Refinery Hydrogen Management:  Cost Analysis of Chemically-Integrated Facilities

Abstract

Market forces and environmental legislation are increasing demand for hydrogen in oil refineries, while simultaneously restricting traditional hydrogen sources such as catalytic reforming. Effective recovery and efficient use of hydrogen are necessary if refiners are to maintain feedstock and product flexibility while avoiding unnecessary capital expenditure. A methodology for assessment of hydrogen resources is developed by analogy with the problem of process heat recovery. The effectiveness of hydrogen use is related to the cost of hydrogen recovery and the value added in hydrogen-consuming processes. The costs of hydrogen recovery by pressure-swing adsorption and membrane permeation are described. The value added in hydrogen-consuming processes and the availability of hydrogen are determined by the process chemistry and the prevailing economic conditions. A graphical display of the availability and distribution of hydrogen resources provides insight into refinery design and operations that supplements the information available from optimization by linear programming.

MILP Model for the Nonlinear Problem of Optimal Purifier Placement

“…This case is taken from Towler (Towler et al 1996). The system consists of four hydrogen consuming processes: hydrogen cracker unit (HCU), naphtha hydrotreater (NHT), cracker naphtha hydrotreater (CNHT), and diesel hydrotreater (DHT).…”

“…The first graphical method for the assessment of hydrogen sources was proposed by Towler et al (Towler et al 1996). The effectiveness of hydrogen reuse is investigated by comparing the hydrogen recovery costs against the added value generated by hydrogen-consuming process.…”

Off‐Gases Optimization in a Hydrogen Network Refinery

“…It has been performed in graphical and mathematical models. The first systematic approach for the assessment of hydrogen resources of a hydrogen network was proposed by Towler et al [5] based on cost and value composite curves. Alves and Towler [6] developed a framework of sinks and sources for the hydrogen network similar to pinch analysis for a heat exchanger network.…”

Methodology for the design of industrial hydrogen networks and the optimal placement of purification units using multi-objective optimisation techniques

“…In this study, process units of the refinery are defined as hydrogen sources and sinks, each being defined by a hydrogen flow, purity, contaminant and pressure. Considering the analogy heat load/flow rate (quantity) and temperature/purity (quality), the minimum hydrogen requirement may be defined by applying pinch based techniques A first representation has been proposed by [5], it was improved by [3] in the form of total flow rate ─ purity diagrams and surplus diagrams. The graphical methods suffer from the fact that these are not able to consider simultaneously purity and other contaminant constraints or the pressure constraints.…”