Technology

Reducing Environmental Risk and Plant Inventory of Coal Combustion Products

Our modular process permits partners to tailor the technology best-suited to their market needs. Our modules are designed around three types of feed, each forming a unique set of products.

Today’s coal combustion products (CCP) market is ripe for disruption. Whoever develops and deploys the next generation of technologies to extract the valuable materials contained within CCPs will own the platforms to enable tomorrow’s products – globally in multiple market sectors.

Elixsys offers our partners a value-packed option to extract valuable materials from this energy byproduct. Our technology development applies a modular approach to extract gypsum, industrial metals, and rare earth elements through the entire research and technology (R&T) continuum.

Burning coal produces a variety of solid wastes known as coal combustion products (CCPs). These include coal ash (fly ash and bottom ash), boiler slag, flue-gas desulfurization (FGD) gypsum. A large U.S. coal-fired power plant can produce up to 15,000 tons of ash a day. Much of this ash is currently stored in impoundments, used in abandoned mines, or disposed of in landfills where it presents risks to the environment.

Elixsys was founded specifically for this reason, providing our partners with a value packed option to extract valuable materials from these waste byproducts with near zero process waste. Our technology development applies a modular approach to extract gypsum, industrial metals, and rare earth elements through the entire research, development, demonstration, and deployment (RDD&D) continuum. Our process provides production capacity that accommodates these unique materials and product requirements of our coal energy partners to unlock their untapped value potential, reduce operating costs, mitigate operational impact to the environment, and reduce demand on natural resources.

The market potential for these products is currently valued at $90B. Our products may be used in many industries comprising fertilizer and feed applications, rubber products and plastics, coatings, petroleum refining, and chemical industries.

Types of Feedstock

  • Flue Gas Desulfurization (FGD) materials are produced by scrubbers that are used to capture sulfur from flue gas. FGD gypsum is one of the more common FGD materials.
  • Pulverized Coal (PC) Ashes – These ashes are produced by plants that pulverize the coal and burn it with heated air to produce energy. PC ashes typically contain little or no sulfur. PC ashes can be used as feedstock in Module 2 without requiring sulfur separation.
  • Fluidized Bed Combustion (FBC) Ashes – These ashes are produced by plants that burn waste coal and inject limestone to capture sulfur that is released during the combustion of the coal.

For PC ashes, where ash and gypsum (FGD) are separate, the gypsum may be processed separately in Module 1 while the ash proceeds to Module 2. For FBC ashes, the combined ash and gypsum may be processed through Module 1 to remove and convert the gypsum and the remaining ash may proceed through Module 2.

Module 1

Conversion of Flue Gas Desulfurization (FGD) waste or gypsum (calcium sulfate) to two marketable products

Process: Use of gaseous reagents to convert FGD gypsum into ammonium sulfate crystals (fertilizer) and powdered technical grade calcium carbonate (industrial filler).
Options to reduce reagent costs are available and are being investigated thoroughly.

Current Stage: Demonstration scale plant designed and ready to build.

Demo-Scale Goals:

  • Validate design in continuous operation
  • Demonstrate processing of multiple feedstocks
  • Produce product samples
  • Improve product quality
  • Process optimization and troubleshooting
Module 1 Products: Ammonium Sulfate Fertilizer and Technical Grade Calcium Carbonate

Module 2

Ash Leaching, Precipitation, and Separation

Process: A leach process for separating silica and metals from coal combustion products.

Current Stage: Bench scale testing complete, ready for pilot scale-up

Pilot-Scale Goals:

  • Validate design in continuous operation
  • Integrate Modules 1 and 2 and validate in continuous operation
  • Produce additional product samples
  • Improve product quality
  • Process optimization and troubleshooting
Module 2 Products (left to right): Ferric Hydroxide (may be calcined to ferric oxide), Precipitated Silica, Precipitated Calcium Carbonate, Aluminum Hydroxide, Magnesium Hydroxide, and Calcium Hydroxide.

Module 2 has been demonstrated on a batch scale with repeatability and economic optimization. Sufficient samples have been produced for market testing and additional process options have been developed to further improve the quality of products as required. Options to reduce reagent costs are abundant and are being investigated thoroughly.

Elixsys has the flexibility of producing hydroxides, oxides, or carbonates depending on the marketing needs.

Intellectual Property

Elixsys has created an innovative, modular process approach to the mineral and metals separation/extraction business. Our novel sequencing and trade secret chemical recipes transform proven chemistry into stable and repeatable quick extraction results.