FAQs
Q. What is CMAP?
A. CMAP stands for Carbonate Mineralization via Aqueous Precipitation. Calera is able to form specific, mostly undescribed, carbonate minerals that can be formed into cements, supplementary cementitious materials, and synthetic limestone which is useful as aggregate. The CMAP process removes dissolved ions from natural waters like seawater or geologic formation waters, producing softened water that can be economically desalinated.
Q. Can the carbon dioxide escape?
A. Calera converts carbon dioxide to carbonates. The three species of carbonate produced are carbonic acid, bicarbonate, and carbonate. For the carbon dioxide to escape from these forms requires strongly acidic conditions or very high heat. All of the applications of CMAP technology leave the converted carbon in the stable and permanent carbonate state where carbon dioxide will never likely be released.
Q. What is unique about Calera’s technology?
A. The Calera technology is a portfolio of patented technologies associated with the carbon conversion and mineralization of carbon dioxide (CO2) in the form of carbonate and subsequent conversion to building materials and fresh water. Also included is the high efficiency production of alkalinity using a low voltage base production technology. Calera pioneered these developments at its state of the art laboratories in Los Gatos, California and scaled the technology to pilot scale and demonstration scale at its affiliate, Moss Landing Cement Company, in Moss Landing, California.
Q. What are the inputs to the Calera process?
A. The inputs are a source of carbon dioxide, a source of water, a source of alkalinity and a source of divalent cations.
Q. How much alkalinity is required and what is the source?
A. The amount of alkalinity required depends on the particular site location specifics and the carbonate species that is required for the local market. Some applications require no alkalinity; others require one equivalent of alkalinity per carbon dioxide molecule, while others require two units of alkalinity per carbon dioxide molecule converted. Calera has developed techniques to secure useful alkalinity from a number of sources of material including alkaline surface waters, certain types of natural geologic brines and minerals, solid industrial effluents or byproducts such as fly ash from coal fired boilers, cement kiln dust, iron smelter residue, aluminum anodization byproducts, and paper mill effluent. If insufficient alkalinity is available for the particular production plan from these sources, the alkalinity is supplemented by producing caustic soda from a proprietary technology known as “Low Voltage Base” that uses only salt water and electricity as inputs.
Q. What is the source of divalent cations?
A. Divalent cations are principally calcium and magnesium that are abundant in natural waters. These ions are what is known as the hardness of the water. According to the USGS Produced Water database, a significant fraction of the waters currently produced from oil production have calcium concentrations greater than 20,000 ppm. Calcium enriched brines are formed by several natural processes that are well known to geochemists. Hard brines can also be supplied from man-made sources such as desalination concentrates, fracking waters from tight shales and other produced waters from oil and gas fields. Calcium and magnesium are also present in solid waste products such as fly ash and cement kiln dust.
Q. Will the Calera process only work with seawater?
A. This is a common misconception due to the fact that Calera’s initial process was demonstrated at a site in California where seawater was used as one of the potential sources of alkalinity and divalent cations. The Calera process is well suited to locations that do not have access to seawater. In fact, it is easier to use waters such as geologic brines due to the significantly higher concentration of calcium than in seawater. The testing at laboratory, pilot scale and demonstration scale has proven the robustness and flexibility of the CMAP process to effectively use a variety of hard water and alkalinity sources.
Q. What products does Calera produce?
A. The outputs from the Calera process are clean air, building materials (sand, aggregates, and/or supplementary cementitious products), fresh water, and excess carbonated water for re-injection. If the proprietary low voltage electrochemical process is required for additional alkalinity, hydrochloric acid will also be produced.
Q. What will happen to the hydrochloric acid?
A. The hydrochloric acid can be sold on the open market for industrial uses, used for oil well or brine production or be injected in deep geologic reservoirs.
Q. What is the intended use of the water product?
A. It is possible to produce fresh water from the Calera process in a similar way to desalination. Since the hardness is removed from the water by the CMAP process, the remaining soft water stream is ideal as the feed for a process that requires lower energy than a typical seawater desalination process. In certain areas of the world where there is a water shortage or drought conditions (e.g. Australia), the production of fresh water for sale will be an added benefit. A pilot scale test unit is already in operation at Moss Landing Cement Company to develop and scale up this technology.
Q. How will you deal with the seasonality of cement production and use in cold climates?
A. In severe winter climates the flexibility of the CMAP process allows the capture of CO2 with brines and its conversion into carbonate species for deep geologic re-injection. This is the CMAP process in its simplest form and the requirement for alkalinity is reduced to that required for producing carbonate products.
Q. Are there sufficient brines available at all locations for the Calera technology to work?
A. Most of Earth’s continental crust hosts sedimentary basins. Most stationary sources of carbon dioxide are on sedimentary basins. Sedimentary basins contain ancient seawater that is modified over geologic time by the geologic strata that it occupies. The shallowest connate waters in these basins are often the lowest salinity because they are influence by glacial melting and other surfical waters. There is enough hardness in the waters occupying sedimentary basins to form carbonate mineral from the world’s anthropogenic carbonate dioxide for millennia.
Q. What is the carbon footprint of your product?
A. All Calera building materials have a “negative” carbon footprint because the products contain carbon that would have been emitted from a stationary point source and there is also an offset of the avoided carbon emission from the traditional techniques used to generate the building materials i.e. the cement plant emissions. For example, every ton of Portland cement production release about one ton of carbon dioxide into the atmosphere. We have directly measured the carbon balance around our process using state of the art isotopic techniques on both the inputs and outputs so we can track the carbon from the coal through to the carbon in the solid product. We have conducted carbon lifecycle analysis that clearly demonstrates the beneficial carbon footprint of the Calera process.
Q. Can the CMAP process be cleaner that nuclear, wind or solar?
A. Yes. The CMAP process is carbon “negative” due to the offset of the avoided carbon emission from the cement plant emissions. Since every ton of cement produced in a Portland cement plant generates one ton of CO2. Even if the Calera carbon conversion process were carbon-neutral (meaning it produced as much carbon dioxide as it converts), it would still be still have a huge benefit because of the Portland cement it is replacing. Every ton of Calera product has captured within it approximately a half ton of CO2 from the power plant flue gas stream and it offsets an additional one ton of CO2 from the traditional cement production, resulting in a carbon negative footprint. Nuclear, wind, or solar cannot achieve this impact on global CO2 emissions.
Q. How does Calera's process compare to CCS, Nuclear and Renewables?
A. Calera is fundamentally different from the other power generation options because they only produce electricity. Calera plants produce electricity, cement, aggregate, and potable water. The cost to build a Calera plant, and the levelized cost of electricity from a coal power generation unit in tandem with a Calera plant, is significantly lower than any of the other options. There are risks associated with implementing the Calera infrastructure, but they are lower than the risks associated with nuclear, wind or solar. There are additional risks with CCS from a liability perspective.
Q. Have you verified the “carbon capture” of your products?
A. Yes, we have verified the “carbon content” of our products and have also confirmed that the carbon captured originated from the flue gas source (as opposed to atmospheric CO2) using stable isotopic methods.
Q. Where will you sell your products?
A. Our products will, in most cases, be sold and distributed in markets in close proximity to the flue gas CO2 sources i.e. close to the power or industrial plants. Large power plants are typically located close to big population centers, which provide a large product market.
Q. When can we expect to see an actual Calera cement?
A. Initially we will focus on the production of aggregates and supplementary cementitious products to make carbon negative concrete for use in applications such as carbon negative roads.
Q. Can the Calera process handle the other pollutants in a typical coal flue gas such as mercury?
A. At the pilot plant at Moss Landing, we have evaluated the flu gas emissions from several different coal types from a coal-fired boiler simulator and can confirm that most of the other pollutants (e.g. SOx and mercury) present in the flue gas are removed at very high efficiencies.
Q. What percentage of the CO2 in a typical flue gas can the Calera process capture?
A. At our Moss Landing 10 MW demonstration absorption unit, we have proven 86% capture of the CO2 from a flue gas slip-stream from Dynegy’s adjacent gas powered power plant. We have also achieved similar capture percentages from the flue gas from our pilot size coal combustion test unit.
Q. When are you going to prove that your process works at coal fired power plant?
A. We have a coal boiler in our Moss Landing pilot plant and results from this were used to successfully design our demonstration plant at a scale up factor of 100 fold. We are also working with several US coal power companies as well as developing a large coal demonstration project in Australia with the support of the Government of Victoria and the Australian Federal Commonwealth.
Q. Do Calera building materials meet the ASTM standards?
A. Yes, our intent is to meet the current ASTM standards for building materials and the EPA standards for water products. All our tests on initial samples have demonstrated that our products are comparable to traditional concrete products although we realize that validation of these tests will be required by the building industry. Continuous testing to these industry standards will be carried out as we scale up our process to full commercial scale.
Q. How robust is the Calera process?
A. The Calera process is applicable to any stationary point source of carbon dioxide and provides a solution other pollutants as well.
Q. Is the Calera process scalable?
A. We are currently operating a demonstration plant in Moss Landing, California to determine the commercial scale processing and energy requirements to remove carbon dioxide from power plant flue gas. The Demonstration Plant removes carbon dioxide from a slipstream of the flue gas produced by the adjacent Dynegy Moss Landing natural gas fired combined cycle power plant. The design rate of flue gas flow that can be processed in the Demonstration Plant, approximately 20,000 standard cubic feet per minute, is equivalent to approximately 10 MW of electrical power from a coal-fired plant. We have proven, and the engineering firm RW Beck has independently verified, that we met our goal of a minimum of 80 percent carbon dioxide removal with less than 10 percent power consumption. We have successfully designed the Demonstration Plant and the supporting equipment with sufficient flexibility in testing equipment components and operating conditions such that we are able to select and then confirm or subsequently modify promising internal configurations and operating conditions that ultimately lead to producing “best” results. The scale of the Demonstration Plant is sufficiently large that any issues specific to large scale can be observed and corrected. The Demonstration Plant also has sufficient flexibility in the scrubber liquid preparation area to allow Calera to test synthetic versions of the brines and base sources that we will use commercially.
Q. Are there major risks associated with the scale up of your technology?
A. Calera, as with any new technology, will face challenges, but overall, the risk is lower than that related to other carbon capture approaches. Ian Copeland, President of Bechtel Renewables and New Technology, said about Calera in a recent press release; “While there are challenges to bringing the Calera process to commercial scale, they are not as great as those facing other carbon sequestration approaches”.
Q. The failure of Copenhagen and of carbon legislation (Waxman-Markey) in the US makes a hard case for developing clean technologies. How does this affect Calera?
A. Calera has both a cost and revenue advantage over other carbon sequestration approaches as well as nuclear and renewables. In most markets, the revenues from building materials and fresh water will make our projects economically viable in their own right. This fundamental difference makes Calera a true global solution, applicable in both developed and developing countries. Having, for example, “cap and trade” legislation will only help speed adoption of the Calera technology.
Q. Some skeptics of the Calera process say this has been tried before and does not work. What is your response to these skeptics?
A. We understand that some people may have doubts about a technology capable of converting CO2 (a bad thing) into building materials (a good thing). However, Calera’s CMAP technology works and we have proven it in our pilot plant, and at our demonstration plant. After reviewing our technology in depth under confidentiality agreements, many independent scientists, researchers and industry experts agree with our conclusion. Also, we have filed over 170 patents around the world with over 3,500 claims and now have patents actually granted, demonstrating novelty. Over time, as more patents are granted and the details become public, the skeptics will learn more and more about what we actually do in our process.
Q. Your critics say that you would emit more CO2 than what you would capture because the feedstocks you use are energy intensive.
A. To supplement our CO2 capture chemistry in some locations we will make our own alkalinity/CO2 capture feedstock through a new electrochemistry process. This is a dramatic improvement over the current chlor-alkali process and our proprietary technology is capable of delivering a sodium hydroxide feedstock with only a third to a fifth of the energy traditionally used in a chlor-alkali process. Patents have already been granted on this electrochemistry process.
Q. How do you plan to build enough plants to capture the planet’s CO2?
A. Calera and Bechtel have signed a strategic alliance to develop projects worldwide and we are also building out a senior management team with the experience to execute large projects globally.
Q. Cement is a hundred year old industry, how do you plan to replace it?
A. We do not plan to replace the cement industry but intend to work alongside it in developing products and markets that can continue to ensure its economic and environmental sustainability. In fact, Calera will allow the cement and concrete industry to continue to be an option for road paving, as opposed to asphalt. If a price is established for carbon, the concrete industry would face the possibility of losing its market share to asphalt.