How to choose the right RTO/RCO equipment for your machine?

The Chinese translation of RCO is regenerative catalytic oxidation technology, while the Chinese translation of RTO is regenerative thermal incineration waste treatment technology. Both are technologies to achieve VOCs emission standards. But there are some fundamental differences between the two.

 

First, the concept and characteristics of RTO:

 

RTO heats the organic waste gas to above 760 degrees Celsius, so that the VOCs in the waste gas are oxidized and decomposed into carbon dioxide and water. The high-temperature gas generated by oxidation flows through the special ceramic regenerator, which makes the ceramic body warm up and "restores heat". This "heat storage" is used to preheat the organic waste gas that enters later, thereby saving the fuel consumption of exhaust gas heating. The ceramic regenerator should be divided into more than three (including three) zones or chambers. Each regenerator undergoes procedures such as heat storage, heat release and cleaning in turn, and it works continuously. After the regenerator "releases heat", some qualified clean exhaust gas should be introduced immediately to clean the regenerator (to ensure that the VOC removal rate is above 99%), and the "heat storage" procedure can only be entered after the cleaning is completed. . RTO regenerative waste gas treatment equipment has the advantages of low operating cost and high treatment efficiency of organic waste gas. It is suitable for waste gas concentration of 1000~10000mg/m³, and decomposition efficiency: 99%-99.5%. It is a relatively economical and reliable VOCs treatment technology that reaches the strict emission standard of 50mg/m³, and has been widely used.

 

3. Comprehensive processing capacity and cost analysis

 

1) Compliance:

1. RCO is commonly used as a precious metal honeycomb catalyst with cordierite ceramic honeycomb as a carrier, and precious gold Pd and Pt are active components. Since the catalyst is selective to the exhaust gas components, and the cigarette pack printing uses a mixture of various components and solvents, any catalyst cannot ensure that all components VOC can be completely oxidized and decomposed.

2. The comprehensive purification efficiency of RCO in treating VOC organic waste gas is as high as 97%. Under the condition that the emission concentration of non-methane total hydrocarbons is lower than 50mg/m³, RCO cannot treat waste gas with a concentration higher than 1.67g/m³.

2) Energy saving

Thermal efficiency: refers to the ratio of the actual heat utilization to the theoretically usable total heat.

The surface heat loss and waste heat recovery ability of the RTO furnace body are two important factors that affect its thermal efficiency. After testing, the thermal efficiency of RTO is 97%, and the thermal efficiency of RCO is 95%.

For example: the exhaust gas temperature is 30°C, the RTO oxidation chamber temperature is 800°C, the inlet and outlet temperature difference is 20°C, and the outlet temperature is 50°C; RTO thermal efficiency: = (800-50)/(800-30) = 97.4%.

The exhaust gas temperature is 30°C, the RCO oxidation chamber temperature is 450°C, the inlet and outlet temperature difference is 20°C, and the outlet temperature is 50°C; RCO thermal efficiency: = (450-50)/(450-30) = 95.2%.

The filling volume of RTO regenerative bricks is 16m³. Under the cold furnace startup condition, the time for RTO to heat up to 800℃ is 1.5h. The filling volume of the RCO heat storage brick is 8m3, and the catalyst of the other ceramic carrier is 2.5m3. Under normal starting conditions, the RCO with less ceramic filling volume is started to heat up to 400 °C for 0.7h. The RCO consumes less heat during the cold start phase.

3) Economical:

From the perspective of economic performance of equipment manufacturing, the filling amount of RTO and RCO regenerative ceramics is 16m³ and 8m³ respectively, but RCO still needs to be filled with 2.7m³ catalyst (the space velocity of the catalyst is selected according to 15000 /h, the amount of catalyst △ = (air volume ÷ space velocity)×10/12=2.4, considering the actual filling of the catalyst, the actual catalyst to be filled is 2.7m³). The price of common brand precious metal catalysts is about 170,000 yuan/m³; the overall structure and other configurations of RCO and RTO are basically the same, that is, the investment of RCO equipment is about 1.2 times that of RTO equipment.
The service life of the RCO catalyst is 8,000-10,000 hours. If the production condition is 24 hours and 280 days/year, the service life of the catalyst is about 1.5 years, and the service life of the ceramic regenerator is about 8 years. The maintenance cost of the RTO due to the replacement of the ceramic regenerator is about 24,000 yuan/year, and the maintenance cost of the RCO due to the replacement of the catalyst and the ceramic regenerator is about 318,000 yuan/year. The maintenance of other components of the RCO is the same as that of the RTO.

4) Applicability :

RTO is suitable for the treatment of waste gas in the production process with high continuous emission concentration, and can effectively treat all VOCS organic waste gas volatilized in the production process;
RCO has fast cold start and low cost, and is suitable for waste gas treatment in intermittent production conditions. The exhaust gas must not contain S, P, AS, halogen and other components that poison the catalyst, and the trace dust in the exhaust gas needs to be deeply filtered, otherwise it will affect the effect of the catalyst; the corrosive exhaust gas containing S, Cl, etc. is in the RTO, RCO Can't handle it.

Additional TIPS: RTO applications in various industries