Deriving energy from food waste
Of the 15 million tonnes of food wasted in the UK each year, around 4 million comes from the manufacturing sector, says FareShare.
It says the real problem is that most edible food is being disposed of at manufacturing sites. Sean Robinson, service leader at food automation specialist Novotek UK and Ireland, agrees but argues that as well as reducing waste, manufacturers should seek to derive energy from it.
Nearly 100 of the UK’s leading food and drink manufacturers and retailers have signed up for the Courtauld 2025 drive, including all the major supermarkets. At the drive’s heart is a ten-year commitment to cut the carbon, water and waste associated with food and drink by at least one-fifth. This commitment to preventing food waste is not only admirable, but it could also save businesses up to £300mn a year. But there’s another way to derive value from food waste.
After all, food production creates both waste and by-products with potential energy value. The repurposing of waste can be key to creating stronger overall operations with improved manufacturing effectiveness and higher efficiency. In the overall food value chain, manufacturing sites have the greatest opportunity to maximise the use and value of food waste — particularly if we focus on energy.
One prominent example is biomass from waste units. Another is for manufacturers to make the most of ingredient yields. Given that 4 million tonnes of food wasted each year comes from the manufacturing sector alone, the possibilities here are huge.
Power from anaerobic digestion
A unique and major problem of food waste management is the relatively short shelf life of the waste itself. There is a precedent to recycle food waste into animal feed, which is then sold to farms. Elsewhere, top food manufacturers reuse sludge from municipal wastewater treatment plants (WWTPs) for land applications or composting to produce fertilizer; and then there is anaerobic digestion (AD).
AD is the breaking down of organic matter, in the absence of oxygen, with micro-organisms called methanogens. This waste is broken down to produce energy-rich biogas (methane plus carbon dioxide) and digestate. Food waste can be converted into biogas that, when fed through a combined heat and power unit, becomes energy used to power businesses, homes and communities.
The potential of AD for generating power is significant. According to findings by the Society for General Microbiology, a typical food waste AD plant can generate up to 900 cubic metres of biogas from one tonne of dry organic matter. That’s enough energy to produce 1,800 kilowatts per hour (kWh) of renewable electricity, more than half the average annual consumption of a UK household.
In many respects, AD is the proven winner. However, food plants present unique challenges when maximising gas — and therefore heat, steam and electricity — production. Variability in the mix of food waste inputs into the AD system, and the calorific content of these inputs, can make it a challenge to be sure of getting the most from the energy system.
Better control over processes
Fortunately, software and computing power advancements have made it easier to optimise the overall energy system performance. As a supplier of industrial IT and automation solutions, Novotek has found that solutions like GE Digital’s Predix Operations Performance Management (OPM) allow firms to conduct analysis of the complex mix of factors that affect gas production. Through this analysis, they can learn the best ways to run digestion processes with different blends of food waste.
With SCADA systems, operations can be optimised based on insights derived from OPM, which helps operators have a clear understanding of performance, day-by-day and hour-by-hour. A mix of historical, real-time and predicted performance indicators can support decision making and speedier responses to unusual conditions.
According to a research paper by the UK’s Loughborough University, the advantages of real-time digitised tracking were experienced by a ready meal factory that specialised in chicken tikka masala ready meals. Food waste was a significant problem for the plant, with around 1400 kg being produced each week.
The plant’s traditional paper-based system for recording food waste had, unsurprisingly, proven inaccurate and time-consuming. Instead, the plant opted for a digitised and IoT-based tracking system. Among its hardware and software aspects were a weighing scale and touchscreen to measure the weight of food waste; and a software application with which staff could confirm the type and reason for waste. The software included real-time food waste, data visualisation, alerts and detailed analysis — all contributed towards better decision-making and food waste management.
With the food waste tracking system, coupled with staff training, the company was able to reduce its overall food waste by 60.7 per cent. Financially, the company saved approximately £306,873 on food waste compared with the previous year’s results. These savings represented a huge financial gain for the factory.
Similarly to these advantages, advanced control offerings like Emerson’s CPL400 provide a bridge between the real-time process control and the complex analysis being performed by OPM. These systems offer highly compact, very powerful processing capabilities, with the further advantage of segregated resources for the control functions and the IT interactions.
Whether through bespoke modular IoT solutions or inventive recycling technologies like AD, a marriage of processes and technologies will be key to deriving energy and value from food waste. However, the crucial point to take away here is that these automated, smart and analytical solutions must be up to standard to ensure the maximum extraction of energy.
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UK must stop blundering into high carbon choices warns CCC
The UK Government must end a year of climate contradictions and stop blundering on high carbon choices, according to the Climate Change Committee as it released 200 policy recommendations in a progress to Parliament update.
While the rigour of the Climate Change Act helped bring COP26 to the UK, it is not enough for Ministers to point to the Glasgow summit and hope that this will carry the day with the public, the Committee warns. Leadership is required, detail on the steps the UK will take in the coming years, clarity on tax changes and public spending commitments, as well as active engagement with people and businesses across the country.
"It it is hard to discern any comprehensive strategy in the climate plans we have seen in the last 12 months. There are gaps and ambiguities. Climate resilience remains a second-order issue, if it is considered at all. We continue to blunder into high-carbon choices. Our Planning system and other fundamental structures have not been recast to meet our legal and international climate commitments," the update states. "Our message to Government is simple: act quickly – be bold and decisive."
The UK’s record to date is strong in parts, but it has fallen behind on adapting to the changing climate and not yet provided a coherent plan to reduce emissions in the critical decade ahead, according to the Committee.
- Statutory framework for climate The UK has a strong climate framework under the Climate Change Act (2008), with legally-binding emissions targets, a process to integrate climate risks into policy, and a central role for independent evidence-based advice and monitoring. This model has inspired similarclimate legislation across the world.
- Emissions targets The UK has adopted ambitious territorial emissions targets aligned to the Paris Agreement: the Sixth Carbon Budget requires an emissions reduction of 63% from 2019 to 2035, on the way to Net Zero by 2050. These are comprehensive targets covering all greenhouse gases and all sectors, including international aviation and shipping.
- Emissions reduction The UK has a leading record in reducing its own emissions: down by 40% from 1990 to 2019, the largest reduction in the G20, while growing the economy (GDP increased by 78% from 1990 to 2019). The rate of reductions since 2012 (of around 20 MtCO2e annually) is comparable to that needed in the future.
- Climate Risk and Adaptation The UK has undertaken three comprehensive assessments of the climate risks it faces, and the Government has published plans for adapting to those risks. There have been some actions in response, notably in tackling flooding and water scarcity, but overall progress in planning and delivering adaptation is not keeping up with increasing risk. The UK is less prepared for the changing climate now than it was when the previous risk assessment was published five years ago.
- Climate finance The UK has been a strong contributor to international climate finance, having recently doubled its commitment to £11.6 billion in aggregate over 2021/22 to 2025/26. This spend is split between support for cutting emissions and support for adaptation, which is important given significant underfunding of adaptation globally. However, recent cuts to the UK’s overseas aid are undermining these commitments.
In a separate comment, it said the Prime Minister’s Ten-Point Plan was an important statement of ambition, but it has yet to be backed with firm policies.
Baroness Brown, Chair of the Adaptation Committee said: “The UK is leading in diagnosis but lagging in policy and action. This cannot be put off further. We cannot deliver Net Zero without serious action on adaptation. We need action now, followed by a National Adaptation Programme that must be more ambitious; more comprehensive; and better focussed on implementation than its predecessors, to improve national resilience to climate change.”
Priority recommendations for 2021 include setting out capacity and usage requirements for Energy from Waste consistent with plans to improve recycling and waste prevention, and issue guidance to align local authority waste contracts and planning policy to these targets; develop (with DIT) the option of applying either border carbon tariffs or minimum standards to imports of selected embedded-emission-intense industrial and agricultural products and fuels; and implement a public engagement programme about national adaptation objectives, acceptable levels of risk, desired resilience standards, how to address inequalities, and responsibilities across society.
Drax Group CEO Will Gardiner said the report is another reminder that if the UK is to meet its ambitious climate targets there is an urgent need to scale up bioenergy with carbon capture and storage (BECCS).
"As the world’s leading generator and supplier of sustainable bioenergy there is no better place to deliver BECCS at scale than at Drax in the UK. We are ready to invest in and deliver this world-leading green technology, which would support clean growth in the north of England, create tens of thousands of jobs and put the UK at the forefront of combatting climate change."
Drax Group is kickstarting the planning process to build a new underground pumped hydro storage power station – more than doubling the electricity generating capacity at its iconic Cruachan facility in Scotland. The 600MW power station will be located inside Ben Cruachan – Argyll’s highest mountain – and increase the site’s total capacity to 1.04GW (click here).
Lockdown measures led to a record decrease in UK emissions in 2020 of 13% from the previous year. The largest falls were in aviation (-60%), shipping (-24%) and surface transport (-18%). While some of this change could persist (e.g. business travellers accounted for 15-25% of UK air passengers before the pandemic), much is already rebounding with HGV and van travel back to pre-pandemic levels, while car use, which at one point was down by two-thirds, only 20% below pre-pandemic levels.