Tuesday, September 16, 2014


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

Tuesday, March 11, 2014


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


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.

Friday, November 8, 2013


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