PROJECT DESCRIPTION
BACKGROUND
According to the EU‘s New Circular Economy Action Plan, the construction and building sector accounts for 50% of all extracted materials and is responsible for over 35% of the EU‘s total waste generation. In addition, greenhouse gas emissions from material extraction of construction products, as well as construction and renovation of buildings, are estimated at 5-12% of total national GHG emissions.
At the same time, cement is a major contributor to climate change, about 8% of the world’s total CO2 emissions comes from cement production. About 60% of the total CO2 emission of the cement manufacturing is process inherent (calcination of limestone CaCO3 to CaO); fuel combustion for heating generates the rest of the CO2 emission.
Fibre cement is mainly composed of ordinary Portland cement, water, quartz sand, and fibres. For the time being, there is no solution to fully recycle fibre cement, and the current model for fibre cement production is linear. Limestone mined from quarries is used for the cement, and the subsequent fibre cement production; fibre cement production and demolition waste is either landfilled or down-cycled to lower-value applications, such as road filler.
It is expected that measurable flows of fibre cement demolition waste suitable for recycling will gradually come on stream from the mid 2020‘s onwards. On the other hand, the directive on landfill of waste requires that from 2030, waste suitable for recycling or other recovery methods shall not be landfilled anymore. This combination creates an urge to find a sustainable solution for fibre cement waste.
OBJECTIVES
The overall objective of the CEMLOOP XL project is to establish a closed-loop process for fibre cement, allowing the recycling of fibre cement waste into a secondary raw material substituting clinker in the cement production. The resulting circular and low carbon cement will then be used for the production of new fibre cement products and of alternative applications.
CEMLOOP XL will implement a three-step closed-loop production process as an alternative to the current linear model. In the first step, fibre cement waste will be transformed into Recycled Cement Paste (RCP). In the second step, this paste will be carbonated, capturing CO2 emitted in cement production, to restore its cementitious properties (cRCP). The third step is the production of a novel circular low carbon cement.
Specific objectives are:
- To implement, test and demonstrate the combined fibre cement recycling and enforced carbonation process for the first time. For this purpose, two full-scale installations will be implemented: a Fibre Cement Recycling Plant, and an Enforced Carbonation Plant.
- To organize separate collection system on the market, with appropriate control and regulation, to generate clean and safe fibre cement waste streams (e.g. without asbestos).
- To offer a solution to construction companies to minimize landfilling of waste produced on jobsite, in line with extended producer responsibility (EPR) legal obligations.
RESULTS
CEMLOOP XL will demonstrate the technical and economic feasibility of the described circular process. By reusing recycled fibre cement waste, the demand for raw materials required for clinker production can be reduced. Moreover, the CO2 emissions related to clinker and cement production can be lowered by at least 20%.
The project aims to achieve the following results:
- Diversion from landfill and recycling of 60,000 tons/year of fibre cement waste (40,000 tons of production waste and 20,000 tons of construction and demolition waste).
- Production of 53,000 tons RCP from recycling the 60,000 tons waste.
- Production of 70,000 tons/year of cRCP, substituting 70,000 tons of Portland cement clinker.
- Savings of 112,000 tons/year of cement raw materials (approximatly 100,000 tons of limestone).
- Avoidance of 61,358 tons CO2 equivalent/year of greenhouse gas emissions.
In addition, it is foreseen to initiate at least five replications of the CEMLOOP XL concept five years after project end.
