In many European countries with plentiful forest resources, novel forest-based businesses play a key role in the transition from our current fossil-based economy towards a circular bioeconomy. For example, kraft lignin, a by-product from the pulping industry, is produced in large amounts globally. To date, however, it is still only offered on the market by a small number of pulping companies. The successful innovation diffusion of related new technologies and businesses requires establishing a collective effort among multiple societal actors to motivate the sharing of value creation processes. In this paper, potential innovation diffusion pathways are modeled and simulated by means of an agent-based approach (Biorefinery Products Innovation Diffusion model, BioPID). The paper investigates the conditions needed to encourage the diffusion of kraft lignin innovations as a (partial) replacement for fossil-based feedstock in selected applications. The results reveal the basic mechanisms behind potential innovation diffusion pathways. The major barriers were found to be the high level of uncertainty surrounding the additional costs arising in lignin processing, the small number of lignin providers, and the presence of relatively homogeneous pricing strategies based on opportunity and basic preparation costs. The analysis of two product categories revealed different patterns in terms of innovation diffusion and potential greenhouse gas emissions. A novelty of BioPID is that it allows for iterative technology evaluation and technology foresight analysis of biorefinery projects (e.g., by combining techno-economic, socio-technical, and environmental aspects). This produces knowledge for diverse stakeholders involved in the lignin innovation ecosystem, thus enabling better communication on shared values and furthering innovation diffusion.