CROSS-REFERENCE TO RELETED APPLICATION

This application claims priority to Indian application number 201721031771 filed at Indian Patent Office, Mumbai on 08/09/2017 which is incorporated herein by reference in its entirely.

FIELD OF THE INVENTION

The present invention is related to organic synthesis & speciality chemical industries wherein toxic effluent having various characteristics like acidic, alkaline, neutral, high organic and inorganic impurities are generated at large scale in form of liquid, solid or semisolid. The invention is featuring easier, energy-time-cost saving and more convenient improved method for treatment of aforesaid toxic effluent and to make it harmless to the environment. Moreover, to convert such effluent into valuable byproducts.

BACKGROUND OF INVENTION AND PRIOR ART

Organic synthesis & speciality chemical industries are one of the largest field of all time generating harmful toxic effluent like acidic, alkaline, neutral, high organic and inorganic impurities at the large scale. Such effluent contains toxic organic compounds, inorganic salts, sulfuric acid & other acidic waste water typically derived from production of one or more unit operation of industrial process. If such waste are not disposed off carefully, it can be extremely hazardous to human health as well as to the environment. Any inaccuracy may comprehensively affect to human health, animals, sea creatures, plants, natural water resources and overall environment.

In the one of the known prior art, the said effluent is processed through various treatments like primary treatment, secondary treatment, tertiary treatment and incinerated or spray dried. Finally the waste is interred in government approved solid land-fill sites.

Specifically, in the prior art, the said effluent is firstly treated for removal of inorganic salts. Then the effluent is neutralized with Hydrated Lime to remove acid in the form of gypsum. The gypsum is filtered off and filtrate is concentrated. The concentrated effluent rich in organic compounds and some inorganic salts is either incinerated or spray dried. The incinerated or spray dried liquid / solid / semisolid waste is carefully & safely packed in bags and interred in government approved solid land-fill sites.

DRAWBACK OF THE PRIOR ART

In the prior art, substantial manpower are involved in the process of treatment given to the hazardous effluent generated by organic synthesis & speciality chemical industries. Such treatment must be processed under strict attentiveness conditions. It deserves intensive awareness and consciousness during the treatment in prior art. There are serious chances of accidental circumstances as well as human error in such treatment. Any inaccuracy may end into the critical hazard to their health.

The manpower involved in such treatment process, must strictly follow the regulatory guidelines & safety manual and carefully maintain the safety instruction at work place. Further, though the regulatory guidelines have been followed strictly, there are chances of long term risk to their health.

In the prior art, raw material i.e. Hydrated Lime is used to neutralize acid from the effluent. This necessitates filtration to remove acid in the form of gypsum which is a solid waste.

After neutralization, in the prior art, the neutral filtrate is evaporated using multi- effect and Forced Effect Circulation. The concentrated effluent is either spray dried or incinerated to get the solid waste. Finally this solid waste carefully & securely packed in bags and interred in government approved solid land-fill sites.

Moreover, the respective Government Authorities have applied safety regulations and guidelines for the disposal of effluent generated in organic synthesis & speciality chemical industries. Accordingly, such effluent must be processed, treated, disposed and interred to the approved land-fill sites strictly. The effluent is processed through specific treatment and finally converted into liquid / solid / semi waste and interred in government approved solid land-fill sites.

However, the liquid / solid / semi solid waste contains toxic effluent having various characteristics like acidic, alkaline, neutral, high organic impurity and inorganic impurity. In the event of natural disasters like earthquakes and floods, the secured solid land-fill site can get damaged allowing for seepage of water. The solid / semisolid waste dissolves in the water re-generating the aforesaid toxic effluent. The effluent can contaminate the underground water-table leading to highly polluted water at large scale.

However, the overall process of safe disposal of effluent are expensive and energy intensive, which is again affecting the environment.

In another closest prior art, the acidic effluent from plant is processed in various steps including Crystallization, Evaporation, Spray Dryer, Carbonization, Separation of inorganic salts and carbon, Distillation of water, Belt Filter Process.

The said Prior Art mainly performs three major tasks.

Carbonization of solid waste

To recover Carbon from Carbonaceous Powder

To recover inorganic salts In this prior art, the process of crystallization does not help in total recovery of inorganic salts. Moreover the partial quantity of salt recovered which is reused, is not of good quality.

In the prior art, useful byproducts were recovered from the solid waste during the treatment in various steps. All these steps involve continuous exposure of manpower to highly hazardous and toxic environment. Manpower had to work in hazardous and toxic environment during all these steps of the Closest Prior Art.

Moreover, all these steps of this prior art are high on manpower usage, energy consumption, capital and recurring cost.

Solution Provided in Present Invention

In the prior art, the hazardous effluent was converted into solid / powder form, which is still containing hazardous materials. Such hazardous solid / powder was processed through various steps and finally byproducts were recovered from it.

The present invention prevents the exposure of manpower to highly hazardous and toxic environment and obviates various stages of solid waste generation during treatment. In the present invented method, byproducts are generated directly from the acidic effluent rather than converting effluent into solid waste and then processing on the said solid waste for recovery of byproducts.

The invented method simply bypasses various stages of solid waste generation and recovers high quality byproducts while featuring the safe work environment for the manpower.

Saving of energy and raw material

In the prior art the effluent was neutralized by using hydrated lime. Neutralized effluent were processed through multi effect evaporation or force effect evaporation. Even after evaporation, the material is still containing small amount of water. Finally, the spray dryer was used to remove the remaining ratio of water from the solid material. The remaining material is still containing organic and inorganic materials.

In the present invention, the effluent is directly processed through evaporation and converted into powder / semi solid during the initial steps of treatment. Hence the invented method obviates the spray drying process. Moreover, the present invention obviates the usage of hydrated lime during the treatment.

OBJECTS OF THE INVENTION

The principle object of the present invention is to provide human friendly, cost saving, safe and improved environment friendly zero discharge treatment used in organic synthesis & speciality chemical industries. Another object of the present invention is to provide improved effluent-treatment method which helps in conservation of natural resources.

A further object of the present invention is to obviate the usage of hydrated lime during treatment and to provide the easier, energy-time-cost saving and more convenient treatment in comparison to the prior arts.

Another object of the invention is to recover white sodium sulphate from the hazardous effluent.

Another object of the present invention is to obviate the requirement of spray dryer during the treatment which was required in the prior art.

Another object of the present invention is to safeguard environment from the hazardous effects of toxic effluent having various characteristics like acidic, alkaline, neutral, high organic impurity and inorganic impurity generated in organic synthesis & speciality chemical industries.

Another object of the invention is to destroy the toxicity of the organic and inorganic compounds present in the effluent.

A further object of the invention is to overcome the possibly risk of environmental hazard in the event of natural disasters like earthquakes and floods. Whereas the solid / semi solid waste of secure land-fill sites may dissolve in the water re-generating the aforesaid toxic effluent.

Another object of the present invention is to eliminate the generation of aforesaid toxic liquid / solid / semi solid waste produced from organic synthesis & speciality chemical industries. This invention obviates the implementation of interring aforesaid toxic waste in land-fill sites. Whereas such land can be usable for farming, housing and other general purposes.

Another object of the present invention is to simplify the waste management operation officially implemented in organic synthesis & speciality chemical industries. Wherein the waste management is complicated and multi-operation task starting from factory up to land-fill sites. Moreover, the present invention will save the expenses associated with effluent disposal process. Which includes various expenses namely transportation, labor, handling, packing, disposal charges etc.

Another object of the present invention is to convert the waste effluent into usable by-product and to avail the benefit of valuable by-products. At the end of the invented process certain by-products are recovered namely Carbon, inorganic salts and mother liquor containing inorganic salt.

STATEMENT OF THE INVENTION

The present invention provides the human friendly, time saving, cost effective, method of effluent treatment. It also safeguards the environment from the hazardous effluent at large scale. It further helps in the conservation of natural resources. The invented process will simplify the treatment of liquid / solid / semi solid waste materials namely toxic effluent having various characteristics like acidic, alkaline, neutral, high organic impurity and inorganic impurity generated in organic synthesis & speciality chemical industries.

Using the improved process, the present invention will convert the toxic effluent into environment friendly, valuable by-products and will safeguard environment in various ways.

Specifically, in present improved method, the effluent is processed through various steps including Evaporation, Carbonization, Drowning in water, Filtration, Evaporation and Separation of final by product.

Detailed Description of the Invention

The present invention is related to organic synthesis & speciality chemical industries wherein toxic effluent having various characteristics like acidic, alkaline, neutral, high organic and inorganic impurities are generated at large scale in form of liquid, solid or semisolid. The invention relates to an improved method of treatment given to aforesaid toxic effluent and to make it harmless to the environment. Moreover, to convert such effluent into valuable by-products.

Moreover, the improved method obviate the usage of hydrated lime during treatment. It also obviates the requirement of spray dryer during the treatment. The present invention provides the easier, energy-time-cost saving and more convenient treatment and at the same time recovers inorganic salts from hazardous effluent.

The present invented process mainly performs following major tasks.

Evaporation of acidic effluent

Carbonization of concentrated effluent

Drowning of carbonized material into water

Separation of salt and carbon

Drying of inorganic salts and carbon

Step-1 Collecting Toxic Materials

Collection of acidic, neutral & Alkaline mother liquor from organic synthesis & Speciality Chemical industry from production area. Acidic, neutral or any other kind of effluent in form of liquid is stored in storage tank.

Step-2 Distillation

In this step, water is distilled and recovered from the effluent. The recovered distilled water can be used in step-5 of the present treatment or in plant process.

Step-3 Recovery after Distillation

The remaining leftover material after distillation from step 2 is in form of semi-solid mass.

Step-4 Carbonization of Semisolid Mass

Carbonaceous material is carbonized for two to six hours in heating chamber at 200°C to 2000°C in presence of a non-reactive gas, Nitrogen "N2". In this step, the mixture of Carbonaceous material is converted into carbon and inorganic salts by aforesaid heating process.

Step- 5 - Drowning in water

The carbonized material which contains carbon and inorganic salts is drowned in water having 80°C to 100°C temperature.

Step-6 Filtration

Salt and carbon are having different property when drowned in water. Salt is having property of being soluble in water at the given temperature while carbon is insoluble in water.

At the end of this step, the mixture of effluent is divided into two parts using filter press. Inorganic salts are separated in form of liquid by dissolving in water. Carbon is separated in form of solid. Which is converted to a powder after drying.

Step-7 Distillation

Finally the water containing inorganic salts from step-6 is processed through distillation. Here water is distilled using two alternative methods namely "Multi- Effect Evaporation" and "Forced Effect Circulation". During this step, 50% to 70% of distilled water will be recovered. This distilled water can be reused in Step-5 as described above or in plant process.

Step-8 Filtration

The residue of step-7 is inorganic salt is in thick mixture form. In this step the said concentrated material is cooled and filtered. Filtration will separate inorganic salts and mother liquor which is used in plant process. The recovered inorganic salt is pure and moist.

Step-9 Drying

The recovered inorganic salts are in moist form which by time is converted into a dry powder.

Brief Description of drawing

Figure 1 : Indicates an improved & environment friendly zero solid discharge treatment used in organic synthesis & speciality chemical industries.

Detailed Description of drawing

Figure 1 indicates an improved & environment friendly zero solid discharge treatment used in organic synthesis & speciality chemical industries.

Wherein the effluent / toxic materials i.e. "Acidic, Neutral & Alkaline Mother Liquor"(l) which is in liquid form, is collected and stored into tank. Water is distilled and recovered from the effluent (2). After distillation carbonaceous material remains in semi-solid form(3). It will further be carbonized(4) in in heating chamber at 200°C to 2000°C in presence of a non-reactive gas, Nitrogen "N2" for two to six hours. It will convert carbonaceous material into carbon and salt. The mixture of carbon and salt is drowned into water at 80°C to 100°C of temperature (5). As salt is soluble in water, it will be separated using filtration process (6) and carbon will be separated in form of moist solid. Water containing salt is distilled (7) using two alternative methods namely "Multi-Effect Evaporation" and "Forced Effect Circulation". During this step, 50% to 70% of distilled water will be recovered. After water distillation, the remaining material is inorganic salt in form of thick liquid. Water is separated from the said thick liquid using filtration process (8) and finally white inorganic salt is recovered. Water i.e. mother liquor separated after filtration process is reused in plant process. The recovered inorganic salts are dried (9).