How to grow and go with the flow

Neil Riding examines how waste flow modelling and the WRATE tool can help smaller contractors invest in and develop the right solutions

Imagine you’re an established contractor with a good site, and a good base of industrial customers. You’re handling maybe 50,000 tonnes a year, recycling a reasonable proportion for a small revenue, and sending the rest to landfill. Now, you want to protect and grow your business. You know there are technologies like MBT, anaerobic digestion and in-vessel-composting that can recycle more, generate renewable energy and increase your income. But how do you decide what technology to go for, and what plant to invest in?

A good place to start is to get an understanding of the waste streams that you’re accepting. Without this you can’t establish your market or the right treatment technology. But making predictions over a long period is difficult. Demographics change. Legislation is constantly changing and getting tougher. The composition of waste streams moves on with improvements and reductions in materials and packaging. And any change to waste composition can impact on the operation of any new facility.

Of course, local authorities and the large contractors who bid for their PFI waste contracts have been engaged with issues like this for years. They follow rigorous procedures and procurement guidelines laid down by government. To ensure that the proposed solutions are as robust as possible, a life cycle analysis tool known as WRATE is used to establish the best practical environmental treatment option and the best available technique or technology. Both involve looking in depth at the quantity and composition of the waste stream before doing the financial modelling.

Experience is filtering down

But here’s the good news for smaller contractors. The sophisticated work undertaken for large scale municipal waste projects has created a high level of skilled expertise which is now available and directly transferable to help the development of merchant facilities serving local and regional markets. So let’s get back to our traditional waste contractor looking to invest and develop. How do you assess and analyse the available waste in your area? How do you predict future waste streams? How do you evaluate the best technology? What are the costs, the revenue streams and the payback period?

WRATE (waste and resources assessment tool for the environment) is a sophisticated life cycle assessment software tool for comparing the environmental impact of different systems for the management of wastes. It can estimate the greenhouse gas emissions of waste management operations in a consistent and objective way, so that environmental impact can be assessed alongside financial and technical performance.

Thus, WRATE is an important tool in the development of any new facility.

It can help you understand the best technology from an environmental performance point of view, but it’s only one piece of the jigsaw. It needs to be connected back to a close understanding of the waste streams involved. This is because the use of WRATE depends on the amount, accuracy and robustness of the input data that’s used to create model scenarios – and one of the fundamental elements is the detailed waste flow model that accurately maps the movement of waste through a potential treatment facility, from source through transportation to final recovery or disposal.

A tailored approach

Waste flow modelling work is highly bespoke, and tailored to the specifics of each project. These are likely to include waste quantity, composition, the most appropriate technology for processing, and the further treatment of offtake materials such as recyclables or residues. Understanding the waste flow in-depth is key to determining the income streams from recyclate and from energy generation, and the cost of residues to landfill. As well as being critical to understanding technical performance, it naturally links to financial modelling.

Another factor that needs to be taken into account is that incoming waste streams may well go in sequence into several linked facilities such as MRF, anaerobic digestion and then gasification to achieve the best results. Waste flow modelling can run different operational scenarios based on manipulating and changing numbers within parameters such as the capacities of each facility, waste composition and quantities. This, in turn can, assess the impact on recycling levels, energy generation and commercial performance.

Any waste flow model needs to be connected to a financial model to assess business opportunity, payback and risk, in order to complete the overall assessment of project feasibility. By taking the right steps at the feasibility stage – putting in the time and effort to understand the waste streams and the technologies capable of treating them, doing the waste flow and financial modelling and establishing that there is a business case – operators who are thinking of developing a new facility can avoid costly mistakes and give themselves the best possible chance of success.

Neil Riding is a waste resource management expert with Wardell Armstrong

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