Optimising clean-in-place processes in food and beverage operations - Part I

Clean-in-place (CIP) processes are often intensive and waste large amounts of energy, water and chemicals. New innovations in CIP technology allow plant operators to cut costs in an environmentally friendly manner while still conforming to regulatory safety standards.

A typical clean-in-place (CIP) process requires large amounts of water, chemicals and energy. It is estimated that, on average, a food and beverage plant will spend 20% of each day on cleaning equipment, which represents significant downtime for a plant. Energy usage varies depending on the process. For example, a milk plant is likely to use 13% of its energy on CIP, whereas a powdered milk, cheese and whey process is likely to use 9% of its energy on CIP¹. In a fruit jam manufacturing facility in Manchester, England, cleaning hoses in the fruit room were identified as one of the highest end users of water in the facility (17% of total site water consumption)².

Many manufacturers are unsure of how their CIP systems are performing. Therefore, additional steps are often introduced as a safeguard to ensure adherence to sanitation standards. This practice results in higher consumption of water, chemicals and energy than is necessary in order to avoid the contamination issues.

A number of companies have addressed CIP improvements with small modifications such as altering the chemical concentration, or by adjusting the time taken for each stage of the CIP process. However, very few food and beverage manufacturers have put tools in place that render the CIP process efficient. In fact, in an informal poll conducted by Schneider Electric on food and beverage clients in France, only 12% thought that their CIP systems were efficient yet only 18% of those surveyed had commenced a study around CIP optimisation. Yet industry leaders are clearly indicating that progress needs to be made in the areas of waste reduction and water and energy efficiency (see Figure 1).

Figure 1: Top sustainability priorities of food and beverage, and consumer products industries³.

Recent innovations in technology now enable plant operators to calculate the optimal mix of water, chemicals, temperature and flow required to achieve safety standards while saving at least 20% in energy cost and by reducing the downtime for cleaning by at least 20%. In addition, all the steps in the process can be easily traced and automatically documented, which simplifies any auditing requirements that need to be performed by regulatory inspectors.

Risks of inefficient and ineffective CIP systems

Food safety and litigation

With many hundreds of metres of pipework, and a multitude of valves, pumps and instrumentation that make up a typical CIP system (see Figure 2), the risk of equipment failure is high and can happen at any stage of the process with a potential impact on food safety. It is quite difficult to verify that all aspects of the cleaning process have been taken into account. Consider the instance of an operator who runs a cleaning process and does not even realise that a particular component (such as a pump) did not work because no alarm was generated.

The result of improper cleaning is costly to a plant in violation of food and beverage industry safety regulations. The all-too-frequent incidences of food safety disasters around the globe are often caused by simple mistakes or faulty processes in a food or beverage factory which lead to sickness, injury and even death for those who consume contaminated products. In addition to the human tragedy, these contamination incidents lead to the expense of product recalls, loss of confidence in a company’s brand and ultimately loss of revenue.

Food safety authorities conduct plant audits to ensure that the critical control points identified as HACCP (hazard analysis and critical control points) are monitored and reviewed for regulatory compliance and continuous improvement. In the event of a contamination incident, full traceability (enabled by software) and ‘proof of clean’ will reduce the legislative and legal impact. The company involved will be in a better position to identify the contamination impact and to minimise the effort required to implement a withdrawal or recall procedure.

Figure 2: Example of a simple, single line CIP system.

Production downtime

Lowering operational expenditure and reducing waste to lower the cost of production without impacting product quality are universal goals of food and beverage enterprises. However, when a CIP process is in operation, production is stopped. This impacts profitability. As a result, two tendencies which are both negative to the business manifest themselves:

1. When a problem occurs, there is a natural reaction to avoid seeking the root cause of the problem. Such an intervention could involve even more time-consuming maintenance work.
2. With the risk of contamination at the forefront of most operators’ minds, the tendency of the CIP operator is to overcompensate with increased cleaning time.

Fortunately, new CIP technologies alleviate the above problems because of significant improvements in efficiency:

• More advanced CIP automation enables dramatic reductions in troubleshooting time in the event of a problem, cutting what once took hours to perform into minutes of diagnostics.
• An optimised CIP process can reduce cleaning times by up to 20%. If CIP currently takes around five hours of each day, a 20% reduction in cleaning time will deliver approximately an extra hour of production time.

High consumption of energy and water

Efficiency improvement does not only focus on reducing cycle time, as well as energy, water and chemical consumption. The primary purpose of the CIP system is to remove fouling from the equipment. When production equipment is not completely clean, expensive raw materials have to be thrown out. Effective cleaning results in fewer instances of contamination and therefore improved production efficiency.

The cleaning function, however, is energy intensive. Almost half of a milk-processing facility’s energy is used to clean the processing lines and equipment⁴. Calculating the precise temperature needed to clean equipment is critical to reducing the energy consumption. For every 1°C reduction in CIP temperature there will be a 1/60th reduction in the energy needed to heat the fluid⁵.

The amount of water or chemicals used can also be reduced by introducing recovery tanks so that the liquid can be re-used instead of sent down the drain.

Loss of innovation and flexibility

Food and beverage manufacturers must innovate in order to remain competitive. Recipes need to be improved and new product lines developed. Therefore, CIP systems need to be flexible in order to adapt to different types of fouling on the equipment as product lines evolve. Operators need to be able to alter cleaning recipes to suit particular types of fouling, whether product (sugar, fat, protein or minerals) or microbial (vegetative microorganisms or spore-forming microorganisms) and ensure that the CIP system is operating in an efficient manner. Chocolate, for example, will require a different cleaning recipe for butter than it will for flour.

Modern CIP systems equipped with automation software enable a simple drilldown into any aspect of the process. This traceability of the system offers a number of benefits:

1. Operators can check each CIP operation to verify whether it has worked correctly.
2. Diagnostics are simple to perform and deliver detailed information on each element of the cleaning cycle.
3. Faults and issues can quickly be highlighted and rectified.
4. Plant managers can generate detailed operational reports.
5. Food security reporting to regulators is easy to assemble and more comprehensive.

Incremental process improvements

Equipment manufacturers ensure that CIP systems are installed and in good working order but these systems need to be fine-tuned based on the environment of the particular plant.

Some food and beverage manufacturers have tried to improve the efficiency of their CIP systems. The process usually involves a manual, trial-and-error approach which does not consider a holistic view of the system. These efficiency improvement techniques involve the following:

• Modifying chemicals - New chemicals can be experimented with or the concentration of existing chemicals can be altered to see if cleanliness is achieved more easily. The risk is that new versions may prove to be more costly.
• Altering cleaning times - Increasing or decreasing the time taken for rinse or for chemical solution cycles may result in some efficiency gains although the balance of downtime to production output and impact on safety tolerance levels will need to be reconsidered.
• Adjusting water temperature - Increasing the temperature of water to decrease the cleaning time or conversely decreasing the temperature to lower energy costs are also possible options.
• Reconfiguring settings - A study of CIP line usage can be a useful way to improve production efficiency. For example, if line 1 is at 100% capacity and line 2 is rarely used, a simple rebalancing would be to move some equipment cleaning to line 2.
• Maximising chemical effectiveness - The introduction of enzyme-based detergents to speed up chemical reactions or membranes to filter chemicals and enable them to be re-used for longer helps save resources.
• Implementing eco-friendly solutions - Bio-decontaminants eliminate the need for the use of harsh chemicals and can help reduce the amount of energy, time and water for the cleaning process.
• Using ozonated water - Disinfection with ozonated water is effective on a range of microorganisms and can save on water, chemicals and energy. The typical five-tank process is reduced to just three and it is extremely safe for the environment because its by-product is oxygen. However, it may be more costly to implement into an existing CIP system as it requires the addition of an ozone station and other equipment on-site.
• Developing a conservation mindset - The replacement of faulty valves and fittings, switching off water sprays and hoses when not in use, and disconnecting or removing redundant pipework help to improve efficiency. Installing meters on equipment will help to monitor water consumption. An example of this is installing flowmeters on inlet and outlet pipes to verify the volume of liquid sent and received. This can be analysed to identify any unusual losses through the leak chamber of the valve.

Each of these above strategies is often performed in isolation and the outcomes documented. The downside of this trial-and-error approach is that it is time-consuming and much waste is generated in trying to determine the proper mix of water, chemicals and energy.

This tweaking of the CIP system can deliver some benefits; however, a holistic approach incorporating automation software makes the biggest impact on cost savings and safety improvement. The complexity of finding the optimal combination for cleaning the equipment while meeting required standards is simplified, thereby saving time, reducing errors and lowering water use and energy consumption.

In Part 2

In Part 2 of this article, the benefits of using an automated CIP system will be discussed, along with examples of the efficiencies that are gained by doing so.

*About the authors

Benjamin Jude is a Global Solution Architect/Food & Beverage Vertical Expert at Schneider Electric. For over 20 years he has specialised in automation and process engineering, and has provided turnkey solutions for firms within the food and beverage and pharmaceutical industries. He has particular expertise in process design and electrical control engineering, batch management (MES) and FDA compliance.

Eric Lemaire is Food & Beverage Group Marketing Director with Schneider Electric. He holds a degree in Food and Beverage Process Engineering and has more than 20 years’ experience in the process automation industry. He has held many different engineering, R&D, marketing and sales positions, including manager of the French Food and Beverage and Pharmaceutical Industry operations.

References

1. Eco Efficiency for the Dairy Processing Industry - the UNEP Working Group for Cleaner Production in the food industry. Environmental Management Centre, the University of Queensland.
2. Energy Efficiency Improvement and Cost Saving Opportunities for the Dairy Processing Industry, Ernest Orlando Lawrence Berkeley National Laboratory.
3. Making an Impact: Environmental Sustainability Initiatives in Canada’s Food Beverage and Consumer Products Industry, KPMG.
4. Next generation clean in place report from 2009 Innovation Center for US Dairy.
5. Based on the caustic soda temperature being 80°C and acid temperatures at 65°C with an ambient temperature of 20°C. Carbon Trust : Industrial Energy Accelerator - Guide to the Dairy Sector.