Yuli Amalia Husnil

Does lower energy usage mean lower carbon dioxide emissions? — A new perspective on the distillation process

Although fossil fuels play an important role as the primary energy source that currently cannot be replaced easily with other energy sources, their depletion and environmental impact are becoming major concerns. Improvements in energy efficiency are believed to solve both problems simultaneously. We examined the relationships between the improvement in energy efficiency, energy usage and CO2 emissions in industry, especially in the distillation process. The energy efficiency improvement of dimethyl ether (DME) purification performed with dividing-wall column distillation (DWC) and acetic acid recovery performed with mechanical vapor recompression (MVR) were evaluated by recalculating the amount of fuel burnt and its CO2 emission. The results showed that the paradigm of lower energy being directly proportional to lower CO2 emissions is not entirely correct. To avoid this confusion, a tool for examining the uncommon behavior of various systems was developed.

Modeling and simulation of multi-stream heat exchanger using artificial neural network

Abstract A multi-stream heat exchanger (MSHE) is the heart of LNG plant where 40% of the entire energy is consumed in this section. Moreover, the plant operation is subject to number of variations from the plant inlet such as ambient temperature, pressure, feed flow or composition. In industrial application, the mitigating of these variations is usually performed using trial and error approaches. Thus developing a competent and accurate model to predict the performance of the MSHE is an inevitable step to overcome those variations. In this study, a model for the MSHE operation is developed using artificial neural network. The modeling is made in such a way that the information about the internals of heat exchanger could allow the MSHEs from any variation that arises from the process itself or upstream conditions. A number of simulation runs have been made by taking a case study for the MSHE operation. The developed model can predict and provide prior information for the MSHE in order to take action during the plant performance.

Robust control of Propane Pre-cooled mixed refrigerant process for natural gas liquefaction

Natural Gas are often found at remote locations to bring it to the world market liquefaction is required. In liquefaction natural gas is cooled to around -160°C, hence required considerable amount of energy. To maximize the profit from the existing design it is necessary that the process should operate efficiently, reliably and safely. Hence a good and Robust control is required. Due to tight control strategy the stability is an issue in the main cryogenic heat exchanger(MCHE) and in the Refrigerant flash drum. In this study the C3MR process was considered and the dynamic model was made in Hysys simulator and used to implement the proposed control algorithm. By judiciously choosing control variables we have proposed more robust control strategy and its performance was observed under simulation environment which provide satisfactory robustness for stability and performance.

Application of Mechanical Vapor Recompression to Acetone - Methanol Separation

 Abstract—This paper proposed a novel integrated design of azeotropic mixtures distillation process based on mechanical vapor recompression (MVR). The extractive distillation of acetone - methanol binary system that forms a homogeneous minimum - boiling azeotrope was studied. Based on the simulation result, the total energy consumption of the proposed sequence is 62% less than the existing extractive distillation configuration.

Simulation based Heuristics Approach for Plantwide Control of Propane Precooled Mixed Refrigerant in Natural Gas Liquefaction Process

Abstract In this paper a simulation based heuristic approach is used to configure the control structure of propane precooled mixed refrigerant (MR) natural gas (NG) liquefaction process. The liquefaction of NG in cryogenic exchanger involves MR stream condensation and vaporization in different sections of cryogenic exchanger. This increases the interactions among MR streams as illustrated using dynamic simulation. To identify these interactions, first the sensitivity analysis of propane precooled MR was carried out and then several heuristic based on dynamic simulation were proposed for disturbance rejection and increased liquefied natural gas (LNG) production rate. Major findings from several case studies suggest that the maximization of available cold energy is possible by utilizing temperature difference between MR streams as set point for controlling LNG production rate.