Tuesday, March 11, 2014

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 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

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

Thursday, September 12, 2013

ENERGY-EFFICIENT MOTORS – NOT NECESSARILY A NO-BRAINER


Induction motors are ubiquitous in industry and invariably
offer energy-efficiency opportunities. These opportunities are
however not necessarily in the form of viable motor
replacement options.
Induction motors are used extensively in industrial facilities, and consequently can be responsible for a significant proportion of energy consumption and demand. Older designs are inefficient, and there are now a range of motors available which require less input power (for the equivalent amount of shaft power) than these older designs. In many countries, the use of high-efficiency designs is becoming mandatory. This is not the case in South Africa, and in my experience the uptake of these motors remains quite low, despite sustained increases in electricity prices. This got me thinking about why this is the case, and in this post I will explore some potential reasons for the relatively poor penetration of these devices, and also what you need to consider when assessing motor replacement opportunities. I won’t get into issues of torque in this post, but will remind you of the fact that a motor’s torque characteristics are an important factor, and the torque requirements of the driven process must be well understood when assessing replacement options.

Motor efficiency refers to the ratio/percentage of input power to output or shaft power for a given motor. The efficiency values you will see on a motor’s nameplate are quoted for full-load conditions. Energy-efficient motors require less input power for a given amount of shaft power. However, it is wrong to speak of a motor having a specific efficiency level. As discussed in a number of previous posts, motor efficiency is a function of load, with load being the proportion of the motor’s capacity that is actually used. If a motor is poorly loaded, replacement with an energy-efficient alternative of the same capacity would yield lower levels of efficiency improvement than replacement with a standard-efficiency motor of the correct capacity. Hence for poorly-loaded motors, correcting the loading problem is a higher priority than motor replacement.

Running hours are important, since the more hours that a motor runs, the more energy can be saved (remember that energy = the product of power and time). The energy savings are the product of the input power differential between the existing motor and its replacement and the running hours: Energy savings = (kWexisting – kWreplacement) x running hours. Clearly, even where a large power differential exists, if running hours are low, energy savings will be low, and the costs of replacement become difficult to justify.

As outlined above, if you can find motors with long annual running hours and which are well-loaded, high-efficiency replacement options should be further investigated. However, motor efficiency is not the only driver of operating cost for induction motors. A further consideration is the difference in power factor between the existing motor and the replacement motor. Power factor is the ratio of real power (in kW) to apparent power (in kVA). The lower a motor’s power factor, the higher the flow of current to the motor for a given real power requirement, and the greater the line losses (also called I2R losses) incurred in operating the motor. For a site that does not have power factor correction systems installed, a motor with a lower power factor (which could be a replacement motor with higher efficiency than the existing motor) will result in increased demand charges as well as some energy losses (these are typically small) due to the increased current flow in the site’s internal distribution system. A reduction in both of these costs can be achieved through the use of local capacitors close to the motor. Sites that have power factor correction systems installed at the point of supply will experience reduced site demand levels, but will not reduce I2R losses in their distribution systems, since excess current will still flow between the capacitor banks and the motor. For such sites, motor efficiency gains are still generally a bigger economic driver than these efficiency losses, particularly when you consider that it is the difference in power factor that is of interest, not only the power factor of the replacement motor.

The above are however not the only important issues when considering motor replacement. Something to bear in mind is that high-efficiency motors tend to operate at slightly higher speeds than standard-efficiency models, due to reduced slip. For fixed speed applications, this can have significant consequences for energy consumption. For example, for centrifugal pumps and fans, flow is proportional to speed, but power varies with the cube of speed. Small increases in speed can result in significant power increases for motors used in these applications. The situation could therefore be one in which the high-efficiency motor uses less energy than a standard-efficiency equivalent would have used for the same output power, but with this benefit negated by operation at a higher output power than was the case before the replacement. Such a situation is only acceptable where the increased power output is actually required, or can be managed - for example through reductions in operating time. How big a problem could this be? Consider a motor replacement option with a speed that is 1.3% faster than a standard-efficiency motor. Input power would increase such that Pfinal = Pinitial x (speedfinal / speedinitial)3 = Pinitial x (1.013 x speedinitial / speedinitial)3 = Pinitial x 1.0133 = 1.04 x Pinitial, which is a 4% power increase! This could easily match or exceed the efficiency differential.
 
One final thought is that motors are part of systems, and system efficiency is the product of the efficiency levels of the individual components of the system. No matter how efficient a motor is, if it is driving an inefficient machine or process, replacement of the motor will have a limited impact on the efficiency of the system. For example, an inefficient motor driving a machine producing products in which only 50% of production meets specification with the balance ending up as scrap cannot be considered a high-leverage energy efficiency opportunity.  Not until the scrap problem has been resolved. This highlights the relationship between operational excellence and sustainability on industrial sites, something I will explore more in future posts.

What I've tried to show is that motor replacement on the basis of efficiency improvement is not a straightforward matter, and that hasty replacement without a considered analysis can actually lead to higher operating costs. Motor replacement is certainly not a "no-brainer" and calls into question moves to regulate motor efficiency standards.

Copyright © 2013, Craig van Wyk, all rights reserved