A prefeasibility study on coupling of pulp and sugar mills using advanced pulping technology | |
| Author | Mughal, Arshad Saleem |
| Call Number | AIT Thesis no. ET-89-17 |
| Subject(s) | Cogeneration of electric power and heat Bagasse |
| Note | A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering |
| Publisher | Asian Institute of Technology |
| Abstract | A systematic investigation for potential in an integrated package through the coupling of sugar and pulp mills "to achieve the best efficiency in using sugarcane through rational chain" was carried out, using the Advanced Soda Pulping process. Starting from the mass balance modeling of the AP process an attempt has been made to explore all the inherent energy resources attached to the AP process. The potential of producing power for grid from burning surplus bagasse was also investigated. Finally various coupling strategies were developed and their adaptation to the existing Thai sugar mills was investigated. The established mass balance model is applicable to Advanced Soda Pulping of the bagasse. The model can be used to calculate the material requirements along with the quantity and composition of the various products, for putting a bagasse based pulp plant anywhere in the world. Using developed model for Thai bagasse one ton of the non-bleached pulp requires 6.327 ton of the mill run bagasse along with 0.1667 ton of NaOH and 0.042 ton of NaiC03• The by products include 4.7535 ton of the black liquor (25 % dry solids) and 1.466 ton of pith. The beginning strategy in exploring the inherent energy resources of AP process involves the employment of a venturi scrubber evaporator in concentrating black liquor using flue gases from the fluidized bed com buster. This furnishes 5.511 tons of black liquor (45% dry solid contents) for a 50 ton per day of pulp production capacity. After it, the fluidized bed combustion system was followed to achieve high efficiency in recovering black liquor waste heat. This is followed by gating the potential of pith firing in the sugar mill boiler. As a whole the firing of the pith and the black liquor furnishes 1.27 x 109 kJ/day of heat or 283 ton/day of the steam at 360°C and 22 kg/cm2 , upon a 50 ton/day of the pulp production capacity. Finally the cogeneration adaptation to the AP process through burning black liquor and pith beside meeting the process thermal requirements can met 74 - 87% of the process electricity requirements, which brings a saving of US$ 618,365 to 729,014 per year. An investigation for producing surplus electricity for grid by burning surplus bagasse from the sugar mills located near Banpong (a town near Karnchanaburi, Thailand) reveal a quantity of about 96,000 to 98,000 MWh per milling season. Generally a 15,000 TCD capacity sugar mill can provide about 12,700 MWh of the surplus electricity per milling season. Finally the adaptation of the developed coupling modes to Thai sugar Industry suggest that the quantity of the surplus bagasse in Banpong is enough to put 5-6, 50 ton/day capacity of pulp production lines. The Coupling of sugar and pulp mill reveals that a 200 ton/day capacity of pulp plant requires 380,000 to 448,000 ton of the mill run bagasse per year. The retrofitting of the existing energy system of the Thai sugar mills to adopt a 50 ton/day capacity of pulp production line brings savings of about 10,000 ton of bagasse or 125,800 to 180,000 US$ per annum. |
| Year | 1990 |
| Type | Thesis |
| School | School of Environment, Resources, and Development (SERD) |
| Department | Department of Energy and Climate Change (Former title: Department of Energy, Environment, and Climate Change (DEECC)) |
| Academic Program/FoS | Energy Technology (ET) |
| Chairperson(s) | Mora, Jean-Claude; |
| Examination Committee(s) | Bhattacharya, Sribas C.;Prida Wibulswas; |
| Scholarship Donor(s) | The Government of Norway; |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1990 |