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Timber Bridges
Published in Wai-Fah Chen, Lian Duan, Bridge Engineering Handbook, 2019
As mentioned previously, one of the major advances in the 20th century allowing for continued and expanded use of timber as a bridge material is pressure treatment. Two basic types of wood preservatives are used: oil-type preservatives and waterborne preservatives. Oil-type preservatives include creosote, pentachlorophenol (or “penta”), and copper naphthenate. Creosote can be considered the first effective wood preservative and has a long history of satisfactory performance. Creosote also offers protection against checking and splitting caused by changes in MC. While creosote is a natural by-product from coal tar, penta is a synthetic pesticide. Penta is an effective preservative treatment; however, it is not effective against marine borers and is not used in marine environments. Penta is a “restricted-use” chemical, but wood treated with penta is not restricted. Copper naphthenate has received recent attention as a preservative treatment, primarily because it is considered an environmentally safe chemical while still giving satisfactory protection against biological attack. Its primary drawback is its high cost relative to other treatments. All these treatments generally leave the surface of the treated member with an oily and unfinishable surface. Furthermore, the member may “bleed” or leach preservative unless appropriate measures are taken.
Foundations, Framing, Sheathing, and Vapor Barriers
Published in Kathleen Hess-Kosa, Building Materials, 2017
Copper naphthenate (CuN) is an organometallic compound. Beyond its use as a pressure treatment preservative, CuN (oilborne) is available as a stand-alone wood treatment. In other words, it may be superficially sprayed or brushed on wood products. The AWPA does not, however, recommended its use within inhabited structures where occupants may potentially be exposed—exposures resulting in severe eye, skin, and respiratory irritation. Although it is not considered toxic to humans, CuN is very toxic to aquatic life. Wood products treated with CuN should thus not be used in and/or around surface water. According to manufacturers, thermal decomposition products of CuN are carbon dioxide, carbon monoxide, and other “unknowns.”
Thermocatalytic upgrading and viscosity reduction of heavy oil using copper oxide nanoparticles
Published in Petroleum Science and Technology, 2020
Yi-Tang Zhong, Xiao-Dong Tang, Jing-Jing Li, Tian-Da Zhou, Chang-Lian Deng
From Figure 3, viscosity reduction of heavy oil with different catalysts has different catalytic effects. Among them, the viscosity reduction effect of nano-CuO catalyst was more effective than the copper naphthenate (PAS-Cu) catalyst. Under this reaction condition, the viscosity reduction of the two catalysts of nano-CuO and PAS-Cu reached 85.75% and 80.19%, respectively. It was observed that different types of catalysts of the same transition metal have certain effects on viscosity reduction of heavy oil. In this paper, the effect of nano-CuO catalyst on upgrading of heavy oil was mainly studied.
Effect of oil-solubility catalysts on the low-temperature oxidation of heavy crude oil
Published in Petroleum Science and Technology, 2019
Wanfen Pu, Zhezhi Liu, Jihui Ni, Huancai Fan
For several decades, previous researches mostly focused on in situ combustion process in heavy oil reservoirs and low-temperature oxidation process in light oil reservoirs. High pressure air injection (low-temperature oxidation) were successfully utilized in light oil reservoirs, while the main technology used in heavy oil reservoir is in situ combustion (ISC) process (Wu, Guan, and Wang 2007). Recently, the catalytic oxidation of heavy oil at low temperature with air, as a new technology, was proposed by some researchers but had not still been subjected to widespread concern (Kuhlman 2004; Torabi et al. 2012). The main mechanisms of the technology included thermal effect, flue gas flooding, surfactant flooding, and viscosity reduction, (Tang, He, and Cui 2007) etc., The technology overcame the problems such as complex implementation process and complex ignition process for ISC process (Olayiwola and Ayeni 2011). Strazzi et al. studied the effect of catalyst and clay on ISC process. Results showed that stable combustion front would only be get when the clay was added into the system, which indicated that clay had catalysis (Strazzi and Trevisan 2014). Wichert et al. (1995)studied the low-temperature oxidation process of heavy oil. The study found that when used oil-soluble organic acid icon as a catalyst, the viscosity reduction ratio can reach 96.77% and the mole fraction of oxygen in effluent gas was 4.75%. Pu et al. (2015) used oil-soluble cobalt naphthenate as a catalyst, the viscosity reduction ratio was 88.71%, while the viscosity reduction ratio was −281.3% without catalyst. Tang, He, and Cui (2007) found that water-soluble copper naphthenate had good catalytic effect. The viscosity reduction ratio was 96.66%, which was higher than that used the emulsion and viscosity reduction technology. Mayorquin et al. mixed propane (53.1%) into air to improve the diffusion rate of mixed gases, which ultimately improved the reaction rate of low-temperature oxidation (Mayorquin-Ruiz and Babadagli 2012). Abdrabo et al. conducted a serious of low-temperature oxidation experiments. He found that the metal heteroatom in heavy oil can be converted into metal oxide nanoparticles in the presence of catalyst and oxygen (Abdrabo and Husein 2012). Maity, Ancheyta, and Marroquín (2010) classified the types of catalysts for low-temperature oxidation. The catalysts can be divided into oil-soluble catalyst, water-soluble catalyst, dispersed catalyst, and reservoir mineral. The most commonly used catalyst was oil-soluble organic acid salts.