Design and Compare Process Routes of Methyl Chloride Production Using a Framework That Comprises Life Cycle Analysis

Abstract

The environmental ramifications of methyl chloride (MeCl) production are pronounced, with the process classified as toxic by the Environmental Protection Agency, United States Environmental Protection Agency. Here, we evaluate the two baseline industrial routes: MeCl-1 (Methanol hydrochlorination, baseline) and MeCl-2 (Methane chlorination, baseline). Both pathways present considerable environmental burdens and fail to meet the United Nations Sustainable Development Goals. To delineate these impacts, we conducted a comprehensive life cycle assessment, which revealed that MeCl-2 consumes twice the chemical inputs of MeCl-1. In response to the toxicity and resource intensity, we integrated heat exchanger networks (HEN) into both processes, resulting in retrofitted designs: MeCl-3 (Retrofitted MeCl-1) and MeCl-4 (Retrofitted MeCl-2). The life cycle assessment of these retrofitted pathways demon-strated marked improvements: MeCl-3 achieved a 20% reduction in resource consumption relative to MeCl-1, while MeCl-4 reduced resource usage by 33.5% compared to MeCl-2. Notably, indices for human health impacts declined by 80% for MeCl-3 and 66% for MeCl-4. These retrofits substantially mitigate environmental and health risks and reduce global warming potential relative to conventional methods. Our findings establish a comprehensive environmental benchmark for MeCl production and highlight the imperative for adopting retrofitted technologies to advance sustainability in chemical manufacturing.

Keywords: methyl chloride, life cycle analysis, life cycle costing, environmental impact assessment, greenhouse gas emissions