Understanding waste terms and what they mean

Waste processing plant

Understanding the terminology used by the waste industry can be a little confusing for those new to incineration.

We’ve put together a helpful list of typical terms that are commonly used in the waste disposal industry. They will help you understand the terminology better and give you a better understand when you come to make your decisions on which method is right for you.

The calorific value or the heat value of a solid, liquid or gaseous fuel is defined as the number of heat units developed by the complete combustion of unit mass or unit normal volume of a given fuel. It may be expressed as kJ/kg or kJ/normal m3.

Each of these terms are important to an effective incineration process and ensure you incinerate waste in a safe and effective manner.

1. Calorific Value of waste

Any type of substance that contains energy has a calorific value. Waste can be burnt because the incineration process harnesses the energy stored within it. All waste has a different amount of calorific value and therefore releases different amounts of energy as it burns. Calorific value simply refers to the heat created from the waste.

The challenge with calculating the calorific value of waste is that different materials have different calorific values. PVC plastic has a value of 41MJ/kg whereas paper only has a value of 13.5 MJ/kg. 

So unless your waste stream is made up of one single material, you’ll need to work out the composition of your waste.

Generally speaking, mixed domestic waste will have a calorific value of between 7 and 16 MJ/kg.

Waste TypesCalorific Value
(MJ / kg)
Calorific Value
(kCal / kg)
 Medical waste18 – 254530 – 5745
 Industrial & hazardous waste23 – 395247 – 9548
Domestic waste (un-processed)7 – 161663 – 3813
Domestic waste (recycled)10 – 142379 – 3335
Plastic (PVC)419787
Wood14,43431
 Paper13,53216
Petrol (gasoline)45 – 4710583 – 11241
 Coal15 – 273594 – 6462
 Diesel46

2. Moisture Content of waste

It’s important to know the amount of moisture in your waste can dramatically affect its ability to burn efficiently, the less moisture your waste stream contains, the less fuel required for combustion.

The moisture content of waste can be calculated by comparing the dry weight with the total weight. 

Different types of waste will have different levels of moisture content. Organic waste and food have high moisture content, whereas plastic, glass and metal have very low moisture content. We always recommend where possible to dry any waste out as much as possible before incinerating it.

3. Particle Size of waste

The particle size of waste simply refers to the size of the individual items in your waste stream. This will be dependent on the type of waste you are incinerating. Municipal Solid Waste could have a wide range of particles, from small cotton buds to large plastic containers and agricultural waste could contain small animal parts all the way up to fallen stock such as cows, horses and sheep. 

4. Standardisation of waste

There are many common types of waste streams, and standardisation refers to a set of averages to ensure the waste mixture remains in roughly the same ratio.

The standardisation of waste can also refer to segregating waste into separate defined streams, so for example, there is a standard paper waste stream, a glass waste stream, and MSW (municipal solid waste) stream and a medical waste stream. This is not only designed to keep similar waste types together but also limits the chances of hazardous waste exposing nearby surroundings and helps when disposing of the remaining residue and ash after the incineration process has taken place.

5. Daily Volume 

In the incineration process, daily volume refers to the amount of waste a site or incinerator can combust during a 24-hour period. It’s calculated by multiplying the volume of the incinerators combustion chamber (in metres cubed) with the number of operating hours in the day, the bigger the chamber the bigger the daily volume. For example, if you were incinerating the exact same waste – a 5.0m2 chamber could process twice as much as a 2.5m2 chamber over the same period.

6. Waste Brokers & Partnerships 

A waste broker is any company or organisation that arranges to recover and dispose of waste for another business, organisation or individual.

Waste brokers will typically collect all types of waste streams, though some may specialise in specific types of waste such as medical or fallen stock. Some businesses may partner with waste brokers if they have a specific type of waste that cannot be easily recycled, combusted or sent to landfill, it is always important to make sure your waste goes through the correct steams in order for it to be disposed of the best way it can.

If you need to find more information regarding processing your waste on site, in a safe, quick and efficient manner, visit our main page: Incinerator Manufacturer & Waste Incineration Expert | INCINER8 or alternatively call us on +44 (0) 1704 884020 or email our expert sales advisors at sales@inciner8.com

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