Study of the eco-efficiency of acrylonitrile production processes

Abstract

Highlights

Simulation of acrylonitrile production processes.

Simulation of utilities for more realistic results.

Analysis of the gain in eco-efficiency considering five eco-indicators.

The process with partial condensation step proved to be the most sustainable option.

Objective

To evaluate the gain in eco-efficiency by introducing a partial condensation step in the conventional acrylonitrile production process.

Methodology

The conventional and modified acrylonitrile production process, as well as the associated utilities plant, was simulated computationally using the UniSim Design Suite R390.1 software. Based on the results, five eco-indicators were developed (water, fuel and energy consumption, CO₂ emission and liquid effluent generation), which were simultaneously evaluated through the Eco-efficiency Comparison Index of the considered processes.

Results

The modification of the conventional process of acrylonitrile production, from the introduction of a partial condensation stage with the main purpose of reducing the consumption of process water, resulted in a 76% increase in eco-efficiency, considering the eco-indicators used in the study. The reduction in water consumption was evidenced by the calculation of the corresponding eco-indicator, which was 47% lower for the modified process.

Limitations of research

Eco-efficiency was evaluated, disregarding social and safety factors. In addition, the few data provided on the process and scaling of recovery section equipment, by the reference authors, limited the comparison of results.

Practical implications

The paper presents a practical example of the use of eco-indicators in the analysis of the increase of eco-efficiency by the modification of industrial processes, mainly for the reduction of water consumption. Although the modification evaluated in this work has been implemented in an acrylonitrile production plant, the methodology can be applied in a similar way to other industrial processes.

Originality

The present work shows a quantitative evaluation of the gain in eco-efficiency (notably with regard to water consumption) by the introduction of a partial condensation stage in the conventional acrylonitrile production process.