Project GAYA passes historic milestone
In France, ENGIE has revealed that its GAYA project semi-industrial Research & Development platform took a historic step forward in November 2020, when it produced renewable natural gas (RNG) from solid recovered fuel (SRF).
Et Quoi? One can be forgiven for putting the headline down to media hype as there have been numerous biomass and waste gasiﬁcation projects, both failed and successful ones.
In short, the big deal with ENGIE’s GAYA project is demonstrably being able to gasify dry (≈20 percent moisture content) biomass or SRF, clean the synthesis gas (syngas), convert it catalytically into biomethane (aka renewable natural gas – RNG), upgrade and condition the RNG for injection into the (French) gas grid.
All at a semi-industrial scale, and as a continuous high yield process – 1 tonne of dry feedstock yields ≈600 Nm3 of biomethane as well as heat.
ENGIE has deliberately taken its time with the GAYA project. Located in the heart of Lyon’s “Chemical Valley” in Saint-Fons, south of Lyon itself, the GAYA project was launched in 2010.
Coordinated and led by ENGIE, a considerable EUR 47 million budget was allocated at the launch which included some EUR 18.7 million in support from the French Agency for Environment and Energy Management (ADEME). The total (2019) investment is up at EUR 60 million.
It transpires that Lyon’s Chemical Valley is a major European energy and chemical industry hub and is the “cradle” of the French chemical industry sector reputedly accounting for some 25 percent of all R&D in France.
A global energy provider like ENGIE has of course several reasons for initiating and leading a project like GAYA, pushing its knowhow and role in the circular economy and increasing the share of renewables in its energy mix.
Green gas a driver
A key driver though is the 2015 Energy Transition Act that amongst other things sets a target of 10 percent green gas in the French national grid by 2030. In energy terms around 30 TWh per annum. In addition, the Act targets a 50 percent reduction in the quantity of waste going to landﬁll by 2025 compared with 2010.
Technology and economy
Fundamentally a scientiﬁc and technical research and development project to remove the main technical barriers from the process of converting dry biomass-to-gas, GAYA is unique in its ultimate aim of developing a sustainable and competitive industrial concept that includes the supply chain.
Unlike other, higher-capacity biomass supply chains, GAYA aims to meet smaller-scale, decentralized needs from a few dozen megawatt-hours (MWh), in order to use local biomass deposits, reduce transport, and minimize the carbon footprint.
This approach is well reﬂected in the ten research partners and value-chain stakeholders that ENGIE has in the project.
The idea is to make the supply chain competitive with other renewables and thereby encourage its local development. Creating a network of SMEs and non-outsourceable jobs is a key priority, said Alessandra Barba.
According to her, this multi-criteria methodology makes it possible to assess any impact on the greenhouse gas (GHG) eﬀect and on the consumption of water, electricity, and other resources.
Furthermore, it has helped to orient R&D decisions in order to develop a technology that supports optimum environmental balance while at the same time identify other possible barriers to commercial adoption.
Selecting, developing, and verifying each and every aspect of the core process technologies is one aspect but from the very start, GAYA has included a global life-cycle assessment to evaluate every environmental impact of the value-chain – from aggregating the raw material to the end of life of the biomethane – taking in every phase of conversion and distribution along the way. For instance, the most appropriate and least costly biomass mix including SRF, ﬂexibility of the gasiﬁcation reactor to avoid restricting plant capacity, and the recycling of any heat produced in the process, explained Alessandra Barba.
For France, and indeed many other countries, the absence of dedicated recycling channels for non-hazardous waste such as wood, paper, cardboard, and plastic opens for the production of solid recovered fuels (SRF), diverting these materials from landﬁll while adding a distributed energy recovery value in the form of biomethane and heat.
The demonstrator in Saint-Fons was inaugurated in October 2017, and the ﬁrst injection of biomass into the gasiﬁer and production of puriﬁed synthesis gas took place in November 2018, while the ﬁrst production of biomethane from forest biomass a year later in November 2019.
This latest mile-stone a year later saw biomethane produced from SRF.
The reason it seems such a long time from when the plant was built to actually producing biomethane is that each and every aspect of the key process technologies have been tested and veriﬁed, ﬁrst individually and then step-by-step together, explained Alessandra Barba.
At Saint Fons, the plant is divided into four process zones – feedstock preparation, gasiﬁcation, methanation, and gas upgrading. The biomass or SRF arrives at the receiving area, unloaded, and stored in one of three on-site storage bunkers. The feedstock is screened for oversize and contaminants.
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GAYA Project Partners
The partners include Renewable Power Technologies Umwelttechnik GmbH (Repotec), French Forestry Cooperative Association (UCFF), LGC Ensiacet Chemical Engineering Laboratory Toulouse (a Paul Sabatier University and the Toulouse Institut National Polytechnique partnership), LRGP – Process Reaction and Engineering Laboratory, Lille Solid Catalysis and Chemistry Unit (UCCS), RAPSODEE Center at the Albi-Carmaux Ecole des Mines, French Atomic
Energy and Alternative Energy Commission (CEA), International Cooperative Agronomic Research Center for Development (CIRAD), Grenoble Technical Center for the Paper, Cardboard, and Cellulose Industry (CTP), French Technological Institute for Forestry, Cellulose, Construction Timber and Furnishings (FCBA), and TENERRDIS Energy Cluster.