High-Temperature Gasification of Chlorinated Hydrocarbons: Thermodynamic Calculation

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🔬研究者:Provides thermodynamic modeling methodology and optimal gasification parameters for CHCs, relevant to waste-to-energy and chemical engineering researchers.

🏢実務担当者:Offers a potential design basis for industrial gasification plants treating chlorinated waste, including HCl recovery.

🏛政策担当者:Illustrates a viable technology for stringent waste treatment regulations, potentially informing policy on hazardous waste management.

The disposal of chlorinated hydrocarbon (CHC) waste represents a severe environmental challenge due to the high risks of generating extremely hazardous ecotoxicants, such as dioxins, furans, and phosgene, during conventional thermal treatment. Although high-temperature plasma destruction ensures environmental safety, its widespread implementation is constrained by high energy consumption and substantial capital costs. This work aims to determine the optimal thermodynamic conditions for the allothermal, high-temperature, non-catalytic steam-carbon dioxide gasification of various CHCs to achieve their comprehensive conversion into non-toxic and industrially valuable products. Thermodynamic modeling was performed using the Aspen Plus software package in a zero-dimensional approximation based on the minimization of the Gibbs free energy at atmospheric pressure. The gasifying agent (GA) was modeled as the products of the detonation of ternary methane–oxygen–steam mixtures expanded to 0.1 MPa, with an initial temperature of 2450–2850 K (pre-calculated using Cantera and SDToolbox software packages). The computational methodology was previously validated against independent literature data on the catalytic steam conversion of a hydrocarbon surrogate (n-hexadecane) and various CHCs. The operating zone boundaries were determined for every studied compound in terms of the specific feedstock consumption m (per 1 kg of GA). Within these zones, no free oxygen, soot, or hydrocarbons are detected in the gasification products. The results show that a 100% carbon conversion efficiency (CCE) is achieved under all gasification conditions. The dry syngas yield reaches up to 5.7 nm3/kg of feedstock, with a lower heating value (LHV) of up to 17 MJ/kg (the volume fraction of combustible gases reaches 99%). The cold gas efficiency (CGE) exceeds the 100% threshold (up to 138%), confirming the efficient transformation of the energy of the detonation gases into the chemical energy of the syngas. It was established that the chlorine heteroatom is bound exclusively into hydrogen chloride (HCl), while the equilibrium volume fractions of dioxins and phosgene do not exceed a threshold value of 10-6 (1 ppm). A method for complete syngas purification via HCl dissolution in the inherent condensate of the residual steam was proposed, yielding commercial-grade hydrochloric acid. For highly chlorinated CHCs (with a chlorine content above 70%), the necessity of utilizing a blended feedstock (e.g., a CHCl3 + C4H8O2 mixture) was justified to compensate for the moisture deficit and eliminate residual free oxygen. The proposed technology of detonation-driven steam – carbon dioxide gasification can serve as an efficient, environmentally safe, and economically accessible alternative to expensive plasma-chemical methods for the disposal of toxic chlorinated organic waste.

• Research Square https://doi.org/10.20944/preprints202606.0273.v1first seen 2026-06-06 04:25:21 · last seen 2026-06-16 04:28:58