Fouling Characteristics of Hydrocarbon Streams Containing Olefins and Conjugated Olefins

Abstract

The fouling characteristics of a coker gas oil (CGO) containing measurable amounts of olefins and conjugated olefins were investigated using a bench-scale hot liquid process simulator and a batch autoclave reactor at different temperatures. At low surface temperatures (∼200 °C), the fouling propensity of CGO is very low, and at surface temperatures between ∼250 and 325 °C, the fouling propensity is slightly higher because of polymerization of unsaturated olefins. When the surface temperature is further increased to above 350 °C, fouling is observed to increase significantly because of familiar coking reactions. Slow polymerization of olefins and conjugated olefins was observed at temperatures of 270 and 300 °C. However, at 350 °C, thermal cracking reactions that produce olefins and conjugated olefins take place and significant amounts of fouling deposits can be formed at this temperature. The fouling deposits of CGO exhibit typical polyaromatic coke structures. A better understanding of how the various mechanisms interact with temperature will improve management of fouling in process streams containing olefins and conjugated olefins.

Adsorption of heptane–toluene binary mixtures on a hydrophobic polymer surface

“…We therefore transition from a total internal reflection (TIR) regime for heptane, to external reflection for toluene. The intensity in an SFG experiment is proportional to the magnitude squared of the effective second-order susceptibility χ (2) where the refractive indices in the denominator are for the incident phase (polymer thin film), and the reflected angle of the SFG beam θ SFG may be obtained from phase-matching considerations knowing the frequencies and angles of the incident visible and IR beams, and the refractive indices of both adjacent phases. The index of the heptane-toluene mixture has already been described above in the determination of J. Chem.…”

“…In the ssp polarization scheme, we probe a combination of yyx and yyz elements of χ (2) . As there is no orientation of the polymer in the (x, y) plane of the film, it is not possible for the substrate to impart any orientation on the heptane or toluene molecules that would break their rotational C ∞v symmetry at the surface.…”

“…(2) yyz 2 spectra may be compared with the bulk IR-Raman spectra, there are several advantages to instead obtaining the Im{χ (2) yyz } spectra for the discussion.…”

“…Industrial fouling is the process whereby particles in solution adsorb on surfaces and adversely affect the performance of equipment. [1][2][3] This may occur in pipes, reactors, distillation towers, compressors, and heat exchangers. A heat exchanger provides a surface where two materials, usually liquids, can transfer thermal energy.…”

Analytical Techniques to Characterize Scales and Deposits

“…A technique coupled with TGA is differential thermal analysis where the differentiation of the thermal curve for mass loss is plotted as a function of temperature [33]. In scaleforming minerals, these changes will be associated with water content, loss of waters of hydration, and decomposition of anions (e.g., loss of CO 2 from CO À 3 and SO 2 from SO 2À 4 to give oxides).…”