Impact of nanoparticle inclusion on bioethanol production process kinetic and inhibitor profile

Photocatalytic nanomaterials and their implications towards biomass conversion for renewable chemical and fuel production

Photocatalytic processes have recently gained popularity as a sustainable and energy-efficient method for converting biomass. This article gives a comprehensive overview of recent improvements in the photocatalytic conversion of biomass into useful chemicals and fuels utilizing various photocatalytic materials. The work delves into the assessment of diverse biomass sources and their preparation techniques, in addition to the synthesis of plasmonic nanoparticles as photocatalysts from biomass, offering a thorough examination. This review article provides detailed techniques for fabricating and synthesizing plasmonic nanoparticles. Furthermore, the study discusses advancements in coupling photo-oxidation alongside the hydrogen evolution mechanism for water splitting. Furthermore, prospective research topics are suggested, such as conducting a systematic analysis of photocatalysis's redox potential, developing more effective catalysts, broadening the variety of reaction types, and establishing industrial-scale photocatalytic production. Plasmonic photocatalysts have been utilized to convert biomass into H2 for energy, and to explore hypothesized molecular routes for the photocatalytic oxidation of 5-hydroxymethylfurfural (HMF), which may then be converted into 2,5-furandicarboxylic acid (FDCA). This review also discusses the surface functionalization of nanophotocatalysts with -COOH, NH2, and OH groups to increase their reactivity. Reactive oxygen species (ROS) formed on the surface of nanophotocatalysts under UV or solar light play a crucial role in photocatalytic reactions. Our review has shown many challenges and difficulties related to CO2 hydrogenation reactions in the presence of sustainable H2, powered by renewable energy sources. This is very critical for achieving a transition to net-zero emissions. These technologies will drive forward the development of biomass conversion processes into CO2-based fuels. This paper explores recent advancements in the conversion of biomass-derived CO2 into valuable chemicals using plasmonic nanophotocatalysts. In addition to this, density functional theory (DFT) calculations also reveal how functional groups help stabilize these nanoparticles and enhance electron density through photo-adsorption. This study provides a remarkable and significant review that examines current trends, future directions, and ongoing debates in this field, focusing on reaction conditions, catalyst design, and proposed mechanisms for producing valuable chemicals. These chemicals include single-carbon compounds like formaldehyde, formic acid, and methanol, as well as C2 + compounds such as acetic acid, ethanol, methyl formate, and oxyethylene ethers. Additionally, it addresses the current state of liquid-phase CO2 hydrogenation in the presence of photocatalysts, highlighting existing challenges and potential research paths. The paper also provides an overview of the advances and challenges in the electro- and photocatalytic oxidation of HMF (hydroxymethylfurfural), detailing strategies for creating high-value chemicals through these oxidation processes. These methods, which may involve reactions like the hydrogen evolution reaction, organic substrate reduction, CO2 reduction reaction, or N2 reduction reaction, are summarized and analyzed. Furthermore, the catalytic efficiency and mechanisms of various catalyst types in these conversion systems are introduced and discussed. Electron paramagnetic resonance and scavenger studies reveal the major active species (˙OH and ˙O2 -) in the photocatalytic conversion of biomass to different value-added products.

Dual strategy for bioconversion of elephant grass biomass into fermentable sugars using Trichoderma reesei towards bioethanol production

In this study, biodelignification and enzymatic hydrolysis of elephant grass were performed by recombinant and native strain of Trichoderma reesei, respectively. Initially, rT. reesei displaying Lip8H and MnP1 gene was used for biodelignification with NiO nanoparticles. Saccharification was performed by combining hydrolytic enzyme produced with NiO nanoparticles. Elephant grass hydrolysate was used for bioethanol production using Kluyveromyces marxianus. Maximum lignolytic enzyme production was obtained with 15 µg/L of NiO nanoparticles and initial pH of 5 at 32 °C. Subsequently, about 54% of lignin degradation was achieved after 192 h. Hydrolytic enzymes showed elevated enzyme activity and resulted in 84.52 ± 3.5 g/L of total reducing sugar at 15 µg/mL NiO NPs. About 14.65 ± 1.75 g/L of ethanol was produced using K. marxianus after 24 h. Thus, dual strategy employed for conversion of elephant grass biomass into fermentable sugar and subsequent biofuel production could become potential platform for commercialization.

Impact of nanomaterials on sustainable pretreatment of lignocellulosic biomass for biofuels production: An advanced approach

Biomass to biofuels production technology appears to be one of the most sustainable strategies among various renewable energy resources. Herein, pretreatment is an unavoidable and key step to increase free cellulose availability and digestibility to produce green fuels. Various existing pretreatment technologies of lignocellulosics biomasses (LCBs) face distinct challenges e.g., energy consuming, cost intensive, may lead partial removal of lignin, complex inhibitors production as well as may cause environmental pollutions. These, limitations may be overcome with the application of nanomaterials, employed as nanocatalysts during the pretreatment process of LCBs. In this prospect, the present review focuses and summarizes results of numerous studies and exploring the utilizations of magnetic, carbon based nanostructure, and nanophotocatalysts mediated pretreatment processes along with their possible mechanisms to improve the biofuels production compared to conventional chemical based pretreatment approaches. Furthermore, different aspects of nanomaterials based pretreatment methods with their shortcomings and future prospects have been discussed.

Perspectives on Nanomaterials and Nanotechnology for Sustainable Bioenergy Generation

The issue of global warming calls for a greener energy production approach. To this end, bioenergy has significant greenhouse gas mitigation potential, since it makes use of biological products/wastes and can efficiently counter carbon dioxide emission. However, technologies for biomass processing remain limited due to the structure of biomass and difficulties such as high processing cost, development of harmful inhibitors and detoxification of produced inhibitors that hinder widespread usage. Additionally, cellulose pre-treatment is often required to be amenable for an enzymatic hydrolysis process. Nanotechnology (usage of nanomaterials, in this case) has been employed in recent years to improve bioenergy generation, especially in terms of catalyst and feedstock modification. This review starts with introducing the potential nanomaterials in bioenergy generation such as carbon nanotubes, metal oxides, silica and other novel materials. The role of nanotechnology to assist in bioenergy generation is discussed, particularly from the aspects of enzyme immobilization, biogas production and biohydrogen production. Future applications using nanotechnology to assist in bioenergy generation are also prospected.

The Expansion of Lignocellulose Biomass Conversion Into Bioenergy via Nanobiotechnology

Lignocellulosic biomass has arisen as a solution to our energy and environmental challenges because it is rich in feedstock that can be converted to biofuels. Converting lignocellulosic biomass to sugar is a complicated system involved in the bioconversion process. There are indeed a variety of techniques that have been utilized in the bioconversion process consisting of physical, chemical, and biological approaches. However, most of them have drawbacks when used on a large scale, which include the high cost of processing, the development of harmful inhibitors, and the detoxification of the inhibitors that have been produced. These constraints, taken together, hinder the effectiveness of current solutions and demand for the invention of a new, productive, cost-effective, and environmentally sustainable technique for LB processing. In this context, the approach of nanotechnology utilizing various nanomaterials and nanoparticles in treating lignocellulose biomass and bioenergy conversion has achieved increased interest and has been explored greatly in recent times. This mini review delves into the application of nanotechnological techniques in the bioconversion of lignocellulose biomass into bioenergy. This review on nanotechnological application in biomass conversion provides insights and development tools for the expansion of new sectors, resulting in excellent value and productivity, contributing to the long-term economic progress.

Current Trends and Future Prospects of Nanotechnology in Biofuel Production

Biofuel is one of the best alternatives to petroleum-derived fuels globally especially in the current scenario, where fossil fuels are continuously depleting. Fossil-based fuels cause severe threats to the environment and human health by releasing greenhouse gases on their burning. With the several limitations in currently available technologies and associated higher expenses, producing biofuels on an industrial scale is a time-consuming operation. Moreover, processes adopted for the conversion of various feedstock to the desired product are different depending upon the various techniques and materials utilized. Nanoparticles (NPs) are one of the best solutions to the current challenges on utilization of biomass in terms of their selectivity, energy efficiency, and time management, with reduced cost involvement. Many of these methods have recently been adopted, and several NPs such as metal, magnetic, and metal oxide are now being used in enhancement of biofuel production. The unique properties of NPs, such as their design, stability, greater surface area to volume ratio, catalytic activity, and reusability, make them effective biofuel additives. In addition, nanomaterials such as carbon nanotubes, carbon nanofibers, and nanosheets have been found to be cost effective as well as stable catalysts for enzyme immobilization, thus improving biofuel synthesis. The current study gives a comprehensive overview of the use of various nanomaterials in biofuel production, as well as the major challenges and future opportunities.