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New Concepts and Future Trends
Published in Cesar Ovalles, Subsurface Upgrading of Heavy Crude Oils and Bitumen, 2019
The concept involves the use of RF heating coupled with hydrocarbon solvent addition (chain lengths of C2 to C5) for enhanced heavy oil recovery. As shown in Figure 10.4, the radiofrequency emitted from the antenna in an SAGD-type of configuration preheats the hydrocarbon-containing formation, allowing the solvent to dissolve the bitumen with the concomitant increase in oil production. The hydrocarbon solvent is added from the top horizontal well (Figure 10.4), and the oil is produced from the bottom. By using this concept, the formation does not have to be brought up to a steam temperature which reduces greenhouse gas emissions. The solvent reduces the viscosity of the bitumen, increasing its mobility, which in turn leads to enhanced heavy oil recovery and possibly subsurface upgrading via solvent deasphalting [Trautman et al. 2014, Trautman and MacFarlane 2014, Despande et al. 2015, Wise and Patterson 2016].
Carbene or C1 Polymerization
Published in Samir H. Chikkali, Metal-Catalyzed Polymerization, 2017
Bas de Bruin, Samir H. Chikkali
As noted in Chapter 2, metal-catalyzed polymerization of carbon–carbon double bond (C=C) containing monomers is most widely known and today we produce roughly 180 million tons of polyolefins every year.1 In this so-called olefin polymerization or vinyl insertion polymerization method, each monomer delivers two carbon (C2) atoms in each propagation step. Insertion polymerization of monomers delivering only one carbon unit in each chain growth step is named as C1 or carbene polymerization (see Figure 3.1).2 In the recent past, C1 polymerization techniques are being viewed as a valuable alternative to the classical C2 polymerization methods. Not only this but also C1 polymerization offer distinct advantages over C2 polymerization and thus opens up new avenues for the development of new material with polymer properties that are very difficult to achieve using traditional C2 polymerization methods. In this chapter we will discuss the significance of C1 polymerization and the different methods used for C1 polymerization, will summarize the recent developments, and will highlight the elementary steps involved in it.
60 buckminsterfullerene formation process: new revelations after 25 years
Published in Harry Kroto, 60: Buckminsterfullerene, 2016
It needed to be proven that the larger fullerenes resulted from carbon incorporation into the pre-formed C60. Therefore, I exposed C60 to nearly pure 13C-carbon vapour under identical parameters to track carbon incorporation events (Fig. 5). This experiment neatly and unambiguously revealed that C2 and atomic carbon were ingested by C60 to grow into larger fullerenes. Facile atom exchange events were also observed. Harry contacted a former colleague and
High-performance polymers based on PEG and PAMAM dendrimer to inhibit clay swelling in water
Published in Petroleum Science and Technology, 2023
Hugo Noronha da Silva Barros, Matheus Andrade Weisblum, Maximiliano de Freitas Martins, Luiz Carlos Bertolino, Ítalo Guimarães Medeiros da Silva, Thiago Marconcini Rossi, Bluma Guenther Soares, Elizabete Fernandes Lucas
The structures of PEG2 (molar mass 200 g/mol) and PEG4 (molar mass 400 g/mol), modified at their ends with linear hydrocarbon chains of differing lengths (C2, C4, C6, C10 and C12), show that the inhibition capacity is associated with the length of the hydrocarbon chain, the molar mass of the entire molecule, and the sample aqueous solubility. For both PEG2 and PEG4, the best results are obtained for the derivative with hexanoic acid (C6), evidencing an optimum hydrocarbon chain length, in contrast to that statement by the literature, that is the efficiency increases as increasing the length of the hydrophobic chain. The molar mass of the molecule also affects the efficiency of this kind of additive: although PEG2C6 and PEG4C12 presents similar hydrophilic-lipophilic balance, the best performance is exhibited by PEG2C6, which presents lower molar mass.
An Experimental Investigation of Supersonic Combustion of Mildly Cracked N-Dodecane
Published in Combustion Science and Technology, 2022
Naifu Cui, Wei Rao, Yujun Li, Taichang Zhang, Xuejun Fan
The Laval nozzle is adopted to accelerate the high-enthalpy vitiated air flow to designed supersonic flow, which is Mach number of 3.0 in this work. The schematic diagram of the combustor is shown in Figure 1, the isolation section is 400 mm long with an expansion angle 0.7 deg, the combustion section is 800 mm long with an expansion angle 2.0 deg, and the expansion section is 300 mm long with an expansion angle 5.3 deg. The upstream cavity (C1) and the downstream cavity (C2) integrated fuel-injection/flame-holder are installed on the opposite sides of the combustor. The spacing ∆X between two fuel injectors is variable in the range of 40–390 mm through varying the relative location of C1 and C2. ∆X is 90 mm in this work. The two cavities have a depth of 12 mm, and the cavity aft ramp angle and L/D ratio are 45 deg and 7, respectively. The distance between the upstream injection position of fuel and the isolator entrance is 572 mm, and the downstream injection position of fuel is 662 mm from the isolator entrance. The upstream and downstream fuel injectors have two orifices with the diameter of 2 mm, respectively. The distance between the cavity upstream transverse fuel injection ports and the cavity leading edge is 56 mm, respectively. The pilot hydrogen is injected from five orifices of 1 mm diameter. The distance between the upstream pilot hydrogen injection ports and the cavity leading edge is 8 mm. Fuel and hydrogen are injected into supersonic airstream vertically and then ignited by a spark plug of 50 J/pulse energy at the bottom of upstream cavity.
Response of flames with different degrees of premixedness to acoustic oscillations
Published in Combustion Science and Technology, 2018
A.M. Kypraiou, P.M. Allison, A. Giusti, E. Mastorakos
For flames P-15-070-160-30, NPR-15-070-160-30, and NPR-15-055-160-30, the variance, and thus the level of OH fluctuations associated with the whole frequency range, is the greatest in the near wall region, unlike flame NPA-15-042-160-30, where the highest values of the variance are found in the ISL region (Figure 4(a1, b1, c1, d1)). This difference is explained by the fact that in the latter flame, the impingement on the wall is less pronounced compared to the other flames. The proportion of OH fluctuations at 160 Hz versus the overall fluctuations, , is greater in the ISL region than in the other regions for flames NPR-15-070-160-30, NPR-15-055-160-30, and NPA-15-042-160-30, whereas for flame P-15-070-160-30, these values are greater in large regions on the downstream side of the OH PLIF plane than those in the ISL region close to the bluff body plane (Figure 4(a2, b2, c2, d2)). Flame NPA-15-042-160-30 shows that in the region downstream of the fuel injection point, is negligible. The comparison between Figure 4(b2,c2) suggests that in the ORZ region is relatively high in flame NPR-15-070-160-30, unlike flame NPR-15-055-160-30, due to the penetration of unburnt reactants in the ORZ in the case of the higher overall .