(221c) Logistics Fuel Catalytic Cracking for Hydrogen Generation

Authors: 
Karanjikar, M., Chevron Energy Technology Co
Stevens, J., Chevron Technology Ventures LLC
You, L., Chevron Energy Technology Company


Fuel cells offer a unique way to convert chemical energy of a fuel directly into electrical energy. Thus fuel cell technology is a more efficient power generation method. Proton-Exchange-Membrane fuel cells (PEMFC) in the near future and solid oxide fuel cells (SOFC) in the later future are projected to be the most promising technologies. Since PEMFC require hydrogen, reforming of hydrocarbon based fuels (also known as Fuel Processor) is one of the better known techniques for hydrogen generation.Hydrocarbon fuels such as JP 8 (Jet Propulsion Fuel) and diesel have logistics and safety advantages for military applications compared to compressed hydrogen. Energy densities of both diesel and JP8 (11.8 and 11.1 kWh/Kg respectively) are much higher compared to lower hydrocarbons (e.g. natural gas). Processing of heavy hydrocarbon fuels is particularly challenging due to high molecular weight, sulfur content, and aromatic contents of the fuel. This paper presents simulation as well as experimental results from catalytic cracking of heavy hydrocarbon fuels viz. JP 8 and diesel. The simulations are performed using ASPEN® simulation software. System modeling and overall system efficiency calculations are discussed as part of the simulation effort. The experimental part focuses on parametric analysis of the process, mainly effect of temperature and liquid hourly space velocity on the performance of catalysts. The experiments have been carried out in a quartz reactor (1.2 cm dia) using commercial cracking catalysts. Gas analysis is done using HP 5890 ® GC (hydrocarbons) and Del Mar® sulfur analyzer 5504 (H2S and COS).