Shimin Deng

This paper investigates on a gas-to-liquids (GTL) plant with ATR syngas production and proposes a new process to use a gas turbine and waste heat recovery gas/steam streams preheater to replace the fired heater. The new process features cascade utilization of fuel gas energy, as fuel gas is firstly used in a gas turbine (GT) at very high temperature and then lower-temperature GT exhaust gas is further used for preheating. Large exergy loss of heat transfer in the fired heater is eliminated. The improved process has an equivalent power generation efficiency of 80% which is significantly higher than conventional technology. Economic analysis indicates 129.8 M$ revenue would be produced over the lifetime if the extra power from a 15,000 bbl/d GTL plant can be exported to the grid at the price of cost of electricity for a conventional natural gas fired combined cycle plant.

In this paper, the issues and challenges of capturing CO₂ from a pulverized coal (PC) power plant have been summarized and assessed and a hybrid power generation configuration is developed, which features a gas-turbine cogeneration unit supplying steam for stripping CO₂, thereby decoupling the CO₂ capture from the steam cycle of PC units. The hybrid power generation cases are modeled by using GTPro^TM and SteamPro^TM. The performance of the hybrid power plant is compared with the base case that uses extraction from the steam cycle. Retrofitting existing power plants by this hybrid concept is also assessed; performance comparison and economic analysis indicate that this kind of retrofitting is attractive to utilities with PC power generation fleet.

In this paper, a hybrid solar and coal-fired steam power plant with secondary air preheating is proposed, which has much higher thermal efficiency than existing hybrid solar and coal-fired power generation systems. Five cases in total are modeled using GateCycle™. The simulation indicates that the solar-to-power efficiency of the new system is 5.5–6.5% points higher than solar-feedwater (HP) systems. The performance of the base case is compared with other cases to identify the potentials of the new system. Thermodynamic analysis is carried out and bleed steam heat-to-power conversion ratios are calculated for comparison. In addition, boiler operating parameters are investigated and fuel saving mode and power boost mode are compared.