Execute a feasibility study and preliminary technical evaluation of various system configurations for a unique biomass-to-power facility.
BIOMASS TO POWER FACILITY FEASIBILITY STUDY AND ALTERNATIVES EVALUATION
Process Engineering Associates, LLC (PROCESS) was contracted by the client, an advanced gasification technology provider, to execute a feasibility study and preliminary technical evaluation of various system configurations for a unique biomass-to-power facility. The client had previously completed a preliminary mass and energy balance and PROCESS had previously completed a preliminary process design for the client. From this information, PROCESS had developed an early stage capital cost estimate for a plant with a given configuration and size. Subsequent to these projects, the composition of the biomass feedstock changed significantly based on the proposed geographical location of the plant. To this end, the client asked PROCESS to execute a feasibility study and selected technology technical evaluations for the new design basis feedstock plant.
Initially, PROCESS developed a comprehensive mass and energy balance using its licensed commercial computer process simulation software, CHEMCAD, and compared this to the preliminary mass and energy balance that had previously been completed. This revealed that there was less energy available in the offgas than was previously thought, and that there was significantly more water present. The addition of a dryer to the design to remove water from the feedstock resulted in additional capital cost and decreased the energy efficiency of the process.
PROCESS then developed a comprehensive heat integration model of the entire facility (feedstock preparation, gasifier, gas cleaning system, power island) utilizing CHEMCAD. This led to the development of several process improvement alternatives for the purpose of re-establishing more favorable energy efficiency, and thus viable plant economics. These included:
- Increasing the gasifier capacity
- Using waste heat to increase the capacity of the combined-cycle gas turbines via an adsorption chiller system
- Altering the configuration of the combined-cycle system to maximize the utilization of the gas turbines
- Testing the operation of the gasifier at elevated pressures to reduce the parasitic load of required downstream compression.
Even though implementation of one or more of these process improvements showed improvement for the economics of the plant, the project was ultimately cancelled due to the loss of investment capital.
During the course of this project, PROCESS utilized unique visual basic programming language to link the proprietary Excel-based gasifier mass and energy balance models to an overall plant CHEMCAD simulation model.
- Alternative Fuels
- Feasibility study
- Technology options technical evaluation