Sharif Digital Repository

Through our work, we conducted a three-stage solution to effectively reduce the impact of 'concentration polarization' and 'fouling' on ultrafiltration process. The stages were compromise of: 1. the design and selection of appropriate equipment along with outlining the operational parameters, 2. the pretreatment process design, and 3. the cleaning process design. Because of the presence of fat, there are incline both in permeate flux and the quality of the final product. Therefore, we studied the different methods of removing the lipid content, during pretreatment stage. After examining these methods, finally, we found that adding chitosan parallel with employing centrifugal separator is the... 

Nowadays bioethanol is one of the main factors in the fuel market. It is currently produced from sugars and starchy materials, but lignocelluloses can be expected to be major feedstocks for ethanol production in the future. Agricultural residues such as wheat straw are being considered a potential lignocellulose raw material for fuel-ethanol production as an alternative to starch or sugar-containing feedstock. In order to produce bioethanol, it is necessary to decompose the wheat straw into soluble sugars. But lignocellulosic materias needs pretreatment before hydrolysis and fermentation. The main goal of pretreatment is to increase the enzyme accessibility improving digestibility of... 

Production of cellulosic ethanol from lignocellulosic biomass represents a alternative to the petroleum fuel due to its renewable nature and sustainable availability. The major strategy used for cellulosic ethanol production includes three main steps of biomass pretreatment, enzymatic hydrolysis and ethanol fermentation. The enzymatic hydrolysis contributes significantly to the cost of cellulosic ethanol and from the process economics perspective, the improvement in the enzymatic hydrolysis step is a prerequisite. The fiber is composed of cell wall fractions and residual starch which can be hydrolyzed to reducing sugar.A method of hydrolysis of polysaccharides in corn fiber, feed... 

Membrane fouling is the main cause of permeate flux decline and loss of product quality in reverse osmosis (RO) systems, so good pretreatment of the feed solution was required to prevent membrane fouling. One of the most common applied pretreatment methods to prevent or control the scaling of different salts in feed water is to add scale inhibitors. Due to the great variety of commercial scale inhibitors RO plant operators must evaluate these chemicals before use in real plants. In this project three different types of antiscalants at concentrations of 10 ppm and one type of magnetic descaler on the RO pilot for the R.O plant feed water of agro-industrial Hakim Farabi evaluated and function...