A techno-economic and environmental assessment of hydroprocessed renewable distillate fuels

Abstract

This thesis presents a model to quantify the economic costs and environmental impacts of producing fuels from hydroprocessed renewable oils (HRO) process. Aspen Plus was used to model bio-refinery operations and supporting utilities. Material and energy balances for electricity, carbon dioxide, and water requirements as well as economic costs were obtained from these models. A discounted-cash-flow-rate-of-return (DCFROR) economic model was used to evaluate minimum product values for diesel and jet fuels under various economic conditions. The baseline gate cost for distillate fuel production were found to range between $3.80 and $4.38 per gallon depending on the size of the facility. The additional cost for maximizing jet fuel production ranged between $0.25 and $0.30 per gallon. While the cost of feedstock is the most significant portion of fuel cost, facility size, financing, and capacity utilization were found to be sensitive parameters of the gate cost. The total water use of the system was found to be 0.9 pounds of water per pound of vegetable oil processed. Lifecycle greenhouse gas emissions (GHGs) for the processing step were found to range between 10.1 and 13.0 gCO 2e per MJ of distillate fuel using an energy allocation method consistent with methods in the literature. Finally, the policy landscape for producing jet and diesel fuels from renewable oils was reviewed from the perspective of a fuel producer. It was found that the potential of HRO fuels penetrating the market is dependent on the availability of feedstocks and access to capital.