• Energy Research
• 2016-2025close

Biosurfactants have garnered increased attention lately due to their superiority of their properties over fossil-derived counterparts. While the cost of production remains a significant hurdle to surpass synthetic surfactants, biosurfactants have been anticipated to gain a larger market share in the coming decades. Among these, glycolipids, a type of low-molecular-weight biosurfactant, stand out for their efficacy in reducing surface and interfacial tension, which made them highly sought-after for various surfactant-related applications. Glycolipids are composed of hydrophilic carbohydrate moieties linked to hydrophobic fatty acid chains through ester bonds that mainly include rhamnolipids, trehalose lipids, sophorolipids, and mannosylerythritol lipids. This review highlights the current landscape of glycolipids and covers specific glycolipid productivity and the diverse range of products found in the global market. Applications such as bioremediation, food processing, petroleum refining, biomedical uses, and increasing agriculture output have been discussed. Additionally, the latest advancements in production cost reduction for glycolipid and the challenges of utilizing second-generation feedstocks for sustainable production are also thoroughly examined. Overall, this review proposes a balance between environmental advantages, economic viability, and societal benefits through the optimized integration of secondary feedstocks in biosurfactant production.

Abstract Biorefinery is an emerging strategy to progressively replace the conventional refinery. This technique aims to produce biofuels and value-added products from lignocellulosic biomass. With intensive research efforts, a number of innovative technologies have been developed to utilize the building block chemicals from biomass. However, application of the new technique needs to consider the three pillars of sustainable development, i.e., economic, social and environmental development. The concerns could be feedstock- or region-specific, resulting in completely different requirement of desired process under different circumstances. This study reviews the key design concepts and the strengths of the most promising techniques for biomass conversion. Particular attentions are paid to complete utilize all the building block components in the feedstock. Operational parameters such as energy, water, and chemicals are investigated to select desired processes for bioenergy production. The review aims to present the past, current and future research and process development for high efficiency biofuel production.

Biochar generated from thermochemical conversion of biomass reduces greenhouse gas emissions and is useful for improving ecological systems in agriculture. However, certain biochars function well in improving soil, and other biochars do not. Why? Because it is not clear how to prepare the best biochar for soil. There is a disconnect between biochar preparation and returning the biochar to the soil. To elucidate this relationship, this paper reviews (i) technologies for preparing biochar, (ii) how preparation conditions affect biochar properties, and (iii) the effects on soil physical and chemical properties. In addition to reducing greenhouse gas emissions, biochar improves the physicochemical and microbial properties of soil and absorbs poisonous and pernicious substances. Therefore, as biochar is produced by pyrolysis, optimizing processing conditions to improve its properties for agricultural use is a key issue explored in this article.

With the development of technologies and the change of consumer attitudes, the amount of waste electrical and electronic equipment (WEEE) is increasing annually. As the core part of WEEE, the waste printed circuit board (WPCB) is a dangerous waste but at the same time a rich resource for various kinds of materials. In this work, various WPCB treatment methods as well as WPCB recycling techniques divided into direct treatment (landfill and incineration), primitive recycling technology (pyrometallurgy, hydrometallurgy, biometallurgy and primitive full recovery of NMF-non metallic fraction), and advanced recycling technology (mechanical separation, direct use and modification of NMF) are reviewed and analyzed based on their advantages and disadvantages. Also, the evaluation criteria are discussed including economic, environmental, and gate-to-market ability. This review indicates the future research direction of WPCB recycling should focus on a combination of several techniques or in series recycling to maximize the benefits of process.

Industrial-scale upcycling of waste polyethylene terephthalate (PET) plastic into porous carbon globally for CO2 capture was verified as a multifunctional alternative to conventional CO2 absorption and plastic waste management technologies.

Excessive utilization of fossil fuels has resulted in serious concerns about climate change. Integrating biorefinery technology to convert waste-derived-lignocellulosic biomass into biofuels and biopolymers has become an emerging topic toward our sustainable future. Pretreatment to fractionate the building block chemicals from the biomass is a crucial unit operation to ease the downstream processes in biorefinery. However, application of solvents and chemicals in the process can create many operational and environmental challenges in sensitive areas like highly populated cities. To shed light on how to determine a green biorefinery, this study presents the sustainability metrics of various pretreatment techniques and their operational risks during urbanization. The proposed green indexes include fractionation outputs, chemical recyclability, operational profile, and safety factors. In line with the design principles of lignin valorization, the issue of urban biomass and water-and-energy nexus are addressed to support future development and application of urban biorefinery for municipal waste management.

Abstract The recovery of waste cooking oil has long been known for second life uses without chemical modification. However, the concepts of bioeconomy and circular economy are much more recent and include a ranges of tasks such as recovery, storage, use, chemical modification. International research into the use of modified and unmodified waste cooking oil and their potential uses has been the subject of incessant research in both academia and industry. The main purpose of this review is to present the recent breakthroughs obtained in the field of recovery of used cooking oils for the last decade. The review discusses advances obtained in major production pathways recently explored splitting in the following categories: (i) transesterification of waste cooking oil including biodiesel production with heterogeneous/homogeneous base and acid catalysis, magnetic heterogeneous catalysis, biocatalysis and alternative technologies such as electrolysis, continuous flow, microwave irradiation, ultrasound irradiation; (ii) transesterification of waste cooking oil including catalytic biolubricant production; (iii) interesterification; (iv) hydrolysis and (v) hydrodeoxygenation, hydrocracking and hydrogenation. This review also briefly overviews current understanding of waste cooking oil valorization and the underpinning mechanism.