Title of Invention

A PROCESS FOR PRODUCING SUGAR AND ALCOHOL FROM SUGARCANE

Abstract

This invention relates to a process for producing sugar from sugarcane comprising the steps of adjusting pH of primary juice by adding lime sucrate, screening the treated juice to remove coarse and suspended particles, primary heating of the primary juice at 65-80°C as herein described, phosphoflotation in a clarifier, secondary heating of the clear juice obtained from the clarifier, introduction of heated juice into evaporator.

Full Text

FIELD OF INVENTION This invention relates to a process for producing sugar and alcohol from sugarcane. PRIOR ART A known process for producing sugar from sugarcane comprises in the sulphiting process. In such a process, sugarcane is subjected to the step of milling to produce primary and secondary juice. Secondary, juice is added to primary juice and the filtrate from the rotary vacuum filter, which is then subjected to the step of primary heating at approximately 70°C so as to allow a reaction with sulphur and lime. The heated juice is subjected to the step of sulphiting and lime in order to allow a formation of a precipitation of non-sugars. The sulphited juice is subjected to the step of secondary heating at a temperature of 100-105°C and then clarified to produce clear juice, which is concentrated in an evaporated to produce syrup. The syrup is subjected to the step of crystallization followed by centrifugation to produce molasses and sugar. In the known process, alcohol was produced from molasses. Such a step of producing alcohol was expensive as steps involved for producing sugar were not reduced. It is known that primary juice extracted during the first milling of sugarcane is high in sugars and low in non-sugars. As molasses is a byproduct obtained from the treatment of primary juice, it contributed to the end cost of alcohol. Yet another disadvantage is that use of lime and sulphur increases inorganic load and is also injurious to sucrose. Such a process involved a considerable consumption of chemicals. Yet another disadvantages is that the sugar contained sulphur. The disadvantages of the prior art can be listed as follows: 1. Use of Lime & Sulphur increases inorganics load. 2. It is injurious to Sucrose. 3. High inorganics lead to sealing in heat exchangers. 4. Increase in molasses quantity. 5. Molasses quality is not best suited for fermentation. 6. Retention times are high leading to higher unknown losses. 7. Keeping quality of sugar is poor and therefore it deteriorates fast 8. Process chemicals comsumption is high. 9. Sugar quality is poor e.g. Colour, SCb, SPM, floe potential etc. OBJECTS OF THE INVENTION An object of this invention is to propose an improved process for producing sugar and alcohol from sugarcane. Another object of this invention is to propose an improved process for producing sugar and alcohol from sugarcane, which avoids the use of suphur. Yet another object of this invention is to propose an improved process for producing sugar and alcohol from sugarcane, which has a higher yield of sugar and alcohol. Yet another object of this invention is to propose an improved process for producing sugar and alcohol from sugarcane, which involves a lower consumption of chemicals and lower costs of production. A further object of this invention is to propose an improved process for producing sugar and alcohol from sugarcane, which produces superior quality of sugar. A still further object of this invention is to propose an improved process for producing sugar and alcohol from sugarcane, which has lower retention times. Further objects and advantages of this invention will be more apparent from the ensuing description. STATEMENT OF INVENTION According to this invention there is provided a process for producing sugar from sugarcane comprising the steps of: -adjusting pH of primary juice by adding lime sucrate, - screening the treated juice to remove coarse and suspended particles, - primary heating of the primary juice at 65-80°C as herein described, - phosphoflotation in a clarifier, - secondary heating of the clear juice obtained from the clarifier, - introduction of heated juice into evaporator. Further, according to this invention there is provided a process for producing alcohol from sugarcane comprises a steps of clarification of secondary juice followed by evaporation and transfer of the same to distillery to obtain ethanol. BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS Further objects and advantages of this invention will be more apparent from the ensuing descriptions when read in conjunction with the accompanying drawings and wherein: Fig 1 : shows a flow chart for the preparation of sugar from sugarcane. Fig 2 : shows a flow chart for the preparation of alcohol from sugarcane. DETAIL DESCRITPION OF THE INVENTION WITH REFERENCE TO THE ACCOMPANYING DRAWINGS. Reference is made to fig 1 wherein the primary juice is used to directly produce sugar. The primary7 juice and secondary juice is obtained by milling of sugarcane. According to this invention, the primary juice in the receiving tank is added with lime sucrate to increase PH because primary juice has low PH of 4.5 to 5.5. The PH value is increased to neutral or above. After the addition of lime sucrate, some precipitates are formed, which requires to be removed to reduce load on clarifier. Hence, the treated juice is subjected to screening to remove coarse and suspended particles. The screened juice is incorporated in a reactor after being primarily heated at 65-80°C. Thereafter, phosphoric acid in the amount of 150-300 PPM is added with lime sucrate so that, phosphoric acid can react with calcium obtained from the addition of lime sucrate to create calcium phosphate floes which then captures the suspended impurities. The acid reduces PH and to maintain the PH lime is added. Thereafter, the entire mass is added with a flotation flocculant in the amount of for example 8-15 PPM which is followed by aeration and phosphoflotation in flotation clarifier. The flotation flocculent helps to make sum float on surface with the aeration. The scum is obtained as a by- product from the primary juice. The retention time in the clarifier is for example 12-20 minutes. The clarified juice is transferred to polishing filter to remove suspended matter from the juice which is followed by secondary- heating at 100-105°C and introduction of the same into an evaporators, the syrup is sent to vacuum pan for crystallisation and then to crystallisers. The crystallised mass obtained from crystallisers is subjected to the step of centrifugation to obtain sugar and molasses. In a further embodiment, certain polymeric colour precipitants are used to physically precipitate the colouring matter and this, too, is absorbed in the calcium phosphate floes and floated as a scum that is continuously removed through the use of rotating scrapper. This achieves decoloursation along with clarification. Further, according to this invention, secondary juice is used for the manufacture of alcohol. Reference is made to fig. 2. The secondary juice with the scum obtained from the phosphfloatation of the primary juice is separately clarified and concentrated and sent to the distillery alongwith the molasses recovered from the processing of the primary juice. From the distillery ethanol is obtained. Specifically, but without intending to imply any limitation, the process invention comprises in a first route to produce alcohol directly from sugarcane and a second route to produce sugar. The major advantages of the present invention are: 1. Simple to operate, much fewer steps 2. Lower losses, higher recovery' 3. No sulphitation, sulphur-free sugar 4. Molasses is edible grade, higher alcohol yield 5. Lower chemicals consumption, lower cost of production 6. Environmentally friendlier 7. Louder retention times 8. No injury to the sucrose 9. Superior sugar quality 10. Better keeping quality 11. Lower scaling in heat exchangers PERFORMANCE DATA ( As an Example) CANE CRUSHED 1000 TONS PRIMARY JUICE Quantity 700 Tons Brix " 18 Purity 85 SECONDARY JUICE Quantity 300 Tons Brix 10 Purity 76 PRIMARY JUICE PROCESSING YIELDED : SUGAR (Pol 99.8%) : 95.9 Tons MOLASSES (Purity : 30): 28.9 Tons (Brix : 90) ALCOHOL (ETHANOL) PRODUCTION:Directly from secondary juice : 21.9 KI From molasses obtained from primary juice processing and the : 7.2 KI scum of phosphoflotation of primary juice TOTAL :29.1KI It is to be noted that the present invention is susceptible to modifications, changes, adaptations by those skilled in the art. Such modifications, changes adaptations are intended to be within the scope of the present invention which is further set forth under the following claims. I CLAIM: 1. A process for producing sugar from sugarcane comprising the steps of: -adjusting pH of primary juice by adding lime sucrate, - screening the treated juice to remove coarse and suspended particles, - primary heating of the primary juice at 65-80°C as herein described, - phosphoflotation in a clarifier, - secondary heating of the clear juice obtained from the clarifier, - introduction of heated juice into evaporator. 2. A process as claimed in claim 1 wherein the heated juice is added with phosphoric acid in the amount of 150-300 PPM and lime sucrate. 3. A process as claimed in claim 1 wherein the treated juice is added with a flocculant in the amount of 8-15 PPM which is subjected to the step of aeration in the clarifier. 4. A process as claimed in claim 1 wherein the clear juice obtained from the clarifier is filtered in a polishing filter before being subjected to secondary heating at the temperature of 100-105°C. 5. A process as claimed in claim 1 wherein the screening is followed by addition of colour precipitant for the precipitation of coloring matter present in the primary juice. 6. A process for producing alcohol from sugarcane comprises steps of clarification of secondary juice followed by evaporation and transfer of the same to distillery to obtain ethanol. 7. A process as claimed in claim 1 wherein the secondary juice is added with scum obtained from phosphoflotation of the primary juice before being subjected to the step of clarification and the clarified juice after being evaporated is sent to the distillery alongwith molasses obtained from primary juice. 8. A process for producing sugar from sugarcane and a process for producing alcohol from sugarcane substantially as herein described with reference to examples.

Documents:

1625-DEL-2003-Abstract-(13-02-2009).pdf

1625-del-2003-abstract.pdf

1625-DEL-2003-Claims-(13-02-2009).pdf

1625-del-2003-claims.pdf

1625-DEL-2003-Correspondence-Others-(13-02-2009).pdf

1625-del-2003-correspondence-others.pdf

1625-del-2003-correspondence-po.pdf

1625-DEL-2003-Description (Complete)-(13-02-2009).pdf

1625-del-2003-description (complete).pdf

1625-DEL-2003-Drawings-(13-02-2009).pdf

1625-DEL-2003-Drawings.pdf

1625-del-2003-form-1.pdf

1625-del-2003-form-18.pdf

1625-DEL-2003-Form-2-(13-02-2009).pdf

1625-del-2003-form-2.pdf

1625-DEL-2003-Form-3-(13-02-2009).pdf

1625-del-2003-form-5.pdf

1625-del-2003-gpa.pdf