Ismael Matino

Process Integration Solutions for Water Networks in Integrated Steel Making Plants

Process Integration capabilities of promoting the internal recycling and reuse of material and energy streams allow reaching the goals of sustainable processing. Water is one of the main industrial resource which use has to be optimised to decrease freshwater intake and wastewater blowdown. Preliminary studies on the feasibility of different options are developed through Process Modelling and Simulation to predict process behaviour before plants conversion. The paper presents the approach to the problem of water reuse for an Italian integrated steelmaking plant. Application to a real case has been developed, related to reuse of continuous casting wastewater blowdown in basic oxygen steelmaking gas washing system. Process Modelling with main assumptions and results are described. The option is promising, as it involves a reduction of fresh water drawing up to 33 %, with changes in blowdown features of 2 % for pH value increase and 13 % for electrical conductivity reduction at constant global mass balance.

Simplified Ionic Representation of Industrial Water Streams

Industrial focus on environmental impact involves exploitation of internal resources. Water reuse is one of the topic and some characteristics have to be measured in order to evaluate the quality of a process water stream. Analytical estimation of water main properties becomes fundamental when preliminary study about reuse feasibility is required. This kind of evaluation for properties such as pH, electrical conductivity, Langelier Saturation Index, etc. Depends on ionic composition of the solution. A simplified Excel-based model has been developed in order to represent the ionic composition of an industrial water stream, which allows user to obtain approximate but realistic values for some properties of interest. The paper presents the approach to the model development with main assumptions and results.

Evaluation and Monitoring of Physico-Chemical Properties of Water Streams through Unconventional Techniques

Evaluation and monitoring of physical and chemical water properties such as electrical conductivity (EC) and Langelier Saturation Index (LSI) are important in all industrial processes. Analytical representation of these water properties is useful since process modeling and simulation are exploited to investigate industrial system behavior under conditions that cannot be easily or safely tested. Common simulation softwares usually do not estimate the mentioned water properties but using literature information an estimation is possible through unconventional techniques. In particular Aspen Plus software has available calculator blocks to customize in order to represent specific features. In the paper modelling of FORTRAN based calculator blocks are described, which have been developed using literature information to calculate electrical conductivity and Langelier Saturation Index in Aspen Plus software.