Fortera and MLC plan US plant turning lime-kiln CO2 into cement
The agreement covers a plant of more than 300,000 tonnes a year that captures CO2 from lime making and binds it into a cement product.
On 8 September 2026, the US lime maker MLC (Mississippi Lime Company) and the California start-up Fortera signed a development agreement for a cement plant designed to make more than 300,000 tons a year. According to MLC's announcement, the plant will capture carbon dioxide from lime production and turn it into a cement that is almost half captured CO2 by weight.
- 300,000+ tof ReAct cement a year planned at the new plant
- 15,000 ta year at Fortera's existing Redding facility
- Almost 50%of ReAct cement's weight is captured CO2, according to MLC
- 70%lower CO2 emissions than Portland cement, a Fortera claim
- 4 billion tapproximate global cement demand each year
What happened
MLC, based in St. Louis, Missouri, makes lime and limestone products. It says it runs one of the largest lime production facilities in the Americas. Fortera has developed a process it calls ReCarb. The two companies agreed to develop a commercial plant that uses ReCarb to capture carbon dioxide (CO2) released when MLC makes high-calcium lime. The captured gas is then converted into Fortera's product, called ReAct cement. Both companies describe it as the first full-scale commercial plant of this kind.
The plant is designed to produce more than 300,000 tons of ReAct cement each year. The companies have not named the site, the cost, or the construction timetable. They said they would share more details in the coming months. Fortera's stated approach is to work with established producers and use their existing raw materials, infrastructure and delivery networks instead of starting from nothing.
This is a large step for Fortera. Its existing facility in Redding, California, produces about 15,000 tons a year, according to the release. The new plant would be about twenty times bigger. Ryan Gilliam, Fortera's chief executive and co-founder, said the deal lets the company grow to meet demand that already exists. Paul Hogan, chief executive of MLC, said lime and cement are chemically similar businesses.
The market is large. The release puts global cement demand at roughly 4 billion tons a year. In the United States, imports supply about a quarter of the cement used each year, according to MLC, so the plant would also add home-grown supply. Against that total, 300,000 tons is small. The real test is whether the method works at twenty times today's scale, and whether it can be copied at other lime and cement plants.
The engineering behind it
To understand the idea, start with the chemistry of lime and cement. Both begin with limestone, which is mostly calcium carbonate. When limestone is heated strongly in a kiln, it breaks down into calcium oxide, called lime, and carbon dioxide gas. This reaction, called calcination, releases CO2 from the rock itself, not only from the fuel burned to heat the kiln. That is why cement and lime making produce emissions that cleaner fuel alone cannot remove.
Ordinary Portland cement goes further. Lime is combined with clay minerals at very high temperature to form clinker, which is then ground into cement. When water is added, the clinker compounds hydrate and form the hard paste that binds concrete. Fortera's route is different. It captures the CO2 that comes out of the kiln and reacts it back with lime to form calcium carbonate again, in a form that can act as a binder.
Fortera's website says ReAct cement is based on the transformation of vaterite to calcite. Vaterite and calcite are two crystal forms of calcium carbonate. Vaterite is less stable, so as it changes into calcite it can grow crystals that bind particles together. The company says the product can be used on its own or blended with Portland cement. It also sells a blend product that replaces part of the Portland cement in a mix.
A new binder only matters if it meets standards. MLC's release says ReAct has been tested by third parties and complies with ASTM standards. Fortera lists the cement under ASTM C1157, a performance specification. Such a specification judges cement by how it behaves, including strength and setting time, rather than by its exact recipe. Fortera says it was the first low-carbon cement to meet all six ASTM C1157 categories at once.
What it means in Nepal
The sources for this story do not discuss Nepal, so this section is about the skills involved rather than about any Nepali plant or market. The main lesson is that cement is no longer one fixed material. New binders are being designed to cut emissions, and each one behaves a little differently on site. A civil engineer who understands why cement hardens is better able to judge a new product than one who only knows the brand name on the bag.
Testing is where civil engineers meet a new binder in practice. Before any code or client accepts it, someone has to cast cubes or cylinders, measure setting time and strength gain, and check durability over months. That work happens in materials laboratories and on site trials. Reading a standard such as a performance specification, and comparing it with a prescriptive one, is a useful skill for anyone who will specify concrete.
The story also shows how engineers must read carbon claims. Fortera says its process cuts CO2 emissions by 70 percent compared with Portland cement, at a similar cost. The releases do not explain how that figure was calculated or which production steps it covers. On building projects listed on its website, Fortera reports reductions of 37 to 46 percent, with one project reporting up to 70 percent. The result depends on how much ReAct each concrete mix used.
An engineer comparing such figures needs to ask what was counted, what was left out, and what the baseline was. A blended mix that replaces only part of the Portland cement will save less carbon than a full replacement, even with the same product. Learning to read an emissions claim with the same care as a strength certificate is part of materials work, because a carbon figure is only as reliable as the method used to calculate it.
What to study if this interests you
The chemistry starts early. Engineering Chemistry, ENSH 103, in the first semester of BCE, covers the reactions and compounds behind lime and carbonate. Civil Engineering Materials, ENCE 103, also in the first semester, introduces lime, cement and their properties. Concrete Technology, ENCE 205, in the third semester, goes deeper into cement hydration, mix design, admixtures and the strength and durability tests that any new binder must pass.
Words in this story
- Calcination
- Heating limestone so that it breaks down into lime and carbon dioxide gas.
- Clinker
- The hard lumps formed in a cement kiln, which are ground with gypsum to make Portland cement.
- Performance specification
- A standard that judges a material by test results such as strength and setting time, not by its exact recipe.
- Vaterite
- A less stable crystal form of calcium carbonate that can change into the more stable form, calcite.
Where this comes from
- MLC (Mississippi Lime Company), 8 Sep 2026
- Fortera, 8 Sep 2026
- Global Cement, 9 Sep 2026
Written in our own words; no sentence is copied from these reports. Researched with AI assistance on 11 October 2026; no member of faculty has reviewed it yet. If you spot a mistake, call 01-5091616 and we will correct it and say so.
