What are the advantages of a combined organic waste gas treatment system (photocatalysis + biological spraying) over a single process?

1. Synergistic degradation improves removal efficiency
Photocatalysis rapidly oxidizes VOCs to CO₂ and H₂O at room temperature and pressure, achieving a removal rate of over 90%. Subsequently, biological spraying uses microorganisms to further decompose the low-concentration organic matter remaining after the photocatalysis, achieving nearly 100% purification.
2. Lower energy consumption and reduced operating costs
The photocatalytic process itself consumes little energy, while biological spraying only requires moderate temperatures and nutrients. Overall energy consumption is 30%-50% lower than simple combustion or high-temperature oxidation.
3. Wider applicability and greater stability to fluctuating waste gas conditions
Photocatalysis has excellent treatment capabilities for high-concentration, difficult-to-degrade components (such as halogenated hydrocarbons). Biological spraying, with its adaptive microbial community, can smooth out the impact of concentration fluctuations in low-concentration, variable-composition waste gas.

4. Nearly zero secondary pollution

Both processes produce no combustion byproducts (NOₓ and SOₓ), and the effluent from the biological spray can meet environmental standards through conventional biochemical treatment, meeting green environmental protection requirements.

What operational instabilities are common with regenerative thermal oxidation (RTO) systems when treating fluctuating organic waste gas?

1. Fluctuations in inlet air concentration and flow rate leading to temperature loss

Production breaks or feedstock changes can cause significant fluctuations in VOC concentration and waste gas flow. The RTO's switching and thermal storage systems struggle to adapt quickly, leading to sudden temperature increases or decreases, impacting oxidation efficiency.

2. Response lags in the reversing valve and thermal storage element

When the reversing system frequently switches, valve reliability and switching time become critical. Untimely reversal or valve jamming can lead to uneven heat exchange, localized overheating, or inadequate cooling.

3. Decreased heat recovery efficiency leads to increased energy consumption.
When a large amount of heat is carried away by the exhaust gas (especially in the case of high calorific value exhaust gas), the regenerator temperature becomes difficult to maintain, requiring the system to use additional fuel for heat replenishment, resulting in increased energy consumption and potentially triggering a safety shutdown.
4. Temperature drift during startup and shutdown.
During startup, if the intake air concentration is too high, the combustion chamber temperature rises rapidly to over 800°C, potentially causing thermal shock and damage to the ceramic regenerator. During shutdown, if the residual heat is not released promptly, the system temperature will slow to cool, affecting the smooth transition to subsequent processes.