Caustic Recovery Unit Design for Mercerization Machines

Journal of Cotton Science

This review discusses cotton textile process- ing and methods of treating effluent in the textile industry. Several countries, including India, have introduced strict ecological standards for textile industries. With more stringent controls expected in the future, it is essential that control measures be implemented to minimize effluent problems. Industrial textile processing comprises pretreat- ment, dyeing, printing, and finishing operations. These production processes not only consume large amounts of energy and water, but they also produce substantial waste products. This manuscript combines a discussion of waste pro- duction from textile processes, such as desizing, mercerizing, bleaching, dyeing, finishing, and printing, with a discussion of advanced methods of effluent treatment, such as electro-oxidation, bio-treatment, photochemical, and membrane processes.

2017

Cotton is a very popular material that has its own stock market. There are huge amounts of cotton waste and medical cotton waste that can be treated and become a considerable source of energy, instead of buried with other waste in the land-field or incinerated. The purpose of this study was first to examine and then to maximize, if possible, the efficiency of pretreated cotton waste, regarding its gross heat of combustion. More specifically we used a blast furnace in order to torrefy cotton. The cotton torrefaction was achieved through a non-isothermal heating up to 340 oC for 20-50 minutes. The effect of pretreatment conditions, i.e., reaction time and temperature, were investigated using a calorimeter. The diagrams show the heat energy curve and how gross heat of combustion is affected from the conditions applied.

Introduction

Industria Textila, 2020

Attempt has been made to assess the cotton/modal (60:40) blended woven fabric properties after mercerization with caustic lye of different strengths. Cotton/Modal (60:40) fabric was subjected to bulk mercerization process and subsequently dyed with reactive dyes. The colour strength, fastness properties (washing, staining and rubbing etc.), tensile and tear strength and shrinkage were characterized. The results of this study indicate that cotton/modal blended fabric that was considered in this study can be processed under similar conditions as those that are maintained for cotton fabrics generally and that the aforementioned properties are improved generally.

Environmental Quality Management, 2018

The word "textile" means to weave and was taken from the Latin word "texere." Nowadays, textiles not only fulfill humankind's basic necessity for clothing, they also allow individuals to make fashion statements. As one of the oldest industries, the textile industry occupies a unique place in India. It is responsible for 14% of the total industrial manufacture in India. However, the textile industry is also considered to be one of the biggest threats to the environment. Pretreatment, dyeing, printing, and finishing operations are among the various stages of the industrial textile manufacturing process. These fabrication operations not only utilize huge quantities of power and water, they also generate considerable amounts of waste. The textile industry utilizes a number of dyes, chemicals, and other materials to impart the required qualities to the fabrics. These operations produce a significant amount of effluents. The quality of effluents is such that they cannot be put to other uses, and they can create environmental problems if they are disposed of without appropriate treatment. This review discusses different textile processing stages, pollution problems associated with these stages, and their eco-friendly alternatives. Textile wet processing is described in detail, as it is the key process in the industry and it also generates the greatest amount of pollutants in textile processing. The environmental impact of textile effluents is discussed, as textile effluents not only impose negative effects on the quality of water and soil, they also imperil plant and animal health. In this paper, various methods for treating textile effluents are described. Discussion of physical, chemical, biological, and advanced treatment technologies of effluent treatment are included in this paper. K E Y W O R D S remediation, textile effluents, textile industry, wet processing 1 INTRODUCTION Textiles rank second-after food-among the substantial desires of human life. The textile industry alters fibers into yarn, transforms the yarn into fabrics or allied commodities, and dye and finish these materials through diverse operations of production. Numerous dyes, chemicals, auxiliary chemicals, and sizing materials are used during wet processing in the textile industry. This results in the generation of wastewater that may pose environmental problems. Hence, the wastewater produced during wet processing needs to be thoroughly treated before it is released to the environment (Ghaly, Ananthashankar, Alhattab, & Ramakrishnan, 2014; Kamal, Ahmed, Hassan, Uddin, & Hossain, 2016). The composition effluents of textile effluents are extremely heterogeneous. Effluents comprise large quantities of toxic and difficult to treat substances derived from the dyeing and finishing processes. (Al-Kdasi, Idris, Saed, & Guan, 2004; Sabur, Khan, & Safiullah, 2012). The most pertinent problem of textile industry wastewater is the use of dye to impart color (Qadir & Chhipa, 2015). Effluents contain a wide range of contaminants, including surfactants, salts, heavy metals, enzymes, oxidizing, and reducing agents

Desalination, 2005

The recovery of caustic soda and concentration of disodium terephthalate (DST) from alkali waste of polyester fabrics were investigated using SelRo (MPT-34) nanofiltration membranes with membrane area of 0.024 m2 and 5.2 m2, respectively. Flux behaviors were observed with respect to filtration time, volumetric concentration factor (VCF), operating pressure, temperature, and cleaning. The mass balance of caustic soda, DST, and

Oriental journal of chemistry, 2015

Industrial waste generate a supplementary cost to companies seeing that they must, by the force of law , take in charge their wastes whether by their own means or through outside services. Molecular sieves used in the dehydratation section of natural gas, as a matter of fact those of type 4 Å used in GP1/Z complex in Sonatrach Algerian company, become as wastes as soon as they are saturated and with no possibility of regeneration. Within the scope of this work proposition to valorize these industrial wastes are put forward in the light of a series of analyses and experiments with distilled water and water polluted with Methylene blue textile dye using a prototype of filtration device. Eventually, a track is open in this work for further research valorization of the type 4 Å saturated molecular sieves in the gas industry.

The growing cost of energy has required its more effective use. However, many industrial heating processes generate waste energy. Use of the waste-heat recovery systems decreases energy consumption. Drying is often one of the most energy-intensive operations in textile processes and such dryers exhaust large amounts of warm and moist air. The heat-recovery systems utilize the heat produced for the drying process.

The textile industry includes a variety of processes ranging from the manufacture of synthetic fibers and fabric production to retail sales. The wet-processing operations, namely preparation, dyeing and finishing of textile products which are used to give the desired characteristics to the yarn or fabric, require the use of several chemical baths. They consume vast amounts of energy, chemicals and water. Emissions of volatile organic compounds (VOCs) mainly arise from textiles finishing, drying processes, and solvent use. VOC concentrations vary from 10 mg m -3 for the thermosol process to 350 mg carbon m -3 for drying and condensation process. Process wastewater is a major source of pollutants. It is typically alkaline and has high BOD5 (700 to 2,000 mg l -1 ) and chemical oxygen demand (COD) (approximately 2 to 5 times the biochemical oxygen demand (BOD) level), solids, oil and possibly toxic organics, including phenols (from dyeing and finishing) and halogenated organics (from processes such as bleaching). Dye wastewaters are frequently highly colored and may contain heavy metals such as copper and chromium. Wool processing may release bacteria and other pathogens. Pesticides are sometimes used for the preservation of natural fibers and these are transferred to wastewaters during washing and scouring operations. Pesticides are also used for moth proofing, brominated flame retardants for synthetic fabrics, and isocyanates for lamination wastewaters may also contain heavy metals such as mercury, arsenic, and copper. Air emissions include dust, oil mists, acid vapors, odors, and boiler exhausts.

European Scientific Journal, 2016

Pre-treatment plays a significant role for the successful coloration of any kind of natural textile fiber like cotton, wool, flax, silk etc. This research work overview the influence of various types of traditional preparation techniques applied on cotton fiber before coloration such as desizing, scouring and bleaching. The traditional pre-treatment processes consume plenty of environmentally unfriendly chemicals those generate pollution in the effluents. In this research work an endeavour has been made to desize, scour and bleach grey cotton woven fabric simultaneously using caustic soda and hydrogen peroxide. The physical properties like whiteness, percent loss in fabric weight, tensile strength of the treated fabric have been compared with those of the fabric treated to conventional desizing, scouring and bleaching process. It is observed that the whiteness (ready for colouration) obtained by this process is quite satisfactory. Moreover, this process has some other merits such as ecological, economical, energy conserving and time saving aspect.

Journal of Environmental Management, 2015

The treatment of spent caustic produced from an ethylene plant was investigated. In the case of neutralization alone it was found that the maximum removal of sulfide was at pH values below 5.5. The higher percentage removal of sulfides (99% at pH ¼ 1.5) was accompanied with the highest COD removal (88%). For classical oxidation using H 2 O 2 the maximum COD removal percentage reached 89% at pH ¼ 2.5 and at a hydrogen peroxide concentration of 19 mM/L. For the advanced oxidation using Fenton's process it was found that the maximum COD removal of 96.5% was achieved at a hydrogen peroxide/ferrous sulfate ratio of (7:1).

This review discusses cotton textile processing and methods of treating effluent in the textile industry. Several countries, including India, have introduced strict ecological standards for textile industries. With more stringent controls expected in the future, it is essential that control measures be implemented to minimize effluent problems. Industrial textile processing comprises pretreatment, dyeing, printing, and finishing operations. These production processes not only consume large amounts of energy and water, but they also produce substantial waste products. This manuscript combines a discussion of waste production from textile processes, such as desizing, mercerizing, bleaching, dyeing, finishing, and printing, with a discussion of advanced methods of effluent treatment, such as electro-oxidation, bio-treatment, photochemical, and membrane processes.

In this study, several physical properties of causticized knitted fabrics made of bamboo/cotton blended yarns are investigated. To observe the effect of causticizing, the process has been applied to different knitted fabrics with different NaOH concentrations and different process durations. Then pilling, bursting strength and handle properties of the fabrics were evaluated. The results show that the measured physical properties of knitted fabrics changes depend on fabric structure and NaOH concentration. It was also found that the increase in NaOH concentration resulted in good pilling resistance, low bursting strength and stiff handles.

Global Journal of Research In Engineering, 2018

Environmental pollution is the global issue that results in adverse effects on living beings. It is one of the major concern areas for the whole world. During preparation of cotton woven fabric before dyeing mainly involves desizing, scouring and bleaching. Each process drains a plethora of chemicals along with water, in the effluent stream. The released chemicals by the global textile industry are continuously doing unimaginable harm to the environment. The focus of this research is to investigate the opportunities to prevent the pollution by recycling and reusing, the water and chemicals without addition of any treatment.

Chemical engineering transactions, 2014

In this study, environmental performance of a textile mill employing fiber production and subsequent dyeing was evaluated in detail. Cleaner production assessment studies based on Integrated Pollution Prevention and Control (IPPC) principles were conducted. Specific water and chemical consumptions in wet processes were calculated using mass balance analysis. The potential wastewater and/or chemical recovery and reuse options were determined. A company-wide chemical inventory study was conducted and the chemicals were evaluated in terms of their toxicological effects. It was found that a total of 29 chemicals should be replaced with less toxic and more biodegradable counterparts. By the application of suggested cleaner production options, the potential reductions in water and chemical consumptions and wastewater generations were determined. After the implementation of good management practices, wastewater recovery and reuse, machinery modifications, and chemical optimizations/replace...