Innovative carbon capture technology: Q&A with Josh Dalby

At COP26, as representatives from governments and global organisations discussed some of the potential solutions to address climate change, we heard a lot of discussion about approaches to decarbonise energy, including carbon capture technology. Here, Josh Dalby, Chief Engineer on the project tells us more about the project and the technology.

Ricardo and Bluebox Energy are developing innovative carbon capture, utilisation and storage technology to remove greenhouse gases and provide local communities with renewable heat and electricity, and by-products for farming and green construction.

Josh Dalby: “The technology takes sustainably sourced waste wood from timber production and feeds it into the plant. The pyrolysis process turns the biomass feedstock into biochar – a stable, carbon rich material similar to charcoal - and syngas. The hydrogen rich syngas is burnt in a combustor, supplying heat to drive the hot air turbine. The hot air turbine generates electricity and large amounts of clean hot air which is used to power the advanced CO₂ capture system, capturing the carbon dioxide from the flue gas, while producing hot water for on-site use or for district heating.”

“What makes our solution unique is its ability to generate enough energy from its renewable and dependable biomass fuel source, to be energy positive while capturing so much CO₂. This means that in addition to the removal of the carbon dioxide from the flue gas and its capture and storage as a commercial product, the technology will also supply local homes and business with renewable heat and electricity.”

Q: How effective is it at capturing CO₂?

Josh Dalby: “Around 50% of the carbon in the waste material is captured in the biochar resulting from the pyrolysis process. The remaining carbon in the feedstock is released as carbon dioxide in the flue gas coming out of the combustor. Around 90% of this remaining carbon can potentially be captured through a chemical absorption system which is driven by the heat and power generated by the turbine, giving an overall CO₂ capture efficiency of 95% and thus providing significant negative emission and greenhouse gas removal (GGR) potential in comparison to competitive technological solutions.”

Q: The biochar that is produced, what can it be used for?

Josh Dalby: “The biochar (similar to charcoal) from the system can be used by farmers, anaerobic digester operators and wastewater treatment sites. Biochar improves soil fertility, which means that it is much in demand in organic farming for soil enrichment. There has also been a marked increase in demand for biochar as a supplement to animal feed in livestock farming as it supresses methane emissions generated in the digestive process. In regions such as Europe and North America where meat consumption is still very high, the demand for biochar is therefore expected to continue to grow substantially in the future.”

“Given the benefits of carbon sequestration and water retention that biochar offers to the agriculture sector, leading to increased crop yield and productivity, analysts have predicted that the global biochar market size is estimated to reach USD 3.1billion by 2025 and is expected to expand at a compound annual growth rate of around 14% in the next decade.”

Q: What happens to the CO₂ that is captured?

Josh Dalby: “There are many potential uses for the CO₂ that is captured, although some are more sustainable than others. The largest global market for CO₂ is enhanced oil recovery but clearly the net carbon benefit of this is questionable. The food and drink industry represents the second largest market and given the fact that our system produces food-grade CO₂, this is a likely end-user. A potential drawback is that the carbon isn’t removed from the natural cycle for a long period, although given most food-grade CO₂ is produced ultimately by natural gas, there is still a net carbon saving. Longer term carbon stores for CO₂ are in the construction industry, in aggregate manufacture or concrete curing, where the carbon can be stored permanently. In many cases the use of CO₂ in such processes can also increase efficiency and productivity, so there are positive benefits to go along with the carbon capture.”

Q: You mentioned the system runs on waste wood, where is that sourced from?

Josh Dalby: “This is one of the key strengths of our technology. Many existing biomass cogeneration systems are powered by wood pellets, which require additional processing steps before they are suitable for use. These wood pellets are typically sourced from sustainable forestry operations with most UK distributors sourcing from either within the country or from Europe.”

“A key factor in ensuring the maximum amount of carbon capture is to minimise the life cycle or upstream emissions associated with the production and delivery of the feedstock. Because our technology can use un-processed waste-wood, it opens up the opportunities for local sourcing. As well as the sustainable forestry operations mentioned previously, sawmills and furniture factories could also provide sufficient woodchip to be suitable for our system. A further advantage of community-scale systems such as ours is that it can be located near the biomass source thus reducing life cycle impacts.”

Q: How did the collaboration come together?

Josh Dalby: “Our team at Ricardo has over 20 years’ experience in bioenergy and in CO₂ capture and utilisation technologies, advising UK and international government as well as technology and project developers and operators on carbon dioxide capture, utilisation and storage. We have undertaken many due diligence and feasibility studies for combined heat and power (CHP) and district heating sites exploring fuel switching to biomass with carbon capture and storage (BECCS). We are building upon and utilising our existing expertise to develop our innovative carbon capture system and deliver it to market.”

“Ricardo, in general, has a long history, spanning several decades, of delivering engineering solutions which address complex problems. We have particular expertise in innovating to make technology cleaner, more efficient and better performing. We’re drawing on our broad expertise and knowledge and applying engineering methods and tools developed from the automotive sector, including over 20 years’ experience working on waste heat recovery and thermodynamic system developments to engineer an innovative and efficient system for capturing carbon from waste.”

“Since 2014, Bluebox Energy have been developing ultra-low carbon combined heat and power solutions for business parks, communities, industrial and farming processes. During that time the company developed a new method to convert heat to electricity using its hot air turbine technology. Working with system integrators, Bluebox now has a number of facilities operating around the world including a biochar system in Switzerland. Working with Ricardo enables Bluebox Energy to take the next step in capturing the remainder of the carbon dioxide from the flue gas.”

“The benefit of our consortium is that it offers complementary expertise across the carbon capture ‘value chain’: from policy expertise to commercial strategy to technology innovation and implementation.”

Q: When can we expect to see the first deployment of this technology

Josh Dalby: “We have identified a site for our first demonstrator plant, with the aim of beginning planning permission discussions in the coming months. Subject to approval, our intention is to have the first plant running mid-2023.”

“Beyond the first demonstrator, this technology has the potential to be applied to communities all around the globe. By focusing on smaller community-scale applications, we can deploy our technology quickly and widely. We can operate closer to the source of waste, minimising the CO₂ related to the transportation of the raw materials. Additionally, each community can benefit from the by-products, and the potential for carbon credits – where regulation allows.”

“We expect the technology to be ready for wide scale market deployment by 2025 with applications in a wide range of sectors in the UK and worldwide. So, our technology will enable global communities to play an active role in reducing carbon emissions.”