalent and hydrogen bonds thus forming a highly recalcitrant structure. The presence of lignin renders the bio-polymeric structure highly resistant to solubilization thereby inhibiting the hydrolysis of cellulose and hemicellulose which presents a significant challenge for the isolation of the respective bio-polymeric components. This has led to extensive research in the development of various pretreatment techniques utilizing various physical, chemical, physicochemical and biological approaches which are specifically tailored towards the source biomaterial and its application. The objective of this review is to discuss the various pretreatment strategies currently in use and provide an overview of their utilization for the isolation of high-value bio-polymeric components. The article further discusses the advantages and disadvantages of the various pretreatment methodologies as well as addresses the role of various key factors that are likely to have a significant impact on the pretreatment and digestibility of LCB.

/pdf/recent-trends-in-the-pretreatment-of-lignocellulosic-biomass-27tds25s66.pdf

Recent Trends in the Pretreatment of Lignocellulosic Biomass for Value-Added Products

Opportunities and challenges in sustainable treatment and resource reuse of sewage sludge: A review

Lignocellulose is the most abundant biomass on Earth, with an estimated 181.5 billion tonnes produced annually. Of the 8.2 billion tonnes that are currently used, about 7 billion tonnes are produced from dedicated agricultural, grass and forest land and another 1.2 billion tonnes stem from agricultural residues. Economic and environmentally efficient pathways for production and utilization of lignocellulose for chemical products and energy are needed to expand the bioeconomy. This opinion paper arose from the research network “Lignocellulose as new resource platform for novel materials and products” funded by the German federal state of Baden‐Württemberg and summarizes original research presented in this special issue. It first discusses how the supply of lignocellulosic biomass can be organized sustainably and suggests that perennial biomass crops (PBC) are likely to play an important role in future regional biomass supply to European lignocellulosic biorefineries. Dedicated PBC production has the advantage of delivering biomass with reliable quantity and quality. The tailoring of PBC quality through crop breeding and management can support the integration of lignocellulosic value chains. Two biorefinery concepts using lignocellulosic biomass are then compared and discussed: the syngas biorefinery and the lignocellulosic biorefinery. Syngas biorefineries are less sensitive to biomass qualities and are technically relatively advanced, but require high investments and large‐scale facilities to be economically feasible. Lignocellulosic biorefineries require multiple processing steps to separate the recalcitrant lignin from cellulose and hemicellulose and convert the intermediates into valuable products. The refining processes for high‐quality lignin and hemicellulose fractions still need to be further developed. A concept of a modular lignocellulosic biorefinery is presented that could be flexibly adapted for a range of feedstock and products by combining appropriate technologies either at the same location or in a decentralized form.

https://onlinelibrary.wiley.com/doi/pdf/10.1111/gcbb.12586

Integrated lignocellulosic value chains in a growing bioeconomy: Status quo and perspectives

Value-added chemicals from food supply chain wastes: State-of-the-art review and future prospects

wastewater engineering treatment and resource recovery is available in our digital library an online access to it is set as public so you can get it instantly. Our book servers hosts in multiple countries, allowing you to get the most less latency time to download any of our books like this one. Kindly say, the wastewater engineering treatment and resource recovery is universally compatible with any devices to read.

Wastewater Engineering Treatment And Resource Recovery

Global annual production of lignocellulosic biomass including undervalued agricultural residues and greenhouse biomass is about 181.5 billion tonnes. This undervalued biomass has a high potential to produce biogas in anaerobic digestion (AD). Among the various pre-treatment methods, hydrothermal (HT) pre-treatment of lignocellulosic biomass is a promising approach to increase biogas production in AD. However, the high carbon to nitrogen ratio (C/N) of lignocellulosic biomass is reported to be the major limiting factor for a higher biogas yield. Hence, the synergistic integration of low C/N ratio biomass with high C/N ratio lignocellulosic biomass in an AD system appears to be a logical option to enhance biogas yield. High moisture lignocellulosic biomass HT pretreatment and biogas production in AD have the potential for renewable energy production with limited use of process energy. However, hydrothermal process temperature, AD substrate C/N ratio and its inhibitory elements are important parameters for optimum biogas production. Greenhouse biomass pretreatment in hydrothermal process can produce biochar, biogas and biofertilizer, which can be used as input heat and nutrient source for greenhouses. Finally, the operation of greenhouse in this system can manage zero waste and reduce greenhouse gas (GHG) emissions and climate change.

Challenges and opportunities of lignocellulosic biomass for anaerobic digestion

This research is a dual resources recovery approach of biomethane and biofertilizer from as received municipal food waste (MFW) using the concept of circular economy. In this research MFW is first pretreated in hydromechanical process to produce broth suitable for anaerobic digestion (AD). The MFW broth then underwent mesophilic wet AD process to produce biomethane and biofertilizer. Three selected feedstock and inoculum ratios (F/I) of 1:2, 1:1 and 2:1 by volume for 30 days retention time were considered. Among three F/I ratios, the F/I ratio of 1:1 digester was found to be the best batch condition for 30 days retention time for maximum biomethane production. MFW broth had ash content of 31.51% of total solid (TS), higher heating value (HHV) of 18.32 MJ kg−1 of TS and C/N ratio of 15.29. The batch F/I of 1:1 AD produced the maximum biomethane of 347.69 L kg−1 TS, 511.92 L kg−1 volatile solid (VS), 232.74 L kg−1 COD and 701.56 L kg−1 TOC, respectively. The biomethane was accounted for about 60% of the produced biogas in this mesophilic batch digester. Digestate was available as a liquid biofertilizer with 4.61% N, 3.33% P, 0.39% K, 1.17% S, 0.29% Ca, 0.14% Mg and 6.82% Na contents of TS of MFW broth, which will be a substitute of chemical fertilizer. This biomethane and biofertilizer can reduce GHG emission of Ontario, Canada which can contribute to the enrichment of the circular economy.

Municipal Food Waste to Biomethane and Biofertilizer: A Circular Economy Concept

Techno-economic assessment of corn stover for hybrid bioenergy production: A sustainable approach

Biocarbon, biomethane and biofertilizer from corn residue: A hybrid thermo-chemical and biochemical approach

In this research fall time harvested corn residue (CR) was first mechanically pretreated to produce 5 mm chopped and <500 µm ground particles, which underwent an anaerobic digestion (AD) process to produce biomethane and biofertilizer. Another sample of CR was pretreated by an alkaline hydrothermal (HT) process using 1%, 2% and 3% NaOH to produce solid biocarbon and the resulting alkaline hydrothermal process water (AHTPW), a co-product of biocarbon, underwent fast digestion under AD conditions to produce biomethane and biofertilizer. A predetermined HT process of 240 °C for 30 min was considered and the effect of alkali content on the HT process for biocarbon and biomethane product a rate of 8.21 MJ kg−1 and 9.23 MJ kg−1 of raw CR, respectively. Among the three selected alkaline HT processes, the 1% NaOH HT process produced the highest hybrid bioenergy of 11.39 MJ kg−1 of raw CR with an overall energy recovery of 62.82% of raw CR. The AHTPW of 2% and 3% NaOH HT-treated CR did not produce considerable amount of biomethane and their biocarbons contained 3.44 MJ kg−1 and 3.27 MJ kg−1 of raw CR of bioenergy, respectively. The biomethane produced from 5 mm chopped CR, <500 µm ground CR and 1% alkaline AHTPW for 30 days retention time were of 275.38 L kg−1 volatile solid (VS), 309.59 L kg−1 VS and 278.70 L kg−1 VS, respectively, compared to non-treated CR of 144–187 L kg−1 VS. Nutrient enriched AD digestate is useable as liquid fertilizer. Biocarbon, biomethane and biofertilizer produced from the 1% alkaline HT process at 240 °C for 30 min can reduce the greenhouse gas (GHG) emissions of Ontario.

https://www.mdpi.com/1996-1073/11/3/516/pdf

Subhash Paul

Papers

Challenges and opportunities of lignocellulosic biomass for anaerobic digestion

Municipal Food Waste to Biomethane and Biofertilizer: A Circular Economy Concept

Techno-economic assessment of corn stover for hybrid bioenergy production: A sustainable approach

Biocarbon, biomethane and biofertilizer from corn residue: A hybrid thermo-chemical and biochemical approach

Mechanical and Alkaline Hydrothermal Treated Corn Residue Conversion in to Bioenergy and Biofertilizer: A Resource Recovery Concept