Performance Of Industrial Plant Research Articles

The effects of environmental investments on the economic performance of industrial plants – Evidence from Finland

Industrial plants that invest in environmental protection are larger and more productive, but do environmental protection investments also have a causal effect on their economic performance? This study proposes a novel econometric method to analyze the economic performance effects of environmental investments. Propensity score matching and difference-in-differences estimation on matched sample are used to investigate whether Finnish industrial plants that start investing in environmental protection out- or underperform otherwise similar plants. The empirical results show that plants that invest in environmental protection increase their turnover in comparison to control plants and that their labor productivity also increases. The economic gains are stronger when environmental protection investments are combined with environmental R&D, which implies complementarities between these activities.

Scale-up in froth flotation: A state-of-the-art review

Abstract Froth flotation has been one of the most important and widely used methods to concentrate minerals since its introduction over a hundred years ago. Over the last few decades, in order to process more mineral while reducing capital costs, flotation equipment has become exponentially larger. The increase in tank volume, however, has brought new challenges in the operation and design of industrial flotation tanks. This review analyses the literature on flotation tank scale-up for the first time, contrasting several techniques and approaches used in both historical and state-of-the-art research. The study of flotation scale-up is crucial for the optimisation of industrial plant performance and the maximisation of laboratory-scale research impact. While important advances in our understanding of flotation have been achieved, large flotation tank design and scale-up has, to a large extent, remained in-house know-how of manufacturing companies. This review of the literature relevant to flotation tank scale-up has resulted in a new classification, dividing the scale-up literature into two main areas of study, namely “Kinetic scale-up” and “Machine design scale-up”. This review indicates that current scale-up rules governing the design of flotation tanks focus mainly on pulp zone kinetic parameters and neglect the effects on the froth zone, despite the importance of froth stability and mobility in determining flotation performance. Froth stability and mobility are closely linked to the distance the froth needs to travel, which increases with tank diameter. Although including internal elements, such as launders and crowders, has been the industrial solution for enhancing froth transport and recovery in larger tanks, the design and scale-up of these elements have not been thoroughly studied. Gaps in our knowledge of flotation are discussed in the context of addressing the scale-up problem, considering froth transport and froth stability. Addressing these gaps will pave the way for the design and operation of large flotation tanks of enhanced performance.

Preliminary assessment of new approach to scale-up the laboratory results of flotation reagents tests based on mineralogical analysis

The question of introducing new collectors into copper concentrator plants referring to KGHM experience has been presented in this paper. Description of present methodology of flotation reagents testing has been indicated followed by explanation of crucial problems and limitations with proper qualification of reagents. Some attempts to apply scale-up methodology have been reported in technical literature. In this article assumptions of new methodology based on advanced mineralogy tests have been suggested. This methodology should allow the more accurate forecast of flotation performance of industrial plant after the laboratory tests.

Investigation of new control strategies for acid gas absorber columns to improve the response rates using dynamic process simulation

Increasing penetration of intermittent renewable sources of electrical energy such as wind or solar into the energy mix places an increasing demand on the flexibility of other power plant, in particular fossil fuel-based units.The suppliers of natural gas combined cycle equipment have been particularly successful in designing plants with increased ramp rates. In a recent review (Todd et al., 2014) EPRI has analysed the potential for using such equipment to improve the ramp rates of IGCC power plant. The review concluded that this was certainly possible, and identified the limiting equipment to be the acid gas removal system. Experience with such units in chemical applications has shown that at faster ramping rates than about 3%/min, the design sulfur specification cannot be maintained and a short-term sulfur breakthrough occurs. In that review it was postulated that this could be attributed to reduced solvent flow in the lower part of the column, while the hold-up required for higher load operation was being built up.Follow up work has been performed at the Technical University of Darmstadt to verify this hypothesis and propose mitigation measures. A typical tray column using a physical solvent was modeled, initially in ASPEN Plus and then in ASPEN Plus Dynamics. The dynamic model was calibrated against typical performance of industrial plant. The initial hypothesis could be verified and further refined. A number of proposals for mitigation measures were investigated and evaluated. The understanding gained by this work will be applicable also to packed columns and chemical solvents, though in the latter case the model will need to be extended to include kinetic effects.This paper describes the simulation work and a control strategy to improve the ramp rate of an acid gas removal system.

Variedades de cana-de-açúcar submetidas à irrigação suplementar no cerrado goiano

O Estado de Goiás é o segundo maior produtor de cana-de-açúcar do Brasil. Entretanto, ainda apresenta baixa produtividade, devido principalmente à falta de variedades adaptadas a esta região e ao déficit hídrico típico. Assim, objetivou-se avaliar o desempenho de dezesseis variedades de cana-de-açúcar submetidas à irrigação suplementar no Cerrado. O experimento foi conduzido em Goianésia-GO, em um Latossolo Vermelho-Amarelo Distrófico, de textura argilosa de abril de 2011 a maio de 2012. O delineamento foi em blocos casualizados (Bifatorial 16x5), com 16 tratamentos (variedades): CTC2, CTC4, CTC9, CTC11, CTC15, CTC18, IAC87-3396, IAC91-1099, IACSP94-3046, IACSP94-2094, IACSP94-2101, IACSP95-5000, RB857515, RB92579, RB966928 e SP86-0042; e cinco tempos de avaliação: 113; 145; 174; 203 e 285 dias após o plantio (DAP), com quatro repetições. A irrigação suplementar, por aspersão, correspondeu a uma reposição de 50% da ETc. Os resultados, de cana- planta, apresentaram diferenças significativas entre as variedades avaliadas, destacando-se as variedades CTC9, CTC11, IAC87-3396, IAC91-1099 e SP86-0042, em termos de produtividade e de rendimento industrial. Assim, estas variedades podem ser recomendadas para o cultivo no Cerrado, em regime de irrigação suplementar.

Alcoholic Fermentation with Flocculant Saccharomyces cerevisiae in Fed-Batch Process

Studies have been conducted on selecting yeast strains for use in fermentation for ethanol production to improve the performance of industrial plants and decrease production costs. In this paper, we study alcoholic fermentation in a fed-batch process using a Saccharomyces cerevisiae yeast strain with flocculant characteristics. Central composite design (CCD) was used to determine the optimal combination of the variables involved, with the sucrose concentration of 170 g/L, a cellular concentration in the inoculum of 40% (v/v), and a filling time of 6 h, which resulted in a 92.20% yield relative to the theoretical maximum yield, a productivity of 6.01 g/L h and a residual sucrose concentration of 44.33 g/L. With some changes in the process such as recirculation of medium during the fermentation process and increase in cellular concentration in the inoculum after use of the CCD was possible to reduce the residual sucrose concentration to 2.8 g/L in 9 h of fermentation and increase yield and productivity for 92.75% and 9.26 g/L h, respectively. A model was developed to describe the inhibition of alcoholic fermentation kinetics by the substrate and the product. The maximum specific growth rate was 0.103 h(-1), with K(I) and K(s) values of 109.86 and 30.24 g/L, respectively. The experimental results from the fed-batch reactor show a good fit with the proposed model, resulting in a maximum growth rate of 0.080 h(-1).

Enhanced Process Control – Maximizing Coal Handling Preparation Plant Productivity

The benefits of various enhanced methodologies in process control are well documented and include safer operation, reduced environmental impact, and improved efficiencies, qualities, and throughputs [1, 2]. Numerous applications of these techniques exist in the fields of petrochemical, oil and gas, pulp and paper, and mineral processing. However, the application of these has been slow to filter through into coal preparation [3]. Variability associated with plant feed rates and the coal seam(s) often results in problems in achieving plant throughput and the desired quality. Since plants are generally designed to average feed specifications and as the feed material qualities change (more or less ash, fines, etc.), the plant operators and control system must compensate accordingly. This article will present two different case studies demonstrating the benefits achievable through improvements in process control techniques. The performance of industrial plants is significantly affected by control loop configuration and the effectiveness of the operator and the interface in use. The first case study will highlight the benefits of prototyping and simulating enhanced control schemes before implementation on the actual plant. The second case study demonstrates how to improve operator situation awareness through enhanced graphics techniques and process alarm rationalization.

Control System Performance Monitoring

Product quality, operation safety, material and energy consumption, and thus the financial performance of industrial plants are directly or indirectly linked to the performance of control systems. Since process control systems are very complex, usually comprising different hierarchy levels, it is hopeless to maintain them on regular basis by plant personal. This is also the main reason why a large portion of industrial control loops has significant performance problems, as found out by audits carried out regularly since the 1990s. All these factors have contributed to the growing of the control performance monitoring (CPM) technology and applications in the last decade. CPM provides a framework for automatically and systematically assessing the performance of control loops, detecting and diagnosing root-causes of poor performance, as well as suggesting measures to improve control performance or avoid performance degradation. For this purpose, CPM techniques should be non-invasive, i.e., based on only routine operating data with limited or no additional process knowledge and without the need for any experimentation with the plant. This thesis deals with the complete CPM technology, from controller assessment (minimum-variance-control-based and advanced methods), over detection and diagnosis of control loop problems (process non-linearities, oscillations, actuator faults), to the improvement of control performance (maintenance, re-design of loop components, automatic controller re-tuning). It provides a contribution towards the development and application of completely self-contained and automatic methodologies in the field. Moreover, within this work, many CPM tools have been developed that goes far beyond available CPM packages. Industrial data from a large number of control loops in different industrial fields (building, chemicals, mining, mineral and metal processing) have been used to demonstrate the presented strategies and methods. Systematic procedures for automatic and continuous control performance monitoring, maintenance and optimisation are recommended, combining different control performance metrics and assessment, diagnosis and improvement methods. The main objective is to sustain top control performance during the whole life cycle of the control system, despite different and changing operational conditions.

Power quality detection and classification using wavelet-multiresolution signal decomposition

The wavelet transform is introduced as a powerful tool for monitoring power quality problems generated due to the dynamic performance of industrial plants. The paper presents a multiresolution signal decomposition technique as an efficient method in analyzing transient events. The multiresolution signal decomposition has the ability to detect and localize transient events and furthermore classify different power quality disturbances. It can also be used to distinguish among similar disturbances.