Capturing and Converting Gasoline Gas During Top-Hole Filling Using an HDPE Geomembrane

Abstract

The continuous demand for petroleum has driven the evolution of distribution practices despite the inherent environmental and safety challenges. In many regions, top-hole filling (THF) is the norm when loading Bulk Road Vehicles (BRVs) with gasoline, even though this method risks the release of volatile gasoil and gasoline vapors into the atmosphere. This article outlines an innovative project that investigates the use of high-density polyethylene (HDPE) geomembrane technology to capture and convert escaping gasoline vapors during top-hole filling. Results from controlled laboratory experiments demonstrate nearly complete vapor capture, promising enhanced worker safety, reduced product loss, and significant environmental benefits. Moreover, the versatility of HDPE geomembranes extends to upstream operations where they can be employed to prevent seepage, thus protecting both infrastructure and the environment from hazardous leakages.

Introduction and Background

The transportation of petroleum products by BRVs is a vital component of the oil and gas industry. In most developing regions, the inexpensive top-hole filling method is preferred over the more advanced bottom-hole filling due to cost considerations. However, THF is associated with several drawbacks: it exposes personnel to toxic gasoline vapors, contributes to greenhouse gas emissions, and results in measurable product losses. These issues present a dual challenge: ensuring safety and minimizing environmental impact while maintaining operational efficiency.

Against this backdrop, research has increasingly turned to geomembrane technologies. In particular, HDPE geomembranes, long known for their chemical inertness, mechanical strength, and durability under harsh conditions, are being explored as a potential solution for sealing off vapor escape points during petroleum loading operations. Importantly, the application of HDPE geomembranes is not limited to downstream operations. Their excellent sealing properties also make them ideal for preventing seepage in upstream operations, where they can be employed around oil wells, pipeline interfaces, and storage facilities to curb unwanted leakages and environmental contamination.

Problem Statement and Objectives

In the context of increasing regulatory demands and environmental awareness, the emission of gasoline vapor during THF has emerged as a critical operational flaw. The lack of an established method to prevent these emissions poses health risks to workers and contributes to environmental pollution. The project’s principal objective is to evaluate whether an HDPE geomembrane can serve as a robust physical barrier during the filling process that not only stops vapors from escaping but also facilitates their conversion back into liquid form under controlled temperature conditions.

The specific goals include

• Providing a comprehensive review of the properties and applications of HDPE geomembranes in hazardous containment.

• Addressing the significant operational losses and environmental impacts due to gasoline vapor leakage.

• Experimentally assessing the HDPE geomembrane’s performance over a range of temperatures up to 80°C.

• Highlighting the potential for HDPE geomembranes to also prevent seepage in upstream operations, thereby offering a dual benefit for the petroleum industry.

Methodology

An experimental protocol was established to simulate top-hole filling conditions. Key materials and equipment included:

• HDPE geomembrane liners

• Standard gasoline samples

• Brass oil cups and flashpoint testers

• Gas leak detectors and precision thermometers

• Personal Protective Equipment (PPE) for ensuring safety during the test

The experimental setup involved covering a brass cup containing gasoline with an HDPE geomembrane to form an airtight seal. A thermometer was inserted through the membrane to monitor the system’s temperature, which was incrementally raised from 25°C to 80°C. At each 5-degree interval, the system was observed for a fixed duration of three minutes. Gas leak detectors were used to continuously monitor any potential release of gasoline vapors, ensuring that the integrity of the barrier was maintained throughout the testing process.

Results and Discussion

The controlled tests provided compelling evidence of the HDPE geomembrane’s effectiveness. Key findings include:

• High Vapor Capture Efficiency: The experimental configuration demonstrated that the HDPE barrier achieved close to a 100% capture rate for gasoline vapors across the tested temperature range.

• Thermal Stability and Durability: Even under high-temperature conditions (up to 80°C), the HDPE geomembrane maintained its structural integrity and impermeability. This suggests the material’s suitability for various climatic conditions, including those where high ambient temperatures could otherwise exacerbate vapor losses.

• Enhanced Safety and Environmental Impact: By capturing gasoline vapors at the source, the system minimizes the risk of direct exposure to personnel and reduces the overall environmental footprint through lower emissions of volatile organic compounds (VOCs).

• Broader Applicability: Beyond its successful application in top-hole filling operations, the inherent sealing qualities of the HDPE geomembrane have significant implications for upstream operations. In these settings, the membrane can be effectively used to prevent seepage from oil wells, pipelines, and storage tanks, further mitigating environmental hazards and reducing product loss.

The project underscores the importance of integrating materials engineering with environmental stewardship. The experimental results provide a clear demonstration that the use of HDPE geomembranes can contribute to safer and more sustainable practices in petroleum distribution while also offering a promising solution for upstream leakage prevention.

Conclusion and Recommendations

The study presents a compelling case for the adoption of HDPE geomembrane technology in the petroleum industry. By effectively capturing gasoline vapors during top-hole filling and preventing seepage in upstream operations, this technology addresses critical concerns related to worker safety, product loss, and environmental pollution. Despite the higher initial investment, the long-term benefits—ranging from reduced environmental fines and improved operational safety to enhanced public health outcomes—suggest a favorable return on investment.

For future applications, several recommendations are proposed:

• Scaling Up: Explore the feasibility of integrating HDPE geomembrane systems on a larger scale within existing infrastructure, both upstream and downstream.

• Broadening Chemical Compatibility: Extend the testing to include a wider range of hydrocarbon mixtures to assess performance across different fuel types.

• Advanced Monitoring: Incorporate real-time sensors and data analytics to continuously monitor the system's performance and ensure adherence to safety protocols.

• Training and Awareness: Develop comprehensive training programs and awareness campaigns for operators and stakeholders, highlighting the dual benefits of this technology for both downstream vapor capture and upstream seepage prevention.

The project lays a robust foundation for further innovation in emission control and environmental protection within the oil and gas industry. It not only provides a practical solution to long-standing problems but also signals a broader shift toward sustainable industrial practices—a development that is both technically and ethically significant.