The Future of Waste to Energy – RWM Presentation

 

The future of Waste to Energy – Complete talk by James Grant – Addfield Environmental.

In September 2019 during the first day of the Recycling and Waste Management exhibition at the NEC in Birmingham. Our Business Development Director James Grant delivered an information packed presentation to a packed lecture theatre about the future of Waste to Energy and the ways in which Addfield is supporting the development for our customers.

The following is an optimised transcript of the presentation giving you the highlights of the talk.

If you have any questions on how Addfield can help you at the end of this contact us straight away via sales@addfield.com.

The Future of Waste Treatment

At Addfield we have become a recognised and respected provider of thermal waste treatment solutions able to provide a reaching range of solutions from individual small-scale machines through to full high capacity facilities.

I would like to describe to you how these plants can help you with your waste issues. Hopefully you will be able to identify with some of the problems identified here.

We have been manufacturing incinerators for over 35 years and currently export our equipment to over 100 different countries around the world.

To begin with an introduction to the points that we are going to discuss.

Starting with a brief overview of the current risks to waste management and how we can address those.

Followed by a review of our small-scale waste to energy plants and the permits surrounding them, before discussing planning. Finally we will look at your ‘Return on Investment’ in these plants and the main factors as to why you would want to look at something like this.

Risks To Waste Management

Starting off, risks to waste management and why you may want to look into something like this. Firstly something that maybe everyone can identify with and that is ever increasing landfill costs. In recent years they have just increased and increased, in gate fees as well as transport costs.

There is a potential lack of landfill capacity in the UK, resulting in a lot of recent news reports talking about landfill problems especially with regards to exporting waste abroad. And potential tariffs on waste as well which we will go into more detail later. Where a lot of countries around the world are placing import taxes and again risks from Brexit exporting waste to EU countries.

Another risk to waste especially plastics is the reclassification of certain waste types so there is a potential for certain plastics such as car plastics are to be reclassified as hazardous. This would have an impact on how they are disposed and also affect the cost associated with that disposal as well. Finally there is a rejection of waste from traditional waste importing countries.

Waste Makes Headlines

There have been several news reports on waste from all over the world, and how government policy impacts waste disposal costs and how that might challenge future waste disposal routes.

Here are a couple of examples – there are lots of these that keep cropping up on the news I am sure you have seen some.

Here we have ‘Malaysia sends back 3000 tonnes of plastic back to the country of origin.’ This is just highlighting the issues of where waste goes in the future and the options for waste disposal are narrowing.

Equally just last year (2018) ‘China decides to ban 24 grades of rubbish,’ as part of their ‘National Sword,’ campaign. The main key point to take away from this is that China is probably the world’s biggest waste importer, so waste isn’t just an issue for the UK it is a global issue for how people treat their waste in the future.

Talking about tariffs here is an example of how potentially RDF is going to be taxed in January 2020 and this seems to be a running theme with taxation on waste in the future.

And then government policy, a little bit closer to home with landfill tax being a corner piece of Scotland’s ‘Zero Waste’ plan, where government pressure is on looking for where waste will go in the future.

I am going to identify certain areas and outlets for those as well.  Hopefully you can look at those and see where you may have problems with your waste.

Small Scale Waste to Energy Plants.

The future as we see it is small scale waste to energy plants.

What is small scale?

Well small scale is for us a machine that processes less than three tones per hour and that comes down to permitting which we talk about later on.

Just to identify waste types that will be suitable for this kind of plant. Effectively a waste to energy plant can burn any type of waste. However there are certain waste streams that are derived from oil such as plastics which will be a lot more cost effect to run through a combustion plant so if you have something of a higher energy value it uses less auxiliary fuel to run it. Equally if you have something of a low energy value or a high moisture content you will use more fuel to run the plant and fuel is probably the biggest outgoing when running this kind of equipment.

You may recognise a few of these waste types:

Again all plastic derived really, and costs for disposal will come back to the ROI part.

The higher the energy value the quicker the return on investment.

What to expect from a small-scale waste to energy plant. We will discuss the most common layouts that we produce. However every site is different and every waste type is different. So we build them to a customer requirement but these main points will ring true for most sites.

A modern plant layout would contain the large main combustion chamber, which burns the waste and creates off gasses. This is where we will take the heat from generate energy from. This will be surrounded by equipment dealing with the flue gas filtration. Obviously with these kind of plants emissions control is vitally important and this is where we need to comply with Waste Incineration directives, the industrial emissions directive as well.

if we look at the loading systems. We often have a bin tipper system, however if your waste is not in bins then we can look at conveyor systems, loading with skid steel loaders. Effectively with a bin tipper this will feed a hopper feeder, ram feeder that will continuously push waste into the plant. Fundamentally the plant is designed to be as automatic as possible. We are pushing waste in one end, creating the energy from the bottom end we are creating an ash by-product.  The main chamber works on a stepped hearth principal so the waste comes in at the front here, it moves down the steps and the ash drop out zone is at the bottom.

Everything else is about emissions control.

The off gasses are the gasses that we can use to recover energy which will move in to the secondary after chamber. This is the first stage of the pollution control systems and this is operating at 1100°C, as part of the legislation for these type of plants. This is before it goes into the boiler systems, this component is really creating energy but its primary purpose is actually to protect the filter system. As we are running at 1100°C in the secondary chamber and the filter system can manage about 400°C so the boiler protects the filter system and as the by-product from the boiler is that we can create some renewable energy and this can be in the form of hot water and steam and we will cover energy later on.

Coming out of the boiler there are a few utilities used to run the plant, fuel and electricity etc. Then we use reagents such as Lyme or Sodium Bicarbonate which neutralises some of the acids and the gasses. Then we use an active carbon compound which neutralises heavy metals and dioxins and furans from the plant. Then in the ceramic filter tower we have a bank of ceramic candles which stop the spent reagent so that after the reaction has happened, they are stopping the particulate material. We would have a bank of 4 filter towers for a 1.5 tonne an hour unit. These are all scalable towards the size of the machine that we would produce.

In terms of the automation of the plant. The filter has its integrated cleaning system which comes online automatically

Maintenance wise we would run this machine for 670 hours a month and then it would shut down for boiler cleaning once a month and that is the user intervention on a monthly basis then you would shut it down for two weeks at the end of the year for refractory maintenance.

When we look at the filter cleaning system the residues of the air pollution control system when they are collected by the hopper, they are brought out on a screw feed and the ash product will then go to deep landfill.

These will be collected in ash skips.

These systems will change depending upon how the sites are finally laid out. Generally you would have a separating wall between the 50% inside and 50% outside.

Typically we would run on a SWIPS (small waste incineration plants) permit, which is up to 3 tonne an hour. This would be based upon twin 1.5 tonne lines. Having a twin line system of two 1.5 tonnes an hour would improve efficiency.

For building requirements, you would need an 8 metre height on the after-burner for the chimney systems.

In terms of the actual site size. the typical plan size is approximately 35m square which is about the size of a 5-a-side football pitch, so not a massive footprint on the grand scheme of things.

Now we will talk about heat recovery from the boiler. For example on a tonne an hour plant you would generate 500kw of hot water 7000kg of steam at 8 bar pressure. These are the two recoverable options that you get for free as the boiler is already there to protect the filtration systems.

If you can use these on site the ROI is a lot quicker. Part of the planning aspect might be to tick a tick box, where you have to recover this kind of energy. If you have no outlets for this kind of hot water or steam this is where we might look to put a power generation module on the sight. That power generation will use steam from the plant and it will turn it into electrical energy and this would once again generate 500kwh which is the example here but that is very much driven by the energy value in the waste and the size of the plant as well. The power module adds more cost to the machine but the payback with electrical generation is about two years.

And that is what we are looking at specifically small-scale plants we are not looking to export the energy we are usually using it on site. People that will look to install this kind of equipment would usually have huge electrical bills, from sorting equipment, processing equipment, conveyor systems.  So these people will be looking to offset that 10p a kw figure rather than exporting it at 5p kw. Usually the priority here is putting it on a site where we can use this kind of energy.

Looking at SWIPS permitting these are governed by the local authority and the thing to be aware of with SWIPS permitting is that you will get a SWIPS permit. It is not a case of ‘yes’ or ‘no’ it is a case of if you can tick all the boxes you will get a permit.  And that is site dependent and equipment dependent but generally it is relatively straight forward. A SWIPS permit will let you do up to 3 tonnes an hour of non-hazardous waste and up to 10 tonnes of hazardous waste a day.  If you wanted to do any more than that you would need to go through an environmental agency permit which is a bit more painful to go through. These kinds of permits lend themselves to this kind of small-scale plants essentially.

Planning is potentially the biggest hurdle that most people will come across for these sort of plants. So, when you are looking to put waste to energy plants in, there is a general lack of government support in this sort of equipment and planning is not a given. Planning can take 1,2 or 3 years and it is really the thing that people need to put in place first before they go any further as it is the thing that could stop a project in its tracks.

In terms of timelines, you would look at typical timelines on how you would go about installing a plant. Applying for planning permission is the first protocol, after that would be the SWIPS permit these normally take about 8 months to come back and part of that SWIPS permit is to submit the initial design where you would need the help from us the manufacturer to do that.

Once that is all signed off then we would be looking at up to 65 weeks manufacturing time that includes detailed design potentially a HAZOP hazard study. Once that is signed off we would go to a full manufacture and that building process can take about 47 weeks. The final ten weeks are installation, on site commissioning, training of operators, proving the equipment, performance testing and final emissions testing before the final signoff for the plant.

You will see that the planning stage can take as much time as the installation stage.

The numbers and the business case

Why would people look at this? Well ROI is the reason why people would look at this system and again it comes back to having the right waste type. You can see on the example we have the utilities for the plant, as the plant runs 670 hours a month, 8040 hours a year your biggest outgoing here is fuel. So going back to the earlier point, the more energy you have in the waste the less fuel you will use, the lower your fuel bill will be and equally the quicker the return on your investments.

The more moisture you have the lower energy and the higher the fuel bill, it’s as simple as that and equally the bigger plant you go typically your costs might be lower.

When we break this down into fuel, oil, electricity, and the reagents previously mentioned, then there are ways to reduce this further. The fuel oil could be in the gas, it could be a bio-fuel, a few of our customers use waste oils to power the plant so there are a few options there. Our annual operating cost estimates for a tonne an hour plant comes in at about £217,000. We have got a cost per ton at around £27.20 per tonne. If we look at maintenance costs, I cannot give you the cost that the building is going to be but I can give you the maintenance cost. Our plants are deigned to last 20-25 years. Our oldest plant in operation was installed in the early 90’s so that’s about 23-24 years old now and it is still in operation. So as a business we have got a good idea of what goes wrong and when and what needs maintaining and when. So we can build a good idea of what will need replacing at the replacement cost associated to that as well over a 20 year period. We can break it down into an annual maintenance cost, and we can break that down even further into a cost per ton and here we have got £8.01 as a contributing maintenance figure per tonne. For the future and we end up with a total cost per tonne for disposal of your waste and in this particular example a tonne an hour plant we are looking at about £35.21. Having an expected life expectance of 20+ years most people see a ROI in two to four years, some earlier. Most people will be looking at two year payback on this kind of equipment.

To summarise in terms of the waste market and what is happening in the future. There are lots of challenges with news reports every other week about where waste is going to go in future and costs increasing. We feel that small scale incineration and waste to energy plants have come to a point where they’re now economically viable. Whereas 20 years ago there was not the pressure on the industry where it would not have been viable with the costs, but now it is a serious concern for people and it is looking more economically viable to give a payback in a reasonable amount of time.  Effectively it gives waste companies an opportunity to take control of their own waste stream ultimately being in someone else’s pocket is not comfortable and it does not give stability to your company. We feel that as an option it is now more viable and we are building plants today to prove this change.

Obviously this is only a small overview of everything tat is involved in developing a ‘Waste to Energy’, plant.  If you would like to learn more about this please contact sales@addfield.com.