The Pinch Analysis And Optimization Of Hydrogen Network In A Refinery

Increasingly higher sulfur content and heavier of crude oil and stricter product quality regulation leads to more flesh hydrogen consumption. The hydrogen becomes the main material of the refinery and the cost of hydrogen utility has turned to be more and more important in the refinery.Therefore optimizing the hydrogen network to reduce the fresh hydrogen consumption can greatly reduce the cost of hydrogen utility and improve the profit margin.Therefore it is very essential to optimize the hydrogen network, which can provide theoretical basis on utilizing the hydrogen network and reducing the hydrogen consumption.The thesis investigates the hydrogen network of one refinery in Dalian basis on consulting the literature on the recent research about the refinery hydrogen network optimization. We analyze the hydrogen network in the design conditions and the operation conditions with the pinch analysis based on the related data of all the units in the refinery. The analysis show that some units used high hydrogen concentration and too much hydrogen gas have not been used efficiently.Because the new continuous catalytic reforming unit will start work, the hydrogen network will change greatly. After calculating the cost of all the hydrogen production units,we design the hydrogen network including the continuous catalytic reforming with the hydrogen cost minimum. Through analyzing with the pinch analysis, we find that the CCR hydrogen concentration without being purified is above the pinch concentration, and this hydrogen can be used directly.Through analyzing, we find that low purity hydrogen gas under the pinch concentration discharges too much. The thesis respectively simulate and analyze the hydrogen network after adding the membrane separation unit and the PSA unit. The analysis show that after adding the PSA unit the cost of fresh hydrogen is lower, and provide theoretical basis and application foundation for further improvement.