Methods and systems disclosed herein can treat biomass compositions to produce valuable products, reduce emissions, and decarbonize biomass. The biomass compositions can be raw biomass (e.g., green, woody-plant derived) or waste biomass (e.g., industrial waste, pulp and paper processes, construction materials). The biomass compositions can be mixed with a reagent to form a mixture. The reagent can include ammonia. The mixture can be reacted to separate one or more components from the biomass and form a treated biomass composition. The one or more components can include lignin, polylactic acid, carbon oxides, methane, minerals, volatiles, or semi-volatiles. The treated biomass can be dried and processed into heating pellets that have higher calorific value and fewer emissions than conventional heating chips. The separated components can be used to produce valuable products, such as wood composites, bioplastics, fertilizer, fuels, lignin anodes for batteries, additives, glues, resins, and bio-based carbon fiber.