Evaluation of adsorptive desulfurization performance and economic applicability comparison of activated carbons prepared from various carbon sources

Abstract

Adsorptive desulfurization (ADS) using activated carbon (AC) as adsorbent presents competitive potential in separating thiophenic sulfur from liquid fuels with high selectivity under mild operation conditions. It is also a highly economic remedy in ultra-low sulfur content situations. Most importantly, a suitable feedstock for macroscopic quantity preparation of AC adsorbents with good adsorptive desulfurization performance and low-cost is required to satisfy the requirements of this field. In this work, four representative substances (i.e., coal, coconut shell, polyurethane plastic waste, and petroleum coke) were selected as the carbon source for the preparation of various AC adsorbents. The physicochemical properties of the prepared AC adsorbents were characterized using BET, SEM, XRD, XPS, elemental analysis and Boehm's method. The corresponding adsorptive desulfurization performance was investigated. The corresponding desulfurization capacity obtained was in the order: CS-ACA > PUPW-ACA > PC-ACA > AT-ACA. Under the optimal conditions of 30 °C and 30 min contact time, the desulfurization rate of 0.5 g PUPW-ACA can reach about 98%. The HHV of non-condensable gas generated during the experiment was calculated, and the HHV of the pyrolysis oil was measured. The results showed that the by-products produced by PC had the highest HHV. The economics of the desulfurization of the four kinds of activated carbon were analyzed and evaluated. From a comprehensive analysis, PUPW-ACA has the highest economic production value and has the potential for industrial production. This plays a dual role in environmental protection.