/Companies

sublime

Boston, US · Founded 2020 · 67 employees on LinkedIn · 14 known investors

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Sublime Systems develops an energy-saving, carbon-reducing process for manufacturing cement from previously inaccessible minerals. The company serves the cement and construction industries seeking sustainable production methods.

Also known as Sublime Systems

Founders & leadership

sublime was founded in 2020 by Leah Ellis and Yet-Ming Chiang.

LELeah Ellis
Leah EllisFounderShe led Sublime Systems as chief executive from 2020 to 2025 and now works as a rapid evaluator at X, The Moonshot Factory, assessing early-stage technology projects. Her research background includes a Banting Postdoctoral Fellowship at MIT, along with earlier stints as a research associate at E-One Moli Energy in Canada and an internship at Tesla Motors.
YCYet-Ming Chiang
Yet-Ming ChiangFounderYet-Ming Chiang is a materials science professor at MIT with over 300 scientific publications and 100+ U.S. patents, focusing on advanced materials for energy technologies; he has co-founded multiple companies commercializing technologies from his research, including Sublime Systems, Form Energy, 24M Technologies, A123 Systems, American Superconductor Corporation, and Desktop Metal.
RDRob Davies
Rob DaviesChief Executive Officer

Board

KRKatie Rae
Katie RaeBoard MemberCEO and Managing Partner at The Engine Ventures
JWJohanna Wolfson
Johanna WolfsonBoard Member2020–2023Co-Founder and General Partner at Azolla Ventures

Investors · 14

Also in the syndicate · 3

CRHHolcimSiam Cement Group

Funding

SEC filings, press & company announcements

$5.9M disclosed across 1 of 3 rounds · 2021–2024

▶$5.9MraisedMay 2021 · 6 investors · Other
Rule 506(b)
Officers, directors & promoters on the filing
  • Yet-Ming ChiangExecutive Officer, Director
  • Katie RaeDirector
  • Johanna WolfsonDirector
  • Leah EllisExecutive Officer, Director
Offering amount
$5.9M
Amount sold
$5.9M
First sale
Apr 2021
Incorporated
Corporation, Delaware, 2020
Federal exemptions
06b
Full filing on SEC EDGAR ↗

Source: SEC EDGAR Form D. Amounts as filed; amended filings shown once at their latest values.

Company profile

researched Aug 2026

Sublime Systems develops a manufacturing process for cement that replaces the kiln, the most energy-intensive step in ordinary portland cement (OPC) production, with a targeted electrochemical process operating at ambient temperature. The company states this reduces the energy intensity of production by 30-40% and avoids emissions of CO2, CO, NOx, SOx, mercury and particulates associated with conventional production.

The process is designed to convert a wide range of feedstocks, including low-value rocks and toxic industrial solid waste, into cement while co-producing pure streams containing critical minerals. The company contrasts this with conventional manufacturing, where it says roughly 50% of limestone feedstock is lost as pollution and up to 40% of energy is lost. Its product, marketed as Sublime Cement, is presented as a replacement for OPC in concrete, and is described as more durable across most use cases, based on a Roman cement recipe, and whiter in color, a property linked to aesthetics, heat reflectivity and reduction of the urban heat island effect.

Business model

Sublime Systems manufactures and sells cement as a drop-in replacement for ordinary portland cement in concrete, and co-produces critical mineral streams from its process. It works with cement manufacturers, contractors and ready-mix concrete producers, and counts building materials and construction companies among its financial backers.

Traction

The company states it scaled from grams to tonnes within three years, has been deploying cement in real-world projects since 2023, and is building a kiloton-scale plant intended to enable future megaton-scale manufacturing. It is actively hiring.

Latest developments

Sublime Systems is scaling production, constructing a kiloton-scale plant as a step toward megaton-scale manufacturing, and expanding its team.

▸Full profile — market position, technology, go-to-market, geography

Market position

Positioned as a producer of a next-generation replacement for ordinary portland cement, backed by building materials and construction companies including Holcim, CRH, Siam Cement Group and Suffolk Construction, and framed as part of a US-based reinvention of cement manufacturing.

Kiln-free, ambient-temperature electrochemical production; feedstock flexibility including industrial solid waste; co-production of critical minerals; claimed higher durability than OPC; whiter cement color; and grid-flexible operation.

Technology

An electrochemical, ambient-temperature cement manufacturing process that eliminates the kiln used in OPC production. The company reports 30-40% lower energy intensity, the ability to ramp production up and down to integrate with a modern electricity grid, avoidance of CO2, CO, NOx, SOx, mercury and particulate emissions, and the ability to process almost any rock, including toxic industrial solid waste, into cement plus pure minerals. The resulting cement is described as more durable than OPC in most use cases and whiter in color due to the inherently purifying process.

Go-to-market

The company tests and validates its cement to gain acceptance from large cement manufacturers, architects, general contractors and ready-mix concrete leaders, and partners with building materials and construction firms that are also investors. It has deployed cement in real-world projects since 2023.

Cement manufacturers, technology hyperscalers, architects, general contractors and ready-mix concrete producers, as well as owners of projects in high-polish interiors and harsh exterior environments where durability, aesthetics and urban heat island reduction matter, and customers seeking to reduce the carbon footprint of construction materials.

Geography

Headquartered in the United States, with an emphasis on domestic US manufacturing and supply chains.

Compiled by commissioned research from 1 cited public sources — announcements, filings, and press listed under research sources below.

Key figures

latest reported
Energy lost in conventional cement productionJan 202540%
Feedstock lost in conventional cement productionJan 202550%
Reduction in energy intensity of production vs. conventional cementJan 202530%-40%

Company-reported or press-reported figures, each dated to when it was claimed — not independently audited.

Founder mafia

2 people who came through sublime went on to found or lead other companies.

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In the news

▸Research sources · 1

primary sources listed

1 public sources were cited for this profile; the first-party ones are listed here.

Frequently asked questions

What does sublime do?
Sublime Systems makes cement via an electrochemical, kiln-free process that also co-produces critical minerals.
Who founded sublime?
sublime was founded by Leah Ellis, Yet-Ming Chiang in 2020.
Who are sublime's investors?
sublime's investors include Azolla Ventures, Congruent Ventures, CRH Ventures, Energy Impact Partners, Khosla Ventures, Lowercarbon Capital, Prime Impact Fund, Steel Atlas and 3 more.
How much funding has sublime raised?
sublime has disclosed $5.9M raised across 1 of its 3 known rounds.
Where is sublime headquartered?
sublime is headquartered in Boston, US.