Table nbsp shows the other outputs except power
Table 7 shows the other outputs except power for the same three agricultural wastes. The utility heat of the system is obtained in the form of hot water generated from two different sources. One part is the recovered heat during gasification and power islands and the other part is obtained from the ethanol plant. Major fractions of the utility heat from gasification and power islands are utilized as inputs to the vapor Preladenant refrigeration process (∼80% of total) and the rest is available for process heating in a process heater as shown in Fig. 1. On the other hand, heat recovered in the ethanol plant is from the WGS reactor, from the inter-cooler between two compressors and from the ethanol condenser. It is used to generate saturated steam (at a temperature of 101 °C) for process heating. The utility heats from the ethanol plant for the three inputs are shown in Table 7. As most of the utility heat from gasification and power islands is utilized in refrigeration process, available process-heat is relatively lower. Utility heat from the ethanol plant is fully available for process heating and hence its contribution is relatively greater. It is noted from Table 7 that the amount of utility heats are comparable for all input feedstocks though those from sugarcane bagasse and coconut fiber dust are even closer. Utility heats from the gasification and power islands depend on total heat input to these islands through syngas. Most of this energy input through syngas is converted to power. Rest is utilized for utility heating. Thus energy input to the power island through syngas being highest for coconut fiber dust, utility heat output from it is also greatest. This explains relatively higher utility heat outputs for coconut fiber dust and sugarcane bagasse. On the other hand, greater the mass flow rate of syngas to the ethanol plant more is the heat obtained during inter-cooling of compressor discharge. For same fraction of syngas used for ethanol production, mass flow rates of syngas for coconut fiber dust and sugarcane bagasse are greater than that from rice straw (refer to Table 6). However, a fraction of utility heat is also contributed by the exothermic reaction in the WGS reactor depending on composition of syngas and corresponding conversion in WGS reactor to obtain the desired ratio of CO and H2, i.e., 1:2. The amount of utility heat available from WGS reactor thus varies with the mass flow rate as well as the composition of the syngas. The combined effects of available utility heats from the ethanol plant and gasification-power islands for these three inputs are shown in Table 7.