Catalytic Dehydrochlorination of 1,2-Dichloroethane into Vinyl Chloride over Nitrogen-Doped Activated Carbon

Abstract

The pyrolysis of 1,2-dichloroethane (EDC) is the most popular commercialized way of producing vinyl chloride monomers (VCM); however, it is plagued by high-energy consumption and the resulting coke formation. Here, a series of nitrogen-doped (N-doped) activated carbon catalysts (N-AC) were prepared conveniently for EDC dehydrochlorination. The structural and textural properties of N-doped catalysts were characterized by X-ray diffraction, transmission electron microscopy, Raman spectra, temperature-programmed desorption of VCM and EDC, and X-ray photoelectron spectroscopy. The results revealed that doping N into activated carbon supports introduced basicity sites and caused partial graphitization on the catalyst surfaces. Thus, an improved absorption capacity to EDC and VCM and an accelerated desorption rate were obtained, which greatly enhanced EDC conversion and VCM selectivity. EDC was almost completely dehydrochlorided into vinyl chloride at a temperature of 300 °C and an EDC liquid hourly space velocity of 0.313 h –1 . The high catalytic activity and selectivity as well as good stability suggested that the N-AC catalyst would be a promising dehydrochlorination catalyst on an industrial scale.

Improvements in protective measures in factories with acetylene hydrochlorination and ethylene oxychlorination techniques declined risk assessment levels and affected liver health status

“…As Figure 1A indicated, the acetylene hydrochlorination technique could be described as a first-order chemical reaction between calcium carbide and water to generate acetylene (C 2 H 2 ) and calcium hydroxide Ca (OH) 2 , and then, a second-order chemical reaction was initiated with the precondition of a heated environment between purified acetylene (C 2 H 2 ) and hydrogen chloride (HCl) with the acceleration effect of mercury chloride (HgCl 2 ) to catalyze vinyl chloride gas (VCM) and then aggregated into polyvinyl chloride (PVC) under high temperature, and products went through the combined lines of hand-packing and automation after centrifugation and desiccation, with all reactions presented in Equations (11) and (12) ( 36 ):…”

Anion Exchange Resin Based Porous Carbon Spheres for the Catalytic 1,2-Dehydrochlorination of Dichloroethane

“…Generally, the EDC dehydrochlorination reactions are considered according to a base-catalyzed mechanism , on nitrogen-doped carbon catalysts. According to previous reports, ,, pyrrolic and pyridinic nitrogens are considered as Lewis basic sites and active sites. Figure shows the XPS spectra of N 1s of T1-900-RC, and they were fitted by four peaks.…”

Nonthermal plasma in the induction of polycondensation processes and intermolecular dehydrochlorination of chloroethanes in the liquid phase

“…[6,7] Acetylene, ethylene, butadiene, methyl chloride, chloroprene, vinylidene chloride (1,1-DCE), benzene, trichlorethylene, tri-and tetrachloromethane, and other chlorinated products are formed during EDC pyrolysis. [8][9][10] Many of the by-products are hazardous and toxic and require expensive disposal. [11][12][13][14][15] To improve production performance, the amount of byproducts should be minimized to improve the conversion of feedstock to target products, reduce feedstock costs, simplify EDC cleaning, prevent coking in the reactor and tubes during pyrolysis, and reduce waste management and recycling costs.…”