Low-carbon transition technology path: fuel substitution

Because RDF is produced from domestic garbage, the current garbage classification policy in our country is not popular, but only implemented in some cities. Therefore, the RDF prepared in China has high moisture content and low calorific value, which is obviously different from the international mainstream RDF-5.

In 2020, the amount of domestic waste produced in China is about 310 million tons. According to the calculation of the calorific value of garbage derived combustible material after pretreatment of one ton of domestic waste, China's domestic waste can replace 90 million tons of standard coal after combustion. RDF has great potential for development, and the future RDF industry and standards need to be established, especially the waste pretreatment industry.

Conch Cement (stock code: 600585,00914) through the integration and application of step furnace, hot pan furnace and other technologies, the collaborative disposal and CKK project to upgrade, direct RDF fuel into the kiln, further improve the utilization rate of caloric value. The plan is to replace about 10% of fossil fuels with RDF by 2025.

Holcim and Heidelberg Cement have relatively better solid waste management, alternative fuel production systems and operational management systems. Holcim is working to replace traditional fossil fuels with non-extractive fuels sourced locally, alternative and derived from waste, and is beginning to adopt near-infrared spectroscopy technology that can be used to analyze alternative fuel properties during feeding and compensate for mass changes in real time using the optimal fuel mix. This solution increases the use of alternative fuels, thereby reducing CO2 emissions. Our country should learn from its relevant successful experience and perfect the production standard system and quality control management standard system of alternative fuels.

UltraTech Cement: Use municipal solid waste while increasing co-treatment of industrial waste to reduce the amount of waste sent to landfills or incineration. Using municipal solid waste (MSW) as cement plant fuel, waste-derived fuel (RDF) is becoming increasingly popular in India, where RDF has the potential to replace 15-20% of the primary fossil fuel in its cement manufacturing industry.

In addition, in early 2022, Cemex announced the acquisition of Broquers Ambiental, a sustainable company focused on separating, recycling and treating municipal solid waste generated in the city of Queretaro, Mexico. The acquisition is part of Cemex's Future Action Plan, which aims to become carbon neutral; Cemex is an industry leader in the use of renewable diesel, an advanced second-generation biofuel that is fully compatible with its current fleet and can reduce the carbon footprint of transport by 60 to 80 percent when used at 100 percent.

3. Tire derived fuel TRF

Waste fuel has the advantages of high heat value and low water content, so it is also the earliest alternative fuel for the cement industry. In the 1950s, it was first applied in Germany, and it is now more popular abroad. About 40% of cement plants in the United States are burning waste tires, and about 10% of Japanese waste tires are used as alternative fuel for cement kilns. In Eastern European countries such as Poland and Ukraine, waste tires are used as the main energy source for rotary kilns (the fuel replacement rate is more than 60%). [7]Holcim cement, Cemex cement, Heildelberg cement and Lafarge cement tyre derived fuels accounted for 10%, 16%, 11.6% and 19.7% of alternative fuels, respectively. The waste tires in China are mainly produced by recycled rubber, the comprehensive recovery rate is about 50%, and the proportion of used in cement kilns is less.

Waste tires have high calorific value, low renovation cost, simple process, and the nitrogen oxides emitted by combustion and the heavy metals in ash are less than coal (" China Cement production enterprises greenhouse gas emissions Accounting methods and reporting Guide "has also clearly pointed out that 20% of fossil carbon in waste tires is still included in carbon emissions, 80% of biological carbon is not included in carbon emissions). It is one of the alternative fuels that China's cement industry should focus on developing in the future.

4. Hydrogen fuel

Hydrogen fuel substitution in cement production refers to the replacement of fossil fuel heating with clean energy hydrogen in the clinker calcination process, and the hydrogen is injected into the kiln.

Heidelberg Cement: In 2021, a Cement kiln at Heidelberg Cement subsidiary Hanson UK's Ribblesdale plant successfully operated for the first time in the world in a zero-fuel mix, consisting of hydrogen (39%), biomass components (12% of meat and bone meal) and glycerin (49%) delivered by tanker. The government-funded trial achieved a 100% alternative fuel substitution rate.

Cemex: Cemex is a leader in the use of hydrogen, having started using hydrogen in its plants as early as 2019, and will begin the technical transformation of all its European cement plants in 2020. In 2022, CEMEX invested in HiiROC, a start-up company that produces hydrogen using a unique plasma process and has a low-cost, zero-emission hydrogen production technology. The objective of CEMEX's investment is to increase the hydrogen injection capacity of CEMEX cement kilns, thereby increasing the rate of replacement of fossil fuels by alternative fuels.