Process Intensification and Cost Reduction for In-plant Biomass Preprocessing Equipment

With growing concern about the sustainability and environmental impact of fossil fuels, interest in and demand for biomass-derived fuels has risen steadily. To ensure a steady supply of quality biomass at low costs, a variety of feedstocks are being pursued. This variety presents a significant problem for biomass conversion processes because feedstock quality changes depending on the source and each material must be processed differently to ensure a consistently high quality product. In addition, variation in feedstock affects feed flowability and can cause disruptions in supply. It is estimated that for every minute of plant down time, $800 is lost; this results in losses of over $13M during the typical plant lifetime. To avoid downtime, the solids handling and preprocessing systems are custom-designed for each individual plant, increasing costs and limiting feedstock flexibility of biorefineries. Designing low cost feedstock preprocessing systems that can handle a variety of materials is crucial to ensuring efficient and economic plant operation. We propose to narrow the scope of this problem by improving the solids handling and preprocessing for in-plant biomass conversion systems e.g. pyrolysis or gasification) requiring small particle sizes and a low moisture content. Our strategy is to improve the efficiency and to reduce the downtime of the size reduction and drying steps prior to introducing feed into the reactor. Waste heat and existing flue gas will be used efficiently to concurrently dry biomass during the milling and solids handling processes. Having recently developed a 1 ton/day pilot-scale pyrolysis system, we are well suited to demonstrating this process on the pilot scale and later on the demonstration scale. The proposed technology addresses energy security, distributed onsite renewable energy production, and the development of biorefineries. Improving domestic production of biofuels has significant impacts on the energy security and sustainability of the U.S. economy. This proposal improves preprocessing and solids handling of biomass; the ultimate goal is to reduce the capital and O&M costs, leading to the establishment of more biomass conversion plants. Using more renewable sources in our energy portfolio has benefits to both public health and the environment by limiting the production of greenhouse gases that contribute to global climate change. Our system is designed to handle a variety of feedstocks, and the benefits can be applied to pilot, portable, and large-scale systems. In addition, MEC is developing technology to support a distributed approach to biofuel production using a portable pyrolysis process. This approach, which is supported by the proposed feedstock handling equipment, allows for siting the biomass conversion process at the waste biomass source, eliminating the costs needed to transport low density biomass to a centralized facility.