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Sustainable Production and Utilization Technologies of Biojet Fuels
Published in Prasenjit Mondal, Ajay K. Dalai, Sustainable Utilization of Natural Resources, 2017
Philip E. Boahene, Ajay K. Dalai
Today, renewable diesel and jet fuels have proven to be sustainable resources with great potentials for future energy demands and security. That notwithstanding, in order to meet the growing demand for renewable biofuels, which is driven by stringent biofuel mandates and high consumer demands, a wide variety of feedstocks, cutting-edge conversion technologies, as well as the by-products upgrading into more economically valuable products have to be taken into consideration. Unlike other biofuels, including jet fuels, HEFA fuels are chemically similar to their petroleum counterparts and are technically hydrocarbons rather than alcohols or esters. Drop-in fuels from bioalcohols can also be produced during the upgrading process to remove the oxygen present in the bioalcohols to generate hydrocarbons, which could be used directly as fuels or be reformed to generate longer-carbon-chain molecule to produce jet fuels. Currently, HEFA fuels are approved by ASTM International for use in jet engines at up to a 50% blend rate with petroleum jet fuel [43]. HEFA fuels are the most common drop-in biofuels; they can be used in diesel engines, without the need for blending with petroleum diesel fuel.
Hydrothermal Liquefaction A Promising Technology for High Moisture Biomass Conversion
Published in Jaya Shankar Tumuluru, Biomass Preprocessing and Pretreatments for Production of Biofuels, 2018
Ankita Juneja, Deepak Kumar, Jaya Shankar Tumuluru
Products of HTL process include a high heating value biocrude or bio-oil, an aqueous fraction, gases, and solid residues (Fig. 2). Biocrude, with reduced oxygen content (10–20%), contains a mixture of a wide range of molecular weight compounds depending on the feedstock composition and process conditions (Vardon et al., 2011). Due to lower O:C and H:C ratios, the biocrude obtained after liquefaction is of superior quality and has relatively very high heating value (35–40 MJ/kg) compared to raw biomass (15–25 MJ/kg). Bio-oil can be used directly to co-fire with coal or can be upgraded for high-quality fuels (Barreiro et al., 2013). For example, bio-oil can be hydrotreated to produce a highly usable form of fuel, renewable diesel, or jet fuel. Some of the advantages of renewable diesel over biodiesel and petroleum-based diesel are (1) direct use in diesel-powered vehicles without modifications, (2) compatibility with current diesel distribution infrastructure, (3) production using existing oil refinery capacity, (4) use of advance emission control devices due to ultra-low sulfur content and (5) better performance than diesel (Tier, 2010). Aqueous phase after HTL process contains a high amount of organic matter and nutrients. Minerals such as nitrates, phosphorus, iron, and potassium can be separated from the aqueous phase and reused for various purposes such as algae growth (Biller et al., 2012; Jena et al., 2011b; Zhou et al., 2013). The produced gases could be recirculated for various purposes such as CO2 for microalgae production and H2 for biocrude upgradation (Barreiro et al., 2013). Solid residues, also called as biochar, contain nutrients and can be used as a soil enhancer.
Biomass as a Source for Heat, Power and Chemicals
Published in Subhas K. Sikdar, Frank Princiotta, Advances in Carbon Management Technologies, 2021
Vegetable oil refining is a process to transform vegetable oil into biofuel by hydrocracking or hydrogenation. Hydrocracking breaks big molecules into smaller ones using hydrogen while hydrogenation adds hydrogen to molecules. These methods can be used for production of gasoline, diesel, propane, and another chemical feedstock. Diesel fuel produced from these sources is known as green diesel or renewable diesel.
Biofuels from spent coffee grounds: comparison of processing routes
Published in Biofuels, 2022
Sanette Marx, Roelf Venter, Sanjib Kumar Karmee, Jaco Louw, Chantelle Truter
In all instances, the produced renewable diesel fuel had an HHV close to that of conventional fossil-based diesel (45.6 MJ/kg). In contrast, the produced biodiesels had HHVs that were approximately the same as that of the extracted oils. In terms of performance, a car would be able to drive roughly the same distance on either fossil-based diesel or renewable diesel but would require around 1 L of biodiesel per 100 km extra to drive the same distance on biodiesel. The advantage of renewable diesel over biodiesel thus lies in both the HHV value and the fact that it can be used neat or in any blending ratio as diesel fuel in any conventional modern diesel engine.
Comparison of fuel characteristics of green (renewable) diesel with biodiesel obtainable from algal oil and vegetable oil
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2018
Tanisha Manchanda, Rashmi Tyagi, Durlubh Kumar Sharma
Biodiesel has good lubricating properties. Green diesel or renewable diesel has higher calorific value and lower oxygen contents. In fact, green diesel seems to be a good fuel by comparing the fuel characteristics, excepting its pour point is higher and this may need some additives. It may be better to use a blend of both biodiesel and green diesel. This would help in complementing the properties of each fuel and both the biofuels are renewable and help in the biosequestration of CO2. There is a wide scope of further studies in this direction towards setting up biorefineries and establishing bioeconomy.
Current status and future prospects of biological routes to bio-based products using raw materials, wastes, and residues as renewable resources
Published in Critical Reviews in Environmental Science and Technology, 2022
Ji-Young Lee, Sung-Eun Lee, Dong-Woo Lee
Thermochemical processes involving high temperature and/or pressure are widely used to convert lignocellulosic feedstock into transportation biofuels (Tanger et al., 2013). Combustion is widely used to produce heat and power from biomass, accounting for over 97% of global bioenergy production, whereas gasification appears to be more suitable for the production of fuels and chemicals from forestry biomass (Sikarwar et al., 2016). For example, gasification of biomass at high temperature (800 − 1100 °C) combined with O2, steam, and air can produce BioSNG, a mixture of mainly carbon monoxide (CO) and hydrogen (H2) (Figure 2a). BioSNG can be further processed to produce biofuel through microbial fermentation by Clostridium and Acetobacterium strains (Munasinghe & Khanal, 2010), or used directly as building blocks for the production of methanol, methane (CH4), DME, and other typical end products of gasification (Sikarwar et al., 2017). Recently, heterologous expression of genes involved in the butanol biosynthetic pathway in Clostridium ljungdahlii has further improved butanol production (Zhang, Zhao, et al., 2020). Pyrolysis, a thermal degradation process occurring under anoxic conditions, is mainly used to convert dry biomass into gaseous, liquid (bio-oil), and solid (bio-char) intermediates that can be further processed to fuels or chemicals through secondary processes (i.e. hydrogenation, fractionation, gasification, and combustion) (Jahirul et al., 2012). Since dry LCB is well suited to most types of pyrolysis, it can be converted into combined heat and power (CHP), or bio-oils and platform molecules such as 5-hydroxymethylfurfural (5-HMF) and levulinic acid via furfural in a biorefinery process (Melero et al., 2012) (Figure 1). Although liquefaction is suitable for the conversion of biomass feedstock with high water content at low temperatures under high H2 pressure, it is not as established as pyrolysis owing to expensive costs and complex reactor setup (Gollakota et al., 2018). Torrefaction, a mild form of pyrolysis in an inert reducing environment, is beneficial for the production of homogeneous fuels from biomass with improved physical properties such as grindability and pelletability (Tumuluru et al., 2011). Hydrogenation can be used as an alternative process for the production of renewable diesel, such as hydrotreated vegetable oil from vegetable and animal oils (Dimitriadis et al., 2018).