Utvikling av bioraffineri fra dampeksplosjon (ArbaBioRaf)

The underlying idea of the project is to develop a new biorefinery concept that utilizes waste streams from the pellet production to produce important, green bio-chemicals. The project has developed quantitative analyses for furfural and HMF etc. which helps to optimize the biorefinery with regard to the yield of chemicals. Measurement uncertainty is within acceptable limits. The analyses are used in combination with qualitative analyses, which together form a solid basis for further decisions. Experiments have been performed in the lab and in pilot-lab scale at different process conditions. Qualitative guidelines can be drawn from these experiments, but since there is a relatively large difference from full-scale testing, it remains to be seen whether there are quantitative correlations. As soon as full-scale testing can be carried out, this will be implemented. At the same time, washing experiments have been performed, where other green chemicals are being extracted. The experiments so far are considered successful. Analyses have been carried out on solids, condensates, filtrates and washing water. Simple mathematical models have been developed, and more advanced modelling has begun. A good model depends on good input, and due to relative differences between pilot-lab scale and full-scale, the model is dependent on results from full-scale testing that are not yet available. In addition, research has been carried out into unknown challenges that have arisen in the full-scale facility, e.g. the formation of a solid which so far has affected the process in a negative way. There seems to be a connection with some process parameters, but the root cause is still to be uncovered. The project as a whole has been affected by the pandemic, both in terms of available lab time, but also travel and cooperation between the various parties in the project. Also, the pandemic has affected full-scale testing as the completion and commissioning of the facility has been postponed. This caused some delay in the project, and postponement of the project completion. Some of the desired activity must be followed up after project completion.

The new Arbaflame process is operating continuously, producing brown biofuel pellets and furfural in a novel process. In addition to furfural, the condensate and the aqueous phase contains other biomass-based chemicals like methanol, acetone, diacetyl, 5-hydroxymethylfurfural and various sugars. The content of these compounds has been quantified. 5-hydroxymethylfurfural is regarded as a valuable platform chemical for development of renewable materials and may constitute an additional revenue stream for the mill, and basic data required for designing a process for production of 5-hydroxymethylfurfural have been generated. Methanol and acetone are produced in sufficient purity to be used as an onsite biofuel, and less volatile compounds like acetate is digested to form biogas which also is used as an onsite biofuel. There has been a significant improvement in the control of pellet quality, increasing their competitiveness as an alternative to coal.

The goal with this project is to develop a completely new biorefinery concept. The concept incorporates the production of valuable bio-based chemicals in the established Arbaflame pellet production process. In the last years, growing environmental concerns have contributed to an increased attention to efficient resource use, and promoted the shift towards a wider use of renewable resources. In line with this trend, Arbaflame AS has developed a process for the production of steam exploded pellets. These pellets share many of the properties of coal and have been specifically developed to replace fossil fuel in coal-fired power plants to help the green shift. In the production process of steam exploded pellets, several highly valuable chemicals are produced as by-products, but they currently remain un-recovered in the condensate stream or in the residual moisture in the pellet. Among these chemicals, furfural and HMF not only have a high market value, but they have also been appointed as promising bio-based platform chemicals, which represent a valid alternative to chemicals from fossil resources. Moreover, methanol, acetone and acetic acid, if recovered, can directly replace their fossil-derived equivalent. Thus, these by-product represent a significant untapped economic potential, which could be taken advantage of if these chemicals were recovered and added to the Arbaflame product portfolio. In addition, the recovery of these bio-based chemicals can help the transition to the 2050 low-carbon economy envisioned by the EU climate strategy. By integrating the chemical extraction process into the pellet production chain, this new concept will use both residual material streams and waste energy streams as useful inputs for the biorefinery extraction processes.