Low emission hydrogen produced with non-fossil fuels is expected to be key in the efforts de-fossilizing hard-to-abate sectors. Water electrolysis based on fossil-free electricity is regarded as the most promising technology to fulfil the anticipated exponentially growing demand for low emissions hydrogen, however securing the power supply for production of electrolytic hydrogen could in many world-regions be challenging, mainly coupled to the required large expansion of power production and distribution.

Production of hydrogen via biomass gasification currently receives less attention but could be an important complement to electrolysis in many regions with available biomass resources. Biomass gasification possesses several beneficial characteristics such non-intermittent and fossil-free hydrogen production in a wide capacity range. The technology leads to many process integration opportunities, for example with water electrolysers since electrolysers generate significant amounts of oxygen, which potentially can be used as gasification media. Also, low temperature excess heat from electrolysers can be utilized for feedstock drying etc. This paves the way for more cost-efficient hydrogen production systems. One of the most prominent technology features is that the CO2 separation process is an integral part of the gasification system, which means that negative CO2-emissions can be obtained if carbon storage (CCS) is applied. LCA-studies show that combined with CCS, the greenhouse gas emission for hydrogen produced via biomass gasification may be as low as in the range of -15 to -22 kg CO2eq per kg produced hydrogen.

The main aim of this report is to describe different biomass gasification technologies suitable for hydrogen production and to provide information of on-going commercial initiatives. The report also aims at identifying potential techno-economic opportunities and challenges as well as knowledge gaps to better understand its potential future role and need of further development.

The hydrogen yield from biomass gasification varies depending on feedstock and process conditions, but an approximate value is about 100 kg of hydrogen per ton dry biomass. The energy efficiency also varies depending on process design but is normally in the range of 40-70% (based on the lower heating value).

The Technology Readiness Level (TRL) of biomass gasification for hydrogen production is estimated to be in the 5 to 7 range depending on assessment methodology. All the main sub-processes of the conversion have a high technological maturity, but there is a need to demonstrate integrated operation of the complete hydrogen production chain in relevant scale to reach a higher TRL-score. Additional research is required to increase the knowledge on potential impurities, trace elements and their possible effects on for example fuel cells. This could serve as valuable inputs to updated ISO standards where biomass gasification-based hydrogen should be included.

It is estimated that the current production cost for a large-scale gasification plant (200 MW) would be approximately 4 € per kg hydrogen at a biomass price of 20 € per MWh. With potential process improvements and utilisation of CCS, the production cost could reduce to below 3 € per kg hydrogen at the same biomass price. With the current price levels of fossil methane in Europe, these cost levels are comparable to hydrogen produced via steam methane reforming. It is also shown that the cost levels are competitive to future foreseen production cost of renewable hydrogen produced via solar- and wind-based electrolysis in many world regions.

The report concludes that biomass gasification is an economical and environmentally beneficial technology well suited for producing climate-positive hydrogen. It is highly likely that negative carbon emissions will be essential to reach climate targets and hydrogen produced via biomass gasification is one of few hydrogen production pathways that can result in negative emissions.  

Over the duration of the IEA Bioenergy triennium 2022 to 2024, a consortium of IEA Bioenergy Tasks – 32, 33, 34, 36, 37, 39, 40, 42, 44 and 45 – collaborated on an inter-task project called Synergies of green hydrogen and biobased value chains deployment. Hydrogen is a very cross-cutting topic and the strategic inter-task project is a collaborative effort of the IEA Bioenergy TCP Tasks and also in collaboration with the Hydrogen TCP.The objective of the project was to identify and assess technologies for producing hydrogen from biomass as well as synergies in the deployment of green hydrogen and biobased value chains that can enhance the use of biobased value chains in the energy system.In the report on hand opportunities for adding renewable hydrogen to biobased value chains are presented and discussed. In principle, renewable hydrogen integration into biobased value chains can be done to 1) replace conventional, fossil hydrogen use, 2) upgrade the quality of biobased products, or 3) produce (additional) biobased products and by-products. The options differ in the degree of technological and process adaptation and development required. Adding renewable hydrogen vividly shows the potential synergies between renewable hydrogen and biobased value chains that can create various benefits.The description and discussion of potential technologies and concepts - including 1) technology readiness and economic fundamentals and 2) climate effects and role in the energy system - are done through case studies. This serves to increase visibility and share state-of-the-art knowledge of promising applications.From the various case studies the following insights can be gained. One obvious advantage for biobased value chains is the integration of methanation (or generally PtX) into the process without the need to separately capture CO2, thus saving CAPEX and OPEX cost related to the provision of (relatively) clean CO2. Further on, CO2 capture could be beneficial either through efficient process integration and/or due to high CO2 concentrations in the offgases when compared to CO2 captured from air or sea water. While these are general benefits from the integration of CO2 activation in biobased value chains, ultimate cost of available CO2 will always be determined by additional factors such as e.g. cost of electricity, scale of realization, local infrastructure, contaminants in the offgas etc.

Over the duration of the IEA Bioenergy triennium 2022 to 2024, a consortium of IEA Bioenergy Tasks – 32, 33, 34, 36, 37, 39, 40, 42, 44 and 45 – collaborated on an inter-task project called Synergies of green hydrogen and biobased value chains deployment. Hydrogen is a very crosscutting topic and the strategic inter-task project is a collaborative effort of the IEA Bioenergy TCP Tasks and also in collaboration with the Hydrogen TCP.  The objective of the project was to identify and assess technologies for producing hydrogen from biomass as well as synergies in the deployment of renewable hydrogen and biobased value chains that can enhance the use of biobased value chains in the energy system.  The descriptions of technologies and concepts - including 1) technology readiness and economic fundamentals and 2) climate effects and role in the energy system - are done through case studies. This serves to increase the visibility of the topic area of biomass and hydrogen as well as to share the state-of-the-art knowledge of promising applications.  In the report on hand considerations on the current and prospective role of biomass and hydrogen within the energy system and the climate effects for supporting the decarbonization of the energy system have been analyzed. With regards to energy system models, the objective was to understand to what degree renewable hydrogen and in particular biohydrogen value chains are integrated into these models and roadmaps, and what systemic benefits they are anticipated to offer. The key outputs are an overview of the current and prospective role of these value chains in energy system models summarizing the status and future needs and expectations. From the overview on different energy system models, it can be learnt that the production and use of biohydrogen is not foreseen within the majority of projections. In some cases, the role of biohydrogen is small even in the most optimistic scenarios. The provision of renewable hydrogen is thus far entirely considered via electrolysis from VRE sources. Moreover, climate effects assessment studies of selected biohydrogen and hydrogen in biobased processes, recognizing methodological questions and the main factors influencing the GHG balance calculations of the studied value chain concepts have been conducted.  All the biobased systems outperformed their fossil counterparts regarding the impact category Global Warming Potential (GWP), but were rather performing poorly in the impact categories terrestrial acidification (TA), and freshwater eutrophication (FE). The electricity-mix is one dominant parameter that significantly influenced the environmental performance of the biomass systems. Hence, although biomass integrations with renewable hydrogen or e-fuels may be attractive from product yields and diversification perspectives, less resource-intensive green electricity supplies will be critical for their satisfactory holistic environmental performance. The overall findings suggest that, regardless of the region, the biobased systems may play a vital role in reducing carbon emissions in the energy sector. With focus on the biohydrogen value chain relative to the GWP and FE, the biochar credit (i.e., pulverized coal displacement) is a key deciding factor regarding the best-performing biohydrogen route. Regarding fossil-based hydrogen replacement results show, that biohydrogen is a superior choice to PEM hydrogen from an environmental viewpoint. Relative to fossil-based hydrogen, the studied biohydrogen systems could lead to substantial reductions in GWP. Therefore, process energy efficiency enhancements and sustainable green electricity supplies are essential for the holistic environmental success of the biohydrogen systems. 

Combining CO2 electrochemical reduction (CO2R) and biomass gasification for producing methanol (CH3OH) is a promising option to increase the carbon efficiency, reduce total production cost (TPC), and realize the utilization of byproducts of CO2R system, but its viability has not been studied. In this work, systematic techno-economic assessments for the processes that combined CO2R to produce CO/syngas/CH3OH with biomass gasification were conducted and compared to stand-alone biomass gasification and CO2R processes, to identify the benefits and analyze the commercialization potential of different pathways under current and future conditions. The results demonstrated that the process that combined biomass gasification with CO2R to CO represents a viable pathway with a competitive TPC of 0.39 €/kg-CH3OH under the current condition. For all the combined cases, electricity usage for CO2R accounts for 36–76% of total operating cost, which plays a key role for TPC. Sensitivity analysis confirmed that the process that combined biomass gasification with CO2R to CO is sensitive to the price of electricity, while both CO2R performance and prices of stack and electricity are important for the processes that combined with CO2R to syngas/CH3OH.

Electrochemical reduction of CO2 removed from biosyngas into value-added methanol (CH3OH) provides an attractive way to mitigate climate change, realize CO2 utilization, and improve the overall process efficiency of biomass gasification. However, the economic and environmental feasibilities of this technology are still unclear. In this work, economic and environmental assessments for the stand-alone CO2 electrochemical reduction (CO2R) toward CH3OH with ionic liquid as the electrolyte and the integrated process that combined CO2R with biomass gasification were conducted systematically to identify key economic drivers and provide technological indexes to be competitive. The results demonstrated that costs of investment associated with CO2R and electricity are the main contributors to the total production cost (TPC). Integration of CO2R with CO2 capture/purification and biomass gasification could decrease TPC by 28%-66% under the current and future conditions, highlighting the importance of process integration. Energy and environmental assessment revealed that the energy for CO2R dominated the main energy usage and CO2 emissions, and additionally, the energy structure has a great influence on environmental feasibility. All scenarios could provide climate benefits over the conventional coal-to-CH3OH process if renewable sources are used for electricity generation.

In the endeavour to reduce CO₂ emissions from the transport sector, biofuels from forest industry by-products are key. The adaptation of forest-based biorefinery technologies has so far been low which can partly be attributed to uncertainties in the form of policy instability, market prices, and technology costs. These uncertainties in combination with technology learning, which can be expected to reduce future investment costs, could make it favourable to postpone an investment decision. When applying real options theory, it is recognised that there is an opportunity cost associated with the decision to invest, since the option to wait for more favourable market conditions to occur is forfeited. In traditional discounted cash flow analysis, the impact of uncertainty and the value of reducing it (e.g. by waiting), is usually not taken into consideration. This paper uses a real options framework that incorporates the option to postpone an investment to reduce market uncertainties and wait for technology learning to occur. The focus is to investigate how the usage of an investment decision rule based on real options analysis affects technology choice, the economic performance, and when in time it is favourable to invest in pulp mill integrated biofuel production, compared with using a decision rule based on traditional discounted cash flow analysis. As an illustrative case study we examine a pulp mill which has the option, but not the obligation, to invest in either of two different biofuel production technologies that both use the pulp mill by-product black liquor as feedstock: (1) black liquor gasification followed by fuel synthesis, and (2) membrane separation of lignin followed by hydrodeoxygenation. With the usage of the real options framework and the inclusion of the uncertainties regarding future market prices and investment costs, the decision to invest is made later, compared with using traditional cash flow analysis. The usage of real options also reduces the likeliness of a net loss occurring if an investment is made, as well as increases the expected economic returns, showing the added economic value of flexibility in the face of uncertain future conditions.