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Injecting New Life into Cellulosic Ethanol Production

Periodic Reporting for period 1 - NewLiEP (Injecting New Life into Cellulosic Ethanol Production)

Reporting period: 2019-08-01 to 2020-07-31

There is a growing need for sustainable liquid biofuels to be used in transportation sector to replace fossil fuels. Sustainable or advanced bioethanol is produced from renewable feedstock that is not part of the human food or animal feed value chain and has no indirect land use change impacts. The most promising feedstock for advanced bioethanol is lignocellulose from agricultural or forestry residues, but until recently, lignocellulosic bioethanol production has not been economically feasible. In this project NewLiEP a novel approach and concept of more efficient utilization and higher ethanol yield from lignocellulosic residue feedstocks will be further developed and demonstrated in near-industrial scale.
The proposed solution is employing a novel feedstock agnostic concept to build continuous fermentation unit complemented with novel sophisticated fermentation control system. The solution includes several other features developed by the partners that will be used to further increase the performance and operability of the fermentation.
The solution will be verified and demonstrated for various feedstock sources, which will prove a major advantage compared to current 2G ethanol plants and especially important for operators of ethanol plants when using very heterogeneous residue-based feedstock. The project is carried out by two leading technology players, Terranol A/S (TN) and SEKAB E-technology (SEKAB), in cooperation with an investor of a new bioethanol plant, Kanteleen Voima Oy (KANV), where the solution will be taken in use in industrial scale.
The fermentation concept, called CoRyFee, combines and utilizes proven knowhow and technologies of the partners. CoRyFee has previously been developed and demonstrated with straw materials and will be further developed to be optimized for soft- and hardwood raw materials. The combined application of CoRyFee continuous fermentation technology, yeast strain cV-110, and new fermentation control system is expected to enable numerous benefits:
• Increasing the productivity of a given size fermentation facility by more than 100% compared to current state of the art;
• Enabling the use of otherwise hitherto nonfermentable material by utilizing biomass hydrolysate with more than twice the amount of inhibitory compounds with help of inhibitor relief technology and yeast optimised to higher inhibitor level;
• Reducing the needed amount of yeast for inoculation by 80% or more compared with current state of the art as a result of using a more efficient yeast strain and novel continuous fermentation strategy;
• Reducing the amount of required personnel to produce a certain amount of ethanol due to higher production rate and higher level of automatization compared with current state of the art;
• Reduction of CAPEX of fermentation unit of at least 50% due to lower volume requirement to produce the same ethanol volume.
• KANV has conducted an area survey for relevant types of residual biomass sources in the vicinity of the planned production facility. Five suitable subtypes of biomass were identified.
• KANV has determined the supply potential of the five subtypes.
• KANV has collected sufficient amounts of each subtype and shipped to SEKAB.
• SEKAB has conducted chemical component analysis for each subtype, thereby determining the content of sugar, lignin etc.
• SEKAB has performed separate pre-treatment/hydrolysis of each subtype thereby demonstrating actual sugar content at industrial relevant enzyme dosage.
• SEKAB has conducted pre-treatment/hydrolysis of relevant combinations of the subtypes and shipped resulting sugar solution to TN.
• SEKAB has determined the pre-treatment/hydrolysis unit operation contribution to OPEX at industrial relevant enzyme dosages using suitable combination of subtypes.
• SEKAB has conducted continuous pre-treatment/hydrolysis with durations exceeding 2 weeks.
• TN has conducted continuous fermentation trials using feeds derived from combinations of relevant subtypes.
• TN has determined continuous fermentation conditions reaching the ethanol yield target set in the project plan.
• TN has conducted continuous fermentation trials, exceeding twenty days (>40 tank volumes/single yeast pitch).
• TN has determined relevant amendments (micro- and macronutrients) to feed allowing for continuous fermentation.
• TN has developed a “recipe” describing all necessary components for feed amendments and determined the OPEX contribution from the continuous fermentation unit operation.
Sugar analysis of the various biomass subtypes residues show a clear preference for specific types. Thus, by selection of high sugar yielding subtypes substantial higher concentrations of fermentable sugars are achievable. For that reason, KANV will select biomass types containing lower amounts of branches, tops and bark. Notably, during the elapsed time of the NewLiEP project, Kanteleen Voima’s Nordfuel biorefinery got an environmental permit and a positive investment subsidy decision from the Finnish Ministry of Employment and the Economy.
SEKAB will conduct further optimisations to maximize fermentable sugar yields while on the same time minimising the required dosage of hydrolysing enzymes. As biomass (and the logistics involved in procurement) together with enzymes, forms the two major contributions to OPEX, even minor improvements will be of great importance. The fact that the aimed target of ethanol concentration has already been achieved, using considerably lower concentrations of fermentable sugars than originally anticipated, makes further OPEX savings to be expected. Especially, fine-tuning of the temperature and pressure during the pre-treatment unit operation holds potential when optimal combinations of subtypes are employed in the process.
Continuous fermentation has been demonstrated. Also, the complete package of micro- and macronutrients has been determined. In the second part of the project, suitable industrial sources of such vitamins and inorganic growth factors will be determined and optimal concentrations elucidated. Apart for pH regulating compounds, surprisingly low contribution to the OPEX of the fermentation unit operation was found. Only, the pH regulator employed so far was of any significant contribution. For that reason, emphasis will be put on identifying suitable industrial relevant alternatives in the last part of the project. The second part of the project also involves the development of an “on-site” yeast propagation unit, preferentially using hydrolysate as the carbon source.
Reduction of Green House Gas (GHG) emissions, especially from the transportation sector, has been hampered by lack of sufficient technologies to achieve the set targets. Only the contribution from 1G biofuels has been of any significance. As production of 1G biofuels pose a negative contribution to the indirect land-use change within the EU area, the set target of 55% reduction (by 2030) of GHG emissions calls for the implementation of 2G technologies utilizing forest/agricultural waste. The results obtained so far during the NewLiEP project is very encouraging pointing to the feasibility of the NordFuel biorefinery – a production facility providing a needed economic development of an otherwise rural area of Finland. The successful completion will lead the way for the implementation of many more facilities within the EU area and beyond.