The Catalyst Review March 2020 - 8

SPECIAL FEATURE
The concept for making chemicals in modular and small-scale units at a district level, is effectively at the opposite end of the
spectrum to coal and shale-gas fed "mega-methanol" and "mega-ammonia" plants. It is not so difficult to imagine. After all, many
people now order everything at the touch of a button, or by speaking to their domestic AI assistants, such as Amazon Alexa and
Google Siri. Clever local, modular-scale sustainable chemistry units operating CCP could respond to these orders at a reasonable
cost, creating just enough material to meet demand and delivered locally using renewably powered vehicles and drones to avoid
transportation CO2. It is not as far-fetched as it sounds. With the introduction of 5G and smart-meters already set to monitor demand
patterns for utility usage in much more detail; the ability to connect the home, the workplace and everything in between, and the
ability to move larger amounts of complex data around more quickly, keeping ahead of market demand is not such an issue. Delivery
drones and robots are here and now. The role they have played to date in the ongoing coronavirus outbreak in delivering food,
medicine and vital supplies to quarantined patients for instance has demonstrated their efficacy.
Challenging the notion of economies of scale from feedstock through to downstream consumer goods may be harder to imagine-
but it is possible. A combination of existing CRU processes, emerging modular chemical technology, additive manufacturing/3D
printing and Industry 4.0/Smart City technologies could make it happen. In fact, a range of start-ups are making considerable
progress in these areas. As example, Gefn in Iceland is developing a highly innovative approach to making modular chemicals ondemand with favourable process economics (Ívarsson 2019).
In this article we'll review existing CO2 utilization markets, the plethora of catalysts required for CO2 utilization, the carbon recovery
unit (CRU) technologies, opportunities it opens up and the strategies for implementation of CRU-CCP combinations in existing
manufacturing units. Several case studies will be set out and the most promising new investment opportunities highlighted.
CO2 Recovery Unit Technology
Decentralized CCP rely on several technologies; the first being CO2 recovery technology. CRU technology is mature and offered by
many companies globally. It is usually operated in a very short supply chain-with utilization situated near its point of production,
although it can also be transported as freight by road or ship. Some companies such as food and beverage producers like to keep
their own CO2 because they can guarantee its quality and so it is simply generated and cycled around through a CRU and back into
their production process only topping up as necessary. This is an example of a CRU-CCP process in action.
Large scale post-combustion capture (PCC) processes such as those being evaluated for future permanent carbon sequestration
have been developed by several providers. Technologies include: Mitsubishi Heavy Industry (MHI) with its KM-CDR Process™, Fluor's
Econamine FGPlusSM, Shell CanSolv and UOP Selexol. However, this article is aimed at smaller scale CRU of which many hundreds
are already in operation. That is not to say that these larger scale technologies are not employed at smaller scale. For instance,
Mitsubishi's KM-CDR Process™, which it developed in conjunction with Kansai Electric Power Company (KEPCO), employs solventbased absorption with MHIs KS-1™ solvent. The KM-CDR Process™ operates at the scales relevant to industrial micro-emitters (IME)
and to date this process has been installed in at least 13 plants globally. There are other providers at this scale, too. For instance,
Yara International has a process installed at its ammonia plants that uses water as a solvent and produces food grade CO2 for sale
to the market. From a catalyst market perspective, an increase in the number of these plants would boost demand for H2S removal
sorbents, VOC removal and drying molecular sieves. New technologies and providers are also entering this area. Some of the
technologies applied in different industrial plants are considered in the proceeding sections, along with the catalyst and sorbent
products employed within the units.
Biogas Upgrading/Food Grade CO2
Tecno Project Industriale (TPI) in Italy, now part of SIAD
group, offers CO2 and biogas upgrading plants. TPI provided
the CO2/biogas upgrading plant to the site of the Montello
Spa biodigester plant in Italy to simultaneously upgrade
biomethane and to produce food-grade CO2. The plant
processes up to 400,000 tons per year of biomass with a
treatment capacity of 6,250 m3 per hour of biogas. In this
process, the raw biogas undergoes a series of purifications
including water scrubbing, VOC removal, desulphurization and
polishing over activated carbon molecular sieves (SIAD 2017).
The refined biogas is then fed into a three-stage membrane
separation process at 13-16 bar (Figure 2). The process
uses long very fine (1.3 m x 0.5 mm) polyimide hollow fiber
membranes which are commercial SEPURAN modules from
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Figure 2. Three-stage CH4/CO2 membrane separation at the Montello digester
plant in Italy.

Source: Esposito et al. 2019.

The Catalyst Review

March 2020

The Catalyst Review March 2020

Table of Contents for the Digital Edition of The Catalyst Review March 2020