The light industry is a traditional and advantageous sector in China's national economy, playing a vital role in absorbing labor employment, resolving rural problems, and promoting economic development and social stability. Simultaneously, the light industry is also a key domain for pollution prevention, energy conservation, and carbon reduction.
The exhaust emissions from the light industry possess the characteristics of a large base and a diverse range of types. The country has successively released policy documents such as the "Action Plan for Reducing Volatile Organic Compounds in Key Industries", which specify the comprehensive rectification of VOCs in the light industry like printing, shoe-making, synthetic leather, ink, furniture, plastics, and paper. Hence, how to effectively achieve the prevention and control of VOCs pollution in the light industry is currently a highly concerned matter.
Introduction to energy-saving technology
Energy saving approach 1: Selection of exhaust gas treatment methods
|
Purification method |
key points |
characteristics of exhaust gas |
advantages and disadvantages |
|
Combustion method |
Burn off organic matter in exhaust gas as fuel or decompose it at high temperatures, with a temperature range of 600-1100 |
Medium to high concentration |
High decomposition temperature, safe, and reliable |
|
Catalytic combustion method |
Under the action of an oxidation catalyst, it oxidizes into harmless substances, with a temperature range of 200-400 |
Low concentration, continuous exhaust |
For flameless combustion, low temperature requirements, small restrictions on combustible component concentration and calorific value, but high catalyst price |
|
Adsorption method |
Absorbent for physical adsorption, normal atmospheric temperature
|
Low concentration |
High purification efficiency, but adsorbent has adsorption capacity limitations, which can easily generate solid waste |
|
Absorption method |
Physical absorption, normal atmospheric temperature
|
Waste gas containing particulate matter |
The properties of the absorbent itself are not ideal, and the regeneration treatment of the absorbent is not good |
|
Condensation method |
Using low temperature to cool the organic components to below the dew point for liquefaction recovery |
High concentration |
Require simple components, simple equipment and operation, but not cost-effective; Belonging to chemical equipment that requires inspection |
According to the comparison in the above table, medium to high concentration exhaust gas can be treated by the combustion method, while low concentration exhaust gas can be treated by a combination of the adsorption method and the combustion method.
Energy saving approach 2: Performance comparison of different types of regenerative thermal oxidizers (RTOs)
| RTO type | Two-bed RTO | Three-bed RTO | Rotary Valve RTO |
| Technology iteration | First generation | Second generation | Third generation |
| Numbers of regenerative chamber | 2 | 3 | 12 |
| Piping pressure fluctuation | ±500Pa | ±250Pa | ±25Pa |
| Occupation of land( based on two-bed RTO) | 100％ | 130％ | 65％ |
| Weight( based on two-bed RTO) | 100％ | 150％ | 80％ |
| Comprehensive thermal efficiency | 84％ | 92％ | 95％ |
| Maximum purification efficiency | 95% | 99% | 99.5% |
| Structure | 4 valves | 9 valves | 1 valve |
| Maximum treating range | <1g | <5g | <10g |
| Thermal efficiency | 90% | 95% | 97% |
| Valve switching times per year | 350,000 times | 520,000 times | / |
After comparison, the rotary valve RTO has significant advantages in progressiveness, reliability, compliance, energy saving, economy and practicability. Therefore, the rotary valve RTO can be selected to treat medium and high concentration exhaust gas.
Energy saving approach 3: Selection of waste heat energy saving methods
| The method of using waste heat | Temperature | Advantages and disadvantages |
| Hot water | ≤70℃ | Advantages: No need for inspection, atmospheric pressure equipment, stable heating. Disadvantage: The heating temperature range is small; |
| Thermal oil | ≤220℃ | Advantages: High heat capacity value, stable heating temperature; Disadvantage: High temperature and easy carbonization, requiring inspection |
| Steam | ≤160℃, Pressure≤1mpa | Advantages: High heating temperature range, stable temperature control; Disadvantage: Inspection required |
| Hot wind | ≤400℃ | Advantages: Wide temperature range for heating, no need for inspection; Disadvantages: Temperature is difficult to control and fluctuates greatly. |
The reuse of waste heat is crucial for customers to transform their environmental benefits from negative to positive. Customers need to choose their own heat reuse methods based on their own heat requirements, in order to maximize the recovery and utilization of combustion heat energy.
VOCs have a broad range of sources, multiple production processes, and are distributed in numerous production processes, mainly resulting in unorganized emissions. Taking industrial coating enterprises as an example, VOCs are emitted from various processes such as coating blending, coating process, leveling process, drying process, spraying equipment cleaning, and paint residue treatment.
Promote energy-saving and carbon reduction technologies, advocate green production methods, elevate the service targets of enterprises from narrow customers to the entire society, and achieve economic benefits guided by social benefits. While enhancing the core competitiveness of enterprises, it also promotes the improvement and leap of enterprise values."
Media Contact
Company Name: Xi'an Yangling Yurcent Environmental Technology Co., Ltd.
Email: Send Email
Country: China
Website: https://www.yurcentrto.com/
