I. Recovery and Concentration of Propylene from Propylene-Containing Tail Gas

1 I. Overview

In the production of polypropylene, substantial amounts of vent gas and other gaseous emissions are generated, primarily consisting of propylene monomer and nitrogen. Due to the relatively low propylene content and the high nitrogen concentration, this exhaust gas cannot be directly utilized; traditionally, it has been burned as fuel. With advances in technology, membrane separation has emerged as an alternative, yet this method still has certain limitations in some respects. Following intensive research and development by our company’s technical team, we have successfully developed a propylene-specific adsorbent that achieves a separation factor of nearly 100 for propylene over nitrogen—and even over propane. The pressure swing adsorption unit for the recovery and enrichment of propylene using this type of adsorbent features both high propylene purity and high recovery yield.

2 1. Main parameters of the device:

   Unit operating pressure: 0.3–2.0 MPa (G)

    Propylene content in the feedstock: 10–70%

   Propylene purity: ≥98% (Can be customized to exceed 99.5% as required)

   Propylene recovery rate: ≥98%

    Propylene content in exhaust gas: ≤0.5%

    Propylene product pressure: 0.02 MPa (G)

   Unit capacity: 10–5,000 Nm³/h

II. Introduction to New Desulfurization Technologies for Producing Clean Fuels

1 I. Overview

With the rapid development of the global economy, automobile consumption has continued to rise, leading to a corresponding increase in fuel consumption. The exhaust emissions produced by fuel combustion are increasingly harmful to the environment. Consequently, countries worldwide have imposed stringent standards on fuels, making the production of low-sulfur “clean fuels” an inevitable trend. As a result, desulfurization technologies for producing clean fuels have become a major research focus in the petroleum refining industry in recent years.

Refining desulfurization technologies can generally be classified into two categories: hydrodesulfurization and non-hydrodesulfurization.

Hydrodesulfurization is currently the most mature process, but it struggles to achieve deep desulfurization (≤15 ppm). ) requirements, and it employs high-temperature, high-pressure conditions along with highly active catalysts, while also requiring substantial amounts of high-purity hydrogen; moreover, the operating costs are relatively high. If deep hydrodesulfurization is carried out, olefins are easily saturated, which not only consumes the olefins but also degrades product quality.

In response to the emerging standards for clean fuels, countries worldwide are actively researching and developing production technologies for these fuels, leading to rapid advancements in non-hydrodesulfurization methods such as biodesulfurization, oxidative desulfurization, and adsorptive desulfurization.

Building on the combined advantages of the aforementioned technologies, our company’s researchers have developed a new desulfurization process—biological desulfurization—which offers the following benefits: high gasoline and diesel yields with virtually no loss; no adverse impact on octane rating; mild reaction conditions that can be maintained at ambient temperature and pressure; high desulfurization efficiency and large plant processing capacity; low capital investment, low operating costs, and low consumable consumption; and a pollution-free desulfurization process throughout.

Low equipment investment, simple operation, and high desulfurization efficiency ( It features significant advantages such as the removal of refractory organosulfur compounds like thiophene; no consumption of hydrogen; no loss of octane rating in gasoline and diesel; low desulfurization costs; rapid processing; and clean, environmentally friendly operation.

2 1. Characteristics of Our Company’s Biological Desulfurization Technology

1 , For oil products that have not undergone hydrotreating and exhibit high mercaptan content, foul odor, and non-compliant gum content, DKT-611 is employed. For this type of product, simply add the desulfurizing agent to gasoline or diesel in the prescribed ratio, allow it to mix and react thoroughly with the fuel, then let it settle for 1–2 hours before removing the precipitated residue. This desulfurizing solution achieves a mercaptan removal rate of over 99% and also exhibits significant gum-removal capability.

2 For refinery units that have undergone hydrodesulfurization, a biological method is employed to remove refractory sulfur compounds such as thiophenes, sulfides, and carbon disulfide. This technology offers several advantages, including low capital investment, reduced operating costs, simple process conditions, deep desulfurization, and zero pollution.

3 1. Technical Specifications for Desulfurization Equipment

1 , Unit processing capacity: 0.5–5 10,000 tons/h (design capacity can be customized based on user requirements)

2 1. Total sulfur removal rate in crude oil: ≥99% (Adjustments can be made upon user request.)

3 , the device is pollution-free

4 , No loss of octane rating in the oil product

4 , Cooperation Methods

1 , Providing complete sets of desulfurization technology equipment

2 1. Our company has jointly invested with the refinery, with costs for desulfurization calculated per ton of oil processed.

3 Our company will provide the equipment, and for each ton of oil processed that meets the national regulatory standards, a specified desulfurization fee will be collected.

5 , Contact Information

Inquiries about the above cooperation arrangements are welcome by phone or in writing.

Contact: He Baichuan

Email: hebaichuan0546@163.com

Telephone: 028-85249918 / 13708070546

Fax: 028-85256707