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The Tailor-made Fuels from Biomass (TMFB) project aims to develop renewable and environmentally friendly fuels suitable for internal combustion engines (ICEs). The TMFB fuels can be produced from lignocellulose, helping to avoid land competition with edible food for production. After years of research, 2-butanone, 2-methylfuran (2-MF), 2-methyltetrahydrofuran (2-MTHF), n-octanol, and di-n-butyl ether (DnBE), have been identified as the promising TMFB fuels that are suitable for ICEs. This paper first discusses the physicochemical properties of the above five fuels. It then reviews the experimentally measured fundamental combustion characteristics, including ignition delay and flame speed. In addition, progress in detailed chemical kinetic modeling of the TMFB fuels is also presented individually. These models are validated against measured experimental ignition delay or flame speed data. The reaction pathway analysis for the five fuels can be performed based on these validated kinetic models. Next, the effects of the above five TMFB fuels on the combustion and emission characteristics of ICEs are summarized. 2-Butanone and 2-MF can be used as gasoline replacement fuels for spark ignition engines. 2-MF and 2-MTHF can be used in compression ignition engines by blending with highly reactive fuels. N-octanol and DnBE are isomers and can be used either alone or as blended fuels for compression ignition engines. Both the advantages and disadvantages of the above-mentioned fuels used in ICEs have been discussed in this paper. Finally, the remaining research gaps in fundamental combustion characteristics and engine applications are discussed to guide future research directions. • A comprehensive summary of five TMFB fuels is given. • The physical and chemical properties of TMFB fuels are compared. • Experimental and kinetic modeling of the oxidation process are discussed in detail. • Their impacts on engine combustion and emissions formation are presented in detail. [ABSTRACT FROM AUTHOR]

The production of biodiesel through enzymatic routes has attracted significant attention, mainly because this can be regarded as a "green route" for the manufacture of fuels. In this way, an advanced bibliometric analysis comprising the global scientific production of biodiesel through immobilized enzymes was conducted. Thus, 923 papers were retrieved, analyzed, and classified according to the reported substrates, enzymes, supports, immobilization procedures, and reactors. Researchers from 748 institutions of 64 distinct countries authored the analyzed articles, showing the widespread interest in these technologies, although 10 countries concentrate more than 80% of the total number of documents published in this area, including China (23%), Brazil (17%), and India (11%). Particularly, most papers reported the use of vegetable oils (67%) as raw materials. In the last decade, approximately 80% of the published research focused on the use of supports to manufacture immobilized and insoluble biocatalysts. Enzymes have been obtained mostly from fungal sources (64%), especially lipases produced by Thermomyces lanuginosus (14.4%). Among the available commercial immobilized biocatalysts, Novozym 435 is certainly the one cited most frequently (55.9%) followed by Lipozyme RM IM (13.7%) and Lipozyme TL IM (16.7%). Additionally, the majority of the manuscripts reported the use of stirred tank reactors (83.0%) to perform the enzymatic reactions. Based on the surveyed literature, research trends indicate that new technologies are being developed to turn the enzymatic production of biodiesel more sustainable and economically viable, based mainly on the use of more active biocatalysts, more sustainable enzyme supports, and low-cost residues as raw materials. • Advanced bibliometric review about the production of biodiesel by immobilized enzyme was performed. • Chinese and Brazilian scientific communities are the most active in this field. • Novozymes 435 is the commercial biocatalyst used most often in this field. • Emerging technologies were identified for the synthesis of enzyme supports. • Sustainable supports and low-cost feedstocks are trends in the biodiesel production field. [ABSTRACT FROM AUTHOR]

This virtual special issue published in Renewable and Sustainable Energy Reviews contains 25 high-quality selected extended papers presented at the HERAKLION 2019 7th International Conference on Sustainable Solid Waste Management held in Heraklion, Crete in Greece from 26th to June 29, 2019. The articles published in this special issue focus on recent developments in sustainable waste-to-energy systems and waste management practices and highlight the critical challenges and potential solutions. The editorial paper aims to give a brief overview of the key findings and future perspectives proposed in these 25 selected papers. It is worth noting that although the articles presented in this special issue covered a wider range of topics, they are categorized into five categories. These include the latest developments in 1) waste-to-energy technologies, 2) biofuels and bioenergy, 3) waste valorization, 4) emerging renewable and sustainable energy systems, and finally, 5) biorefineries and circular economy. • Twenty five high quality peer-reviewed papers were selected from HERAKLION 2019 Conference. • The mian theme of sustainable waste-to-energy systems catogorised into five topics. • It will support advancement of waste-to-energy technologies and circular economy. [ABSTRACT FROM AUTHOR]

Oil palm wastes (OPWs) are important biomass resources, and approximately 127 million tons of OPWs are generated from the oil palm industry annually in Malaysia. The scientific and reasonable utilization of OPWs is essential to economic and environmental sustainability in the country. Pyrolysis is a mature and revolutionary technology that can convert OPWs into biofuel. The conversion of OPWs into biofuel is in accordance with the national conditions of Malaysia and can simultaneously address the problems of fossil fuel shortage and environmental deterioration. Therefore, Malaysia is the most active country in the research of OPWs pyrolysis and has achieved fruitful results. Bio-oil produced from the catalytic co-pyrolysis of OPWs with hydrogen-rich materials exhibits remarkable fuel properties. Biochar generated from OPWs pyrolysis presents huge application potential as an absorbent, catalyst, soil conditioner, and carbon sequestration agent. Consequently, the paper provides a comprehensive review of OPWs pyrolysis and lays the foundation for the exploitation of OPWs resources. [Display omitted] • Malaysia is the most active country in the research of OPWs pyrolysis. • Effects of reactors and conditions on OPWs pyrolysis are detailed. • OPWs-based biochar exhibits great application potential in various fields. • Building a pyrolysis plant near the oil palm mill is a viable and economic method. • OPWs pyrolysis has great commercial potential and economic value in Malaysia. [ABSTRACT FROM AUTHOR]

The novel coronavirus (COVID-19) is highly detrimental, and its death distribution peculiarity has severely affected people's health and the operations of businesses. COVID-19 has wholly undermined the global economy, including inflicting significant damage to the ever-emerging biomass supply chain; its sustainability is disintegrating due to the coronavirus. The biomass supply chain must be sustainable and robust enough to adapt to the evolving and fluctuating risks of the market due to the coronavirus or any potential future pandemics. However, no such study has been performed so far. To address this issue, investigating how COVID-19 influences a biomass supply chain is vital. This paper presents a dynamic risk assessment methodological framework to model biomass supply chain risks due to COVID-19. Using a dynamic Bayesian network (DBN) formalism, the impacts of COVID-19 on the performance of biomass supply chain risks have been studied. The proposed model has been applied to the biomass supply chain of a U.S.-based Mahoney Environmental® company in Washington, USA. The case study results show that it would take one year to recover from the maximum damage to the biomass supply chain due to COVID-19, while full recovery would require five years. Results indicate that biomass feedstock gate availability (FGA) is 2%, due to pandemic and lockdown conditions. Due to the availability of vaccination and gradual business reopenings, this availability increases to 92% in the second year. Results also indicate that the price of fossil-based fuel will gradually increase after one year of the pandemic; however, the market prices of fossil-based fuel will not revert to pre-coronavirus conditions even after nine years. K-fold cross-validation is used to validate the DBN. Results of validation indicate a model accuracy of 95%. It is concluded that the pandemic has caused risks to the sustainability of biomass feedstock, and the current study can help develop risk mitigation strategies. • Impact of coronavirus (COVID-19) on biomass supply chain is studied. • A case study of a US based biofuel company is presented. • A dynamic Bayesian network (DBN) model is developed to investigate the biomass supply chain's risk over ten years, considering pandemic and post-coronavirus situations. • The DBN model is able to predict risks and their behaviours under uncertainties. • Study identifies high preprocessing costs of biomass resource due to COVID-19. • Model validation indicates an accuracy of 95%. [ABSTRACT FROM AUTHOR]

Over the coming years, the world is projected to witness an upsurge in "drop-in" aviation biofuel production as part of the renewable energy and bioeconomy developments. This paper presents a comprehensive review of the current status of biojet fuel development and uptake in global commercial aviation industry, including state-of-the-art certified technologies (i.e. Fischer-Tropsch (FT); hydroprocessed esters and fatty acids (HEFA); alcohol-to-jet (ATJ); and hydroprocessing of fermented sugars (HFS)); potential feedstock that can be deployed; a comparison of techno-economic and environmental performances of biojet fuel production routes; airlines' commitment in promoting higher biofuel uptake; and global initiatives and policies. This review shows that the HEFA route using oil-based crops is best performing in terms of lowest production cost and greenhouse gas emissions, however it is in competition with the existing road transport biofuel market. Lignocellulosic biomass and waste feedstock should be promoted in view of replacing food/feed crops which have high indirect land use change emissions. Therefore, further improvement should be focused on FT, ATJ and HFS routes to enhance the cost effectiveness of biojet fuel production and promote commercialisation of these technologies. The selection of feedstock and technologies for SAF production should be justified based on production cost and environmental footprint, while avoiding competition with the existing road transport biofuel market. The shortcomings in the SAF policies such as blending mandate and multiplier in RED II should be addressed to reduce the negative impacts of feedstock competition between the road and aviation biofuel sectors and to meet the decarbonisation targets. • Waste and residue feedstock should be deployed for biojet fuel production. • Non-oil based routes require further improvement on cost competitiveness. • Imposing a blending mandate is more effective than voluntary approach. • Multi-stakeholder collaboration promotes uptake of sustainable aviation fuel. [ABSTRACT FROM AUTHOR]