The China Textile Academy (CTA) meeting in Shanghai on 11 October focused on the latest developments in particulate controls for coal-fired plants and industry, especially baghouses. China has the tightest emission limits in the world, setting standards which reduce emissions from large coal plants in target regions to as low as those from gas-fired plants. The industry is therefore turning to control technology manufacturers to provide increasingly effective control systems. Chinese coals range from high to low ash and high to low sulphur and so there is a mix of electrostatic precipitator (ESP) systems and bag houses across the current fleet. However, as emission limits tighten, there appears to be a trend for plants to switch from ESP systems to baghouses or combined systems which incorporate both ESPs and baghouses (or wet ESPs). This is similar to the recent trend seen in the USA following the tightened emission limits of MATS (Mercury and Air Toxics Standard). With longer fly ash residence times, baghouses offer superior co-benefit mercury control over ESP systems. Further, sorbent and/or oxidant addition to enhance capture of mercury and acid gases also works better with baghouses than with ESP systems.
The aim of the CTA conference was to discuss improvements in baghouse materials and manufacturing. Newly developed synthetic materials combined with improved fibre production and filter construction techniques give baghouses extended lifetimes as well as increased capture efficiency. Further, new processing techniques are being developed to promote the potential for baghouse reuse and recycling, to keep costs, and waste, down. In stark contrast with the numerous presentations reporting on improved performance of new materials and systems, there was a paper giving examples of when baghouse systems fail. Although this is relatively uncommon, China is a large country with many plants, some of which operate somewhat outside the prescribed performance requirements, and so there were plenty of examples of baghouse failures to discuss. And some were quite spectacular. In some cases the fault is with the supplier – poorly sewn or even glued seams which collapse and rip under pressure. In other cases, the fault is with installation and maintenance, with pulse jet nozzles being misaligned or corrosion going unchecked to the point of materials’ collapse. These errors are costly, not only in terms of repair expenses and plant downtime, but also in uncontrolled emissions and localised pollution issues. The CTA and others are working to standardise testing and monitoring of baghouse performance in order to predict and prevent such issues. The market for control systems within China is still growing, but the rate of growth is decreasing as new coal build tails off and the existing fleet falls into compliance. Chinese manufacturers are therefore looking to expand sales into new markets overseas.
Over in India, the World Coal Association (WCA) ran a meeting on Sustainable Energy Development: Opportunities and Innovation for Indian Coal. Indian emission standards have been set which are equivalent to those in the EU, the USA and China (excluding the newer performance requirements). This poses a particular challenge for India since they are effectively fast-forwarding through the emission limit process. Whilst Westernised economies have moved to this level of emissions control over several decades, making step-wise moves towards improving control along the way, India has made a leap which requires a significant amount of control technology from a relatively low starting point. There are only a handful of plants in India with flue gas desulphurisation (FGD) systems in place and few, if any, with NOx control. Whilst these systems can be purchased “off the shelf”, the high ash in Indian coals is somewhat unprecedented and many of the available technologies have not been proven to cope with the increased ash in the flue gas. Further, the challenges of older plants (some inefficient and arguably not worthy of retrofitting investment), space constraints, and limited water availability means that the emerging market for flue gas controls in India is large but challenging. The cost of compliance with the new Indian emission “norms” will be in terms of billions of dollars and will take years to achieve. Although the new emission limits would imply a huge market for control technologies on existing plants, the reality is somewhat different. Many older, less efficient plants, will close. Newer plants will be cleaner, more efficient and probably larger – meaning that increased capacity will not run parallel with increase in unit numbers – several smaller plants will be replaced with one larger plant, reducing the estimated number of control technology sales. Others may be able to comply with sulphur emission limits using cleaner coal, avoiding FGD. The market for NOx and mercury controls remains unchartered as Indian coals are outwith the current range of experience. However, with little or no national expertise in this area, India will reply on importing expertise and equipment until they can develop a new national industry of their own.
As discussed at the WCA meeting, there is a strong impetus in India to move forward to USC (ultra-supercritical) technologies as soon as possible. All new plants must be USC, and the NTPC (National Thermal Power Company) and other utilities seem to be committed to speeding up the closure of older, less efficient plants. As discussed in a previous report by the CCC, a scenario where all coal plants in India are retired after 25 years and replaced by USC, and eventually AUSC (advanced USC), will mean potential emission reductions, including CO2, being achieved in a matter of years rather than decades. This will have a significant effect on the market for control technologies.
In terms of market potential, China and India are indeed huge. However, it is a complex and relatively unpredictable market. My new report on the emerging technology markets in India and China, and also in other emerging regions, should be available soon.