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FLSmidth’s HOTDISC® Reactor helps China reach targets on emission reductions
In 2020, Chinese government announced that China would attempt to reach ‘peak carbon’ by 2030 and achieve carbon neutral status by 2060. As a result, all the country’s heavy emitters are seeking ways to reduce their carbon emissions and meet this ambitious target. The pressure on the cement industry is high. Fuel substitution is one of the most straightforward routes to emissions reduction, as something that can be done immediately with readily available technology.
The HOTDISC® Reactor enables up to 100% fuel substitution in the calciner, making it an excellent solution for those plants seeking a relatively ‘quick win’.
New orders have come in since Chinese government’s announcement about ‘peak carbon’ and carbon neutrality. One contract came from SS Group, which has purchased a HOTDISC for its new plant in PY site, initially to burn municipal solid waste (MSW), but with the potential to add refuse-derived fuel (RDF) to the mix later on. This unit is due to be installed in June 2022, and the company plans to purchase more HOTDISC Reactor in the coming year.
The HOTDISC has been widely used in cement plants since 2002, enabling greater use of a variety of alternative fuels, from sewage sludge to whole truck tyres. But since its introduction in China in 2014, the HOTDISC has really taken off, thanks to its ability to deal with one of China’s main alternative fuel source – MSW. This unprocessed household waste has an average moisture level of 50% and a calorific value of around 900 kcal/kg. Compare this with the calorific value of coal (around 5000-6000 kcal/kg) and it’s clear that this would be a very challenging fuel to burn in conventional ways. But the HOTDISC makes it a viable fuel source, enabling cement plants to reduce fossil fuel consumption and provide an environmentally responsible means of dealing with waste that would ordinarily go to landfill.
The HOTDISC Reactor – how it works
The HOTDISC is the most efficient way to substitute calciner fuel with a wide range of lower cost alternative fuels. From wet powders to solid waste up to 1.2 m dia., the HOTDISC Reactor can burn them all. The waste to energy process eliminates the need for expensive shredding and gives cement plants the flexibility to select the most economical choice from a wide range of alternative fuel options.
As an integrated part of the kiln system, the HOTDISC Reactor is added onto the calciner and functions as a slow-moving disc furnace. When alternative fuel, preheated raw meal and tertiary air are fed into the HOTDISC, it produces combustion gases, partly calcined meal and combustion residues. These are then processed in the calciner alongside the other streams entering it. The result is calcined meal, ready for the kiln, and low, controlled emissions.
The high retention time of the HOTDISC, as well as its flexibility to take on such a wide range of fuels, gives it near unlimited potential in the field of alternative fuels for the cement industry. As environmental pressures grow, we expect more and more cement producers will look to the HOTDISC to reduce fossil fuel use and provide a safe solution for waste disposal.
Proven successes and ambitious targets drive orders
The first HOTDISC within China was installed at the CRC HSH plant, where it proved so successful that soon other cement producers followed suit. To date, CRC, JYJD, HS and SS Cement have purchased eight sets of HOTDISC to burn MSW and refuse-derived fuel (RDF). These plants benefit from a higher thermal substitution rate in the calciner, contributing to their local environment and their sustainability goals.
HOTDISC HDR63 installed at Tianyang site
A solution for hazardous waste
In 2017, the 5000 tpd LZ cement plant in ZiBo city, Shandong province, was having problems with an unstable pyroprocess. The issue came when feeding hazardous waste directly to the calciner. The plant team got in touch with us to discuss the possibility of installing a HOTDISC as a solution to this problem.
This was the first time the HOTDISC had been proposed for such an application, and so our specialists approached the project with all due care. After much discussion, we identified that the high chlorine content of the waste would require special measures. As such, we designed a four-feed point especially for the LZ plant that enables it to burn solid waste, semi-solid waste, liquid waste and waste packaging. In addition, we added a 10% bypass system to the design.
Start-up and commissioning commenced in October 2018. Within a week the plant was able to double the previous waste feed rate, thanks to the HOTDISC’s long retention time. The pyroprocess is far more stable than it was previously, and the plant team is very satisfied with the performance of their bespoke HOTDISC system.
Thanks to the success of this project, the HOTDISC has become a go-to solution for the safe disposal of hazardous waste in cement plants. CY company, one of China’s largest hazardous waste operations, has purchased three sets of HOTDISC since 2019 to dispose of waste in WH, LYZL and YY sites. Two of these projects are already in operation, while the third will soon be ready.
With so many successful projects completed in China and around the world, we are excited to see which waste source the HOTDISC will tackle next.