English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Heavy fuel oils are the oil fractions produced from petroleum refining processes with at least 50 vol% in the boiling range above 250 °C. Heavy fuel oils usually contain significant amounts of sulfur compounds, so combustion as fuel leads to emissions of SOx, especially SO2, which are important contributors to air pollution1). Consequently, commercial shipping, which is the biggest user of heavy oil fractions, has been forced to reduce the sulfur content of fuel oil from 3.5 to 0.5 wt% according to the regulations of the International Maritime Organization (IMO)2). However, desulfurization of heavy fuel oil is harder than for light fractions, because of the following properties3),4): (a) Complex and aromatic sulfur compounds including bulky thiophenic structure compounds are very common components. (b) High contents of organic metal components, which deactivate the catalysts used in desulfurization processes. (c) High molecular weight components and presence of asphaltene, which lead to coke formation. Desulfurization methods include hydrodesulfurization (HDS), extractive desulfurization, adsorptive desulfurization, biodesulfurization, supercritical water desulfurization and oxidative desulfurization (ODS)5). The conventional method for desulfurization is catalytic hydrodesulfurization performed under specific conditions (high temperature and pressure) with the consumption of hydrogen, but involves significant costs, especially for heavy oils. Additionally, aromatic sulfur compounds are difficult to remove with the HDS method6)~8). ODS is considered by researchers to be one of the most useful desulfurization methods, and consists of two steps. First, a chemical reaction occurs between the oxidant and sulfur compounds to form the corresponding sulfones, which have different properties to the unoxidized sulfur compounds9). Second, sulfur is removed from the oxidized feedstock, which can be achieved by extraction, adsorption, thermal dissociation, etc.5),10). Most of the above-mentioned methods remove the entire organic content of oxidized sulfur compounds rather than only the sulfur atoms. If the sulfur content is low and contained in low molecular weight compounds, such elimination causes substantial feedstock losses. However, the sulfur content in the heavy oil fraction is usually more than 1 wt% and the sulfur compounds have higher molecular weights in comparison with light fractions. Therefore, the loss of feedstock will be significantly higher during the extraction of the oxidized sulfur compounds. Sulfur removal from 136 Journal of the Japan Petroleum Institute, 62, (3), 136-140 (2019)

Desulfurization of Heavy Oil by Using Combination of Oxidation and Mild Thermolysis