The Differences between autoclave and incineration are many. It is hard to decide which is the right one. Here is a blog to help you choose the right one.

Biomedical waste is a type of hazardous waste, and its disposal seems a concerning issue. Disposal of Biomedical waste requires unique methods except landfilling. Medical wastes are divided into two categories, i.e., Infectious waste and Non-infectious waste. Non- infectious waste can be disposed of directly like municipal waste. But infectious waste needs treatment before disposal. Incineration is the oldest way, while autoclave is one of the recent alternatives for biomedical waste treatment. In this blog i will tell  you the difference of autoclave and incinerator. For the first starters, let’s know something about these technologies then we will know about the difference of autoclave and incinerator.

What Are Incinerators?

Incineration is the burning of waste at a high temperature in the specialized furnace. It converts organic and combustible waste into inorganic, non-combustible matter. But its usage faces many objections due to hazardous gas emissions. In addition, sometimes, due to incomplete combustion of substances like PVCs, it produces carcinogens. For detailed information on this topic, you can go through our blog, namely, find the right technique for the treatment of infectious waste and the 7 types of incinerators you must know.

What Are Autoclaves?

An autoclave is a type of wet thermal sterilization treatment. Waste material is heated at 121°C (minimum) and 1 bar (100kPa) for at least 20 minutes. It only needs to treat exhaust gas and the left water.

For detailed information on this topic, you can go through our blogs, find the right technique for treatment of infectious waste, and autoclave: an effective bargain for biomedical waste treatment

Now let me tell you about some of the the difference of autoclave and incinerator. Before deciding which option is better one has to check many factors some of the important deciding factors are mentioned below.

Infographic for points to consider when choosing between autoclaves and incinerators
Points to consider when choosing between autoclaves and incinerators

Suitable waste: Autoclave Vs. Incinerator

To decide which of these are best we need to know how many types of waste these can deal with. That’s why in first step in the difference of autoclave and incinerator you should know for what waste this technology is used for. To answer the question below is a comparative summary. Incinerators are widespread and can treat all types of waste. But autoclaves are ideal for many types of waste. Different biomedical waste treatment based on both technologies is compared below:-

The difference of autoclave and incinerator: Suitable waste type
Suitable waste type
  1. Sharps – Can be treated with autoclave, but incineration is not advisable as metal items will remain in ash, and glass items can blast during the process, cause harm to machinery, and cause severe injury to operators.
  2. PVC plastic waste- Autoclave can efficiently sterilize them, and with a shredder, volume is reduced. At the same time, incineration of plastic is banned as they produce dioxins. 
  3. Radioactive substances and heavy metals like mercury:-  Treatment of these are not advisable through both these technologies. Because these elements will be present in the ash that can cause severe problems.
  4. Pathological wastes:- Can be treated through large autoclaves. Small ones having shredders can deal with them. Incinerators can only burn them with extra fuel and can affect the rate of quantity.
  5. Pharmaceutical Waste:- Autoclaves cannot treat them, but encapsulation of pharma waste is permitted by EPA. Incinerators can treat them. 
  6. Infectious waste:- Both technologies can treat infectious waste efficiently. 
  7. Liquid infectious waste can be treated with autoclave easily but can only be incinerated with specially designed incinerators. 

Environmental Impact: Autoclave Vs. Incinerator

 

Difference of autoclave and incinerator: Environmental Impacts
Environmental Impacts

 

One of the deciding factors of the difference of autoclave and incinerator is the environmental effect of the technology. Autoclave causes very low pollution to soil and water. However, discharged effluent may affect water quality. Odors are an issue to close nearby areas if not equipped with a proper ventilation system. Gas and water generated during the process should be treated then discharged.

Incinerator emissions vary depending on the waste type. For example, in the presence of halogenated materials, carcinogens like Dioxins and furans are formed. Therefore, it causes air pollution at a high rate. On the other hand, residual ash should be treated because it contains harmful effluent. New incinerator models with filters can reduce pollution to some extent.

Efficiency: Autoclave Vs. Incinerator

For autoclaves, minimum exposure time and temperature is required for proper disinfection. From the number of references, time-temperature recommendations are found for different circumstances. Autoclaves efficacy is 99.99% reported. Color-changing strip indicators or biological indicator strips are used to detect efficiency. Autoclaved wastes are post-tested for many microorganisms, even thermostable. For all the tests, the results are satisfactory.

Difference of Autoclave and incinerator: Efficiency of Microwave technology
Efficiency of Autoclaves and Incinerators

Modern incinerator efficiency is 70-80% with proper ash, gas emission treatment setup. These measures reduce air pollution standards. But many viable spores of microbes like B. Anthracis, B. subtilis, B. Stearothermophilus, a heat resistant bacteria, are found in incinerated wastes. Very appropriate data is not present.

Requirements: Autoclave Vs. Incinerator

Autoclaves are mostly electric-based. It is a problem in places with limited electricity supply. In addition, most primitive incinerators need electricity for fuel pumps, fans, temperature, and other gauges. So, incinerators are also power-dependent.  

Difference of autoclaves and incinerators: Requirements
Difference of autoclaves and incinerators: Requirements

Utility

Autoclave

Incinerator

Electricity

All autoclaves run on electricity. Either for the whole process or control systems.

All need electricity. The primitive ones need fuel pumps, fans, temperature, and other gauges. 

Water

Need for steam generation. Water should be free from salts to prevent clogging of pipes and corrosion.

It is needed for wet scrubbers.

Lime 

No need

For drying the scrubbers. 120kg/ ton of burned waste.

Ventilation

The working area must be cool. 

The working area must be cool. Prevent exposure to toxic gases.

Drainage

For used water discharge.

For washing and disposing of effluent from scrubbers.

Fuel

No need

Diesel for large ones and kerosene for smaller ones.

Area requirement for setup: Autoclave Vs. Incinerator

Difference of autoclave and incinerator:Requirements for setup area
Difference of autoclave and incinerator:Requirements for setup area

For the waste treatment plant, the site needs careful considerations as autoclaves are machines, so it needs a medium-sized room area to set up. However, autoclaves have fewer restrictions on setup location because they don’t emit pollutants and have few sound and odor problems.

Incinerators need large setup areas for their different sections. It can cause problems in the neighborhood. Incinerators need to be set up with following points in mind:- 

  • It should be away from the human population.
  • Wooden areas like forests, valleys ridges are avoided and may cause dispersion.
  • Hilltops, open fields are favored for their setups.  
  • Locations where surrounding areas don’t have crop fields.  

User friendly: Autoclave Vs. Incinerators

Autoclaves are primarily automatic. They come with pre-installed disinfection programs. This makes handling them very easy. All these functions make it very user-friendly.

 Incineration needs a trained and educated operator. An operator must know about the:-

Difference of Autoclaves and incinerators:User friendly
User friendly
  • The correct measure of waste.
  • The calorific value of different waste.
  • When to increase or decrease the temperature.
  • The correct procedure to start and shut down the incinerator.
  • The correct rate for maintaining suitable operating temperature.
  • When to add extra fuel, etc.

Waste capacity: Autoclave Vs. Incinerators

Autoclave and incinerators both are available in small as well as large sizes. Benchtop models of ten liters for upto 5kg/ hour to large models of 500 liters or above with more than 50kg/ hour capacity. Every model has its significant advantages. Like small benchtops, autoclaves are used to treat highly infectious wastes, up to250 liters for a developing hospital. For a hub or waste from many large surrounding hospitals, 250-500 liters are used. > 500 liters are used for central treatment plants. The same goes for the incinerator also. 

Maintenance: Autoclave Vs. Incinerator

All the waste management equipment needs periodic maintenance and repair. The operator can do most routine maintenance and repair. Autoclaves maintenance comes from:-

Maintenance
Maintenance of autoclave and incinerator
  • Pipes leakage
  • Door sealing gasket failure
  • Burnout of heating elements
  • Control panel failure
  • Corrosion and pipe blockage, because of supplied water 
  • Shredders failure, if autoclave have
  • Rotatory platform problems, if autoclave have  

It has been observed around the globe that with proper maintenance, autoclaves possibly remain operational for 10-20 years. 

In incinerators, Photocell, spark electrode, the oil filter element of primary thermocouple, and heated refractory screens may need renewal once in two years. Fire bars approx; every five years; pumps and burner motors may need substitution in 10 years. Manufacturers say the lifespan of their machinery is ten years, but it’s closer to 5 years.

Economics: Autoclave Vs. Incinerator

The World Health Organisation has developed a costing tool used to estimate the expenses related to different treatment technologies. Autoclaves turn out to be the most convenient option for most situations. 

Cost and operation costs of Autoclaves and incinerator

Capital cost

Money is an important difference of autoclave and incinerator. Like any resource, treatment technology is also dependent on the brand and technology. The price of autoclaves and incinerators varies greatly. High-end technology made in the US and Europe is relatively expensive than those made in places like India and China.

Cost related with technologies

According to a report by UNEP, the estimate of a diesel incinerator capable of meeting air pollution standards corresponding to the Stockholm Convention was $275,000 for an installation burning 50kg/hour. For autoclave US $110000 for 80kr/hr and larger and sophisticated models, it is averaged about $220000 for 1300kg/hr. 

Operation cost

Operation costs are often missed while purchasing new equipment. But, in the long term, operation costs outweigh the purchase cost. 

UNEP technology compendium estimates in a report that treatment costs for autoclaves to be 0.14-0.33US$/kg. And incineration with air pollution control costs US$ 0.27-1.66 per kg.

 

Some Other factors: Autoclave Vs. Incinerator

Other factors regarding autoclave and incinerator
Other factors regarding autoclave and incinerator

Factors

Autoclave

Incinerator

Volume Reduction

If equipped with shredder, upto 85-90%

90% reduction in volume

Mass Reduction

No mass reduction

Upto 70% of mass reduction

Dioxin, Furan production

No production

Only if the waste has halogenated substances.

Bothering

Sometimes odor may be a minor issue; otherwise, none

High, often complained from the neighborhood because of noise and odor. 

Resource Recovery

Materials like syringes, metal plates, etc., can be recovered.

None

Residual waste

Recycling is easily possible but may be a problem where recycling and final disposal options are limited.

Ash can be toxic and may have sharp residue. The exhaust also produces toxic residue.

Conclusion

Every technology has pros and cons and this is no different. However, according to the evaluation for the difference of autoclave and incinerator, autoclaves seem to have the upper hand. Either from an environmental point of view or technological autoclaves are better. The only limitation is that it is more costly than an incinerator.

However, if you require consistent destruction and removal of hazardous medical and pathological waste for many years the next generation high quality environmentally optimised Medical Incinerators are your options. I hope you enjoy the blog like it if you have. For more related blogs, please subscribe to us. And please mention anything you want to say regarding the subject in the comment box below. 

Join us

 

andleep zahra
Author

She is a biotechnologist and received her master degree in biotechnology from V.B.S. Purvanchal University. Being a biotechnologist she loves to do research and write articles on the same. She’s best known for writing articles and blogs on environmental issues. Through her writings she likes to provide more information on environmental conservation and provide knowledge on how to address the issue, mainly focused on waste management. She looks for ways to get involved and also attended several conferences, workshops and webinars. “Increasing waste around the globe that is affecting our ecosystem and reducing our biodiversity is the most critical issue we humans often overlook and it will be the greatest challenge our younger generation will ever face,” she says.

Write A Comment