The drive to reduce benzene emissions from process wastewater is evident amongst industries and governments. The topic also receives considerable attention in scientific circles, with universities, institutes and other authorities undertaking numerous research initiatives. To help disseminate information, (abridged) titles and abstracts of recent technical publications are provided below. The titles, journal/platform names, and dates of publication should facilitate access to the full texts.
By KCI Editorial
Examination of Compliance Refinery Fenceline Monitoring for Benzene Across the US – Atmospheric Pollution Research, October 2025
Analyses of U.S. compliance benzene air databases from refinery fenceline sites were conducted using 2019 measurements. Annual averages of maximum minus minimum benzene values (Δc) and mean benzene were summarized and compared by Petroleum Administration for Defense Districts (PADDs) for the country. Of the 104 refineries analyzed, thirteen refineries had annual average Δc values above an “action level” of 9 μg/m3 suggesting most refineries were in compliance. For Δc and benzene values, nonparametric paired comparisons of PADDs at the 5 % significance level indicated that the major oil-producing Gulf Coast was higher than other PADD regions, except for benzene at the East Coast. The West Coast was lower than each of the other PADDs at the 5% significance level, except Δc in the East Coast and benzene in the Rocky Mountain region.
No seasonal variation was found for the PADDs, except the West Coast for benzene. Overall results here present an opportunity to assess benzene fenceline impacts at specific U.S. refineries, such as those exceeding the annual average Δc action level.
Selective Benzene Capture by Metal-Organic Frameworks – Advanced Functional Materials, July 2025
Benzene plays a pivotal role in industrial chemistry as a crucial precursor for a wide range of chemicals, from plastics to pharmaceuticals. However, its status as a hazardous volatile organic compound presents significant environmental and health risks due to its toxicity and persistence in the environment. Addressing these challenges requires effective benzene capture strategies capable of mitigating emissions and ensuring environmental safety. Metal‐organic frameworks (MOFs), characterized by their tailored pore structures and versatile surface chemistries, have emerged as promising materials for benzene capture.
In the gas phase, MOFs exhibit exceptional adsorption capabilities for removing trace benzene from industrial emissions and ambient air, thereby improving air quality and reducing health risks. In the liquid phase, MOFs enable the selective extraction of benzene from complex hydrocarbon mixtures during petroleum refining, improving process efficiency and product purity. … By optimizing MOF design and understanding molecular interactions, this review aims to advance benzene capture technologies for sustainable industrial practices and environmental stewardship.
Reducing Benzene Emissions in Amine-Based Gas Processing Unit at LNG Plant – SPE/IATMI Conference (ResearchGate.net), October 2025
This paper aims to present insights gained from the Tangguh LNG plant on minimizing benzene emissions from acid gas in amine unit. The scope of this paper includes describing the efforts to reduce benzene content in acid gases, operational interventions to adjust offshore wells supplying feed gas, and tactical actions to modify key operating parameters in amine units. A systematic review was carried out to reduce the benzene content in acid gases going to the incinerator.
The first focus was on the offshore well gas supply. Wells were reorganized to ensure minimal benzene in the feed gas onshore with minimal impact on the onshore unit performance. The second focus was the amine unit, adjusting parameters like circulation rate, amine strength, and activator content to enable greater benzene absorption in the sweet gases, thereby reducing the benzene in the acid gases sent to the flare.
Although there were some initial challenges in determining the optimal composition for the wells—where the amine unit’s performance was significantly impacted by feed gas with higher CO2 content in exchange for lower benzene content— the operational interventions were successful. Benzene in the feed gas was reduced by 23% without interrupting LNG production. The combination of adjusting amine strength and circulation rate effectively decreased benzene levels in the acid gases by 47%. This series of data demonstrates that the operational interventions have successfully reduced benzene emissions in acid gases from amine unit. … This experience offers valuable insights for other operators of amine-based gas plants aiming to minimize the acid gas emissions.
Analysis of VOC Emission Characteristics in the Petrochemical Industry & Fenceline Monitoring – Atmosphere (MDPI.com), May 2025
Volatile organic compounds (VOCs) contribute to air pollution and pose health risks. This study investigates VOC emissions from petroleum refining and petrochemical industries using passive and active fenceline monitoring techniques.
The primary objective of this research is to compare the characteristics and detection performance of passive and active sampling methods for VOC monitoring, particularly focusing on benzene and other major components, such as BTEX. A total of 87 VOC species were analyzed, with benzene, toluene, ethylbenzene, and xylene (BTEX) being dominant. Passive sampling detected benzene at an average concentration of 3.60 μg/m3, whereas active sampling recorded 1.33 μg/m3, showing up to 2.5 times higher values in passive sampling. In certain locations, benzene levels exceeded the EPA action level of 9 μg/m3, with a peak value of 18.37 μg/m3 at one sampling point.
Meteorological conditions significantly influenced VOC concentrations, with stronger winds dispersing emissions more widely. This study provides crucial data for VOC emission control and regulatory policy development, emphasizing the need for continuous monitoring and targeted reduction strategies in industrial zones.
Benzene Removal in a Petroleum Refinery Moving Bed Biofilm Reactor System – WEFTEC conference (accesswater.org), October 2024
A study was performed to evaluate benzene removal and biomass concentrations in two parallel moving bed biofilm reactors (MBBRs) at the Valero Ardmore Refinery, Ardmore, OK. Three rounds of daily testing were completed between July and November 2022. Study results indicated greater than or equal to 99.8 percent benzene biodegradation across the MBBRs. Effluent benzene concentrations were generally below the analytical limit of detection. The average MBBR biomass concentration was 478 milligrams per liter (mg/L) as total suspended solids (TSS), with an approximate 50:50 split between biomass in the bulk liquid and that attached to the MBBR media.
Study results led to the State of Oklahoma making a regulatory determination that the MBBRs as operated by Valero meet the definition of an ‘Enhanced Biodegradation Unit’ under the federal Benzene Waste Operations National Emissions Standard for Hazardous Air Pollutants (BWON). Thus, going forward, air emissions controls are not required for the MBBR off gas.
Systematic Review on BTEX Emissions; Health Impact Assessment; and Detection Techniques – Springer Nature, December 2024
This study analyzed peer-reviewed research articles to provide BTEX emission profiles from three primary ONG operations and their associated health risks. PRISMA (Preferred Reporting Items for Systematic Reviews) was used to choose relevant articles for this review paper. ….. The study highlights BTEX emissions in all three ONG sectors, with significant contributions from midstream tanker loading and downstream refinery and refueling stations. E-nose techniques are promising for BTEX detection due to their real-time measurement capabilities and ease of use. Some Asian countries have reported benzene concentrations exceeding permissible limits during tanker loading and refueling operations. Overall, BTEX emissions are a cause for concern and should be addressed in ONG operations.
Fence Line Monitoring of Petroleum Refining Plants in Korea – Springer Nature, July 2024
Increasing public interest in air pollutants driven by climate change and high concentrations of particulate matter (PM) has highlighted the importance of managing pollutants, such as SO2, NO2, and benzene. These compounds are known precursors of secondary PM that affect the climate and human health, with benzene being particularly carcinogenic. …. To comprehensively manage emissions, leaks, and point sources, a fence line monitoring study was conducted at petroleum refining industrial complexes in Daesan-eup, Chungcheongnam-do, and Yeosu-si, Jeollanam-do in Korea. Ultraviolet Differential Optical Absorption Spectroscopy (UV-DOAS) technology was used to confirm measurement reliability and monitor emissions.
High SO2 concentrations emitted in a specific direction were identified at the Yeosu-si, and further investigation identified the flare stack of a suspected plant as the emission source. Fence line monitoring was effective in identifying and addressing unknown high-concentration emission sources and devising measures to manage fugitive emissions and leaks.
