L. TANG, KBR, Houston, Texas
The energy transition, reshoring efforts and rapid growth in emerging markets are driving the demand for new materials that must be produced efficiently and cost-effectively. Increased demand for energy-efficient chemical intermediates used in diverse sectors such as automotive industries, medical devices, low-emissions paints and supplies for renewable energy are creating vast opportunities across fast-growing industries.
This shift has significantly impacted the acetic acid market, which has witnessed remarkable growth in recent years. With the market expanding from $10.19 B in 2015 to $13.81 B in 2023, experts forecast the global acetic market to have a compound annual growth rate (CAGR) of approximately 7% from 2023 to 2030.1
A growing market with untapped potential. Acetic acid is a key ingredient across industries such as construction, pharmaceuticals, automotive and textiles. The global demand for acetic acid is approximately 16 MMtpy.2
Emerging sustainable applications (e.g., biofuels, bio-based plastics, bio-medical innovations) are further accelerating acetic acid’s market growth. These new opportunities are complemented by the existing role of acetic acid use in traditional markets, producing derivatives like vinyl acetate, acetic anhydride, ethyl acetate and others (FIG. 1).
Pioneering innovation in acetic acid production. The author’s company’s proprietary acetic acid production technologya leads the way in acetic acid production through methanol carbonylation, utilizing a highly stable, proprietary heterogenous catalyst. This process maximizes catalyst efficiency while the proprietary reactor design prevents catalyst loss from the process, thereby minimizing operating costs.
The acetic acid processa (FIG. 2) comprises a unique bubble column reaction section to produce crude acetic acid, a recovery section to maximize acetic acid yield and a simplified product purification section.
This carbonylation reactor utilizes a three-phase bubble column system, allowing high selectivity and improved catalyst activity. First, fresh methanol scrubs the reactor offgases to recover any entrained acetic acid before being charged to the bottom of the bubble-column reactor. Carbon monoxide (CO) is sparged into the bottom, and the solid catalyst is contained within the reactor.
The reactor effluent liquid is withdrawn, and the crude acetic acid is sent to the purification section to recover water, light components—which are recycled—and heavy byproducts, which are routed to battery limits. Before it is routed to storage, the final acetic acid product is treated to remove the trace iodide components.
Flexibility in feedstock utilization. Methanol and CO—the raw materials for acetic acid production—constitute two key building blocks in the energy transition. The selection of the source of syngas for methanol and CO is highly dependent on specific considerations, such as environmental goals, economic feasibility and technological readiness.
The author’s company’s acetic acid processa offers flexibility in feedstock utilization, allowing it to process conventional feedstock, methanol and CO derived from natural gas or coal, blue feedstock derived from carbon dioxide (CO2) and green feedstock, such as biogas and e-methanol. The conventional feedstock has an established infrastructure, comparatively low cost and reliable supply for many regions.
However, recent environmental regulations and the implementation of carbon credits across regions have provided incentives to move towards sustainable feedstocks, paving the path for CO2 to value-added chemicals, such as acetic acid. For instance, the industry in the European Union is increasigly steering towards CO2 utilization.
Putting CO2 to use. New pathways to utilize CO2 in the production of fuels, chemicals and building materials have captured industry interest. Investments in carbon capture, utilization and storage (CCUS) are forecast to reach $135 B by 2034.3
As industries shift to a net-zero economy, CO2 will increasingly be sourced from biomass or directly from air. CO2 can serve as an alternative to fossil fuels in the production of chemicals such as plastics, fibers and synthetic rubber. Among the most technologically mature processes is the conversion of CO2 into methanol. Methanol can subsequently be converted into other carbon-containing high-value chemical intermediates used to manufacture plastics and aromatics in a range of sectors including health and hygiene, food production and processing. Acetic acid, derived from CO2, also finds application in products like vinyl paints, effectively sequestering carbon for extended periods.
Addressing catalyst challenges. For decades, methanol carbonylation has been the dominant technology to efficiently produce acetic acid at high yields. The carbonylation reaction mechanism involves a complex organometallic catalytic cycle taking place over a transition metal active catalyst.
Traditional methanol carbonylation processes rely on the solubility of the transition metal, which can only be maintained at one given oxidation state. Multiple factors within the reactive system can move the cycle towards changing the oxidation state of the expensive transition metal. Once the oxidation state moves away from the only soluble form, the transition metal precipitates and is no longer available to catalyze the main reaction.
A key factor that helps maintain the transition metal in active form is the presence of dissolved CO in the reactor solution. Given that traditional carbonylation reactors are continuously stirred tank reactors (CSTRs), CO-depleted zones are likely to form. Catalyst precipitation is a frequent operational reality that must be addressed via a constant make up of a catalyst salt, which has a price that is both high and volatile.
The author’s company’s acetic acid processa is a unique methanol carbonylation technology designed to overcome catalyst loss through two key features (FIG. 4):
A proprietary polymeric-based support to which the transition metal binds and its exposure to redox reaction is minimized, reducing the risk of precipitation.
A plug flow-type proprietary bubble column reactor that ensures even distribution of CO, eliminating depletion zones and extending catalyst life.
These unique features of the acetic acid processa can maintain a catalyst active charge for longer catalyst life with no costly or unplanned makeup required. After the operating cycle, > 95% of the transition metal is recoverable from the polymeric support for metal reclamation.
Furthermore, a hydrostatically-driven catalyst circulation loop allows for reaction heat recovery without the need of high-maintenance mechanical devices such as agitators with high differential pressure seals or slurry circulation pumps.
Maximizing synergies. The proprietary acetic acid processa integrates seamlessly with the author company’s broader technology portfolio, unlocking synergies in both upstream (with blue/green syngas and methanol) and downstream [with vinyl acetate monomer (VAM)] processes.
Green methanol. Green methanol, also known as e-methanol, has emerged as a promising alternative to traditional methanol used as a base chemical to produce acetic acid, formaldehyde and other goods. Therefore, fossil-based methanol can be readily replaced by e-methanol without impacting the existing downstream production infrastructure. The author’s company has developed an advanced e-methanol technologyb that utilizes biogenic CO2 and green hydrogen as primary feed components. Alternatively, this e-methanol technologyb can also process feedstock from biomass or municipal solid waste gasification.
VAM technology. The author’s company’s VAM technologyc is a safe and reliable process for the reaction of acetic acid with ethylene and oxygen, accounting for a long history of good operation and demonstrated catalyst performance. VAM is essential to produce polymeric films used in photovoltaic cells for solar panels, making it a critical component in the renewable energy sector. The demand for VAM is forecast to grow significantly as its applications in renewable energy expand.
Takeaways. In a volatile environment that will increasingly focus on building tangible assets to provide economic growth in multiple regions in a sustainable manner, the chemicals in the acetyl chain—anchored by acetic acid and VAM—will be in increasingly high demand for their role in many value-adding end use applications, including sustainable applications such as solar panels, low-volatile organic compound paints and more.
With a 7% CAGR by 2030 and beyond, acetic acid presents an investment choice with a favorable return. In that context, the author’s company’s acetic acid processa with highly selective catalyst and distinctive design is an asset that is highly adaptable to any methanol and CO feedstock source. Whether using conventional or renewably derived feedstock, methanol and CO, this proprietary acetic acid processa is an attractive choice in this volatile market, helping businesses in the upcoming era of energy transition and essential materials. HP
NOTES
KBR’s Acetica® technology
KBR’s PureMSM technology
KBR-CSCVAM technology
LITERATURE CITED
Research and Markets, “Acetic acid market size, share and trends analysis report 2023–2030: Growing demand for vinyl acetate monomer,” November 17, 2023, online: https://finance.yahoo.com/news/acetic-acid-market-size-share-065800522.html?guccounter=1&guce_referrer=aHR0cHM6Ly93d3cuYmluZy5jb20v&guce_referrer_sig=AQAAAD4qeMv5dSjz6_0i8h2xMy_3MooarYBVroqzJ8rttCQ83hmKcvnFiNmeUQrP7fyItNVQG0pjjmvP0g5HpnBOgFYvkfugK9hUKMKwLPda2efOPrHjLrrtbIDyY-CKJkWeE8vTEgTdV1pAkdkUzM9fuVHCVvXAbwhhHldM9Tq38Dck
S&P Global, Chemical Economics Handbook, September 2023, online: https://www.spglobal.com/commodityinsights/en/ci/products/chemical-economics-handbooks.html
Biniek, K., et al., “Global energy perspectives 2023: CCUs outlook,” McKinsey & Company, January 24, 2024, online: https://www.mckinsey.com/industries/oil-and-gas/our-insights/global-energy-perspective-2023-ccus-outlook
Lily Tang is the Director and Global Head of Essential Materials Technology for KBR. In her current role, she is responsible for technology development, business operations and global project execution for KBR’s Essential Materials portfolio, which includes both ethylene and propylene downstream applications.
With more than 20 yr of experience in the energy sector and sustainable process technologies, Tang has held various executive management and leadership roles. She has been with KBR for nearly 15 yr and has worked in areas such as process technology licensing, proprietary equipment, catalyst business development and product management, among others.
