Displaying items by tag: Water

China: Henan Province has announced a planned rise in water and energy tariffs for cement producers that fail to meet current emissions standards and clean transportation requirements. Reuters News has reported that companies subject to the measures will pay US$0.07 – US$0.14/m3 more for water and up to US$0.01/kWh more for electricity. Henan enacted ‘ultra-low’ emissions limits of 10Mg/Nm³ of dust, 50Mg/Nm3 of NO_x and 100Mg/Nm³ of SO₂ in 2018. Cement plants in the province produce 105Mt/yr of cement.

Greece: Titan Cement has published its integrated annual report for 2019, a year in which its net profit fell by 5.5% year-on-year to Euro50.9m from Euro53.8m in 2018 and sales rose by 8.0% to Euro1.61bn from Euro1.49bn. The company noted its ‘sustained performance and stronger cash flow generation’ throughout the year, with growing demand in the US and Southeastern Europe and the beginning of growth in Greece, in spite of a 7.0% year-on-year fall in cement volumes to 17.0Mt from 18.2Mt in 2018. Challenging conditions in Egypt and Turkey caused the group’s performance to deteriorate.

Titan Cement said that it is ‘on track to meet the Group’s 2020 sustainability targets and has already met ‘all targets related to emissions and water consumption.’
It acknowledged inevitable ‘short-term impacts’ of coronavirus, including reduced sales volumes ‘particularly and more severely in the second quarter of 2020,’ and has strengthened its liquidity position to Euro400m.

Cement and concrete products with sustainability credentials have increased in recent years as societies start to demand decarbonisation. In spite of the recent drop in the European Union (EU) Emissions Trading Scheme (ETS) price, there has been a trend in recent years in the construction industry towards offerings with better environmental credentials. Indeed, this week’s position paper from Cembureau on a carbon border mechanism concerns directly the growth of these kinds of products within Europe. Typically, the higher profile projects have been slag cement or concrete implementations such as Hanson’s use of its Regen cement substitute in a London sewer project or David Ball Group’s Cemfree concrete in a road project also in the UK. In this short review we’ll take a selective look at a few of the so-called low carbon cement and concrete products currently available.

Table 1: Some examples of methods to reduce embodied CO₂ in cement and concrete. Note - the product examples are selective. In some cases many other products are available.

Looking at cement first, the easiest way for many producers to bring a lower carbon product to market has been to promote cements made using secondary cementitious materials (SCM) such as granulated blast furnace slag or fly ash. These types of cements have a long history, typically in specialist applications and/or in relation to ease of supply. For example, cement producers in eastern India often manufacture slag cements owing to the number of local steel plants. However, cement producers have more recently started to publicise their environmental credentials as they reduce the clinker factor of the final product. Alongside this though, in Europe especially, a number of so-called low carbon cement producers have appeared on the scene such as EcoCem and Hoffman Green Technologies. These newer producers tend to offer SCM cement products or other low carbon ones built around a grinding model. It is likely that their businesses have benefitted from tightening EU environmental legislation. How far cement producers can pivot to SCM cement products is contentious given that slag and fly ash are finite byproducts of other industries that are also under pressure to decarbonise. Although it should be noted that other SCMs such as pozzolans exist.

As will be seen below a few of the methods to reduce embodied CO₂ in cement and concrete can be used in both materials. SCMs are no exception and hold a long history in concrete usage. As mentioned above David Ball Group sells Cemfree a concrete product that contains no cement. Harsco Environmental, a minerals management company, invested US$3m into Carbicrete, a technology start-up working on a cement-free concrete, in late 2019.

Limestone calcined clay cements are the next set of products that are starting to make an appearance through the work of the Swiss-government backed LC3 project, more commercial offerings like FutureCem from Cementir and H-EVA from Hoffman Green Technologies and today’s announcement about ThyssenKrupp’s plans to fit the Kribi cement plant in Cameroon with its Polysius activated clay system. They too, like SCM cements, reduce the clinker factor of the cement. The downside is that, as in the name, the clay element needs to be calcined requiring capital investment, although LC3 make a strong case in their literature about how fast these costs can be recouped in a variety of scenarios.

Calcium silicate cements offer reduced process emissions by decreasing the lime content of the clinker lowering the amount of CO₂ released and bringing down the temperature required in the kiln to make the clinker. Solidia offers its calcium silicate cement as part of a two-part system with a CO₂ cured concrete. In the US LafargeHolcim used Solidia’s product in a commercial project in mid-2019 at a New Jersey paver and block plant. Solidia’s second core technology is using CO₂ to cure concrete and reducing water usage. They are not alone here as Canada’s CarbonCure Technologies uses CO₂ in a similar way with their technology. In their case they focus more on CO₂ mineralisation. In Germany, Schwenk Zement backed the Celitement project, which developed a hydraulic calcium hydro silicate based product that does not use CO₂ curing. Celitement has since become part of Schwenk Zement.

Solidia isn’t the only company looking at two complementary technologies along the cement-concrete production chain. A number of companies are looking at recycling concrete and demolition waste. Generally this splits into coarse waste that is used as an aggregate substitute in concrete and fine waste that is used to make cement. LafargeHolcim has Evopact for the coarse waste and Susteno for the fine. HeidelbergCement has EcoCrete for the coarse and is researching the use of fines. Closing the loop for heavy building material producers definitely seems like the way to go at the moment and this view is reinforced by the involvement of the two largest multinational producers.

Of the rest of the other low carbon cement methods detailed in table 1 these cover other non-Ordinary Portland Cement (OPC) such as geopolymer and calcium sulphoaluminate cements. The former are a type of alkali activated binder and generally lack common standards. The latter are similar to slag cements in that they are established specialist products with lower CO₂ emissions than OPC.

With concrete when trying to make a low carbon product the first choice is whether to choose a low-carbon cement as the binder or even not to use cement at all in the case of Regen or Cemfree. From here the next step is to simply use less cement in a concrete mixture. There are a number of ways to do this from optimising aggregate gradation, following performance specifications more closely, using strength tests like maturity methods and generally adhering to quality control protocols better to deliver more consistency. Read the Mineral Production Association (MPA) publication Specifying Sustainable Concrete for more detail on this. Using concrete admixtures can also help make concrete more sustainable by improving quality and performance at construction sites through the use of plasticisers and accelerators, by decreasing embodied carbon through the use of water reducers and by improving the whole life performance of concretes. The use of locally-sourced aggregates is also worth noting here since it can reduce associated transport CO₂ emissions.

More novel methods of reducing embodied CO₂ emissions in concrete include the use of geopolymer concrete in the case of Zeobond Group’s E-Crete or adding graphene as Concrene does. Like geopolymer cements, geopolymer concretes are relatively new and lack common standards. Products like Concrene, meanwhile, remain currently at the startup level. Finally, if all else fails, offsetting the CO₂ released by a cement or concrete product is always an option. This is what Cemex has done with its Vertua Ultra Zero product. The first 70% reduction in embodied CO₂ is gained through the use of geopolymer cement. Then the remaining 30% reduction is achieved through a carbon offsetting scheme via a carbon neutral certification verified by the Carbon Trust.

As can be seen, a variety of methods exist for cement and concrete producers to reduce the embodied CO₂ of their products and call them ‘low-carbon.’ For the moment most remain in the ‘novelty section’ but as legislators promote and specifiers look for sustainable construction they continue to become more mainstream. What has been interesting to note from this short study is that some companies are looking at multiple solutions along the production and supply chain whilst others are concentrating on single ones. The companies looking at multiple methods range from the biggest building material producers like LafargeHolcim and HeidelbergCement to smaller newer ones like Solidia and Hoffman Green Technologies. Also of note is that many of these products have existed already in various forms for a long time like SCM cements and concretes or the many ways concretes can be made more sustainable through much simpler ways such as changing aggregate sourcing or working more efficiently. In many cases once markets receive sufficient stimulus it seems likely that low carbon cement and concrete products will proliferate.

Global Cement is researching a market report on low carbon cement and concrete. If readers have any comments to make please contact us at This email address is being protected from spambots. You need JavaScript enabled to view it.

Colombia: Cementos Argos has announced that its Green Bags initiative has seen the production of over 5 million bags from recycled paper, of which 808t was saved from going to waste. Cementos Argos supply chain manager David Restrepo that the initiative provides an alternative to ‘the felling of over 8000 trees and use of 64,000m³ of water, the equivalent of 26 Olympic swimming pools.’

Argentina: Loma Negra and tyre manufacturer Bridgestone have started a partnership to re-use water in the Llavallol suburb of Buenos Aires. Bridgestone will provide Loma Negra with 200,000l/days of filtered water for use at its operations, according to the Mercado newspaper. In return Loma Negra will use less water from the local aquifer.

Bolivia: SEDEM, the government’s business development agency, has refuted accusations that a new cement plant being built in Caracollo, Oruro does not have enough water or raw materials. Patricia Ballivián, the general manager of SEDEM, presented reports from PricewaterhouseCoopers and C & C Ingeniería y Procesos defending the supplies to the unit. The reports were released in response to accusations by a local politician that the project had been poorly planned.

The reports revealed that the Empresa Publica Productiva Cementos de Bolivia’s (ECEBOL) plant will recycle the industrial portion of its water supply. It will have a supply of 4l/s and a 3.5Ml reservoir. It also has limestone, gypsum and clay reserves sufficient for the production of 100Mt of cement. These are expected to last the plant 60 years.

Pakistan: Bestway Cement has promoted its environmental credentials following the Supreme Court’s mandated investigation into water usage by cement companies near the Katas Raj Temples in 2018. The cement producer says that all of its cement plants are ISO 14001:2004 Environment Management Systems certified. Specifically on the issue of water conservation, it has installed air-cooled condenser systems at two of its plants at Chakwal and Kallar Kahar respectively and it has built rain-harvesting ponds. In total the company has spent around US$14m on water conservation measures. Altogether it says that it has achieved 80% and 88% reductions in consumption of ground water for industrial use, respectively, at the two plants.

Other environmental measures the company has made include installing waste heat recovery (WHR) units at all four of its cement plants. Its total WHR capacity is 45.5MW giving it 28% of its total power needs. The company is recognised by the United Nations Framework Convention on Climate Change (UNFCCC) under its Clean Development Mechanism (CDM) Program for its initiative to reduce carbon emissions/footprint. It has also implemented tree plantation at its plants and surrounding areas, it uses drip irrigation and sewerage waste management and its head office in Islamabad has been certified as a Green Office by the World Wide Fund for Nature (WWF).

Pakistan: The Supreme Court has ordered DG Khan Cement to pay nearly US$0.6m into a dam fund in relation to falling water levels at the Katas Raj Temples in Chakwal, Punjab. The cement producer must make a deposit of US$0.5m as payment for water it used and US$0.1m as a penalty for ‘misleading’ the court, according to the Nation newspaper. The court has accused the company of pumping water from boreholes leading to water loss at a pond at the temples.

Pakistan: The Supreme Court has appointed a special committee to visit the DG Khan’s cement plant in Chakwal to investigate how it stores water. The committee will report back to the court about the capacity of the reservoirs built by the plant as well as whether they were filled by extracting water from the aquifer or from rainwater, according to the Dawn newspaper. The committee will also take samples of water from the reservoirs.

The court has been looking into how DG Khan and Bestway Cement set up cement plants in the Potohar region related to water issues at the nearby Katas Raj Temples. Previously, the court was told that the DG Khan Cement was only operating tube-wells for domestic use by its workers but a witness alleged that the plants were extracting water for industrial use from the water table.

Pakistan: The Supreme Court has ordered cement producers to pay for underground water used by cement producers near Katas Raj. Chief Justice Mian Saqib Nisar said that underground water is ‘very precious’ and added that cement factories using it near the temple at the site would no longer be able to do so for free, according to the Nation newspaper. The Chief Justice has also directed the Punjab Food Authority to audit local companies to assess how much water they are using and how much they are paying for it. The on-going case was started in response to a pond drying out at the Hindu heritage site due to water consumption by nearby cement plants.