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Published in Brajendra K. Sharma, Girma Biresaw, Environmentally Friendly and Biobased Lubricants, 2016
Kenneth M. Doll, Bryan R. Moser, Zengshe Liu, Rex E. Murray
In the industrial use of metathesis technology, the 18-carbon diacids from self-metathesis of oleic-rich oils serve as precursors to polyamides, polyurethanes, lubricants, and adhesives. Other products from the cross metathesis reaction with ethene of high-oleic plant oils to yield 1-decene and methyl 9-decenoate (Figure 5.5) are also industrially significant [88]. Decene is a valuable α-olefin used in the production of polyalphaolefins (PAOs) and other important chemicals [110]. However, markets for and applications of methyl 9-decenoate are still under development. In addition, practical and scalable methods for production of this emerging biobased chemical intermediate are needed. Existing literature on chemical modification of methyl 9-decenoate includes metathetical dimerization to yield an 18-carbon diacid, identical to that obtained from self-metathesis of methyl oleate [111]. Other chemical modifications include oxidative hydroformylation to yield an 11-carbon diacid for polyesters; derivatization to 10-aminodecanoic acid needed for nylon-10 production; and epoxidation to 9,10-epoxydecanoic acid used as a monomer for epoxy resins [112]. Additionally, transesterification of methyl 9-decenoate with simple diols followed by acyclic diene metathesis polymerization yields unsaturated polyesters which are used in adhesives, coatings, fibers, and resins and which are potentially biodegradable [113]. Nonpolymer applications of methyl 9-decenoate include hydrolysis and hydrogenation to yield decanoic acid or decanol, both of which are used in the synthesis of lubricants and plasticizers [114]. Methyl 9-decenoate is also used to produce fragrances (9-decen-1-ol), pheromones (9-oxo-trans-2-decenoic acid), and prostaglandin intermediates (9-oxodecanoic acid) [115,116].
Organocatalysis with carbon nitrides
Published in Science and Technology of Advanced Materials, 2023
Sujanya Maria Ruban, Kavitha Ramadass, Gurwinder Singh, Siddulu Naidu Talapaneni, Gunda Kamalakar, Chandrakanth Rajanna Gadipelly, Lakshmi Kantham Mannepalli, Yoshihiro Sugi, Ajayan Vinu
In another interesting report, Biswas and Mahalingan presented the synergistic impact of combining g-C3N4 with tetrabutylammonium bromide (TBAB) to convert epoxides to cyclic carbonates for the first time at 1 atm pressure under solvent-free conditions [197]. Epichlorohydrin, styrene oxide, phenyl glycidyl ether, and allyl glycidyl ether were all converted to cyclic carbonates using 50 mg of g-C3N4 and 1.8 mol% of TBAB relative to an epoxide (13.7 mmol) at 1 bar of CO2 at 105°C for 20 hours. However, very modest conversions were found for other epoxides such as 1,2-epoxy hexane, 1,2-epoxy octane, and 1,2-epoxy-9-decene, and no ring-opening of the internal epoxide cyclohexene oxide occurred. The authors have reported only conversions rather than separate yields of the cyclic carbonate products. Catalyst recycling studies revealed no loss of activity after 7 cycles. Tests performed with these reagents separately showed conversion rates below 40%. It is therefore proposed that both g-C3N4 and TBAB work cooperatively. By interacting with the epoxide ring through hydrogen bond formation, the g-C3N4 amino groups increase the electrophilicity of the epoxide carbon. By doing so, the carbon atom becomes more susceptible to nucleophilic attack by the bromide anion of TBAB, ring opening the epoxide and thereby initiating its conversion into cyclic carbonate (Figure 17).
Co-pyrolysis of seaweeds with waste plastics: modeling and simulation of effects of co-pyrolysis parameters on yields, and optimization studies for maximum yield of enhanced biofuels
Published in Energy Sources, Part A: Recovery, Utilization, and Environmental Effects, 2020
Benjamin Bernard Uzoejinwa, Xiuhua He, Shuang Wang, Abd El-Fatah Abomohra, Yamin Hu, Zhixia He, Qian Wang
GC-MS analysis of oils from pyrolysis experiments of EP, HDPE and their mixtures at different blending ratios were performed to examine their chemical compositions. It was observed that HDPE bio-oil contains many chemical compounds whose components are mostly the aliphatic hydrocarbons (alkanes and alkenes) with carbon number C5-C20 (a detailed account of the identified compounds is given in the supplementary material attached to this paper), and the highest peak areas of total ion chromatogram (TIC) of the compounds were Pentadecane, Hexadecane, n-Heptadecane, n-Octadecane, 1-Pentadecene, 1-Decene, and 1-Nonadecene. However, Table 10 presents a summary of the main compound classes in the pyrolysis oil of HDPE via GC-MS analysis. On the other hand, algal oils are very complex mixtures of organic compounds with different molecular structures and weights. Aysu and Sanna (Aysu and Sanna 2015) investigated the major compounds in the oils from pyrolysis of green microalga (Nannochloropsis) and divided the compounds into several groups such as aliphatics, aromatics, oxygenated compounds, nitrogen-containing compounds and their derivatives. Zhang et al. (2015) also investigated the effects of water washing and torrefaction pretreatments on rice husk pyrolysis via microwave heating, and classified the oil compositions into eight main groups: acids, ketones/aldehydes, furans, phenols, esters, sugars, nitrogen-containing compounds and others. In this present study, many compounds were identified in the oils obtained the pyrolysis of EP and their mixtures with HDPE at different blending ratios via GC-MS and classified into several chemical groups, based on their functional groups: furans, saccharides, phenols, aldehydes/ketones, carboxylic acids/esters, hydrocarbons, and nitrogen-containing compounds. Table 11 presents the main chemical compounds in the bio-oils as well as their relative contents, while Figure 9 presents a summary of relative compositions of identified main group of compounds in the oils. From the figure, it can be seen that the dominant compounds in the oil from pyrolysis of EP alone are mainly the carboxylic acids/esters (41.72 ± 0.06%) and nitrogen-containing compounds (19.73 ± 0.04%). Likewise, the relative contents of oils from co-pyrolysis of EP and HDPE at different blending ratios can also be observed directly from Figure 9. Obviously, the GC-MS results revealed a considerable decrease in contents of furans, oxygenates, nitrogen-containing compounds and saccharides in the bio-oils owing to the synergistic interactions between the co-feeding materials during the co-pyrolysis process, which results in increase in relative contents of hydrocarbons as the mass percentage of HDPE in the feedstock increases, when compared with those of the EP oil. These significant differences were associated with the notable role of the secondary reactions in the fixed-bed reactor and the oligomerization reaction of volatiles in condensation process (Butler et al. 2013; Patwardhan et-al., 2011).