Stable Half-Year Operation! RTO Drives 8-Million-Ton Green Transformation

Project Overview

Located in Yulin City, Shaanxi Province, this refinery boasts a crude oil primary processing capacity of 8 million tons per year and a secondary processing capacity of 2.4 million tons per year. It is equipped with units for 1.3 million tons/year of reforming, 0.9 million tons/year of gasoline refining, 2 million tons/year of diesel hydrogenation, and 0.2 million tons/year of DCC light oil and naphtha processing.

Main products include automotive gasoline and diesel, petroleum benzene, mixed xylene, and liquefied petroleum gas (LPG), all compliant with the China VI emission standards.

Project Background

From “Practicing the Concept” to “Upgrading for Compliance”

Previously, to protect the blue skies of the Loess Plateau, the refinery installed a Catalytic Oxidation (CO) unit. However, as environmental standards tightened, Yulin City mandated that non-methane total hydrocarbons (NMHC) emissions be ≤60mg/m³.

What was the solution? Upgrade the equipment!

This time, a more efficient Regenerative Thermal Oxidizer (RTO) was installed. The VOCs treatment project was undertaken by Xi’an Yurcent Environmental Technology Co., Ltd., which developed a tailored solution for high-concentration waste gas—prioritizing both safety and compliance.

As of now, the project has been running stably for six months!

Waste Gas Sources

Where Are These "Invisible Pollutants" Hiding?

The waste gas mainly originates from three areas:

1. Loading Bay 

2. Loading Bay 

3. Atmospheric Storage Tank Breathing Vents

The VOCs are primarily composed of C1–C6+ hydrocarbons, xylene, trimethylbenzene, and tetramethylbenzene.

Previously, these “invisible pollutants” quietly evaporated into the atmosphere—now they’re all captured and treated by this advanced system! 

Design Solution

Revealing the Three-Step VOC Treatment Process

Based on the client’s specific situation, the total exhaust flow of the project is approximately 7000 Nm³/h, with concentrations peaking at 25.7 g/m³.

Given the high concentration of waste gas, both safety and compliance were key concerns. Our RTO solution provides the perfect answer:

Step 1: Flue Gas Dilution

Cooled exhaust gas is used as a “diluent” to reduce the high-concentration 7000 Nm³/h waste stream to a safer 40000 Nm³/h flow—ensuring operational safety.

Step 2: Rotary RTO “Hardcore Treatment”

At high temperatures (over 800°C), VOCs are completely oxidized into CO₂ and H₂O. The system is highly efficient, energy-saving, and capable of heat recovery to reduce operating costs.

In Simple Terms:

Waste Gas Collection → Dilution & Mixing → High-Temperature Purification → Compliant Emission

Each step is precisely controlled, delivering cutting-edge environmental tech performance.

Operating Results

The Data Speaks for Itself—Tangible Environmental Benefits

The system has now been in stable operation for six months. Just how effective is it?

Real-time DCS data shows NMHC emissions consistently below 10 mg/m³

(National standard: ≤60 mg/m³—more than halved!)

Key pollutants like benzene and xylene are virtually undetectable, achieving ultra-clean emissions.

What Has Changed?

• Cleaner air around the plant, reassuring nearby residents

• Environmental compliance achieved, supporting sustainable corporate development

• Unexpectedly strong results for local air pollution control efforts

On the Road to Environmental Protection, We Never Stop Moving Forward

From “meeting the standards” to “exceeding the standards,” the RTO system from Xi'an Yurcent Environmental Technology Co., Ltd. represents more than a technological upgrade—it’s a testament to the company’s commitment to the principle of “lucid waters and lush mountains.”

Looking ahead, Yuchang will continue to empower environmental protection through innovation, promoting industrial development and ecological preservation in harmony.