Transforming waste into a resource

Mario Marchionna, Saipem SpA, Italy, outlines a selection of sustainable solutions that can be utilised to optimise waste management.

Technology innovation, one of Saipem’s strategic pillars, is a key lever to drive the company faster towards novel and fully decarbonised energies. Saipem acts as an innovative global solutions provider to the energy industry, which means the company provides varied tools to its clients to solve their complex problems, in particular those presented by the energy transition. It is a real mutation process along with all the actors of the energy sector that are accelerating on the transition whilst simultaneously reducing the weight of their traditional business.

In this respect, selective technology access is decisive to allow the company to offer the most competitive solutions.

Saipem is pursuing several diversified actions with a strategy that reflects four main pillars, along with natural gas that is the cleanest and least carbon dioxide-emitting fossil source and will continue to play a relevant role in the energy transition, especially in the short- to mid-term. The main pillars include the following:

F Renewables: offshore renewable energies are particularly relevant for Saipem, especially offshore wind and floating solar parks. Their systemic integration is decisive, also through the production of hydrogen that could act as an energy source capable of providing greater independence from the intermittent nature of most of renewables.

F Decarbonisation of carbon-intensive industries: energy still produced from fossil fuels but the related climate-impacting emissions are significantly reduced. This may impact not only the oil and gas downstream industry but also other carbon-intensive and energy-intensive industries (i.e. steel, cement, and waste treatment).

F Biomass conversion and circular economy: embracing new models that create value and safeguard the environment by improving the management of resources, eliminating waste through better design, and maximising the circulation of products.

F Hydrogen: it can fill an important role as a totally decarbonised gas that could progressively substitute natural gas.

It is evident that the four areas are tightly interconnected, thus cases of overlap among them can be frequently encountered.

The different targets are pursued through a mix of efforts with different maturity: innovation activities aimed at intercepting new and potentially disruptive technologies and related markets (scouting activities are continuously underway to identify potential

partners with whom Saipem can co-operate); technologypushed business development efforts aimed at helping clients to re-design their carbon footprint; and already structured commercial projects where the innovative approaches find full exploitation.

As a consequence of this approach, Saipem has identified specific opportunities for providing cutting-edge, sustainable solutions that will help the company’s clients meet the demand for a low-carbon future. These opportunities are mapped over a timeline that starts with Saipem’s current operations (projects that may be awarded over three years) and runs into the mid- and the long-term (Figure 1).

Circular economy and waste management

Embracing new models that create value and safeguard the environment by improving the management of resources, eliminating waste through a better design, and maximising the circulation of the products, is one of the pillars of Saipem’s strategy towards a more extensive decarbonisation.

Technology is a key enabler to all four elements of a circular economy – i.e. reduce, reuse, recycle, and remove – and the development of solutions to sustainably treat any kind of waste produced by urban, commercial, and industrial activities (oil and gas, petrochemical, cement, iron and steel, pulp and paper, etc.), with their consequent valorisation to energy and/or valuable products, is becoming an important asset.

Saipem has already gained significant experience in the field of power generation and this has matured over the years. In terms of power generation, this is related to both gasification of oil residues and the treatment of different types of waste – such as industrial, toxic, hazardous, and municipal. Moreover, a floating waste to fuel project was also conceptualised and engineered at the start of the last decade.

The company also has a strong interest in plastic recycling, with the disposal and recycling of plastic wastes key topics for which a comprehensive solution needs to be found and developed soon. With plastic recycling, a potential new and important market is growing but many challenges need to be faced.

As a major international contractor, Saipem has started the analysis, planning, and implementation of plastic recycling projects. Several very diverse stakeholders are involved, including plastic producers, waste sorters and transporters, municipalities, etc., and it is important to realise the contribution expected from each of them as well as the state-of-the-art nature of this developing business with its different possible operating models (Figure 2). There is no one-solution-fits-all approach and there is a great need for players who can have a holistic, high-level vision to the problem while maintaining the ability to implement specific projects tailored to regional situations with specific operating and financial constraints.

In this respect, and in the frame of Saipem’s Innovation Factory activities, the company has performed structured interviews with several stakeholders in order to better realise the different viewpoints so as to further refine its understanding of the matter.

As an ambitious final target, Saipem envisages a modular facility that could bring together the different technologies to treat all type of plastics in one location, to produce new plastic, chemicals, power, and steam to ensure the circularity of plastics. The facility will seek the highest energy efficiency possible and will capture CO2. With this aim in mind, the company is investigating several technology options in order to develop different solutions to be flexibly deployed according to the specific situations. Among them include the following: clean combustion with CO2

Figure 1. Empowering the energy transition through technology innovation. Towards decarbonisation: Saipem’s roadmap.

Figure 2. Plastic waste treatment: from collection to final use. recycled (also managing the CO2 issue strictly linked to waste management); gasification to produce syngas to be converted to chemicals; and pyrolysis with product recycled to the steam cracker in order to produce the olefins monomers which can make plastics production by polymerisation possible.

Waste-to-energy/products

In the aforementioned context, it is worth mentioning the License Agreement with ITEA (a company of the Sofinter Group) to produce, through ITEA’s proprietary ISOTHERM Pwr® flameless oxy-combustion technology, steam, electricity, and pure CO2 by flexible

use of low-ranking fuels such as waste, heavy oils, petcoke, and several other feedstocks. The agreement gives Saipem access to the technology for several applications, allowing the company to offer original and circular sustainable solutions to its clients.

A typical example is represented by the use of waste streams as feedstock to generate energy and valuable chemical products such as urea or methanol, but also for the optimisation of the hydrogen value chain.

Since 2017, Saipem has investigated applications of the ITEA technology for the urea plant value chain – CO2 can be efficiently produced by using waste streams, with an additional overall energy production. This innovative concept allows synergies within an industrial complex and decreases its carbon footprint.

With similar principles, ITEA technology may be used to produce CO2 for methanol plants and other refinery products, helping with the decarbonisation of the petroleum industry.

Figure 3. A typical example of plastic waste.

Plastic waste treatment

The ITEA oxy-combustion technology is also being investigated with the aim of studying new processes for the disposal of plastic waste that is difficult to recycle, such as plastic scraps (called Plasmix in the Italian market), and the integration of this step in a broader process with CO2 capture and possibly reutilisation.

Until recently, plastic recycling from differentiated waste has been rather limited. In fact, according to recent studies, only 30% of material collected is recycled, leaving the problem of Plasmix (non-recyclable mixed plastics consisting of a group of heterogeneous plastics included in post-consumption wrappings which cannot be recovered as single polymers) unsolved. In Europe, most of these plastic scraps are thrown away and lost; gate fees are very high for non-recyclable mixed plastics sent to energy recovery plants in some European areas (e.g. Italy, where this type of waste amounts to more than 500 000 tpy).

Among the several opportunities to better exploit it, Saipem has examined the possibility of coupling its experience in ITEA technology to produce water, energy, and pure CO2 that can be also opportunistically sold to the market under particular situations, without directly emitting to the atmosphere (Figure 4). To put this into perspective, the process will allow for the amount of reused material to be increased; furthermore, it is very flexible, relatively simple, and is able to be exploited in plants with reduced dimensions. Another advantage of the technology is that it provides the opportunity to process Plasmix along with sewage sludge deriving from wastewater treatment – a material which is difficult to dispose of at present.

Saipem has experimentally verified the ‘slurryfication’ capability on different samples of mixed plastic waste in order to allow a homogeneous feeding to the oxy-combustion reactor. Technical-economic feasibility studies are underway

Figure 4. Novel technologies for plastic scraps conversion: Oxycombustion.

together with a comparison with other potential technologies for the treatment of this feedstock.

The slurryfication process is now being scaled up in collaboration with Corepla, an Italian national consortium, for the collection, recovery, and recycling of plastic packaging waste. The next steps will be about experimentally demonstrating the concept on a significant scale (approximately 5 MWth) and examining different CO2 conversion technologies for integration in the overall scheme.

In addition to the oxy-combustion, other approaches to plastic recycling are currently under careful investigation in order to directly recycle the product of plastic waste treating to an olefins-producing unit or to fuels production units.

In this respect, Saipem has an agreement with a technology provider in order to co-develop a pressurised gasification technology to produce syngas from waste.

As regards to pyrolysis technologies, Saipem has recently entered into an agreement with Corepla and Quantafuel, a Norwegian technology provider, to jointly promote circular economy models for plastic waste, and to seek building chemical recycling plants throughout Italy.

Work is in progress and Saipem is confident that its cuttingedge and robust EPC experience will be able to close the loop of waste plastic recycling and conversion, in a holistic fashion, by creating the right connection between the waste recycling world with the chemical (oil and gas) one.