DON’T KNOW WHERE TO BEGIN WITH ENERGY EFFICIENCY FOR SERVICES? HERE’S YOUR ANSWER.

To have a chance at being efficient, a boiler must

first be adequately loaded. This is a system issue.

Services (sometimes called “utilities”) in manufacturing plants are typically a large contributor to site energy consumption. With these services, an energy carrier such as a fossil fuel or electricity is used to transfer energy into a fluid, which is then distributed to point of use.

Some examples of common services are compressed air, steam, chilled water, thermic oil and refrigerants. Of course, the supply of electrical power may itself be considered a service.

In general, manufacturers tend to focus more on core manufacturing processes than on services, and since often the services section of a manufacturing site is managed by someone other than the managers responsible for production processes, there is poor integration between services and manufacturing when it comes to energy efficiency. The result can be a piecemeal, component-level approach to energy efficiency, when what is required is a systems approach. I started this post by saying that services tend to be large users, but we need to take a step back to appreciate that while the energy input is to the service, the drivers of that energy use lie in various plant areas, and even include environmental factors. When resource efficiency practitioners talk about “systems” with respect to services, generally we mean the generation, distribution and user side of the service infrastructure, considered as an integrated whole. In the case of some services, there is an additional system element, that of recovery (e.g. returning condensate, thermic oil or refrigerant vapour).

Let’s consider for a moment why a systems approach is important. The first point to note is that by considering an individual element of a system in isolation, one can make small improvements but miss the far larger opportunities available. Hence there could be focus on boiler efficiency which could reduce steam system costs by 5%, when all the while an opportunity exists to reduce the quantity of steam consumed, potentially reducing system costs by 25%.  

A second problem with taking a component-level approach would be that in attempting to save energy, there could be unintended consequences which lead to a net decline in performance, either in energy use or in some other operational area. A simple example would be to reduce the fan speed on a refrigerant condenser in order to reduce the energy consumed by the fan motors, but to inadvertently increase the energy consumption of the vapour compressors, thereby increasing system-level refrigeration energy consumption.

A third and vital reason to take a systems approach to services optimisation is that the individual elements of the system interact with each other, and when implementing a basket of solutions comprising projects in each individual area, the implementation of each solution will influence the impact and viability of the others. A heat recovery project for a compressed air system will reduce in attractiveness should the amount of air required be significantly reduced, for example. The point here is that the benefit of implementing a portfolio of solutions for a given system will generally always be less than the sum of the individual solutions. This implies that it is useful to have a view of the full portfolio of planned solutions before proceeding with implementation, and while this is not universally true (e.g. one should not hesitate to fix air or steam leaks), it is important when considering capital-intensive options.

Reducing the pulse frequency for this bag filter

would reduce compressed air consumption. This

would reduce the loading of the air compressors.

Almost without exception, the approach to energy efficiency I see in most manufacturing plants as regards services is as follows:

         i.        Tinkering with the distribution network e.g. insulating distribution pipelines, fixing leaks and the like;

       ii.       Investing heavily in generation e.g. an “efficient” new air compressor, replacement of slide valve control with VSD control for refrigeration compressors etc.

There is no harm in dealing with obvious inefficiencies in distribution. The costs for implementation in this area tend to be low. At very large facilities, the savings can be significant. In general, however, projects involving the distribution network tend to yield only modest savings, and if this is all you are going to do, don’t expect breakthroughs on the bottom line. There are some distribution problems that do however require system-level considerations – an example would be a project to increase the size of air distribution pipelines to reduce pressure drop, which may become unnecessary should air use be significantly reduced.

The focus on generation I referred to above is in part due to the fact that there is a relentless focus on technological development in this area by OEM’s. Shiny new machines are attractive, and tend to come with assurances from suppliers with respect to increased levels of efficiency. Exercise extreme caution however. Many technologies only operate optimally when used in the correct context. Establishing this context requires a consideration of the system. As a simple example, a VSD air compressor as a replacement for a fully-loaded fixed-speed machine will not yield savings. A second reason that organisations tend to focus on the generation side of the system is the common misconception that efficiency needs to be “bought”, and that older installations cannot operate efficiently without investment. Since the generation side of the system is where capital tends to be concentrated, the tendency is to spend in this area. The reality is however that there are any number of no-cost and low-cost options that may be employed to drive energy efficiency.

The recovery aspect of some systems offers significant opportunities. In steam systems, condensate and flash steam recovery options can offer large savings at relatively low capital cost. Their viability is however impacted on by system-level considerations. A change in the steam pressure supplied to a user could significantly reduce the amount of flash steam produced, for example.

Given the above, you have most likely figured out by now that the place to start when optimising services is on the user end of the system. This means finding ways to reduce the amount of service fluid required. This comes with a lot of good news. In general, user-side opportunities abound. And in many cases, a common-sense approach can yield large benefits. Close those freezer doors. Insulate those process vessels. Recover energy from the leaving process stream. Automate the operation of that system so that switching off equipment is not dependent on someone remembering to do so. It may also be necessary to challenge paradigms in your business to reap these benefits. Does that process really need to operate at that temperature? Do we really need to wash this pipeline with hot water after each and every batch? Does the air pressure to that nozzle really have to be 8 barg. or can we get away with 5 barg?

When you take the time out to do this, you could be surprised by the quantum of the savings possible. That is one big reason to start here. The second is that there will be knock-on effects for the rest of the system. You may now only require two vapour compressors in your refrigeration plant room instead of three. The back-pressure turbine you thought was viable is now no longer so, since the amount of steam used has been significantly reduced. Your fully-utilised chiller plant is now a candidate for the implementation of a VSD compressor, since you now operate at part-load conditions for much of the time. You thought that you needed a VSD air compressor, but can now switch one of your compressors off. Had you made investments in generation, distribution and recovery before optimising your users, you could have ended up with a sub-optimal system.  

Copyright © 2016, Craig van Wyk, all rights reserved

LEVERAGING SHORT-INTERVAL CONTROLS TO DRIVE OPERATIONAL EXCELLENCE

Operations-orientated environments such as manufacturing are mastered by those who pay strict attention to detail. The organisations that do this tend to be the most successful, but the real champions in manufacturing are those who understand which details are most important. These organisations know immediately when an out-of-control situation (such as a quality or cost problem) arises, and also immediately understand why, and what to do about it. They then react quickly, rapidly restoring desired performance levels and maintaining high levels of delivery against a multitude of performance indicators. How is this possible? The answer lies in the short-interval control systems implemented on the shop floor.

 

As the name implies, "short-interval controls" refers to systems that deal with operational matters over short time-frames. Hence while senior management may be interested in tracking process yields for raw materials at monthly intervals or longer, the frequency for assessing these yields should be far higher on the shop floor. In a batch manufacturing environment, process yields may be calculated for every batch, for example. The principle is essentially that the monthly process yields are simply a result of the process yields for individual batches, and that by maximising the yields for each batch, monthly process yields will be maximised.  This approach can be followed for all indicators of operational performance, including product quality, throughput, safety, reliability and whatever indicators a business may choose.

 

It is one thing to measure performance at short intervals, but while this is a step in the right direction, and in my experience is itself often lacking, the best-performing organisations take it one step further. Instead of only measuring outcomes at short intervals, these organisations also track the drivers of performance at short intervals. These are tracked in one system so that the relationships between the drivers and the outcomes are readily apparent and can immediately be acted upon. The principle behind this approach is that by keeping the drivers of performance in control, performance will be maintained or where possible, improved. If the drivers have been comprehensively identified, then when performance deteriorates, it should be a simple process to scan the measured drivers, identify the one that is out of control, and then take steps to restore this driver to desired levels. Trends in the driver data can also be used to draw conclusions with regards to trends in outcomes, so that process owners can be proactive about performance management. If the reasons for poor performance do not show up in any of the drivers, this means you need to identify more drivers. You can use root cause analysis techniques to do this (WHY-WHY analysis is my personal favourite) or even do this by trial and error. I can tell you from experience in manufacturing management that this process works, and in my career has been one of my most powerful "secrets" to enhanced performance.

 

To make this less abstract, let me illustrate with a concrete (but hypothetical)  example. Say you are dissolving a solid in a liquid e.g. making a sugar solution in a beverage facility. The process needs to be completed in a given time period in order to meet the throughput requirements of the factory in which it is operated. The outcomes for this process would be the volume produced for each batch, the time taken to prepare each batch and the final concentration or density of the solution being prepared. Each of these would need to be monitored for each batch. The process is carried out in a heated, agitated vessel, into which the liquid is pumped. The solid is manually added after being weighed by the process operator. Typical inputs that would also be monitored using the short-interval control system would be:

• The volume of liquid added (affects turnaround time, throughput and yield)
• The time taken to pump the liquid into the vessel (affects turnaround time)
• The time taken to heat the liquid to dissolution temperature (affects turnaround time and possibly also product quality e.g. burn-on if rate is too high)
• The actual initial and final temperatures of the liquid (affects turnaround time and dissolution rate)
• The mass of solid material added (affects density of the solution and process yield)
• The speed of the agitator - this is equipped with a variable speed drive (affects turnaround time and dissolution rate)
• The time taken to pump the solution into the holding tank (affects turnaround time)
• The mass of solution produced (affects throughput and yield)

By monitoring these variables on a continuous basis, this process can be kept in control and this data can immediately be consulted should there be a problem with throughput, yield or product quality. Without it, management and the plant operator is pretty much in the dark with regards to the reasons for performance problems, and the time to correct these would be much longer, impacting negatively on the performance not just of this process, but of the wider processes in the facility impacted upon by it. If this process is the bottleneck in the facility, for example, turnaround problems would affect the throughput of the entire factory, with potentially disastrous consequences. We see therefore that something as seemingly small as the time taken to pump a liquid into a vessel can impact on the performance of en entire business. This is what I meant when at the start of this post I spoke about "details".

Copyright © 2016 Craig van Wyk, reproduction only with written permission.

Craig is the founder and Managing Consultant at VWG Consulting, a Johannesburg-based productivity and resource efficiency consulting and services company serving the industrial and commercial sectors.

ENERGY EFFICIENCY IN COMPRESSED AIR SYSTEMS

Compressed air is a common utility and  often a significant energy user in factories and commercial installations.  Compressed air systems comprise the compressed air source (the compressor), the distribution system and the users of compressed air. To save energy, review all 3 areas.

 

Why the system and not just the compressor?

A systems approach is necessary because the compressor interacts with the rest of the system, and changes made downstream affect compressor operation and energy efficiency. As a simple example, if the amount of air used is reduced, the loading of the compressor would reduce, with potentially significant implications for the approaches required to increase its efficiency.  It is commonly advised that when evaluating and optimising systems, one should start with users and then work back to the energy source. I will take the same approach with this post.

 

Air Users

Minimising compressed air use reduces the amount of air that has to be compressed and is a powerful way to reduce the energy required by a compressed air system. I am always amazed by the low level of awareness in factories with respect to the cost of compressed air, and how it is almost treated as being "free". In generic terms, one can reduce air use by reducing the time for which the air is used and/or the flow rate it is used at. What this means in practical terms varies widely between different facilities.

 

Reductions in flowrate are typically achieved through local pressure regulation or restrictions in flow at point of use (e.g. through use of a modulating valve), and this should be considered for larger users in particular. This effectively reduces the mass of air used, but clearly this can only be done if the process objectives are still met. In some instances, compressed air use can be eliminated and replaced with low-pressure blowers. Where more air is used than is required to perform a task, this is known in the industry as "artificial demand".

Reducing the time for which air is used is really about stopping the air flow when it is not required. This can either be done manually, in which case training and work practice optimisation is needed, or via some form of automation. A common example is an unscrambler, as found on packaging lines, which uses compressed air to move/orientate items (e.g. caps for aerosol cans) in a hopper prior to them being fed to the point of use. Solenoid valves fitted onto the air supply and hardwired to the conveyor switch would ensure than when the line is not producing, air supply is terminated. Be aware that such "open blowing" applications are often considered to be inappropriate air users, and should be minimised as far as possible.

Another inappropriate use for compressed air is the use of air-driven pumps (compressed air is very inefficient as an energy source, since most of the energy that goes into the production of compressed air is dissipated as heat). Since compressed air is easily distributed around factory sites, it is not surprising that some creative approaches are applied in exploiting its convenience. I once arrived at a factory for an energy assessment and was greeted by an employee cleaning the walkway with a custom-made "air broom" - a shaft and handle with an air supply used to blow dust away.

 

Distribution System

Compressed air distribution systems have a significant impact on energy use. It is important to ensure that pressure drops are minimised, otherwise higher source pressures are required to deliver the air at the pressure required by users. Line sizes are hence important (if lines are too small, pressure drops are higher), as is the minimisation of bends in pipework. It is also important to ensure that the condition of the pipework is maintained in good order. Corrosion roughens up pipe surfaces, increasing frictional losses. While I have seen some facilities with very large (in diameter) air distribution lines, and this is also good from a storage perspective, there are implications in terms of installation costs. I recommend welded pipework or even better, screw joints rather than flanged pipework for air distribution systems. It is not uncommon to find defunct equipment that is still in the compressed air network, and through which air is still passed, contributing to pressure drops and energy losses. Equipment such as air filters should be sized correctly for the pressures and flows required. I have seen a few plants in which incorrect equipment was specified with astronomical impacts on costs. Each item in the distribution network represents an additional pressure drop, so use correctly specified equipment and only use the equipment that is absolutely necessary to do the job.

Compressed air leaks can add hugely to operating costs, and should be minimised through an ongoing leak detection and repair programme. This should be integrated into routine maintenance practices rather than be a stand-alone initiative. Take care in selecting equipment when seeking to minimise leaks. Quick-release couplings are notorious sources of air leaks, for example. Look out also for "intentional" air leaks, such as drain ports that are left open in order to allow for the constant removal of moisture, and which leak air continuously as a consequence. Most leaks are audible and the best time to detect them is during breaks, when equipment is not running but the compressed air network is still pressurised. These days there is some very advanced condition monitoring equipment available (such as ultrasonic detectors) that can not only detect leaks but also quantify them.

Incoming air has a humidity level, and hence has to be dried, since compression concentrates this moisture. Driers are a topic all of their own, each with their own energy use implications. Most larger screw compressors come equipped with integrated refrigerated driers these days, and most sites provide further backup with stand-alone drying systems, which can themselves be refrigerated or be of the desiccant type (other types exist but these two are the most common). Be aware of the consequences of not drying air effectively. Liquid in the distribution pipelines not only accelerates corrosion, it also contributes directly to pressure drop. Pay attention to automatic drains, which can fail and become leak points, or can also be cycled too frequently, leading to excessive amounts of air being lost with the water removed.

 

Compressors

Efficiency in compressed air production is about minimising the amount of energy required to produce a given quantity of air, and different compressors have different inherent efficiency levels. Various compressor-specific factors impact on efficiency, including the compressor motor, drive and the air-end design. Loading is an important driver of efficiency, and like with most equipment, low loading levels lead to inefficient operation.  The pressure of the air produced is related to the efficiency with which it can be produced, and it is best to produce compressed air at as low a pressure as possible. The location of the compressor is important, and cool (and therefore dense) incoming air is better than warm air. This is not only about atmospheric conditions, but also about keeping the compressor location away from heat sources in your facility. This includes the heat generated by the compressor itself, which should be removed from the immediate vicinity of the compressor intake. Dusty areas should also be avoided, as dust blocks intake filters/screens and increases pressure drop.

 

Poorly loaded screw compressors are inefficient, and VSD's can assist in reducing energy consumption where air demands are variable. A further important consideration is that of heat recovery from oil-flooded screw compressors. Much of the input energy to a compressor is rejected as heat from the oil and the air produced, with some OEM's reporting recovery levels as high as 90%. The common practice is to reject this heat to the environment, either in an air stream or via cooling towers in the case of water-cooled compressors. This heat can be recovered and used to produce hot water (temperatures in excess of 70 deg.C are possible) or hot air. The hot air can be used for space heating (not so attractive for warmer/temperate climates as in my home country of South Africa, where this application is only needed for a few months of the year) or for processes requiring hot air. The idea is to choose a heat sink that requires more input energy than is rejected by the compressor, in order to maximise recovery levels. A good application would be to supply combustion air for a boiler or furnace. 

 

The reason I am mentioning heat recovery here is because it has a marked impact on whether to go with a VSD replacement, or whether to rather keep your existing fixed speed screw compressor and employ heat recovery. While a poorly loaded screw compressor is inefficient, a VSD replacement compressor is typically very expensive, and it may be more attractive to employ heat recovery, since this is cheaper to implement. The point is that while your poorly loaded screw compressor will be inefficient, most of these losses would be recovered with a heat recovery system. A case-by-case approach is however required. The economics of heat recovery depend on electricity and fuel prices (assuming you are not using an electrode boiler or electrical heating system), and an analysis specific to your circumstances is essential.

The above is but an introduction to the energy efficiency considerations associated with compressed air. Where multiple compressors are employed, system optimisation becomes more complex. Remember also to back up each opportunity with a quantitative assessment of savings when making decisions regarding implementation.

Copyright © 2015, Craig van Wyk, all rights reserved

 

BASIC OPPORTUNITIES IN INDUSTRIAL LIGHTING

Linear Fluorescents have largely been superseded by LED's,
but are still a good option in terms of efficiency. Ballast losses
are higher for older electromagnetic designs.

Factories are too diverse and complex for there to be meaningful benchmarks in terms of the contribution of lighting to overall energy consumption. In general however, except for very light industry (no pun intended), the proportion of a site's total energy that is employed for lighting tends to be small. Despite this fact, I always include lighting assessments when reviewing energy usage on any industrial site. My main reason for doing so is that this is often an area heavily laden with low hanging fruit from an energy efficiency perspective.

 

Often the basket of lighting opportunities identified has a payback of under 2 years, with many individual lighting solutions having an almost immediate payback. Of course one wants short paybacks for lighting projects, given that lighting retrofits will not have the lifespan of other larger investments. Savings with regards to lighting are about far more than lighting retrofits however, so be sure to include options such as work practice changes, maintenance and operational improvements when seeking to reduce lighting costs.

 

There is a huge amount of detail associated with the rigorous analysis of lighting opportunities, and I won't get into that here. What I want to highlight in this post is how simple it can be to identify and implement sustainable lighting savings. Firstly, the cost of lighting has to be appreciated along with the drivers of operating cost. The energy used for lighting is a function of input power to the lighting / luminaires and the operating hours involved. It is quite a simple exercise to carry out a lighting inventory which outlines, preferably on a "room-by-room" basis, the number of lights, their individual power consumption levels and their hours of operation. This can then be converted to an annual  energy value (in kWh), and then, depending on applicable tariffs, an annual energy cost can be calculated for each individual room. This is a simple enough exercise - don't forget to include ballast losses. It is also important to appreciate that lighting often contributes to maximum demand, and hence an apparent power value for individual lighting options must be determined. You might need to consider power factors should the site concerned not have a correction system in place, but to keep it simple, perhaps just take the power factor of individual fittings as unity and add the apparent power levels to assess the contribution to site demand. Ignoring demand can make a large difference to the estimated operating cost of lighting.

 

Once you have this inventory, you can set about identifying relevant solutions for each area. The plethora of modern lighting solutions can make this a minefield as you consider issues such as lumen output, lumen depreciation, lifespan, colour rendition, efficacy, lighting and installation costs, disposal considerations, human health impacts etc. The key point I want to convey with this post is that while the temptation often is to pursue the latest innovations in lighting technology, there are very simple ways that lighting costs can be reduced. Before embroiling yourself in cost benefit analyses for individual lighting technologies, take some time to apply some common sense to the matter of finding savings. Questions I often ask as I evaluate individual areas include:

• Are there any obviously inefficient options in place e.g. mercury vapour lamps, T12 fluorescents with magnetic ballasts, incandescent lights etc? If so, what can they be replaced with? - there is no standard answer here, and it depends on the individual installation and characteristics of the room e.g. roof height, reflective surfaces etc.
• Is there too much light available on working surfaces (as measured with a light meter) when the lights are on? This would be wasteful, and often savings are possible through a simple reduction in the number of luminaires. It is sometimes also possible to modify existing luminaires e.g. the control gear for mercury vapour lamps can be bypassed and the existing fittings can be used to house compact fluorescent lights. Be sure to adhere to regulatory lighting standards as a minimum.
• Are daylight harvesting opportunities available? This may result in lights being switched off during the day, or to a reduction in the number of lights used during the day. Existing lighting may require supplementation with options such as transparent roof sheeting for example.
• What are the switching arrangements? It is not uncommon to find a single switch for a large area, but with only part of the area used regularly. By applying a zoning strategy, lights can be switched on selectively, saving large amounts of energy. Switching options can also be used to provide flexibility in terms of the number of lights switched on e.g. all lights on dull days but only a few on typical sunny days.  
• What are occupancy levels for individual areas? Motion sensors can be a useful solution when paired with the correct lighting types.
• Are windows, roof sheeting and lamps themselves cleaned regularly? If not, can a simple cleaning regimen be easily implemented?

These simple solutions are every bit as important as the deployment of efficient lighting technologies, and most often cost very little to implement, if anything.

 

Copyright © 2015 Craig van Wyk, all rights reserved

MAKING THE SWITCH TO SIGNIFICANT FUEL SAVINGS

Fuel switching can be a huge
cost-reduction opportunity

Fossil fuels are used extensively for activities such as steam generation and for process heating applications such as furnaces and curing ovens. There are a range of ways to make these operations more efficient and cheaper to operate, but often the fuel employed is not given much attention. This could however be one of the most impactful ways to reduce energy costs. So what is fuel switching, and how does one determine the nature and quantum of the cost reduction opportunities it presents?

 

Fuel switching is simply a change in the fuel used to one of a different type e.g. a switch from coal to wood pellets. It is sometimes done for operational reasons. Heavy fuel oil is an example of a fuel that if not properly stored and handled, can cause blockages and downtime, particularly in cold weather. Safety could be another factor, for example volatile fuels in a hot climate come with risks if not stored and handled properly (not to mention losses). Some fuels are not freely available, and hence reliability problems could prompt a switch. In the absence of these challenges, the biggest motivation for a fuel switch is however that of cost reduction, and this is what this post is about.

 

In determining whether a fuel switch is financially viable, the first thing to understand is what the cost of the fuel you currently use is relative to the cost of the fuel it could be substituted with. I refer here of course to the cost per unit of energy, not per unit of fuel. You also need to have a sense of the efficiency with which you would be able to use the new fuel relative to current efficiency levels. By noting the energy content per unit of fuel and then applying the efficiency with which the fuel will be used, you will be able to determine the cost of delivering energy to the process you are operating, whether this be steam generation or a heating application.  This immediately conveys the quantum of the potential savings on offer, and these savings then have to be contrasted with the potential additional costs that come with making the switch to determine the net financial benefit.

 

The method I use is to determine the stack losses for the two different fuels, since this is the biggest loss to consider. This is a function of flue gas temperature, flue gas oxygen and ambient temperature, and different fuels typically require different levels of excess air for effective combustion. I would typically use a common flue gas temperature for the two fuels (usually just the one currently achieved), fix the flue gas oxygen content at the minimum required for the fuel being assessed and then determine the boiler/furnace efficiency I could expect when making the switch. If the plant involved is equipped to deliver low flue gas temperatures (e.g. thorough the use of economisers or air pre-heaters) you could fix the flue gas temperature for the analysis at the acid dewpoint temperature for each fuel plus a small margin of safety. Of course if you are switching to a very clean fuel and this allows use of a condensing economiser, the whole equation changes, but let's leave that for another day. The efficiency determination allows me to calculate the fuel rate required (based on heating value per unit of fuel and the heat load of my process), and I can then make a comparison of expected fuel costs to current fuel costs. Where there is a large difference, I move onto the next phase of the investigation, which is a risk assessment.

 

There are several issues to consider when deciding to switch fuels, and it is important that a thorough risk assessment is done before making this change. Some questions you should ask before making any proposed fuel switch include:

• Can you lawfully use the fuel? - local air quality regulations could preclude the use of certain fuels and before doing anything, check this first.
• Can your boiler handle the new proposed fuel, or can it be modified to do so?
• Can your fuel handling infrastructure support the new fuel, and if not, what modifications are required and at what cost?
• Is the supply of fuel going to be reliable, and what price changes are expected going forward relative to the price changes expected for the fuel you currently use? (you may need a crystal ball for that one)
• What are the emission impacts associated with the new fuel, not just in terms of GHG's but also particulate matter, sulphur, mercury and other pollutants?
• What are the water pollution risks?
• What are the safety risks associated with the new fuel? - here characteristics such as flash point are a consideration, among others
• What impact, if any, will the fuel have on manning requirements and operating and maintenance costs?

Note that you could spend money on mitigating some of these challenges if the economics allow. There are examples I have seen where even a change in boiler was financially viable, so keep an open mind. Once all of these issues have been addressed and you are satisfied that none of them is a barrier to the switch, you are in a position to start planning for implementation, but the process is far from finished. Ideally you should observe the fuel in operation at another location (if you haven't already seen one) and engage directly with users of the fuel and suppliers of fuel and equipment to ensure that there are no unexpected surprises. If no plant modifications are needed for the switch, you should also use the fuel on a trial basis before committing to any long-term supply contracts. All of this due diligence can sound like hard work, but I can assure you that this could be one of the biggest cost reduction opportunities at your facility, and if you haven't looked into it, you should do so without delay.

Copyright © 2014, Craig van Wyk, all rights reserved

THOUGHTS ON THE SUSTAINABLE FACTORY

Every manufacturing site can be made more
sustainable, and this is NOT only about
technology

Manufacturing sites are but one component of the value chain, in many cases not even the most important part from a sustainability perspective. Often, the suppliers of raw materials, packaging materials, logistical services, water and energy can have very significant life-cycle impacts. For manufacturing companies however, production sites represent the face of operations. Hence they are a natural place from which to start the sustainability journey.

An organisation’s sustainability strategy will include its entire value chain, and an examination of the life cycle impacts associated with individual products. Strategies at the factory level should of course be integrated with this broader organisational strategy, and hence factories should not develop strategies in isolation from the broader business within which they operate. Factory-level sustainability strategies do however require focus, and there are generic areas I tend to look at when I assess factories, in combination with industry-specific issues, which are typically very well known. Examples of industry-specific issues could be persistent organic pollutants arising from bleaching in the pulp and paper sector, hexavalent chromium pollution in the plating industry, food safety in the food processing industry or the water intensity of wet-cooled power generation processes. You will need to fully understand the issues relevant to your industry in addition to the generic sustainability matters I’ll discuss in this post in making your factory more sustainable.

What then does a sustainable factory look like, and what are the key focus areas that senior factory management should have in mind when embarking on a sustainability programme? My views on this issue are that one needs to take a simple, common-sense approach, identifying the broader issues and then taking action in each key area in an integrated way i.e. appreciating the interrelationships between individual aspects of sustainability. Of course, there is an awful lot of technical detail underneath the conceptual approach I’ll outline in this post, but there are many resources on the web and elsewhere that you can access to fill in the blanks. Simple and simplistic are two distinctly different things – incomplete analysis that does not take a systems view will yield incorrect conclusions that if acted upon will not lead to results, or worse, will lead to unintended consequences. However, when sustainability is made overly complicated the risk is that you will spend all of your time over-analysing and not implementing anything. So it’s important to strike a balance.

In line with keeping things simple, let’s step out of the detail for a moment and consider a broad view of the factory as a point of departure. The generic manufacturing site receives resources across its boundary, transforms these into products, and in the process also produces wastes. Sites interface with the environment, the local economy and local communities, but their influence can also extend to other countries, by virtue of aspects such as emissions to air and water and the geography of the markets for their products. At the factory level, sustainability strategy is not about saving the world. Rather, it is necessary to understand the basics of what sustainability means for a factory, and then to reduce that down to the key drivers of sustainable practice for your specific manufacturing site.

In my mind, the following issues represent the bare bones of the characteristics of a sustainable factory.

1.       The work environment would be safe to work in, not just in terms of the minimisation of safety incidents, but also in terms of long term occupational health. If this sounds like a basic issue to you, be warned that it is fraught with complexity. The safety issues are typically straightforward to identify and manage, and while I often see sites where glaringly obvious safety risks abound, it is the occupational health risks that worry me more. What I can tell you is that generally, even where detailed risk assessments have been undertaken, workers can still easily be exposed to hazardous substances. In most cases it is due to a lack of information on the dangers posed, but there really can be no excuse in this information age. It is necessary for you to research the hazards unique to your industry and to find out what the best practices are in terms of their mitigation. Just because something is not regulated in your country does not make it acceptable to ignore it. Not if you are serious about sustainability. It is useful to involve specialists, who can also assist you with measurements.

 

2.       The products produced should be safe to use and consume. At the site level this typically does not involve product design, though of course nothing prevents the site from giving feedback to the product development team. Manufacturing sites can render well-designed products unsafe to use or consume by virtue of deficient manufacturing processes. A simple example would be the contamination of a food product. The risks at every stage of the manufacturing process should be identified and mitigated, either through process redesign or the institution of robust control measures.

 

3.       Emissions to air should be understood and managed accordingly. Of course this includes GHG’s arising from local fossil fuel combustion and it is also a fairly simple matter to estimate the emissions associated with electrical energy use. However, other pollutants also require consideration, and are best assessed by investigating individual unit operations. A lot of attention is given to the GHG’s, particulates and sulphur compounds associated with coal combustion, for example, but what of the associated mercury pollution? A detailed emissions inventory is therefore essential. Air emissions are not necessarily a consequence of combustion. Dust, volatile organic compounds, fumes emitted from high-temperature manufacturing processes – all require assessment, and many are linked to occupational health as well as broader environmental issues.

 

4.       Water pollution risks should be understood and dealt with. Industrial sites can pollute both surface and groundwater resources, and can do so through a wide range of mechanisms. These problems are not necessarily localised, albeit that many arise from point sources. While the obvious control point would be to carefully monitor effluent discharges from the site, other pollution transport mechanisms could include:

·         Airborne pollution that is deposited in surface water bodies

·         Seepage of contaminants into groundwater

·         Site runoff, which can find its way into rivers or to municipal effluent treatment plants that are not designed to handle industrial pollutants

 

5.       Land pollution risks should be identified and managed. These are generally to do with spills, runoff and localised fumes that can result in deposition onto land. The nature of site surfaces plays an important role. Paving is attractive, but does not form an impermeable barrier between potential spills and the land underneath a site, as a simple example. Be wary of effluent streams that are discharged into un-lined dams or onto open fields.

 

6.       Resources should be used as efficiently as possible. The resources of interest on industrial sites are raw materials, energy and water, all of which have significant life-cycle impacts, and hence offer significant leverage for the reduction of an organisation’s footprint through actions taken at the site level. The cost reduction impacts associated with resource efficiency are generally high, providing good incentive to pursue this aspect of sustainability vigorously.

 

7.       Wastes should be recycled as much as possible. The first prize in terms of resource efficiency is to tackle problems at source, thereby limiting the amount of waste produced. While “zero waste” should be the intent of a sustainable manufacturing site, in most cases the production of some waste is unavoidable. Where possible, these wastes should be recycled. If waste can be employed in production processes, this is ideal, but where this can’t be done, supply chains should be set up to process the waste such that it becomes an input to downstream production processes, either for use elsewhere in the business or for sale on the open market. This is often a way to generate additional revenues, reduce the amount of waste diverted to landfills and create jobs. Where waste is recycled internally, take care that your ability to recycle does not divert your focus from the minimisation of this waste at source. Recycling is certainly not free.

 

8.       The local economy should be supported as far as possible, particularly where it makes sound financial sense to do so. This means providing locals with jobs and also procuring goods and services from local suppliers. This helps to ensure that the site is not an island of economic prosperity in an otherwise impoverished area, but also helps to build rapport with local communities, who are important stakeholders in the site’s sustainability initiatives. This can be particularly important for industrial sites in outlying areas, since a vibrant local economy attracts more residents, who may in turn contribute to economic and social upliftment. This may even support local demand for the organisation’s products.

 

 

9.       Social programmes should be in place to support local communities. While these could include charities, the idea is to make these programmes sustainable, and to structure them such that they help people to help themselves, while also contributing directly to the sustainability of the business. For example, a bursary programme could be instituted to assist students to finance their studies in skill areas critical to the site, thereby creating a pipeline of skills while also empowering local communities.

 

10.   Operational management systems should be well developed and continuous improvement should be part of the culture on the site. In general, good business practice contributes to sustainability. Maintaining productive assets effectively, managing operational risks, ensuring quality standards are met, developing a solid skills pipeline, instituting transparent management systems and all of the various aspects of operations management necessary for efficiency and effectiveness are integral to sustainable operations, not least because they help to ensure economic sustainability. The sustainable factory is hence not a goal requiring reinvention of every aspect of the enterprise. While operational excellence does not necessarily translate into sustainability, it certainly does support it. And hence, in organisations that are leading the way, the lines between operational excellence and sustainability are becoming increasingly blurred as sustainability is integrated into operations.

Is there really such a thing as a “sustainable factory”? To some this may sound like an oxymoron. Of course, this concept is something to aspire to rather than to treat as an end goal, since as I have mentioned many times in previous posts, sustainability is a journey rather than a destination. But as long as we humans are here on earth, the products we consume will continue to impact on the planet, and manufacturing can be considered to be a “hotspot” in this regard. Making factories more sustainable is an opportunity to be taken advantage of by forward-thinking organisations.

WHY THE ABILITY TO IDENTIFY AND DEVELOP SUSTAINABILITY OPPORTUNITIES SHOULD BE VIEWED AS A CORE COMPETENCY

Logging of a large induction motor. Measurement
is a vital aspect of the assessment process.

Realigning an industrial site onto a more sustainable trajectory is a long-term process. It should begin with a strategy or plan, and be supported with the development of scorecard comprising the various measures considered to be indicators of sustainability performance. If the strategy is the GPS determining your direction, the scorecard can be considered to be the dashboard for your efforts as you drive your site towards a more sustainable level of operation.

Your strategy will outline the broad philosophies and focus areas management believes will drive sustainability, while the scorecard will reflect the desired outcomes of the process. However, neither gets into the detail of the precise actions you are going to take to achieve the performance improvements you are after. This is where the rubber hits the road, and where a lot of organisations tend to fall short. Without this detail, there can be no meaningful implementation, and without implementation there can of course be no improvement. The way to get to this detail is through the assessment process. I believe that the ability to conduct assessments is something that industrial companies need to develop internally if they are to integrate sustainability into their operations successfully ,and will explain why in this post.

Assessment is the process through which the various sustainability opportunities on an industrial site are identified and developed into projects that can be implemented to improve performance. While I am often requested to carry out “one-off” assessments at sites I have never seen before, I often find myself thinking of a number of opportunities on these sites long after I have left. The thing is, industrial sites are complex systems, and it is only on deep reflection that all potential opportunities can be unearthed, particularly those that are system-related. So I much prefer longer-term engagements where I get to fully understand the system, since these can lead to richer and more profound sustainability opportunities than those one would find in a typical audit.

The point I am making here is that assessments should not be activities that are only carried out at the outset of a sustainability programme. They should be a routine part of the programme, carried out continuously, open to being updated and revised on an ongoing basis. In this way you can use assessments to feed into a live portfolio of sustainability projects, all at different phases of their life cycles, and all contributing towards the achievement of the targets you have set for your site as defined in your scorecard.

Typical steps in the assessment process would be:

 

Qualitative identification of an opportunity e.g. the furnace is not insulated and is losing a lot of heat energy

Identification of required data for development of the opportunity e.g. dimensions of the furnace, surface temperatures, atmospheric conditions such as typical temperatures and wind speeds, supporting information e.g. the furnaces typical annual operating hours, its temperature profile, seasonality of operation etc.

Carrying out of measurements and specification of assumptions e.g. use of an infra-red thermometer to measure surface temperature,  using an assumption of 0 m/s for wind speed in order to be conservative with respect to convective heat loss effects etc.

Quantification of the resource efficiency potential of solutions. In this example this will mean quantification of the heat losses with and without insulation (with the difference being the potential saving), and then translating those losses into a gas usage value, based on the calorific value of the gas used.

Technical evaluation of the solution e.g. what will the surface temperature of the insulated furnace be, what are the emission reductions associated with this solution etc.

Financial evaluation of the solution, which would mean translating the gas usage into a financial value, determining the costs of insulating the furnace and then assessing the financial impact, using approaches such as the calculation of payback, NPV or ROI.

Identification of any risks associated with the chosen solution e.g. the correct insulation material should be chosen to avoid potential fire risks, critical materials (e.g. asbestos) should be avoided etc.

Insulation is clearly not the only solution when it comes to improving the energy efficiency of a gas-fired furnace. For example, since it important to deal with root causes rather than symptoms, an important question to ask would be: are surface temperatures too high due to poor maintenance of the refractory lining of the furnace? There could be more leverage in approaches such as improved control of air-to-fuel ratio, ensuring that the furnace is not idle at full-flame conditions, limiting the temperature to the minimum required and minimising rework, among others.   Each of these solutions would require an evaluation of their potential, both individually and when considered in an integrated way. Lower operating temperatures would reduce the potential of a solution involving insulation, for example - so one would need to assess how individual approaches may interact with each other.

Carrying out the analyses outlined above requires skills and capabilities that are typically not in evidence on industrial sites, where the focus tends to be more on addressing deviations in process performance rather than ongoing structural change in order to raise performance levels. How then can such capabilities be developed? The answer is – through concerted investments, on the understanding that such investments will have a favourable financial return. Investments would need to be made in:

1.      Skills development – the diversity and quality of training solutions available is growing in areas such as energy efficiency, water conservation and industrial sustainability in general

2.     Measurement equipment – opportunities cannot be developed from assumptions alone, and it is important to build a comprehensive toolbox of specialist measurement equipment that can be used to carry out the required investigations. These measurement tools would require maintenance and calibration, and of course training for users

3.     Software tools – once data has been downloaded or captured it needs to be analysed, and the use of software can make this process faster and easier to do. There are a number of free tools available, as well as very powerful proprietary software for specialist applications. Be sure to use tools from a reputable source

4.     Relationships – it is important to stay close to experts and solutions providers, as well as others in your industry, in order to be aware of the latest trends

5.     People – sustainability is an important enough issue to require dedicated focus. While it needs to be integrated into existing job roles as far as possible, a champion is needed to focus and consolidate efforts and lead the change process. This would probably be someone already in a technical role and senior enough to be able to influence staff from various disciplines in support of the sustainability effort. Project management is a vital skill for anyone in this role

In essence, achieving superior performance in areas such as energy and water use efficiency and waste minimisation is not achievable on a sustainable basis unless assessment capabilities are developed inside your organisation. While you can buy in expertise (this is after all how I make my living) building capacity internally is the only real way to ensure the necessary integration between operational excellence and sustainability. Assessments need to be taking place all the time, with constant revision of the portfolio of potential projects, and must incorporate the learning that comes out of implementation.

 Copyright © 2013, Craig van Wyk, all rights reserved