Some manufacturers are still recovering from the repercussions of the 2008 crisis, and another global recession is impacting industry in 2020. Meanwhile, natural disasters and global warming are proving that we need to do more to preserve our resources. In times of economic instability and environmental concerns, the idea of turning production scrap into usable energy is appealing to many manufacturers. Neil Ballinger, head of EMEA at automation equipment supplier EU Automation, explains how it can be done.

The pressure of reducing waste while maximising productivity is pushing companies to explore ways of generating more power from renewable sources. Energy can be recovered from waste using several techniques, which allow manufacturers to turn the by-products of their processes into power, heat, and even transport fuels.

By repurposing waste, it is possible to benefit from an alternative source of energy while at the same time diverting waste from our already overflowing landfills. Waste-to-energy processes have a number of advantages. They help the country reduce its dependency on energy imports, provide an effective way to manage industrial waste, and can provide a steady and reliable source of heat and power.

The most common waste-to-energy method is incineration. However, this technique is not kind to the environment, since even modern incinerators may release fine particulate, heavy metals and dioxin in the atmosphere. Several emerging technologies can produce energy from waste without direct combustion, such as gasification, pyrolysis and thermal depolymerisation. Though more sustainable than incineration, these technologies also use high temperatures and release almost all of the carbon content in the waste to the atmosphere as carbon dioxide.

On the other hand, non-thermal technologies don’t involve heat in processing industrial waste and are completely environmental-friendly. Among them, anaerobic digestion is on the rise, especially in food processing plants, as a method to turn organic waste into clean energy.

The new frontier of waste management

Anaerobic digestion is an approach with big potential. It can be used to repurpose any kind of organic waste by breaking it down in an oxygen-free tank and transforming it into biogas and biofertilizer. This approach is ideal for firms that produce large amounts of organic waste, such as industrial farms, food processing plants, breweries, distilleries and tobacco plants.

The initial cost of this green technology can generally be amortised in under five years. After that, the plant will benefit from a constant and reliable source of energy that can be reused in the production process, establishing a virtuous circular economy business model. This is the reason why many manufacturers in the food and beverage sector and now investing in an on-site anaerobic digestion facility.

In the presence of an on-site anaerobic digestion plant, biodegradable production scrap can be fed directly to the oxygen-free tank to be processed. Here, naturally occurring bacteria will break down the waste. In the absence of oxygen, this process will release methane, a combustible has that can be repurposed to generate clean energy or heat.

Biogas, heat and electricity produced in anaerobic digestion tanks can replace energy derived from fuels, helping the country meet the European 20/20/20 targets – reducing greenhouse gas emissions by 20 per cent compared to 1990, increasing energy efficiency by 20 per cent, and supplying 20 per cent of energy needs from renewable sources by 2020.