Cane sugar - Import export

The fermentable carbohydrates from sugar cane or sweet sorghum may be directly utilized in the form of cane juice or in conjunction with a sugar factory from molasses. Cane juice is prepared by crushing / diffusing the raw cane and after extraction, clarifying with milk of lime and sulfuric acid to precipitate the inorganic fraction. The extract may then be evaporated to the desired concentration and used directly in the fermentation. A major disadvantage in the utilization of sugar cane juice is its lack of stability over extended periods of storage. Molasses is the non-crystallizable residue remaining after the sucrose has been crystallized from cane juice. This heavy viscous material is composed of sucrose, glucose, and fructose at a total carbohydrate concentration of 50-60 %. Molasses may be easily stored for long periods of time and diluted to the required concentration prior to use.

Cane sugar is produced by means of technologies rather similar to those used in a beet sugar plant that are also fully mastered by DSEC. Sugar cane is however a totally different plant compared to sugar beet: whereas sugar beet is sowed and can be harvested after +/- 6 months, cane takes longer to grow but grows back after it has been cut and can therefore be harvested several consecutive years (4 to 6) before being replanted. Cane can be cut either manually or mechanically before being directly processed in the mill. Cane plantation location in relation of the plant is of paramount importance so as to reduce sugar losses by the degradation of the plant after cutting as well as to minimize logistic costs. DSEC will select the most appropriate methodology for extracting the juice from the cane after its first shredding. The extraction operation will be performed using mill tandem or cane diffusion while additional mills will press the residual solid (bagasse) in order to increase its fiber content while additional mills will press the residual solid (bagasse) in order to increase its fiber content. Pressed bagasse will be used as fuel for the plant combined heat and power generation that will generally export electricity on the public grid. The choice between mill tandem and diffuser will be highly dependent on plant capacity, cane characteristics, expected extraction performances and plant general concept.

Sugar beet is a more versatile crop than sugar cane since it can tolerate a wide range of soil and climatic conditions. As for sugar cane, beet molasses is generated in large volumes from the sucrose recovery operation.

DSEC has dedicated special attention to the design of sugar refinery EPC construction with particular emphasis on energetic efficiency and white sugar quality. A considerable portion of the sugar market is located in areas where neither beet nor cane can be cultivated. Such markets can be fed by large bulk ships with raw cane sugar that needs to be further refined before being commercialized. As the quality of the raw sugar available on the international market varies considerably depending on its origin, DSEC has developed alternative concepts to adapt the refinery design to the feedstock to be processed. The selected alternative for a refined sugar production will be defined after contemplating the necessity of a raw sugar affination (washing) step before the mandatory re-melting operation. Different purification or possibly decoloration technologies will also be analyzed by DSEC so as to optimize capital expenditures in function of feedstock and finished products as well as of the local environment.

DSEC's commitment on the construction of Bioethanol plants is based on a very specialized technical knowledge of the Ethanol production processes; in this article you will find a more detailed understanding about the Downstream Process. The alcohol in the fermented mash is then concentrated by means of distillation and rectification, before the required water content of ethanol is regulated in the dewatering process. The accrued residues from distillation, the so-called stillage, is first evaporated and then dried to animal feed, the so-called DDGS. However, the production (drying) of DDGS requires a considerable amount of primary energy (e.g. fuel oil or natural gas); therefore, if feedlots are nearby, animal feed will be sold in wet condition, so called WDGS. For sugar cane and molasses the residue, so called vinasses, was returned to the fields as fertilizer- due to sustainability reasons and change in legislation, spraying of vinasses on the fields is mostly forbidden in the meantime. In the past, direct combustion of DDGS turned out to be unfeasible because of procedural difficulties and lacking efficiency (due to the high water content of the stillage). The realisation of a biogas plant could not be achieved in large scale so far because of the enormous quantities of stillage and their high organic stress. Combination of ethanol production with biogas respectively, biomass burning results in different biorefinery concepts or so called next generation technology.

Thanks to its deep knowledge of all unitary operations related to edible oil, sugar and sugar fermentation processes, De Smet Engineers & Contractors is the ideal partner for assisting investors in developing and implementing biochemical production plants and bio-commodities production facilities. DSEC has already successfully built for international key players a betain and several inulin plants based on their proprietary knowhow. Moreover, DSEC’s experience in implementing cogeneration units built along with facilities for the production of fermentable grade sugar (derived from sugar beet, cane and grains) allows the company to fine-tune the overall process set-up in order to achieve ideal conditions with regard to material and energy flows. Notable examples of bio-based chemicals include non food starch, cellulose fibers and cellulose derivates, tall oils, fatty acids and fermentation products such as ethanol and citric acid for which. DSEC is fully qualified to provide the facility that will efficiently generate the required feedstock on an industrial scale. From a technical point of view, almost all industrial materials respectively their building blocks made from fossil resources can be substituted by their bio-based counterparts: • C2 building blocks: ethanol, acetic acid • C3 building blocks: lactic acid, 3-hydroxypropanoic acid, glycerol • C4 building blocks: fumaric acid, succinic acid, butyric acid, 1-butanol • C5 building blocks: itaconic acid, furfural • C6 building blocks: citric acid, glucaric acid, 5-HMF, adipic acid