Processes for converting lignocellulose to feedstock and downstream products are disclosed. The processes may include acid treatment of lignocellulose to produce a fermentation feedstock. In various instances, the processes include recovery or recycling of acid, such as recovery of hydrochloric acid from concentrated and/or dilute streams. Downstream products may include acrylic acid-based products such as diapers, paper and paper-based products, ethanol, biofuels such as biodiesel and fuel additives, and detergents.