Project Update: VOCs Waste Gas Treatment Project at a Chemical Company in Inner Mongolia Commences Operation

2025-03-14

April 24, 2023 - The VOCs waste gas treatment project undertaken by Yuchang Environment for a chemical company in Inner Mongolia has been successfully delivered and accepted. The project has been running stably for over 12 months, meeting all the indicators agreed upon in the contract.

Project Background:

A chemical company in Inner Mongolia primarily manufactures and sells indigo powder, potassium guanidinoacetate, and chemical raw materials (excluding hazardous chemicals), among other products. The company holds a certain level of influence within the dye manufacturing industry.

Source of Emissions:

The emissions originate from the oxidation reactor and hydrolysis process during production. The primary pollutants in the emissions include alkaline gases, indophenol emissions, aniline compounds, and ammonia.

Design Proposal:

Basic Design:

The concentration of the project's exhaust gases is approximately 700~4000 mg/m³, with the temperature of the exhaust gases ranging between 30~50°C. The exhaust pressure is at -70Pa, with an oxygen content of 19% and a relative humidity of 72%. The exhaust gases contain nitrogenous organic compounds and ammonia, the combustion of which can produce NOx. Considering the emission concentration limits for nitrogen oxides, the concentration of nitrogenous organic compounds entering the RTO is controlled to meet the emission concentration limit standards for nitrogen oxides. Additionally, an SCR denitrification unit interface is reserved at the RTO outlet. To ensure that the treated exhaust gases meet the discharge standards, a 50,000 m³/h Rotary RTO is used as the core equipment for exhaust gas treatment.

Anti-Clogging Design:

Since the exhaust gases contain aniline compounds and bis-hydroxyindophenol, the combustion of which can produce NOx, NH3, and NO2, which may form NH4NO3. Based on our previous project experience, ammonium salts can clog the regenerative bricks, leading to poor exhaust flow and a decrease in the thermal storage performance of the bricks, thereby increasing the overall energy consumption of the RTO. This is a common challenge in the RTO industry. According to the analysis of the exhaust gas components for this project, the following two methods can be selected to avoid clogging of the regenerative material:

Use of clog-resistant regenerative ceramics

For this project, the upper five layers of the regenerative chamber will use honeycomb ceramic regenerative material, and the lower layer will use a single layer of ceramic regenerative material. The combination of both ensures excellent thermal storage performance while reducing the risk of clogging of the ceramic regenerative material.

Installation of 12 maintenance doors between the bottom and upper regenerative ceramics to facilitate washing and replacement of the regenerative ceramics. As shown in the figure below.

Project Update: VOCs Waste Gas Treatment Project at a Chemical Company in Inner Mongolia Commences Operation

The RTO furnace body has 12 maintenance ports distributed around its circumference, each corresponding to a regenerative chamber. These maintenance ports are located above the bottom layer of ceramic regenerative bricks. In the event of salt-induced clogging of the ceramic regenerative bricks leading to excessive pressure differential at the RTO inlet and outlet, the system can be shut down to quickly open the maintenance ports for washing the internal ceramic bricks. The RTO bottom is specially designed with a complete drainage structure and drainage outlets.

Our company has extensive experience in comprehensive waste gas treatment across various industries in fine chemicals, including dyes, additives, electrolyte solvents, synthetic resins, pharmaceutical intermediates, pesticides, paint spraying, PVC gloves, storage waste gases, phthalic anhydride, maleic anhydride, petrochemicals, coal chemicals, and more. We have numerous project cases and have established high-quality model projects for VOC waste gas treatment in most industries.