Upgrading of bio-oil from palm kernel shell by catalytic cracking in the presence of HZSM-5

Upgrading of bio-oil extracted from palm kernel shell (PKS) was performed using a lab-scale fixed-bed reactor with HZSM-5 as a catalyst. The catalytic cracking was carried out at optimized conditions: 0.3-MPa pressure, temperature of 500°C, and oil to catalyst ratio of 1:5. One of the challenges in upgrading bio-oil by catalytic cracking is deactivation of catalyst due to coke formation on catalyst surface. To overcome coke deposition, the upgrading process was carried out at 0.3-MPa pressure. Characterization of raw and upgraded bio-oil obtained through catalytic cracking was discussed in detail, indicating improvement in its physical properties. The distribution of products after cracking of bio-oil includes 58.89 wt% of organic liquid product, 15.63 wt% of aqueous fraction, 7.84 wt% of coke, and 17.64 wt% of gases. The degree of deoxygenation and calorific value of organic liquid product is 43.74% and 31.65 MJ/kg respectively. Organic liquid product obtained comprises 17.55% of hydrocarbons within the gasoline range. Hence, HZSM-5 proved its effectiveness for upgrading the bio-oil in a continuous mode.     

DEOXYGENATION IN NATURAL STREAMS1

ABSTRACT: Deoxygenation process in which carbonaceous BOD is biochemically oxidized to reduced inorganic compounds is of great significance in the oxygen demand of stream waters. The BOD decay rate traditionally determined in a laboratory might not necessarily be the same as estimated for a natural stream. The variation in biochemical activity could occur due to differences in adsorption, dispersion, and biophysical processes taking place in the two environments. The first stage biochemical oxygen demand and benthal oxygen demand that occur simultaneously in a stream, have been considered together to calculate the gross rate of deoxygenation in polluted waters. The available data on deoxygenation measurements has been analyzed in this study to calculate the carbonaceous BOD rate constants in natural streams. The analysis indicates that the dimensionless deoxygenation parameter is a function of the ratio of the Reynolds number and Froude number of flow. The functional relationship between these two parameters essentially follows a straight line on a log-log plot. The applicability of the relationship does not depend upon the volume of the organic load, size, or location of the stream.